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1
Sun, Zehra Pinar. "Structural And Mechanical Investigations Of Magnesium And Fluoride Doped Nano Calcium Phosphates". Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/2/12610764/index.pdf.
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The aim of this study was to investigate the microstructure and mechanical properties of pure and Mg2+ and F- doped nano-calcium phosphate (CaP) powders, which were synthesized by precipitation method. After the drying and calcination processes, the samples were sintered at 1100ºC for 1 hour. High densities were achieved except for the 7.5 % mole Mg doped samples. Microstructure of the CaPs were investigated by X- ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). Due to the Mg substitution, &
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-TCP phase was detected besides HAp, resulting in the formation of HAp/ &
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-TCP biphasic composites with different compositions. The substitutions of the ions have been verified by the decrease in the hexagonal unit cell volumes of the doped CaPs. FTIR spectra revealed the characteristic absorption bands of HAp, &
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-TCP and the ones that were resulted from the F-OH bonds and substitution of the Mg2+ ions. The SEM results revealed the grain sizes in the range of ~197 nm-740 nm. In general, the micro hardness and diametral tensile strength tests revealed that Mg2+ ions in large amounts (7.5 % mole) had negative effects on the mechanical properties of the samples, while substitution of the F- ions had a positive effect on their mechanical properties.
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Felker, Daniel L. "Studies of oxide-free phosphates film surfaces on magnesium, zinc, and manganese by X-ray photoelectron spectroscopy /". Search for this dissertation online, 2005. http://wwwlib.umi.com/cr/ksu/main.
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Dos, Santos Tavares Débora. "Avaliação in vitro do comportamento de células osteoprogenitoras e macrófagos humanos em pastilhas de fosfato tricálcico com e sem magnésio". Phd thesis, Université de Haute Alsace - Mulhouse, 2012. http://tel.archives-ouvertes.fr/tel-00720079.
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En raison de l'augmentation de l'espérance de vie, le nombre de personnes âgées et par conséquent le taux de maladies chroniques augmente de plus en plus nécessitant le développement de nouveaux biomatériaux permettant la réparation osseuse. Le but de cette étude était d'évaluer le comportement in vitro de cellules ostéoprogénitrices cultivées sur des pastilles de phosphate tricalcique dopées (β-TCMP, Mg/Ca = 0,15) ou non (β-TCP) avec du magnésium dans un environnement statique et dynamique (débit de 0,3 mL/min), ainsi que la réponse de macrophages humains après contact avec des extraits des matériaux (ISO10993-12). Les pastilles de β-TCMP et β-TCP ont été obtenues par frittage respectivement d'une apatite calcium déficiente en calcium dopée au magnésium et de TCP (Merck). Les diffractogrammes et les spectres infrarouge ont confirmé la production de β-TCP et de β-TCMP, ratio Mg/Ca = 0,14. Des cellules osteoprogénitrices STRO+1A ont été cultivées sur des pastilles pendant 21 jours et leur comportement de prolifération et de différenciation cellulaire ont été vérifiés. Aucune différence entre les deux pastilles n'a été observée concernant le nombre de cellules après 21 jours de culture, ni sous condition statique ni dynamique. Cependant, il semble que l'environnement dynamique accélère la différenciation ostéoblastique. D'une façon générale, le β-TCMP n'a pas modifié la réponse des macrophages (le profil des cytokines) activés ou non par du lipopolysaccharide bactérien, cultivés pendant 72 heures avec des extraits de biomatériaux, par rapport au β-TCP. D'après ces résultats, les deux biomatériaux semblent être prometteurs pour le traitement des pertes osseuses.
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Nabiyouni, Maryam. "Biomedical Applications of Magnesium Phosphate Nanoparticles". University of Toledo / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1418327070.
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Clavier, Batiste. "Synthèse, caractérisations et évaluation de l'activité bactéricide de composés inorganiques à base de cuivre". Thesis, Le Mans, 2019. http://cyberdoc-int.univ-lemans.fr/Theses/2019/2019LEMA1041.pdf.
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Les bactéries pathogènes responsables des infections associées aux soins posent des problèmes permanents et croissants dans les établissements de santé. En France, les bactéries Escherichia coli et Staphylococcus aureus sont responsables de plus de 40% de ces infections. Face à l'adaptation permanente de ces bactéries aux nouveaux antibiotiques mis sur le marché, des solutions complémentaires doivent être trouvées. Une des solutions proposée dans ce travail de thèse vise à exacerber les performances de composés bactéricides connus (effet de synergie) ou à procurer des propriétés bactéricides à des composés inactifs en substituant partiellement des ions magnésium par les ions cuivriques ou vice versa. De nouvelles solutions solides ont ainsi été découvertes. Des réactions dans l'état solide, la co-précipitation, la voie hydrothermale ou la mécanosynthèse ont été employées pour synthétiser des particules de taille micro- ou nanométrique des composés désirés. Une fois obtenues, la Diffraction des Rayons X, les Microscopies Electroniques, l'adsorption de diazote, les spectroscopies IR/UV-visible, l'Analyse ThermoGravimétrique couplée à la Spectrométrie de Masse et la Spectrométrie d'Emission Atomique ont été utilisées afin de déterminer la nature, la composition et la taille de ces particules ainsi que leur stabilité dans l'eau ou sous une atmosphère riche en CO2. L'évaluation des propriétés bactéricides dans l'eau et à 20°C révèle que la substitution partielle du magnésium par le cuivre accroît l'activité des composés à la fois en termes d'amplitude et de cinétique. Ces performances accrues ne sont pas nécessairement liées à la teneur en cuivre dans le composé actifBacterial pathogens causing healthcare-associated-infections pose ongoing and increasing challenges to care facilities. In France, Escherichia coli and Staphylococcus aureus are responsible for more than 40% of these infections. Due to the permanent adaptation of these bacteria to new antibiotics placed on the market, complementary solutions must be found. One of these solutions proposed in this thesis work aims to exacerbate performances of known bactericidal materials (synergistic effect) or to provide bactericidal properties to non-active compounds by partially substituting magnesium ions by cupric ones or vice versa. New solid solutions were thus highlighted. Solid state reaction, co-precipitation, hydrothermal routes or mechanosynthesis were employed to synthesize micrometer-sized or nanometer-sized particles of those desired compounds. When obtained, X-Ray Diffraction, electron microscopies, dinitrogen adsorption, IR/UV-visible spectroscopies, ThermoGravimetric Analysis-Mass Spectrometry and Atomic Emission Spectroscopy are used to determine the nature, composition and size of those particles as well as their stability in water or CO2 rich atmosphere. The evaluation of bactericidal properties in water and at 20°C showed that the partial substitution of magnesium by copper enhances the activity of compounds both in terms of magnitude and kinetics. These increased performances are not necessarily related to the copper content in the active compound
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Rostami, Niloufar. "Development of Novel Magnesium Phosphate Bone Cement". University of Toledo / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1418326907.
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Ibasco, Suzette. "Magnesium phosphate precipitates and coatings for biomedical applications". Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=40691.
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Metals are extensively used materials in orthopaedics and oral implants and several research studies have reported that coating the surface improves the osteoconduction and bone bonding ability of the metal. Low temperature aqueous precipitation techniques are advantageous over other coating processes as they allow the incorporation of thermally unstable compounds. Although some magnesium phosphates have been shown to be well tolerated in bone tissue [Zimmermann 2006], they are relatively unstudied as bioceramics. The first part of this research project was to determine the precipitation conditions at which different magnesium phosphate phases form. Ultimately, the primarily goal of this study was to investigate a new low temperature route to produce magnesium phosphate coatings by reacting substrates sputter coated with magnesium metal in an aqueous phosphate solution. X-ray diffraction (XRD) and scanning electron microscopy (SEM) coupled with energy dispersion spectroscopy (EDS) were used to characterize and identify the magnesium phosphate precipitates. SEM revealed that coatings formed by the reaction of magnesium metal with ammonium dihydrogen phosphate formed a continuous coating of struvite crystals. Importantly, this coating was durable enough to withstand the peel test (ASTM D 3359). Furthermore, this coating was also useful as a reactive surface to form hydroxyapatite coating. Biocompatibility assays, showed that magnesium phosphates precipitates and coatings were non-toxic and sustained cell viability. This study shows the possibility of forming a number of potentially biocompatible surface coatings on a metal model through a low temperature in situ process. This process shows good promise in producing enhanced coatings with many advantages over currently used techniques.Les métaux sont largement utilisés comme matériaux dans la conception d’implants orthopédiques et dentaires et plusieurs études ont montré qu’un revêtement de leurs surfaces améliore leur propriété d’ostéoconduction et leur capacité de liaison au tissu osseux. Les techniques de précipitation aqueuse à basse température sont plus élaborées comparées aux autres techniques de revêtement car elles permettent l’incorporation de composés thermiquement instables. Bien que certains phosphates de magnésium soient bien tolérés au sein du tissu osseux [Zimmermann 2006], ils sont relativement peu étudiés comme biocéramiques. La première partie de ce projet de recherche était de déterminer les conditions de précipitations auxquelles les différentes phases des phosphates de magnésium se forment. L’objectif majeur de cette étude était d’explorer une nouvelle méthode, à basse température, pour produire des revêtements de phosphate de magnésium par la réaction de substrats revêtus par pulvérisation avec des métaux magnésiens, dans une solution aqueuse de phosphate.La diffraction des rayons X et la microscopie électronique à balayage, couplée à la spectrométrie par dispersion d’énergie, furent utilisées pour caractériser et identifier les précipités de phosphates de magnésium. La microscopie électronique à balayage a révélé que les revêtements produits par la réaction d’un métal magnésiun avec un phosphate diacide d’ammonium forment un revêtement continu de cristaux de struvite. Ce revêtement présentait également la caractéristique majeure de résister au test d’arrachage. Les tests de biocompatibilité ont montré que les précipités de phosphates de magnésium ainsi que les revêtements de surface étaient non toxiques et amélioraient la viabilité cellulaire. Cette étude démontre la possibilité de former un éventail de revêtements potentiellement biocompatibles à la surface d’un$
8
Berg, Camilla. "Influence of Magnesium in theFormation of Phosphate Spheres : A simple method for the fabrication of sphericalparticles of calcium and magnesium phosphate". Thesis, Uppsala universitet, Oorganisk kemi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-326255.
