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Sample records for accumulate magnesium protoporphyrin

  1. Conserved chloroplast open-reading frame ycf54 is required for activity of the magnesium protoporphyrin monomethylester oxidative cyclase in Synechocystis PCC 6803.

    Hollingshead, Sarah; Kopecná, Jana; Jackson, Philip J; Canniffe, Daniel P; Davison, Paul A; Dickman, Mark J; Sobotka, Roman; Hunter, C Neil

    2012-08-10

    The cyclase step in chlorophyll (Chl) biosynthesis has not been characterized biochemically, although there are some plausible candidates for cyclase subunits. Two of these, Sll1214 and Sll1874 from the cyanobacterium Synechocystis 6803, were FLAG-tagged in vivo and used as bait in separate pulldown experiments. Mass spectrometry identified Ycf54 as an interaction partner in each case, and this interaction was confirmed by a reciprocal pulldown using FLAG-tagged Ycf54 as bait. Inactivation of the ycf54 gene (slr1780) in Synechocystis 6803 resulted in a strain that exhibited significantly reduced Chl levels. A detailed analysis of Chl precursors in the ycf54 mutant revealed accumulation of very high levels of Mg-protoporphyrin IX methyl ester and only traces of protochlorophyllide, the product of the cyclase, were detected. Western blotting demonstrated that levels of the cyclase component Sll1214 and the Chl biosynthesis enzymes Mg-protoporphyrin IX methyltransferase and protochlorophyllide reductase are significantly impaired in the ycf54 mutant. Ycf54 is, therefore, essential for the activity and stability of the oxidative cyclase. We discuss a possible role of Ycf54 as an auxiliary factor essential for the assembly of a cyclase complex or even a large multienzyme catalytic center. PMID:22711541

  2. Induced Protoporphyrin IX Accumulation by the δ-Aminolevulinic Acid in Bacteria and its Potential Use in the Photodynamic Therapy

    Brígido-Aparicio, Cyntiha; Ramón-Gallegos, Eva; Arenas-Huertero, Francisco Jesús; Uribe-Hernández, Raúl

    2008-08-01

    The increasing incident of resistant strains to antibiotic has encouraged the search of new antibacterial treatments, such as the photodynamic therapy. In recent years, photodynamic therapy has demonstrated being a good technology for the treatment of recurrent bacteria infection. PDT presents a hopeful approach to eliminate Gram positive and negative bacteria in immunological compromised patients. This therapy uses a laser in combination with a photosensibilizer in presence of intracellular molecular oxygen. The process generates an effect of phototoxicity in bacterial cells. The aim of this work was to determine the in vitro conditions to accumulate PpIX in effective concentrations in Staphylococcus aureus ATCC25923 and Streptococcus pyogenes, which are responsible of human cutaneous diseases. A cellular suspension of both strains was prepared in TSB to obtain growth in Log-phase, then, the suspensions were adjusted to a final concentration of 2.61×108 cells/mL. The strains were exposed to increasing concentrations from 0 to 160μg/mL of δ-ALA in order to determinate the concentration that induces the biggest accumulation of PpIX. PpIX was measured using the Piomelli method modified for bacteria. The concentration selected was 40 mg/mL of ALA. It was found that in basal concentration of δ-ALA (0 μg/mL) both strains accumulated similar amount of PpIX. In concentrations of 5 mg/mL of δ-ALA it was observed a significant (paureus ATCC25923 accumulated significantly the biggest concentration of PpIX with regard to S. pyogenes. In conclusion, it was found that the optimal conditions to apply PDT will be to expose both strains to 40 mg/mL of ALA and to irradiate at 24 h after the exposition.

  3. Magnesium

    ... Consumer Datos en español Health Professional Other Resources Magnesium Fact Sheet for Consumers Have a question? Ask ODS: ods.od.nih.gov/contact What is magnesium and what does it do? Magnesium is a ...