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Calcium phosphates and recently also magnesium phosphates, are used for medical applications, due to their biocompatibility and bioactivity. These properites makes spherical particles of calcium and magnesium phosphate suitable for carrier materials for drug delivery applications. By creating porous and/or hollow particles itis possible to load the particles with a drug and control therelease of the active substance. In this work, an ion-induced method for the synthesis of spherical calcium and magnesium phosphates was developed. A simple precipitation reaction was used, where substituting magnesium ions could replace the function of templates, such as surfactants or micelles, to induce the formation of spheres of a certain size and morphology. Experimental results showed that magnesium had an inhibitory effect on the nucleation and crystal growth of calcium phosphates. By using substituting ions as a structural regulator, it was possible to alter the size, morphology and phase composition of the spheres. At low magnesium concentrations, the spheres had a smooth surface andwere between 200 nanometer to 1 micrometer in diameter and composed of hydroxyapatite and/or magnesium-substituted beta-TCP. At higher magnesium concentrations, the spheres were about 10-50 micrometer with a rough, flaky surface. Results also proved that calcium ionshave the same effect on the crystallisation and self-assembly of magnesium phosphates. Apart from the magnesium concentration, reaction temperature proved to have a high influence on the sphereformation, whereas Ca/P ratio and reaction times above three hours did not affect the sphere formation to the same extent.
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Barj, Mohamed. "Etude de la structure statique et dynamique de quelques matériaux à mobilité ionique par spectroscopie de vibration et par diffusion de neutrons". Paris 13, 1987. http://www.theses.fr/1987PA132024.
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Etude des composés de la famille nasicon et de composés d'insertion type MPS(3), caracterisés par ir et raman. Les barrières de potentiel locales ont été calculées à partir des modes de phonons des ions conducteurs. Les amplitudes quadratiques spéctroscopiques ont été calculées dans les composés MPS(3) purs. Dans le cas des composés nasicon, on a relié la conductivité élèctrique et le désordre statique. Présentation de résultats de chaleur massique et de calculs d'énergie réticulaire à partir de potentiels atome-atomes. Mise en evidence d'une importante diffusion magnétique des ions Cr(3+) dans Na(3)Cr(2)P(2)O(12)
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Yun, Joanne W. 1970. "Modelling studies of magnesium-dependent phosphate ester processing enzymes". Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/38776.
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Aldaek, Taher A. A. "Untersuchungen zur Beeinflussung der Konzentrationen von Glukose und Phosphat in Blut und Harn bei Milchkühen durch eine Glukoseinfusion". Giessen VVB Laufersweiler, 2009. http://d-nb.info/996005560/04.
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Montero, Jimenez Maria Dorelis. "Neuroprotective effects of magnesium sulphate evaluated by fluoride resistant acid phosphatase, inorganic phosphate, lactate dehydrogenase and nitric oxide in rats with ischemia". Thesis, Uppsala universitet, Institutionen för kvinnors och barns hälsa, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-423794.
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Brain ischemia events are among the first three mortalities causes in the world associated with high treatments costs and in most cases some degree of permanent functional disability, thus it is necessary with new low cost and effective treatments. In the present study the potential neuroprotective effect of magnesium sulphate was evaluated by quantification of ischemic biomarkers: fluoride resistant acid phosphatase (FRAP), inorganic phosphate (Pi), lactate dehydrogenase (LDH) and nitric oxide (NO) in rats with global ischemia. Adult rats were anaesthetized (sodium thiopental 60mg.kg-1) and magnesium sulphate (1mmol.kg-1) (9 animals) or saline solution (NaCl 0,9%) (11 animals) was infused via jugular vein. Cortical sample was extracted 30 minutes after infusion (normoxic condition), thereafter it was induced global ischemia via respiratory arrest caused by jugular administrated muscular relaxant (Flaxedil, 500μL), and 30 minutes after this state a cortical sample of contralateral hemisphere was taken (hypoxia condition). Samples were preserved with proteases inhibitors (PMFS y NaF) and homogenized. Biomarkers were quantified within 24h from the experiment by the following spectroscopic methods: Gomori (FRAP), Ammonium molybdate (Pi), Pyruvate to lactate reduction (LDH) and Griess (NO). FRAP activity was quantified as an inflammatory biomarker for the first time in the cerebral cortex. Global ischemia increased all biomarkers concentrations of the saline group. During normoxia condition magnesium sulphate reduced Pi (P=0,0002) and LDH activity (P=0,001), while during hypoxia it reduces Pi (P= 0,0002) and LDH activity (P=0,03) compared to saline values. These results strongly suggest the cortical neuroprotectiveeffects of magnesium sulphate in global ischemia induced by respiratory arrest, by reduction of cellular acidosis and energetic deficit.
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Liang, Mi. "New possibilities of Magnesium utilization in wastewater treatment and nutrients recovery". Thesis, KTH, Land and Water Resources Engineering, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-12134.
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New possibilities of nutrients removal by additions of magnesium compounds were studied in primary treatment and supernatant of side stream in wastewater treatment. The precipitation product from this method is magnesium ammonium phosphate (MAP) socalled struvite. High efficiencies on NH4-N and PO4-P removals have been demonstrated up to over 90 % respectively in side stream from dewatering of digested sludge. In order to find out the nutrient removal efficiency in raw wastewater and the feasibility of MAP recycling in wastewater treatment, the postulations of combining MAP and nitrification-denitrification process, and MAP and partial nitritation-anmmox process were carried out by experimental works in the laboratory at Land and Water Resources Department, KTH. It was found that 92-97 % of PO4-P and 57 % of NH4-N were removed from raw wastewater by Mg2+ addition at pH10 to pH10.5. The research work revealed that recycling of MAP by nitrification-denitrification and partial nitritation-anmmox processes may be a feasibly process combination. In MAP and nitrification -denitrification process, the released ammonium was mostly oxidized to nitrate in nitrification phase and ready for denitrification. Based on presented results on MAP and partial nitritation-anmmox process, it was found that the released ammonium was consumed by anammox bacteria.
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Abdelrazig, Baha Eldin Ismail. "The hydration of magnesia-phosphate cements". Thesis, University of Sheffield, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.277605.
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Gardner, Laura Jane. "Assessment of magnesium potassium phosphate cements for radioactive waste encapsulation". Thesis, University of Sheffield, 2016. http://etheses.whiterose.ac.uk/14345/.
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Naidu, Prathyusha. "Catalase-loaded liposomal magnesium phosphate nanoparticles for intracellular protein delivery". Scholarly Commons, 2016. https://scholarlycommons.pacific.edu/uop_etds/266.
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Proteins are large biomolecules that have great therapeutic potential in treating many human diseases. Proteins exert higher specificity and more complicated functions; they are well endured and less inclined to evoke immune responses when compared to small molecule drugs. However, exogenous proteins when administered intravenously are prone to immune reactions. Chemical and enzymatic denaturation, and poor penetration into cells are some other challenges for clinical use of intracellular proteins. Proteins that enter cells through endocytosis will be eventually degraded in lysosomes if they do not escape the endosomal pathway before reaching lysosomes. Therefore, the development of protein delivery systems, including liposomal and/or polymeric nanoparticles would substantially facilitate the clinical use of proteins. This approach can protect the proteins from denaturation and immune reactions. Previously, our group has developed cationic lipid-coated magnesium phosphate nanoparticle (CAT-LP MgP NP) formulations to enhance the intracellular delivery of the protein, catalase. The objective of the current research is to improve the physicochemical properties of CAT-LP MgP NP. The magnesium phosphate (MgP) nanoparticles were prepared by water-in-oil micro emulsion precipitation. The cargo protein catalase was complexed with cationic liposome prepared by lipid hydration and extrusion. Then magnesium phosphate (MgP) nanoparticles were mixed with the catalase-complexed cationic liposome to form the final complexed CAT-LP MgP NP formulation. By sonication, extrusion and modification of the lipid composition, we have successfully prepared complexed CAT-LP MgP NP formulations of reduced size. The pH-sensitivity of the improved delivery system was observed at pH 6.0. Furthermore, the improved delivery system reduced the Reactive Oxygen Species (ROS) level inside EA.hy.926 cells (human umbilical vein endothelial cells) to 35% of the control, whereas the previously reported catalase formulation of our group reduced the ROS levels to 50%, indicating that the complexed formulation delivers functional catalase more efficiently into the EA.hy.926 cells. Complexed CAT-LP MgP NP with reduced size has delivered cargo protein more efficiently than encapsulated CAT-LP MgP NP.
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Montague, William. "The suitability of magnesium phosphate cement for uranium metal encapsulation". Thesis, Imperial College London, 2014. http://hdl.handle.net/10044/1/44117.
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Nuclear waste streams consist of a diversity of physical and chemical forms, requiring a toolbox approach in the application of materials to their disposal. Solid uranium metal wastes constitute a disposal challenge due to their tendency to oxidise, making encapsulation within cementitious waste packages for storage potentially troublesome. MKPC (Magnesium Potassium Phosphate Cement) is being considered as an alternative to Portland cement for U-metal encapsulation due to the potential for lower free water content, lower internal pH and the micro-encapsulation of radioactive isotopes as low-solubility phosphate minerals. In this work the development and characterisation of MKPCs optimised for U-metal encapsulation was undertaken. This included the investigation of MKPC property development under both near ambient and elevated temperature conditions, the performance of MKPC/U-metal wasteform corrosion trials utilising temperature elevation (to 30, 40 and 50 °C) for the acceleration of chemical kinetics, and assessment of the impact of dehydration treatments (at 50, 80 and 110 °C) on the cement properties. In general MKPC exhibited excellent processing and mechanical properties. Other significant outcomes of the work include, firstly, the determination that uranium corrosion rate dependencies in MKPC are dominated heavily by the presence of water over other chemical effects, with an anoxic activation energy of 68 ± 6 kJ/mol. Secondly, the development of a methodology for determining the bound water content of MKPC, which allowed the calculation of the extent of reaction. This enabled analysis yielding empirical strength-porosity and kinetic models of the material, capable of facilitating improved mix design for the tailoring of MKPC properties. Finally, the instability of the K-struvite matrix toward dehydration at temperatures of ≥ 72 °C has been recorded. The work concluded that MKPC has many properties which make it suitable as a general encapsulant, whilst being ultimately unsuitable for U-metal storage without further development around the reduction of water availability.
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Martin, Elisabeth. "Phosphate recovery from water using cellulose enhanced magnesium carbonate pellets". University of Cincinnati / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1490351099058308.
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Vadlamudi, Mallika. "Lipid-coated Magnesium Phosphate Nanoparticles for Intrapulmonary Protein Delivery in Mice". Scholarly Commons, 2019. https://scholarlycommons.pacific.edu/uop_etds/3631.
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Proteins are a diverse category of biomolecules with great therapeutic potential. Intracellular delivery of proteins can augment the deficient activities of dysfunctional or poorly expressed innate proteins and therefore represents a promising strategy to treat the associated diseases. One major barrier to intracellular protein delivery is the translocation of the protein across the cellular membrane. Endocytosis provides an important pathway for protein nanocarriers to enter cells across the plasma membrane. However, the cargo protein must then promptly escape from the endosomes to avoid degradation in the lysosome and to exert its cellular function.
Previously, we reported a cationic lipid-coated magnesium phosphate nanoparticle (LPP) system for intracellular protein delivery. The intracellular delivery of catalase, an antioxidant enzyme, by LPP protected MCF-7 cells from a lethal level of exogenous H2O2 and lowered the reactive oxygen species (ROS) levels in EA.hy926 cells. These findings prompted us to further develop LPP to evaluate its protein delivery in animals.
Two categories of LPP formulations, catalase-encapsulated (CE) LPP and catalase-complexed (CC) LPP, were successfully prepared by a modular approach. Catalase-encapsulated liposomes (CE LP) were prepared by hydrating a thin-film of lipids with catalase solution followed by extrusion. However, extrusion of CE LP resulted in substantial loss of catalase activity. Catalase-complexed liposomes (CC LP) were prepared by first extruding cationic liposomes with a LIPEX extruder and then mixing with catalase solution. The resultant CC LP was much smaller than CE LP and preserved all the catalase activity. Magnesium phosphate nanoparticles (MgP NP) were prepared by the microemulsion precipitation technique. CE LP or CC LP were mixed with MgP NP to yield LPP formulations (CE LPP or CC LPP, respectively). The formulations were then rendered isotonic with glucose (5% w/v). Transmission electron microscopy (TEM) confirmed the proposed structure of LPP comprising a shell of lipid bilayers with a core of MgP NP. Furthermore, TEM showed drastic morphological changes of LPP formulations at acidic pH, consistent with an osmotic explosion.
The LPP formulations were administered by intravenous or intranasal routes to CD-1 mice. LPP formulations of fluorescently labeled catalase distributed substantially into the lung following intranasal administration, whereas intravenous administration of the same formulations caused catalase distribution mainly into the liver. In addition, intranasal administration of both the LPP formulations yielded higher pulmonary catalase activity and lowered the ROS levels in the healthy lung compared to free catalase solution. Based on these results, LPP’s antioxidant effects were further evaluated in mice with lipopolysaccharide-induced acute lung injury (ALI).
Lack of LPP distribution into the lung following intranasal administration indicated that intranasal dosing did not deliver catalase substantially into inflamed lungs. In corroboration, the inflammatory biomarker tumor necrosis factor-alpha (TNF-α) remained unchanged after intranasal dosing of LPP formulations. Intratracheal dosing of LPP formulations delivered the fluorescently labeled catalase deep into the lung and significantly reduced TNF-α production in the inflamed lungs compared to free catalase solution. CC LPP, which was smaller and which better preserved catalase activity than CE LPP, showed greater intrapulmonary catalase activity compared to CE LPP in both healthy and inflamed lungs. Taken together, LPP represents a promising nanocarrier for intracellular protein delivery.
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Weidelener, Alexander. "Phosphorrückgewinnung aus kommunalem Klärschlamm als Magnesium-Ammonium-Phosphat (MAP) /". München : Oldenbourg-Industrieverl, 2010. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=019009287&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Stanke, Andrea [Verfasser]. "Regulation der Glykolyse durch Magnesium und Phosphat / Andrea Stanke". Hamburg : Staats- und Universitätsbibliothek Hamburg Carl von Ossietzky, 2020. http://d-nb.info/1232407836/34.
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Ren, Yufu. "Microwave Assisted Synthesis of Alkaline Earth Phosphate Coating and its Applications for Biomedical Implants". University of Toledo / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1513204146096617.
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Gu, Zhengxing. "Dolomite flotation of high magnesium phosphate ores using fatty acid soap collectors". Morgantown, W. Va. : [West Virginia University Libraries], 2007. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=5292.
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Thesis (Ph. D.)--West Virginia University, 2007.Title from document title page. Document formatted into pages; contains xvii, 189 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 150-162).
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HE, ZHUOHUI JOE. "Effects of digestate, magnesium sulfate, and dipotassium hydrogen phosphate/potassium dihydrogen phosphate on microalga, Scenedesmus dimorphus". Cleveland State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=csu1478532413386291.
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Winbow, Howard David. "The chemistry and properties of magnesia-phosphate cement systems". Thesis, University of Sheffield, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.249651.
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Waterman, Jay. "In Vitro Assessment of the Corrosion Protection of Biomimetic Calcium Phosphate Coatings on Magnesium". Thesis, University of Canterbury. Mechanical Engineering, 2012. http://hdl.handle.net/10092/7552.
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The use of magnesium for degradable implants can fill the need for temporary, load bearing, metallic orthopaedic implants without the risks and expense of further surgeries once the bone has healed. Mg is non toxic and biocompatible, but the corrosion rate in the body is too high. The rate will need to be moderated if these implants are to be made clinically useful.
A review of common orthopaedic coatings found that the biomimetic calcium phosphate coating process meets the criteria for a good coating. This process was designed for permanent implants, and its corrosion protection properties were unknown on Mg. The research presented here evaluates and optimizes aspects of the corrosion protection of biomimetic coatings in vitro.
To accurately identify the corrosion mechanisms of such coatings, the in vitro behaviour of several common simulated body fluids and buffer systems was evaluated.
The deposition of biomimetic coatings on Mg was compared to Ti. The effect of common surface treatments on the deposition, composition, and ultimate corrosion protection was identified in order to understand the corrosion properties of these coatings. Following the results, the biomimetic method was modified to optimize the protection by reducing the defects. The corrosion properties of these modified coatings were assessed in vitro.
The limitation of the biomimetic coatings was found to be in all cases sensitive to the defects present in the coating. While these could be minimized, they were not eliminated. This led to unfavourable corrosion properties. To solve this problem, a novel treatment was developed to give the biomimetic coatings self-healing properties. This treatment promoted local repair in the coating at the defects, greatly improving the corrosion properties.
The in vitro model was increased in complexity by adding first amino acids, then proteins. The corrosion behaviour of the coatings was compared in these solutions to understand the effects of these molecules. The data gathered will help to build a better model of in vivo corrosion, and allow better prediction of the performance of biomimetic coatings for corrosion resistance.
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Bernard, Sheldon Ainsworth. "Influence of silicon dioxide, magnesium oxide and zinc oxide on resorbable tricalcium phosphate based bioceramics". Online access for everyone, 2005. http://www.dissertations.wsu.edu/Thesis/Fall2005/s%5Fbernard%5F083005.pdf.
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Yue, Weizhou. "Liposome-coated Magnesium Phosphate Nanoparticle for Delivery of Cytochrome C into Lung Cancer Cells A549". Scholarly Commons, 2017. https://scholarlycommons.pacific.edu/uop_etds/2987.
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Proteins are large biomolecules that have great therapeutic potential in treating many human diseases. However, chemical/enzymatic degradation, denaturation, and poor penetration into cells are some of the challenges for clinical use of intracellular proteins.