  4. Discontinuous Dynamic Recrystallization during Accumulative Back Extrusion of a Magnesium Alloy

    S.M. Fatemi-Varzaneh

    2013-12-01

    Full Text Available The study of nucleation mechanism of new grains during severe plastic deformation of magnesium alloys is of great importance to control the characteristics of final microstructures.  To investigate the role of discontinuous recrystallization, a wrought AZ31 magnesium alloy was deformed by accumulative back extrusion process at 330 °C.  The obtained microstructures were studied using optical and field emission microscopy as well as electron back scattered diffraction techniques.  The results demonstrated that the fine and ultrafine grains formed along the prior grain boundaries yielding a bimodal structure.  The EBSD analysis showed that the new grains exhibit a similar basal texture to deformed grains, which may confirm the operation of strain induced boundary migration mechanism.

  5. Methods of producing protoporphyrin IX and bacterial mutants therefor

    Zhou, Jizhong; Qiu, Dongru; He, Zhili; Xie, Ming

    2016-03-01

    The presently disclosed inventive concepts are directed in certain embodiments to a method of producing protoporphyrin IX by (1) cultivating a strain of Shewanella bacteria in a culture medium under conditions suitable for growth thereof, and (2) recovering the protoporphyrin IX from the culture medium. The strain of Shewanella bacteria comprises at least one mutant hemH gene which is incapable of normal expression, thereby causing an accumulation of protoporphyrin IX. In certain embodiments of the method, the strain of Shewanella bacteria is a strain of S. loihica, and more specifically may be S. loihica PV-4. In certain embodiments, the mutant hemH gene of the strain of Shewanella bacteria may be a mutant of shew_2229 and/or of shew_1140. In other embodiments, the presently disclosed inventive concepts are directed to mutant strains of Shewanella bacteria having at least one mutant hemH gene which is incapable of normal expression, thereby causing an accumulation of protoporphyrin IX during cultivation of the bacteria. In certain embodiments the strain of Shewanella bacteria is a strain of S. loihica, and more specifically may be S. loihica PV-4. In certain embodiments, the mutant hemH gene of the strain of Shewanella bacteria may be a mutant of shew_2229 and/or shew_1140.

  6. Growth, grain yield and calcium, potassium and magnesium accumulation in common bean plants as related to calcium nutrition

    Lucas da Silva Domingues

    2016-04-01

    Full Text Available The objective of this work was to evaluate the plant growth and grain yield characteristics and the accumulation of calcium, potassium and magnesium in the leaves and grains of common bean cultivars grown with different calcium concentrations in the nutrient solution. Two experiments were conducted with nutrient solutions in a soilless system in a greenhouse. In the first experiment, five calcium concentrations (1.10, 1.65, 2.20, 2.75 and 3.30 mmol L-1 and three common bean cultivars (Iraí, BRS Expedito and Carioca were evaluated. Higher calcium concentrations (2.20, 2.75, 3.30, 3.85, 4.40 and 4.95 mmol L-1and two common bean cultivars (BRS Expedito and Carioca were tested in the second experiment. Dry mass of the shoot and root, grain yield and calcium accumulation in the leaves and grains increased linearly in common bean plants supplied with calcium concentrations between 2.20 and 4.95 mmol L-1. The high calcium concentration did not reduce the accumulation of calcium, potassium and magnesium in the leaves and grains. Common bean plants grown with high calcium concentrations present higher dry mass of the shoot and root, high grain yield and high calcium concentration in the leaves and grains.