Previously, our group has developed cationic lipid-coated magnesium phosphate nanoparticle (LP MgP NP-CAT) formulations to enhance the intracellular delivery of the negatively charged protein catalase. The goal of the current research is to develop a formulation to deliver cytochrome c (CytC), a positively charged protein into lung cancer cells A549. Specifically, this thesis research prepares and tests liposome-coated magnesium phosphate nanoparticle for delivery of cytochrome c (CytC LP/MgP).
CytC LP/MgP was designed, prepared and characterized, showing that it had an average diameter around 150 nm and ζ-potential around +30 mV. The morphology of CytC LP/MgP was validated by transmission electron microscopy.
CytC LP/MgP successfully led to the attachment of CytC to A549 cells, as supported by fluorescence imaging. Intracellular delivery of CytC alleviated the cytotoxicity of cationic lipids in A549 cells, as suggested by the MTS assay on cell viability, which could facilitate the clinical use of cationic lipids in drug delivery systems.
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Fuchs, Andreas Rudolf [Verfasser] y Alexander [Akademischer Betreuer] Kübler. "3D-Pulverdruck von Zellkulturträgern mit Magnesium-Phosphat-Chemie / Andreas Rudolf Fuchs. Betreuer: Alexander Kübler". Würzburg : Universitätsbibliothek der Universität Würzburg, 2013. http://d-nb.info/1033751936/34.
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Fang, Yunzhou. "A novel intracellular protein delivery system - Magnesium phosphate nanoparticles with cationic lipid coating for catalase intracellular delivery". Scholarly Commons, 2014. https://scholarlycommons.pacific.edu/uop_etds/270.
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Protein therapeutics have great potential in treating human disease, especially for those caused by alternations in the functions of intracellular proteins. However, clinical use of protein by intracellular delivery has been hampered by the instability due to proteins' physicochemical properties, and some barriers in the delivery pathway. This study was to prepare and test a novel intracellular protein delivery system - magnesium phosphate nanoparticles with cationic lipid coating for catalase intracellular delivery (LP MgP NP-CAT), and investigate whether it can release the encapsulated catalase to cytosol. LP MgP NP-CAT was designed, prepared and characterized, showing that it had an average diameter around 300 nm and zeta potential around +40mV. The pH - triggered catalase release from LP MgP NP-CAT was determined by a hydrogen peroxide degradation assay, where the concentration of remaining hydrogen peroxide was measured by UV-Vis spectroscopy, indicating catalase was released in response to the drop of pH, which was confirmed by the morphology change of LP MgP NP-CAT observed by transmission electron microscopy. The in vitro catalase release behavior was conducted on MCF-7 cells and EA.hy926 cells. LP MgP NP-CAT was delivered into MCF-7 cells and the release behavior was determined by the resultant resistance of the cells against hydrogen peroxide using MTS cell viability assay. The delivery of LP MgP NP-CAT into EA.hy926 cells was determined by the decrease of the reactive oxygen species level. Both of the studies showed that catalase was successfully delivered and released which is supported by the reduction of hydrogen peroxide.
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Frank, Daniel [Verfasser] y Thomas [Akademischer Betreuer] Hirth. "Experimentelle Untersuchung und Modellierung der Fällung von Kalium-Magnesium-Phosphat / Daniel Frank. Betreuer: Thomas Hirth". Stuttgart : Universitätsbibliothek der Universität Stuttgart, 2015. http://d-nb.info/1069107220/34.
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Hlongwa, Ntuthuko Wonderboy. "Nanoparticles-infused lithium manganese phosphate coated with magnesium-gold composite thin film - a possible novel material for lithium ion battery olivine cathode". University of the Western Cape, 2014. http://hdl.handle.net/11394/4467.
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>Magister Scientiae - MScArchitecturally enhanced electrode materials for lithium ion batteries (LIB) with permeable morphologies have received broad research interests over the past years for their promising properties. However, literature based on modified porous nanoparticles of lithium manganese phosphate (LiMnPO₄) is meagre. The goal of this project is to explore lithium manganese phosphate (LiMnPO₄) nanoparticles and enhance its energy and power density through surface treatment with transition metal nanoparticles. Nanostructured materials offer advantages of a large surface to volume ratio, efficient electron conducting pathways and facile strain relaxation. The material can store lithium ions but have large structure change and volume expansion during charge/discharge processes, which can cause mechanical failure. LiMnPO₄ is a promising, low cost and high energy density (700 Wh/kg) cathode material with high theoretical capacity and high operating voltage of 4.1 V vs. Ag/AgCl which falls within the electrochemical stability window of conventional electrolyte solutions. LiMnPO₄ has safety features due to the presence of a strong P–O covalent bond. The LiMnPO₄ nanoparticles were synthesized via a sol-gel method followed by coating with gold nanoparticles to enhance conductivity. A magnesium oxide (MgO) nanowire was then coated onto the LiMnPO₄/Au, in order to form a support for gold nanoparticles which will then form a thin film on top of LiMnPO₄ nanoparticles crystals. The formed products will be LiMnPO₄/Mg-Au composite. MgO has good electrical and thermal conductivity with improved corrosion resistance. Thus the electronic and optical properties of MgO nanowires were sufficient for the increase in the lithium ion diffusion. The pristine LiMnPO₄ and LiMnPO₄/Mg-Au composite were examined using a combination of spectroscopic and microscopic techniques along with cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Microscopic results revealed that the LiMnPO₄/Mg-Au composite contains well crystallized particles and regular morphological structures with narrow size distributions. The composite cathode exhibits better reversibility and kinetics than the pristine LiMnPO₄ due to the presence of the conductive additives in the LiMnPO₄/Mg-Au composite. This is demonstrated in the values of the diffusion coefficient (D) and the values of charge and discharge capacities determined through cyclic voltammetry. For the composite cathode, D= 2.0 x 10⁻⁹ cm²/s while for pristine LiMnPO₄ D = 4.81 x 10⁻¹⁰ cm2/s. The charge capacity and the discharge capacity for LiMnPO₄/Mg-Au composite were 259.9 mAh/g and 157.6 mAh/g, respectively, at 10 mV/s. The corresponding values for pristine LiMnPO₄ were 115 mAh/g and 44.75 mAh/g, respectively. A similar trend was observed in the results obtained from EIS measurements. These results indicate that LiMnPO₄/Mg-Au composite has better conductivity and will facilitate faster electron transfer and therefore better electrochemical performance than pristine LiMnPO₄. The composite cathode material (LiMnPO₄/Mg-Au) with improved electronic conductivity holds great promise for enhancing electrochemical performances, discharge capacity, cycle performance and the suppression of the reductive decomposition of the electrolyte solution on the LiMnPO₄ surface. This study proposes an easy to scale-up and cost-effective technique for producing novel high-performance nanostructured LiMnPO₄ nanopowder cathode material.
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Joensuu, Frida. "Behov av surgörning av urin vid analys för kalcium, fosfat och magnesium". Thesis, Örebro universitet, Institutionen för hälsovetenskaper, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-93001.
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Studier har tidigare visat surgörning urinprover inför analys av kalcium, fosfat och magnesium inte är nödvändigt. Dessa analyter är viktiga att analysera vid njursjukdomar och det görs med instrumentet Advia Chemistry XPT (Siemens AG, München, Tyskland) på Universitetssjukhuset Örebro. Syftet med arbetet var att se om samma resultat erhölls för kalcium, fosfat och magnesium beroende på om urinen var surgjord eller inte inför analys. Tre metoder utvärderades beträffande behov av surgörning av urin: Metod 1; den nuvarande metoden, urinen surgjordes till pH 3-4. Metod 2; utan surgörning, urinen rumstempererades i 30 min före mätning. Metod 3; utan surgörning, urinen värmdes till 36ºC före varje mätning för att lösa upp eventuella saltkristaller. Alla metoderna utfördes på 30 prover och testades efter 0h, 24h, 3 dagar och 7 dagar. Resultaten sammanställdes i ett linjärt regressionsdiagram och ett Bland Altmann-diagram. Ett förutbestämt acceptansmål var att de genomsnittliga analysresultaten inte skulle ha en större skillnad än 10% vid jämförelse mellan metod 1 och metod 2 respektive metod 1 och metod 3, samt att eventuella avvikande enskilda prover skulle undersökas närmare. Fem av proverna höll inte den förutbestämda 10%-gränsen och mikroskoperades för att se om saltkristaller förekom och surgjordes för att se om provsvaren skulle förändras. I tre av fem prover kunde saltkristaller observeras. Detta gav slutsatsen att alla prover fortsatt måste surgöras eftersom det inte går att avgöra i förväg om provet måste surgöras eller inte eftersom ett tydligt samband inte kunde ses mellan proverna som inte höll 10%-gränsen och de som gjorde det.Studies have previously shown that acidification of urine samples before analysis for calcium, phosphate and magnesium may not be necessary. These analytes are important to monitor during kidney disease and are, at USÖ, detected using the instrument Advia Chemistry XPT (Siemens AG, München, Germany). The aim of this study was to examine whether the results from analyzing previously mentioned mineral levels would differ depending on whether the urine had been acidified prior to analysis or not. To examine this, three methods were used. Method 1; the current method, where urine is acidified to pH 3-4. Method 2; without acidification, the urine was warmed at room temperature before analysis. Method 3; without acidification, the urine was heated to 36°C before analysis. All methods were assayed on 30 samples which were all examined after 0h, 24h, 3 days and 7 days. Results were compiled using a linear regression diagram and a Bland Altmann diagram. The predetermined acceptance criterion was a maximum 10% difference between mean analyte levels found using methods 2 or 3, in comparison to using method 1. Five samples deviated from the remainder by breaking the 10% limit and were therefore scrutinized under microscope to search for salt crystals, before acidification and reanalysis. Crystals were detected in three of the five samples. As there was no clear connection between the deviating samples, there is no way of knowing prior to analysis whether acidification will be necessary or not, and it is therefore deemed a necessity to acidify all urine samples.
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Le, Rouzic Mathieu. "Étude des propriétés physico-chimiques et mécaniques des matériaux cimentaires à base d’oxyde de magnésium". Thesis, Paris Est, 2014. http://www.theses.fr/2014PEST1082/document.
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Les ciments phosphomagnésiens sont des ciments inorganiques de la famille des ciments activés par des acides. Malgré le fait qu'ils soient connus depuis le début du XXème siècle, leur utilisation reste assez limitée dans le génie civil. Ces matériaux sont utilisés dans le cadre de réparation notamment pour des réparations routières qui nécessitent un développement rapide des résistances en compression. Plus récemment, ces ciments ont été utilisés pour des applications de stabilisation/solidification (S/S) des déchets et notamment de certains types de déchets chimiquement incompatibles avec le ciment Portland. Toutefois, les défis de mise en œuvre de ce type de ciment sont liés à la nature même de la réaction, très exothermique et très rapide. La phase liante de ces ciments, la k-struvite (MgKPO4.6H2O), est obtenue par un mélange de magnésie (MgO) et de dihydrophosphate de potassium (KH2PO4) en présence d'eau. MgO + KH2PO4 + 5H2O MgKPO4.6H2OLes mécanismes qui régissent la prise de ce ciment sont encore mal connus et plusieurs théories, mettant en jeu ou non la formation de produits secondaires, ont été proposées. Nos travaux de recherche ont porté sur la compréhension des mécanismes de prise des ciments phosphomagnésiens ainsi que sur l'influence des paramètres de formulation sur les propriétés de ces ciments. L'étude a montré que la formation de la k-struvite passe par une réaction de précipitation-dissolution d'un produit intermédiaire, la newberyite (MgHPO4.3H2O). Les réactions de formation de ces deux produits sont contrôlées par le taux de sursaturation des espèces en solution et le pH du milieu réactionnel. L'étude met également en lumière la forte sensibilité de ces ciments à la quantité d'eau introduite. Avec un rapport E/C très faible comparativement à un ciment Portland (rapport E/C compris entre 0,1 et 0,25), une faible variation (0,02) entraine la ségrégation de la pâte de ciment et une hétérogénéité à la surface du matériau. Parmi les paramètres de formulation, le rapport molaire MgO/KH2PO4 (Mg/P) est le plus important. En effet, il influe sur la quasi-totalité des propriétés du ciment : résistance en compression, temps de prise, chaleur de réaction, fluidité de la pâte, …. L'utilisation de faibles rapports Mg/P entraine une mauvaise tenue à l'eau du ciment, la formation de cristaux à l'intérieur de la microstructure et visibles à la surface de l'échantillon (apparition d'une efflorescence) ainsi qu'un gonflement important de la pâte de ciment (pouvant aller jusqu'à la fissuration des échantillons). A l'issue de l'étude paramétrique une formulation d'une pâte a pu être définie. Des mesures de variations dimensionnelles, ainsi que des mesures de retrait chimique ont été effectuées, afin de mieux comprendre les mécanismes mis en jeu pour induire les phénomènes de gonflement. En support, des analyses de la microstructure (MEB, DRX, ATG) ainsi que des essais de lixiviation viennent compléter la campagne expérimentale. Ces résultats viennent confirmer l'influence d'un rapport Mg/P faible sur le gonflement et la tenue à l'eau du ciment phosphomagnésien. Pour finir, une étude sur l'influence des divers ajouts, dans le but d'améliorer ses performances, a montré que les fillers inertes (sable siliceux ou cendres volantes) retardent le temps de prise et réduisent la chaleur d'hydratationMagnesium phosphate cements are the most representative cements of the activated-by-acid cements family. Despite the fact that they are known since the early 20th century, their use in civil engineering is fairly limited. These materials are used for road repairs where the fast compressive strength development is an advantage. Recently they have also been used in wastes stabilization/solidification (S/S), especially with wastes incompatible with Portland cement. The challenges of the use of these cements are related to the nature of their formation reaction: fast, very exothermic, with a very short setting time (only a few minutes).The bonding phase, k-struvite (MgKPO4.6H2O), is obtained from magnesium oxide mixed in water with monopotassium phosphate (KH2PO4).MgO + KH2PO4 + 5H2O MgKPO4.6H2OThe setting mechanisms are still poorly known and various theories, involving or not secondary product formation, have been suggested. Our researches have aimed to understand the setting mechanisms, as well as the influence of the formulation parameters on the properties of the magnesium phosphate cement. Results show that the formation of k-struvite involved a precipitation-dissolution reaction of an intermediate product, the newberyite (MgHPO4.3H2O). Formation reactions of these two products are controlled by the supersaturation rate and the pH of the solution. The study highlights the strong effect of water on the properties of fresh cement paste. With a low mass ratio e/c in comparison of Portland cement (ratio e/c between 0,1 and 0,25), a slight modification of the ratio (0,02) leads to a segregation and a surface heterogeneity of the cement paste. Among the formulation parameters, the molar ratio MgO/KH2PO4 (Mg/P) seems the most important parameter. Indeed, it impacts most of the properties of the magnesium phosphate cement (compressive strength, setting time, reaction heat, paste fluidity …). Low Mg/P ratios lead to poor water resistance, to crystals formation inside the microstructure that can be seen on the surface of the sample (an efflorescence appearance), and to important swelling of the paste, leading to the cracking of the samples. After the parametric study, a magnesium phosphate cement paste has been defined. Dimensional changes and chemical shrinkage measurement were conducted to understand the mechanisms involved in this swelling phenomenon. In support, microstructural analyses (SEM, XRD, TGA) and leaching tests complete the experimental campaign. The results confirm the influence of a low Mg/P ratio on cement swelling and water resistance. Finally, a study on various additions to the paste has been conducted, with the purpose of improving the cement paste performances. It shows that the addition of an inert filler (siliceous sand or fly ashes) has a retarding effect and reduced the reaction heat
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Hoefert, Norbert [Verfasser]. "Automatisierte Wasseranalyse zur Bestimmung von Calcium, Magnesium, Sulfat, Carbonat, Phosphat und Ammonium mit Hilfe potentiometrischer Titrationstechniken / Norbert Hoefert". Karlsruhe : KIT-Bibliothek, 2018. http://d-nb.info/1169212166/34.
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Meininger, Susanne [Verfasser], Jürgen [Gutachter] Groll, Frank [Gutachter] Müller y Uwe [Gutachter] Gbureck. "Processing of calcium and magnesium phosphate cements for bone substitution / Susanne Meininger [geb. Christ] ; Gutachter: Jürgen Groll, Frank Müller, Uwe Gbureck". Würzburg : Universität Würzburg, 2018. http://d-nb.info/1169573037/34.
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Ewald, Bastian. "Borophosphate der Haupt- und Nebengruppenmetalle: Synthese, Charakterisierung und Strukturchemische Klassifizierung". Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2006. http://nbn-resolving.de/urn:nbn:de:swb:14-1165332117390-21543.
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Es werden neue Erkenntnisse über Borphosphat und Borophosphate der Haupt- und Nebengruppenmetalle vorgestellt. Neben Hydrothermalsynthesen und Feststoffreationen, die üblicherweise zur Synthese von Borophosphaten angewendet werden, haben insbesondere die solvothermalen Experimente mit Alkoholen bzw. Alkohol-Wasser-Mischungen zu neuen Ergebnissen geführt. Es wurden neue Borophosphate und Borat-Phosphate in den Systemen MxOy–B2O3–P2O5(–H2O) (M = K+, Rb+, Mg2+, Sc3+, Pr3+, Sm3+, In3+) dargestellt, weitere Verbindungen enthalten neben Mg2+ weitere Kationen der Haupt- und Nebengruppenmetalle (Ca, Sr, Ba, Mn, Fe, Co, Zn). Darüberhinaus gelang die Darstellung bislang unbekannter Scandium- und Lanthanphosphate(III) sowie von sauren Alkalimetall-Scandiumphosphaten(V). Aus Synthesen in Gegenwart von Ethylendiamin und Diazabizyklooktan wurden ferner zwei neue templatierte Scandiumphosphate mit porösen Gerüststrukturen erhalten. Die Kristallstrukturen aller Verbindungem wurden rötgenographisch anhand von Einkristallaufnahmen oder Pulverdaten aufgeklärt. Die Charakterisierung der Präparate erfolgte mit Röntgenpulverdiffraktometrie, EDX- und Elementaranalysen sowie durch Schwingungsspektroskopie und thermische Stabilitätsuntersuchungen. Zur Klassifizierung von (Metallo)borophosphaten wird eine Struktursystematik vorgeschlagen, welche Borophosphate und Metalloborophosphate entsprechend ihrer anionischen Teilstrukturen hierarchisch klassifiziert und in Analogie zur Terminologie der Silikate (nach Liebau) beschreibt. In Anlehnung an bestehende Konzepte für Boratminerale geht das Klassifizierungsschema dabei von einfachen Oligomeren aus. In einer struktursystematischen Übersicht wurden alle bis dato bekannten (Metallo)Borophosphate hierarchisch klassifiziert und sind in einer Übersicht vorgestellt. Beobachtete Verknüpfungsregeln und der Einfluss der Zusammensetzung B:P auf die Dimensionalität und die Verknüpfungsmuster der anionischen Teilstruktur werden diskutiert.