  7. Inhibition of human peripheral blood lymphocyte function by protoporphyrin and longwave ultraviolet light

    Barrett, K.E.; Yen, A.; Montisano, D.; Gigli, I.; Bigby, T.D. [Univ. of California, San Diego, CA (United States)

    1994-10-01

    Modulation of immunologic effector cells by exogenous photoactive substances has been advanced as an underlying mechanism for the efficacy of various photochemotherapeutic regimens. It is also possible that endogenous photosensitizers, such as protoporphyrin, could similarly modify the function of immune cell types. The authors examined the effects of protoporphyrin plus longwave UV light on the ability of human PBL to proliferate in response to mitogens. Noncytotoxic dosages of protoporphyrin plus UV light suppressed PHA-stimulated proliferation of both PBMC and enriched T cells. CD8{sup +} cells were more sensitive to this inhibitory effect than CD4{sup +} cells. The inhibitory effect was also observed when proliferation was induced by the combination of a phorbol ester and ionomycin. Inhibition of PBMC proliferation was associated with inhibition of IL-2 secretion but proliferation was not restored with exogenous IL-2. Instead, the effect of protoporphyrin plus UV light may be on IL-2R. Cells treated with protoporphyrin and UV light did not display the increase in CD25 and {beta}-chain of the IL-2R induced by PHA in control cells. In contrast to the effects of protoporphyrin and UV light on IL-2 and IL-2R {alpha}-chain protein expression, the accumulation of mRNA for these proteins induced by PHA was unaffected. None of the effects of protoporphyrin plus UV light on lymphocytes were observed in control experiments where cells were treated with either protoporphyrin or UV light alone. They conclude that biologically relevant dosages of protoporphyrin and UV light modify the function of circulating lymphocytes. 26 refs., 8 figs., 1 tab.

  8. Seleção de genótipos de cana-de-açúcar para acúmulo de protoporfirina ix com uso de herbicidas inibidores da protox Selection of Sugarcane Genotypes for Protoporphyrin IX Accumulation using Protox-Inhibiting Herbicides

    L.R.M. Barberis

    2009-01-01

    of protoporphyrin IX (PROTO IX, or its precursors in plants. Such compounds can be used as sensitizing agents in photodynamic therapy (PDT, being considered a low cost source for the treatment of malignancies. The experiment was set up on a temperature-controlled chamber, with 9 treatments being applied: (1. oxyfluorfen + monosodium glutamate + vitamin C and E; 2. oxyfluorfen + monosodium glutamate + vitamin C and E + levulenic acid; 3. oxyfluorfen; 4. carfentrazone + monosodium glutamate + vitamin C and E; 5. carfentrazone + monosodium glutamate + vitamin C and E + levulenic acid; 6. carfentrazone; 7. control + vitamin C and E; 8. control + vitamin C and E + levulenic acid; 9. control without spraying in 8 sugarcane genotypes (PO933499, RB806043, RB470355, PO830698, SP701143, PO901387, PO894414 and 8.SP903414; arranged in a factorial 9 x 8, with 4 repetitions. The repetitions were constituted by specific leaves (20 cm from each genotype, which were sprayed with the appropriate treatments in a stationary simulator. Visual evaluations of the control were carried out at 2 DAA (Days After Application, and at the end of the study, analytical determinations were conducted via fresh biomass extraction to verify the protoporphyrin IX contents by high performance liquid chromatography. The results showed that significant short-term increases were observed in the PROTO IX concentrations for the genotypes RB470355, SP903414 submitted to treatment 2 and for genotype SP701143 submitted to treatment 8, indicating that they can be used as accumulating sources of protoporphyrin IX.

  9. The preparation of 58Co-protoporphyrin complex

    It has been known that protoporphyrin(PP) could be accumulated in tumor tissue and its complex with cobalt inhibits the growth of undifferentiated cells. Preparation of 58Co-PP has been carried out using Co-58 labelled CoCl2 in glacial acetic acid and PP in CHCl3-pyridine mixture. It has been studied the influence of CoCl2 as carrier and time of heating against the labelling efficiency and chemical yield. Chemical and radiochemical analysis using thin layer chroamtography(TLC) and high performance liquid chromatography(HPLC) show-ed that the complex was pure enough with 98.50% radiochemical purity. This complex has absorption bands in the vissible region at 531.8nm and 565.0nm and in Soret region at 415.6nm in methanol. (author)