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Hussain, Ahmed Mohammed Ali. "Magnesium Calcium Phosphate as a Novel Component Enhances Mechanical/Physical Properties of Gelatin Scaffold and Osteogenic Differentiation of Bone Marrow Mesenchymal Stem Cells". Kyoto University, 2013. http://hdl.handle.net/2433/174795.
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Christiansen, Michael Lee. "Gastrointestinal acidity, protein and starch digestibility and amino acid absorption in ruminants fed a high-concentrate diet with limestone, magnesium oxide or defluorinated phosphate". Diss., Virginia Polytechnic Institute and State University, 1988. http://hdl.handle.net/10919/54321.
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Twelve wether lambs (32kg) with abomasal and ileal cannula were fed a 90% concentrate basal diet (800 g/d), basal + 1.5% magnesium oxide (MgO)(812 g/d), basal + 1.5% limestone (812 g/d) or basal + 3.0% limestone (824 g/d) to study the effect of·these minerals on intestinal pH, rumen fermentation, N balance, dry matter and crude protein digestibility (DMD, CPD), and small intestinal disappearance of amino acids (AAD). Limestone (3%) increased (P < .03) rumen pH. Magnesium oxide increased (P < .10) ileal and fecal pH. Limestone significantly increased N absorption and pre-abomasal DMD, but decreased (P < .03) AAD. N retention was not improved by the treatments. An 82-d feeding trial was conducted with 72 wether lambs (avg initial wt: 28 kg) to study the effect of 1 or 3% fine (70% < 53 µ) or coarse (85% > 425 µ) limestone on rumen environment, weight gain and feed efficiency of lambs fed an all-concentrate diet. Rumen pH and VFA molar proportions were not affected by the treatments. Limestone (3.0%) decreased (P < .10) total rumen VFA concentrations and increased (P < .10) fecal pH. Weight gain was not different (P > .10) among the treatments. Coarse limestone increased (P < .10) feed efficiency. Five Angus heifers (285 kg) with duodenal and ileal cannulae were fed a 90% concentrate control diet (7.5 kg/d) or the same diet containing 1.60% defluorinated phosphate-regular (5.5%, 19.0% and 33.0% on 1400, 1180 and 850 µ sieves, respectively, DRP-R), 1.60% defluorinated phosphate-coarse (85% evenly among large sieves, DRP-C), 1.28% limestone or .5% MgO to study the effect of limestone or MgO on intestinal pH, DMD, starch digestibility (SD), CPD and AAD in beef cattle fed a high-concentrate diet. Ileal pH was increased by MgO. Fecal pH was increased (P < .05) as follows: MgO > DRP > limestone and control. Minerals increased (P < .05) duodenal liquid flow. Limestone and DRP-C increased (P < .05) acid flow to the duodenum. Total tract DMD, SD and CPD were similar among treatments. Limestone and DRP-R increased (P < .10) AAD. DRP-C tended to increase AAD, but differences were not statistically significant.Ph. D.
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Säkkinen, H. (Hannele). "Variation in the blood chemical constituents of reindeer:significance of season, nutrition and other extrinsic and intrinsic factors". Doctoral thesis, University of Oulu, 2005. http://urn.fi/urn:isbn:9514277732.
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Abstract
Reindeer management in the Fennoscandian area is currently facing challenges such as degradation of winter pastures, which may lead in the most severely affected areas to a concurrent decline in reindeer herd productivity. The use of often expensive supplementary feeding to prevent production losses has increased the demand for studies on the physiological effects of nutritional restriction and supplementary feeding. The knowledge obtained from such studies could be used, for example, to monitor the condition of reindeer in studies assessing herd productivity levels in different pasture conditions and management systems or sustainable use of pasture resources.
In this thesis, the effects of season, year, pasture area, body mass, pregnancy and other extrinsic and intrinsic factors on the variation of blood chemical constituents of reindeer were studied in free-ranging animals under natural foraging conditions. The studied blood chemical constituents covered a wide range of parameters related to protein, carbohydrate, lipid and mineral metabolism. The same blood chemical constituents were studied in captive reindeer under defined feeding conditions, allowing an analysis of the effects of dietary protein, energy and mineral intake on the selected blood constituents and their comparison to a conventional measure of the animals' condition, live body mass.
According to the results, free-ranging reindeer showed great variation in the concentrations of blood chemical constituents compared to the reference values of domesticated ruminants. Intrinsic factors such as body mass, pregnancy and age had only a minor influence on the variation of the studied parameters, whereas extrinsic factors such as season, year and pasture area, which were characterized by marked changes in environmental and nutritional conditions, explained the majority of the variation.
The results obtained from captive animals in defined feeding conditions and from free-ranging animals foraging on natural pastures led to the conclusion that blood total proteins, albumin, urea, creatinine, urea:creatinine ratio, magnesium, inorganic phosphate and, to a lesser extent, globulins and albumin:globulin ratio responded to the changes in feed quality and availability and were the most suitable blood constituents to be used as nutritional biomarkers for reindeer.
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Naduvath, Anu Paul. "Removal and recovery of phosphorus from side-stream hydrolysis". Thesis, KTH, Mark- och vattenteknik (flyttat 20130630), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-210715.
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The report formulates the experiments conducted to remove phosphorus from the return sludge wastewater subjected to side-stream hydrolysis. The experiments are conducted using the wastewater from the outlet of side-stream hydrolysis and is tested in a laboratory at the Duvbackens wastewater treatment plant in Gävle. Chemical precipitation is used in the experiments and displays remarkable results using magnesium chloride and calcium chloride as the precipitants. A successful removal rate of 79-99% is achieved through this method. The phosphate phosphorus content is chosen to be the criterion for estimating the phosphorus removal rate. Possible parametric variations are also reviewed in the report. The decline in ammonium nitrogen is also studied alongside. Struvite and calcium phosphate are the possible precipitates and are recovered with the prospect of recycling. Both the precipitates are known as slow fertilizers and are used in the agricultural industry. If recovered by proper means, these precipitates can reduce the pressure on phosphate industry and on naturally occurring phosphate rocks. Calcium phosphate is selected among the precipitation methods for its rapid reaction and its minimum response to parametric variations. It also expresses a faster settling property with a clear solution after precipitation. The removal and recovery of phosphorus from the side-stream hydrolysis is evaluated with a notion to operate in a pilot scale.
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Dabužinskas, Saulius. "Kalcio gliukonato boratinių kompleksinių tirpalų su magniu ir fosfatais farmakologinis-klinikinis įvertinimas". Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2005. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2004~D_20050429_100219-40705.
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A total of 12 multicomponent solutions of various compositions were developed in which we attempted to blend calcium and phosphoric salts, which usually precipitate and form sediments. Among the medicines of similar composition and purpose registered in Lithuania, there is none containing all three important macroelements: Ca, Mg, and P. After the tests, one of the solutions tested – C2 – was registered in Lithuania and was manufactured by AB Ukmergės Biofabrikas (Lithuania) for several years. Production technology of the developed preparation – Kamavetas – is patented (patent No. LT 4509 B. 1999 05 25). Kamavetas is the first preparation created and manufactured in Lithuania, which contains Ca, Mg, and P salts and glucose. It is convenient to use, because the animal receives several mineral substances within a single infusion.
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Sousa, Robson Thiago Xavier de. "Fertilizantes fosfatados para a cana-de-açúcar aplicados em pré plantio (fosfatagem)". Universidade Federal de Uberlândia, 2011. https://repositorio.ufu.br/handle/123456789/12145.
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Phosphate application is still rarely used in sugarcane and can be done with phosphorus
fertilizers of long residual period. This study evaluated the effect of phosphate fertilizers
applied in the whole area before planting on sugarcane yield and technological quality.
The study was done at Jalles Machado sugar-mill, in Goianésia-GO, during three
growing seasons. The treatments consisted of five different phosphorus sources, soluble
and insoluble, applied in the rate equivalent to 300 kg ha-1 P2O5. The fertilizers used
were: triple superphosphate, mono-ammonium phosphate (MAP), Arad phosphate rock,
Itafós phosphate rock and magnesium thermophosphate. The effects of these fertilizers
were evaluated by analysis of plant height (height from ground to TVD), leaf
phosphorus content, sugarcane yield in cane plant, first ratoon and second ratoon, by
technology parameters in ratoon, by sugar produced and by agronomic efficiency.