  10. Suppressive effect of magnesium oxide materials on cadmium accumulation in winter wheat grain cultivated in a cadmium-contaminated paddy field under annual rice-wheat rotational cultivation

    The effectiveness of two kinds of magnesium oxide (MgO) materials, commercial MgO (2250 kg ha-1) and a material derived from MgO and magnesium silicate minerals named 'MgO-SH-A' (2250 and 4500 kg ha-11), in suppression of uptake and accumulation of cadmium (Cd) into grain of winter wheat (Triticum aestivum L. cv. Ayahikari) was examined in a Cd-contaminated alluvial paddy field under annual rice-wheat rotational system. The MgO materials were mixed into the plough-layer soil only once prior to the preceding rice cultivation. Cadmium concentration in wheat grain produced from the non-amendment control exceeded the maximum limit of Cd in wheat grain adopted by FAO/WHO (0.2 mg kg-1). All of the treatments with the MgO materials significantly lowered plant available Cd fraction in the plough-layer soil. However, only the treatment with the commercial MgO at 2250 kg ha-1 produced wheat grain whose Cd concentration was not only significantly lower than that from the control but also less than 0.2 mg kg-1. It is suggested that the significant suppressive effect of the commercial MgO on Cd accumulation in wheat grain would be mainly attributed to its high soil neutralizing capacity as compared to that of MgO-SH-A.

  11. Suppressive effect of magnesium oxide materials on cadmium accumulation in winter wheat grain cultivated in a cadmium-contaminated paddy field under annual rice-wheat rotational cultivation

    Kikuchi, Tetsuro, E-mail: tetsu-k@hino.meisei-u.ac.jp [Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588 (Japan); Okazaki, Masanori, E-mail: masaok24@cc.tuat.ac.jp [Institute of Symbiotic Science and Technology, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588 (Japan); Motobayashi, Takashi, E-mail: takarice@cc.tuat.ac.jp [Field Science Center for Education and Research, Tokyo University of Agriculture and Technology, 3-7-1 Hommachi, Fuchu, Tokyo 183-0027 (Japan)

    2009-08-30

    The effectiveness of two kinds of magnesium oxide (MgO) materials, commercial MgO (2250 kg ha{sup -1}) and a material derived from MgO and magnesium silicate minerals named 'MgO-SH-A' (2250 and 4500 kg ha{sup -1}1), in suppression of uptake and accumulation of cadmium (Cd) into grain of winter wheat (Triticum aestivum L. cv. Ayahikari) was examined in a Cd-contaminated alluvial paddy field under annual rice-wheat rotational system. The MgO materials were mixed into the plough-layer soil only once prior to the preceding rice cultivation. Cadmium concentration in wheat grain produced from the non-amendment control exceeded the maximum limit of Cd in wheat grain adopted by FAO/WHO (0.2 mg kg{sup -1}). All of the treatments with the MgO materials significantly lowered plant available Cd fraction in the plough-layer soil. However, only the treatment with the commercial MgO at 2250 kg ha{sup -1} produced wheat grain whose Cd concentration was not only significantly lower than that from the control but also less than 0.2 mg kg{sup -1}. It is suggested that the significant suppressive effect of the commercial MgO on Cd accumulation in wheat grain would be mainly attributed to its high soil neutralizing capacity as compared to that of MgO-SH-A.

  12. Magnesium Gluconate

    Magnesium gluconate is used to treat low blood magnesium. Low blood magnesium is caused by gastrointestinal disorders, prolonged vomiting or ... disease, or certain other conditions. Certain drugs lower magnesium levels as well.This medication is sometimes prescribed ...

  13. Magnesium Oxide

    Magnesium is an element your body needs to function normally. Magnesium oxide may be used for different reasons. Some ... to relieve heartburn, sour stomach, or acid indigestion. Magnesium oxide also may be used as a laxative ...

  14. Magnesium Metabolism

    2008-01-01

    Magnesium is the second most common intracellular divalent cation. Magnesium balance in the body is controlled by a dynamic interplay among intestinal absorption, exchange with bone, and renal excretion. Intestinal magnesium absorption proceeds in both a passive paracellular and an active transcellular manner. Regulation of serum magnesium concentrations is achieved mainly by control of renal magnesium reabsorption. Only 20% of filtered magnesium is reabsorbed in the proximal tubule, whereas ...

  15. Magnesium basics

    Jahnen-Dechent, Wilhelm; Ketteler, Markus

    2012-01-01

    As a cofactor in numerous enzymatic reactions, magnesium fulfils various intracellular physiological functions. Thus, imbalance in magnesium status—primarily hypomagnesaemia as it is seen more often than hypermagnesaemia—might result in unwanted neuromuscular, cardiac or nervous disorders. Measuring total serum magnesium is a feasible and affordable way to monitor changes in magnesium status, although it does not necessarily reflect total body magnesium content. The following review focuses o...

  16. Effect of 5-aminolevulinic acid on kinetics of protoporphyrin IX production in CHO cells.

    W Warchoł

    2004-07-01

    Full Text Available 5-aminolevulinic acid (ALA is utilized in a photodynamic therapy as a compound capable of augmenting intracellular pool of protoporphyrin IX (PpIX, which exhibits properties of a photosensitizer. The studies were aimed at monitoring accumulation of endogenous protoporphyrin IX in CHO cells under effect of various concentrations of ALA in culture medium and following removal of the compound from the culture medium. Cell content of PpIX was determined following incubation of the cells for 72 h in a culture medium containing different concentration of ALA. Moreover, the cells were preincubated for 2 h in ALA at various concentrations and separated from the compound by medium change and their PpIX content was monitored following incubation. PpIX content was defined by a fluorescent technique under the confocal microscope. In the course of continuous incubation of cells with ALA, biphasic alterations were noted in cellular PpIX concentration. Removal of ALA from the incubation medium resulted at first in a decrease in PpIX content in cells, which was followed by an evidently augmented accumulation of the compound in the cells. The results suggested that in the case of CHO cells, exogenous ALA was not an exclusive source of PpIX synthesis and that alterations in enzyme activities were responsible for production of PpIX.

  17. Magnesium Hydroxide

    Magnesium hydroxide is used on a short-term basis to treat constipation.This medication is sometimes prescribed ... Magnesium hydroxide come as a tablet and liquid to take by mouth. It usually is taken as ...

  18. Magnesium Test

    ... be limited. Home Visit Global Sites Search Help? Magnesium Share this page: Was this page helpful? Also known as: Mg; Mag Formal name: Magnesium Related tests: Calcium , Potassium , Phosphorus , PTH , Vitamin D ...

  19. Spectroscopy of Ferric Heme and Protoporphyrin IX Ions In Vacuo

    Wyer, Jean; Nielsen, Steen Brøndsted

    2013-01-01

    This chapter deals with gas-phase spectroscopy of protoporphyrin IX and heme ions, two important biochromophores in nature. These ions strongly absorb blue and green light, which accounts for e.g. the red colour of blood. We present absorption spectra of four-coordinate ferric heme cations at room...... conversion to the ground state. This is somewhat supported by spectroscopic characterisation of the long-lived states based on pump-probe experiments. Hence from one time spectrum (a one-laser experiment), triplet quantum yields can easily be estimated....

  20. Production of magnesium metal

    Blencoe, James G [Harriman, TN; Anovitz, Lawrence M [Knoxville, TN; Palmer, Donald A [Oliver Springs, TN; Beard, James S [Martinsville, VA

    2010-02-23

    A process of producing magnesium metal includes providing magnesium carbonate, and reacting the magnesium carbonate to produce a magnesium-containing compound and carbon dioxide. The magnesium-containing compound is reacted to produce magnesium metal. The carbon dioxide is used as a reactant in a second process. In another embodiment of the process, a magnesium silicate is reacted with a caustic material to produce magnesium hydroxide. The magnesium hydroxide is reacted with a source of carbon dioxide to produce magnesium carbonate. The magnesium carbonate is reacted to produce a magnesium-containing compound and carbon dioxide. The magnesium-containing compound is reacted to produce magnesium metal. The invention further relates to a process for production of magnesium metal or a magnesium compound where an external source of carbon dioxide is not used in any of the reactions of the process. The invention also relates to the magnesium metal produced by the processes described herein.