Application of magnesium thermophosphate and triple superphosphate resulted in
greater plant cane height. Leaf concentrations of phosphorus in cane showed the
superiority of MAP, magnesium thermophosphate and triple superphosphate. Phosphate
applications did not affect yield of cane plant, but increased yield of sugarcane ratoon as
well as the amount of sugar produced per hectare. In general, the residual effect of
insoluble phosphates increased over the years. The Agronomic Efficiency Indices (AEI)
of phosphate decreased in the following order: Triple superphosphate (100%)>
Thermophosphate (89%)> MAP (80%)>Itafós phosphate rock (67%)> Arad phosphate
rock (60 %).A fosfatagem é ainda uma prática pouco utilizada na cultura da cana-de-açúcar e pode ser feita com fertilizantes fosfatados de efeito residual longo. Este trabalho teve como objetivo avaliar o efeito de fertilizantes fosfatados aplicados em área total antes do plantio da cana-de-açúcar na produção de colmos e qualidade da matéria prima de cana-de-açúcar. O experimento foi conduzido na Usina Jalles Machado, no município de Goianésia-GO durante três anos agrícolas. Os tratamentos foram constituídos de cinco fertilizantes fosfatados, solúveis e insolúveis na dose equivalente a 300 kg ha-1 de P2O5. Os fertilizantes usados foram: superfosfato triplo, monoamônio fosfato (MAP), fosfato natural reativo de Arad, fosfato natural de Itafós e termofosfato magnesiano. Para avaliar os efeitos imediatos e residuais destes fertilizantes, foram utilizados parâmetros tais como: altura de plantas (altura do solo até TVD), teor foliar de fósforo, produtividade da cana-de-açúcar na cana-planta, soca e ressoca, análise tecnologia na soqueira, quantidade de açúcar produzido e índice de eficiência agronômica dos fertilizantes utilizados. Na cana planta a adubação fosfatada proporcionou maior altura de plantas com a aplicação do termofosfato magnesiano e do superfosfato triplo. As concentrações de fósforo (P) nas folhas de cana-planta indicaram superioridade do MAP, termofosfato-magnesiano e superfosfatto-triplo. A fosfatagem não influenciou a produtividade da cana-planta, porém aumentou a produtividade da cana soca bem como a quantidade de açúcar produzida por hectare. De uma forma geral, o efeito residual dos fosfatos insolúveis aumentou no decorrer dos anos. O Índice de Eficiência Agronômica (IEA) dos fosfatos diminuiu na seguinte ordem: Superfosfato triplo (100 %) > Termofosfato (89%) > MAP (80%) > Fosfato Itafós (67%) > Fosfato Arad ( 60%).
Mestre em Agronomia
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Lahalle, Hugo. "Conditionnement de l'aluminium métallique dans les ciments phospho-magnésiens". Thesis, Dijon, 2016. http://www.theses.fr/2016DIJOS048/document.
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Ce travail porte sur le conditionnement de déchets radioactifs dans une matrice cimentaire. Il vise plus particulièrement à évaluer la compatibilité chimique entre un mortier à base de ciment phospho-magnésien et l’aluminium métallique. Dans un premier temps, les processus physico-chimiques responsables de la prise et du durcissement du ciment phospho-magnésien sont étudiés : la diffraction des rayons X (DRX), la thermogravimétrie (ATG) et la résonance magnétique nucléaire (RMN-MAS du 31P et 11B) permettent d’identifier les phases solides précipitant au cours de l’hydratation du ciment ; la spectroscopie à plasma à couplage inductif (ICP-AES), la conductimétrie et la pH-métrie apportent des informations sur la composition de la solution porale. Dans un second temps, la corrosion de l’aluminium dans des mortiers phospho-magnésiens est étudiée par suivi du potentiel d’équilibre (OCP) et par spectroscopie d’impédance électrochimique (SIE).Le ciment phospho-magnésien est préparé à partir d’oxyde de magnésium (MgO) et de dihydrogénophosphate de potassium (KH2PO4). En présence d’eau, il s’hydrate selon un processus de dissolution / précipitation. La dissolution des réactifs conduit principalement à la formation de K-struvite (MgKPO4.6H2O), précédée par celle de deux hydrates intermédiaires : la phosphorrösslerite (MgHPO4.7H2O) et la phase Mg2KH(PO4)2.15H2O. L’acide borique retarde l’hydratation du ciment en ralentissant la formation des hydrates. La précipitation initiale d’un ou plusieurs composés boratés et phosphatés amorphes ou très mal cristallisés ainsi que la stabilisation des cations en solution (magnésium, potassium) pourraient en être la cause. Par comparaison avec une matrice à base de ciment Portland, la corrosion de l’aluminium dans le mortier phospho-magnésien est fortement limitée.Le pH de la solution interstitielle, proche de la neutralité, est en effet situé dans le domaine de passivation de l’aluminium. La corrosion dépend de plusieurs paramètres : elle est favorisée pour un rapport massique eau/ciment (e/c) très supérieur à la demande chimique en eau du liant (e/c = 0.51) ainsi que par la présence d’acide borique. Au contraire, le nitrate de lithium ajouté à l’eau de gâchage agit comme un inhibiteur de corrosion. Un mécanisme de corrosion en 4 étapes permet de modéliser les diagrammes d’impédance. L’évolution de la vitesse de corrosion et de la production de dihydrogène qui lui est associée peut alors être calculée au cours du temps. Les résultats obtenus sont en bon accord avec les mesures expérimentales du dihydrogène relâché par des plaques d’aluminium enrobées dans un mortier phospho-magnésienThis work deals with the stabilization / solidification of radioactive waste using cement.More particularly, it aims at assessing the chemical compatibility between metallic aluminum and mortars based on magnesium phosphate cement. The physical and chemical processes leading to setting and hardening of the cement are first investigated. X-ray diffraction (XRD), thermogravimetry (TGA) and nuclear magnetic resonance spectroscopy (31P and11B MAS-NMR) arefirst used to characterize the solid phases formed during hydration, while inductively coupled plasma atomic emission spectroscopy analysis (ICP-AES), electrical conductimetry and pH measurementsprovide information on the pore solution composition. Then,the corrosion of metallic aluminum in magnesium phosphate mortars is studied by monitoring the equilibrium potential and by electrochemical impedance spectroscopy (EIS).Magnesium phosphate cement is prepared from a mix of magnesium oxide (MgO) and potassium dihydrogen orthophosphate (KH2PO4). In the presence of water, hydration occurs according to a dissolution – precipitation process. The main hydrate is K-struvite (MgKPO4.6H2O). Its precipitation is preceded by that of two transient phases: phosphorrösslerite (MgHPO4.7H2O) and Mg2KH(PO4)2.15H2O. Boric acid retards cement hydration by delaying theformation of cement hydrates. Two processes may be involved in this retardation: the initial precipitation of amorphous or poorly crystallized minerals containing boron and phosphorus atoms, and/or the stabilization of cations (Mg2+, K+) in solution.As compared with a Portland cement-based matrix, corrosion of aluminum is strongly limited in magnesium phosphate mortar. The pore solution pH is close to neutrality and falls within the passivation domain of aluminum. Corrosion depends on several parameters: it is promoted by a water-to-cement ratio (w/c) significantly higher than the chemical water demand of cement (w/c = 0.51), and by the addition of boric acid. On the contrary, lithium nitrate, dissolved in the mixing solution, acts as a corrosion inhibitor.A 4-step mechanism makes it possible to model the impedance diagrams. The evolution of the corrosion rate and of the amount of dihydrogen released with ongoing hydration is then calculated The results are in good agreement with the experimental determination of the H2 production by aluminum sheets embedded in magnesium phosphate mortar
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Casas, Luna Mariano. "Struktura a vlastnosti kompozitů na bázi hydroxyapatitu a hořčíku, připravovaných metodou proudem asistované slinovací infiltrace". Doctoral thesis, Vysoké učení technické v Brně. CEITEC VUT, 2020. http://www.nusl.cz/ntk/nusl-432909.
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Hořčík a kompozity fosforečnanu vápenatého jsou slibnými materiály pro biodegradabilní a nosné implantáty určené pro regeneraci kostí. Předložená práce je zaměřena na návrh, zpracování a charakterizaci vnitřně propojených kompozitů hořčíku s fosforečnanem vápenatým (Mg/CaP). Fosforečnany vápenaté jako jsou hydroxyapatit (HA), kalcium-deficitní hydroxyapatit (CDHA) a fosforečnan vápenatý (TCP) byly syntetizovány a použity pro výrobu skafoldů s kontrolovanou porozitou pomocí metody robocastingu. Byly připraveny porézní předlisky s ortogonální mřížkou a s vnitřními makropóry o velikosti ~500 µm, které byly následně slinovány za teploty 1100 °C po dobu 5 hodin. Vnitřně propojené Mg/CaP kompozity byly připraveny infiltrací čistého hořčíku a hořčíkových slitin obsahujících malá množství vápníku nebo zinku, například 0,2 hm.% vápníku a 1 hm.% zinku do porézních keramických skafoldů. Infiltrace byla provedena pomocí námi vyvinuté a nově popsané metody známé jako “Proudem asistovaná slinovací infiltrace” (z angl. Current Assisted Metal Infiltration (CAMI)). CAMI metoda umožňuje do 15 minut infiltrovat porézní keramický předlisek roztaveným kovem. Pulzujícím elektrickým proudem bylo dosaženo rychlého tavení a následného tuhnutí Mg/CaP kompozitů. Fyzikálně-chemické vlastnosti finálních vnitřně propojených kompozitů byly stanoveny pomocí rastrovací elektronové mikroskopie, počítačové mikro-tomografie, rentgenové difrakční analýzy a optické mikroskopie za účelem stanovení fázové distribuce a interakce mezi materiály. Kromě toho byla u připravených kompozitů hodnocena jejich mechanická pevnost v tlaku, degradační rychlost pomocí různých metod a biokompatibilita spolu s pokusem o uvedení těchto typů materiálů jako potenciálních degradabilních biomateriálů určených pro výrobu desek a/nebo šroubů pro ortopedické aplikace.