  1. Latex carrier for improving protoporphyrin IX for photodynamic therapy.

    Bui, Brian; Liu, Li; Chen, Wei

    2016-06-01

    Attachment of Protoporphyrin IX (PPIX) to poly (styrene-co-4-vinylpyridine) (PS4VP) nanobeads was carried out to improve its properties in aqueous solutions. After using an oil-in-water heated emulsion polymerization technique to synthesize PS4VP, PPIX was bonded to the particles via the carboxylic acid of PPIX hydrogen-bonding to the nitrogen at the surface of PS4VP, thereby preventing self-reactions between the carboxyl groups and the porphyrin core. Refraining the two parts from interacting while attached to the nanobeads prevented PPIX from aggregating, which then increased water solubility, enhanced luminescence and singlet oxygen production. Attachment also improved cell uptake and cell destruction by photodynamic activity. This shows that PS4VP-PPIX may help improve aspects of photodynamic therapy for the treatment of cancer. PMID:27020668

  2. Mapping of lead, magnesium and copper accumulation in plant tissues by laser-induced breakdown spectroscopy and laser-ablation inductively coupled plasma mass spectrometry

    Laser-Induced Breakdown Spectroscopy (LIBS) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) were utilized for mapping the accumulation of Pb, Mg and Cu with a resolution up to 200 μm in a up to cm x cm area of sunflower (Helianthus annuus L.) leaves. The results obtained by LIBS and LA-ICP-MS are compared with the outcomes from Atomic Absorption Spectrometry (AAS) and Thin-Layer Chromatography (TLC). It is shown that laser-ablation based analytical methods can substitute or supplement these techniques mainly in the cases when a fast multi-elemental mapping of a large sample area is needed

  3. Mapping of lead, magnesium and copper accumulation in plant tissues by laser-induced breakdown spectroscopy and laser-ablation inductively coupled plasma mass spectrometry

    Kaiser, J. [Institute of Physical Engineering, Faculty of Mechanical Engineering, Brno University of Technology, Technicka 2896/2, 616 69 Brno (Czech Republic)], E-mail: kaiser@fme.vutbr.cz; Galiova, M.; Novotny, K.; Cervenka, R. [Department of Chemistry, Faculty of Science, Masaryk University, Kotlarska 2, 611 37 Brno (Czech Republic); Reale, L. [Faculty of Sciences, University of L' Aquila, Via Vetoio (Coppito 1), 67010 L' Aquila (Italy); Novotny, J.; Liska, M.; Samek, O. [Institute of Physical Engineering, Faculty of Mechanical Engineering, Brno University of Technology, Technicka 2896/2, 616 69 Brno (Czech Republic); Kanicky, V.; Hrdlicka, A. [Department of Chemistry, Faculty of Science, Masaryk University, Kotlarska 2, 611 37 Brno (Czech Republic); Stejskal, K.; Adam, V.; Kizek, R. [Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University of Agriculture and Forestry, Zemedelska 1, 613 00 Brno (Czech Republic)

    2009-01-15

    Laser-Induced Breakdown Spectroscopy (LIBS) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) were utilized for mapping the accumulation of Pb, Mg and Cu with a resolution up to 200 {mu}m in a up to cm x cm area of sunflower (Helianthus annuus L.) leaves. The results obtained by LIBS and LA-ICP-MS are compared with the outcomes from Atomic Absorption Spectrometry (AAS) and Thin-Layer Chromatography (TLC). It is shown that laser-ablation based analytical methods can substitute or supplement these techniques mainly in the cases when a fast multi-elemental mapping of a large sample area is needed.