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Webler, Geovana Dresch. "Síntese e caracterização de cerâmicas bifásicas de fosfato de cálcio (Hap - ß-TCP) puras e dopadas com magnésio". Universidade Federal de Alagoas, 2015. http://www.repositorio.ufal.br/handle/riufal/1693.
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The calcium phosphates have been extensively studied for biomedical applications due to their chemical and structural similarities with our mineral phase of teeth and bones. In this work, biphasic calcium phosphate ceramics - BCP (mixture of hydroxyapatite and β-tricalcium phosphate, Hap/β-TCP) pure and doped with magnesium were obtained by solid state reaction. Magnesium (Mg) is known as an important element in the composition of bones and teeth. Recent research has shown that the addition of Mg in BCP structure improves consists mainly in bone metabolism and mechanical properties, without affecting its biocompatibility. The samples were prepared by solid-state reaction, using calcium carbonate, monobasic ammonium phosphate and magnesium nitratehexahydrate, as precursorssource of calcium, phosphate and magnesium, respectively. For pure BCP samples,it was investigated the influence of heat treatment on the formation of the material and for samples doped with magnesium,it investigated the different doping levels in the BCP structure. Several characterization techniques were used. The composition of the crystalline phase and morphology of the prepared materials were characterized by X-ray Diffraction and Electron Scanning Microscopy, respectively. The functional groups were analyzed using Fourier Transform Infrared Spectroscopy and Raman Spectroscopy. Cytotoxicity tests were carried out and the results suggested that the materials prepared in this work have for biological application as biomaterials.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Conselho Nacional de Desenvolvimento Científico e Tecnológico
Os Fosfatos de cálcio têm sido amplamente estudados para aplicações biomédicas devido à sua similaridade química e estrutural com a fase mineral dos nossos ossos e dentes. Neste trabalho, cerâmicas bifásicas de fosfato de cálcio - BCP (mistura de hidroxiapatita e β-fosfato tricálcico, Hap/β-TCP) purase dopadascom magnésio foram obtidas através da síntese de reação de estado sólido. O magnésio (Mg) é conhecido como um importante elemento na composição dos ossos e dentes. Recentes pesquisas tem mostrado que a adição de Mg na estrutura BCP melhora o composto, principalmente, no metabolismo ósseo e nas propriedades mecânicas, sem afetar a sua biocompatibilidade. As amostras foram preparadas através da síntese reação de estado sólido, usando carbonato de cálcio, fosfato de amônio monobásico e nitrato de magnésio hexahidratado, como fonte precursora de cálcio, fosfato e magnésio, respectivamente. Para as amostras de BCP puras, foi investigada a influência do tratamento térmico na formação do material e para as amostras dopadas com magnésio, investigamos os diferentes teores de dopantes na estrutura do BCP. Diferentes técnicas de caracterizações foram utilizadas. A composição da fase cristalina e a morfologia dos materiais preparados foram caracterizadas por Difração de Raios-X e Microscopia Eletrônica de Varredura, respectivamente. Os grupos funcionais foram analisados usando Espectroscopia de infravermelho por Transformada de Fourier e Espectroscopia Raman. Testes de Citotoxicidade foram realizados e os resultados sugerem que os materiais preparados neste trabalho, apresentam potenciais como biomaterial em aplicações biológicas.
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Hirvinen, Laura J. M. "Influence of bone cements on bone screw interfaces in the third metacarpal and metatarsal bones of horses". Columbus, Ohio : Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1243434636.
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Vlasák, Jan. "Zkoumání účinku kreatinu v kombinaci s hořčíkem a vitamínem C na výkonost jedince". Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2017. http://www.nusl.cz/ntk/nusl-316160.
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Creatine is nitrogen-containing organic acid which naturally occurs in the human body. The aim of this work was to determine the optimal dose of creatine in combination with vitamin C and magnesium for male respondents aged 18-26 years. They were divided into two groups differing in the creatine dosage. Group 1 took smaller dose of creatine (3 g per day) and group 2 higher dose of creatine (10 g per day). Both groups took both magnesium and vitamin C at constant doses throughout the study. The effects of significantly different dose of creatine in the individual groups were compared with each other in terms of the performance of individuals in the powerlifting, the anthropological changes and the overal metabolism of the intakes. In all disciplines of powerlifting, group 1 recorded higher average weight gains, which were not found to be statistically significant at a significance level of alpha 0,05. Anthropological changes were measured using the InBody 160 and a diagnostic measuring tape. In both cases, group 1 recorded better results than group 2, but these results were not statistically significant at a significance level of alpha 0,05. The total metabolism of the accepted dietary supplements was investigated through analytical methods. The urine of each respondent was regularly collected and subsequently analyzed during the research. Determination of creatinine, a creatine waste product, was performed by UV-VIS spectrophotometry using the Jaffe reaction. Vitamin C was analyzed by RP-HPLC. Magnesium was determined by the ICP-OES method. After creatine suplemantion of 3 per day, group 1 showed a slight increase in creatinine in the urine, but still in the physiological range. At the significance level alpha 0,05 there was no statistically significant difference. Group 2 showed an increase above the physiological limit which was already a statistically significant difference. Overall, creatine supplementation of 3 g per day has been found as a sufficient intake of creatine needed to build up muscle mass, increase energy metabolism and overall physical performance. The metabolization itself works very well and within the physiological values.
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Brigham, Russell D. "Assessing the Effects of Lake Dredged Sediments on Soil Health: Agricultural and Environmental Implications on Midwest Ohio". Bowling Green State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1593902126203743.
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Maaß, Oliver. "Analyzing Transactions in Linked Value Chains of Wastewater Treatment and Crop Production". Doctoral thesis, Humboldt-Universität zu Berlin, 2019. http://dx.doi.org/10.18452/20128.
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In dieser Dissertation wird der Einfluss von Transaktionen zur Wiederverwendung von Nährstoffen und gereinigtem kommunalen Abwasser auf die Wertschöpfungsketten der Abwasserbehandlung und Pflanzenproduktion untersucht. Ziel ist es, Kosten und Nutzen sowie die Wertschöpfung von Transaktionen in verknüpften Wertschöpfungsketten der Abwasserbehandlung und Pflanzenproduktion zu analysieren. Darüber hinaus wird untersucht, wie Transaktionen und Interdependenzen zwischen Akteuren in verknüpften Wertschöpfungsketten die lokalen Governance-Strukturen für die Wiederverwendung von Abwasser beeinflussen. Die Analyse wird hauptsächlich durch das Wertschöpfungskettenkonzept, das Konzept der Kreislaufwirtschaft und die Theorie der Transaktionskostenökonomie geleitet. Mit verschiedenen Methoden, wie der Kosten-Nutzen-Analyse, der Wertschöpfungskettenanalyse und der Transaktionskostenanalyse, werden zwei Fallstudien in Deutschland untersucht: (1) die Fällung von Struvit (Magnesium-Ammonium-Phosphat) und dessen Verwendung als Dünger in Berlin-Brandenburg und (2) das Modell der landwirtschaftlichen Abwasserwiederverwendung in Braunschweig. Die Ergebnisse zeigen, dass die Wiederverwendung von Nährstoffen und Abwasser zu geringeren Kosten für die Abwasserbehandlung, höherer Rentabilität und Wertschöpfung in der Pflanzenproduktion und zu einem hohen Anteil an regionaler Wertschöpfung führen. Die Ergebnisse verdeutlichen aber auch, dass die Wiederverwendung von Abwasser zu Einschränkungen, Verdrängungseffekten und Veränderungen in der Verteilung der Wertschöpfung führen kann. Des Weiteren zeigen die Ergebnisse, dass differenzierte Governance-Strukturen erforderlich sind, um den unterschiedlichen Eigenschaften der Transaktionen zwischen Abwasserbehandlung und der Pflanzenproduktion gerecht zu werden. Interdependenzen zwischen Abwasseranbietern und Landwirten erhöhen den Bedarf an hybriden und hierarchischen Elementen in den Governance-Strukuren für die Wiederverwendung von Abwasser.This dissertation explores the impact of transactions for reusing nutrients and treated municipal wastewater on the value chains of wastewater treatment and crop production. It aims to analyze what costs and benefits and what added-value can result from transactions in linked value chains of wastewater treatment and crop production. Furthermore, it aims to analyze how transactions and interdependences between actors in linked value chains shape the governance structures for reusing wastewater at the local level. The analysis is mainly guided by the value chain concept, the concept of the circular economy and the theory of transaction costs economics. Different methods including cost-benefit analysis, value chain analysis and transaction cost analysis are used to investigate two case studies located in Germany: (1) the precipitation of struvite (magnesium ammonium phosphate) in the wastewater treatment plant in Waßmannsdorf and its application as fertilizer in Berlin-Brandenburg, and (2) the agricultural wastewater reuse scheme of the Wastewater Association Braunschweig. The results show that transactions for reusing nutrients and wastewater result in the development of linked regional value chains with lower costs of wastewater treatment, higher profitability and added-value in crop production, and a high share of regional added-value. However, the results also highlight that the reuse of wastewater can lead to restrictions (e.g., cultivation bans on certain crops), crowding out effects and changes in the distribution of the added-value. Furthermore, the findings suggest that different governance structures are needed to match the different properties of the transactions between wastewater treatment and crop production. Interdependences resulting from transactions between wastewater providers and farmers increase the need for hybrid and hierarchical elements in the governance structures for reusing wastewater.