  4. Mapping of lead, magnesium and copper accumulation in plant tissues by laser-induced breakdown spectroscopy and laser-ablation inductively coupled plasma mass spectrometry

    Kaiser, J.; Galiová, M.; Novotný, K.; Červenka, R.; Reale, L.; Novotný, J.; Liška, M.; Samek, O.; Kanický, V.; Hrdlička, A.; Stejskal, K.; Adam, V.; Kizek, R.

    2009-01-01

    Laser-Induced Breakdown Spectroscopy (LIBS) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) were utilized for mapping the accumulation of Pb, Mg and Cu with a resolution up to 200 μm in a up to cm × cm area of sunflower ( Helianthus annuus L.) leaves. The results obtained by LIBS and LA-ICP-MS are compared with the outcomes from Atomic Absorption Spectrometry (AAS) and Thin-Layer Chromatography (TLC). It is shown that laser-ablation based analytical methods can substitute or supplement these techniques mainly in the cases when a fast multi-elemental mapping of a large sample area is needed.

  5. Linoleic acid, thymine, and tryptophan radiosensitization by protoporphyrin in presence of oxygene

    Sensitizing effect induced by protoporphyrin, an active molecule in photooxidation is studied. Studied substances are tryptophan, thymine, linoleic acid, each component representing one of the great groups of biological components, nucleic acid, proteins, lipids

  6. Magnesium in Clinical Practice

    E.L. Trisvetova

    1989-01-01

    Magnesium is a macronutrient that is needed for normal body functions. Magnesium deficiency resulting from the influence of exogenous and endogenous factors, is diagnosed by clinical manifestations, resembling the known disease. Magnesium deficiency corrected with the magnesium therapy. Studies show the effectiveness of magnesium orotate for many cardiovascular diseases.

  7. Magnesium compounds

    Kramer, D.A.

    2006-01-01

    In 2005, seawater and natural brines accounted for 51% of US magnesium compounds production. World magnesia production was estimated to be 14.5 Mt. Most of the production came from China, North Korea, Russia and Turkey. Although no specific production figures are available, Japan and the United States are estimated to account for almost one-half of the world's capacity from seawater and brines.

  8. Magnesium in diet

    Diet - magnesium ... Magnesium is needed for more than 300 biochemical reactions in the body. It helps to maintain normal ... There is ongoing research into the role of magnesium in preventing and managing disorders such as high ...

  9. Heme oxygenase: the physiological role of one of its metabolites, carbon monoxide and interactions with zinc protoporphyrin, cobalt protoporphyrin and other metalloporphyrins.

    Marks, G S

    1994-11-01

    In 1991, we postulated that carbon monoxide, which is formed endogenously from heme catabolism catalyzed by heme oxygenase and shares some of the chemical and biological properties of nitric oxide, may play a role similar to that of nitric oxide as a widespread signal transduction mechanism for the regulation of cell function and communication. We review the experimental evidence that tests this postulate. Carbon monoxide appears to be involved in the neurophysiological phenomenon of long-term potentiation, which appears to play a key role in memory and learning. Zinc protoporphyrin, an inhibitor of heme oxygenase, prevents induction of long-term potentiation. Zinc protoporphyrin is an endogenous substance, the levels of which are increased in iron deficiency states and in lead poisoning, and by inhibiting heme oxygenase may modulate long-term potentiation and memory. It has been shown that, when cobalt protoporphyrin is injected into the medial nuclei of the rat hypothalamus, weight loss occurs. These nuclei contain heme oxygenase, and we postulate that weight loss is due to cobalt protoporphyrin induction of heme oxygenase and increased formation of carbon monoxide, which serves as a signal transduction mechanism in the medial hypothalamus to suppress appetite. PMID:7849553

  10. Molecular mechanisms of the killing effects on Ehrlich ascites tumor cells by sono-chemical-activated protoporphyrin

    LIU Quan-Hong, XIAO Li-Na; Li, Xiao-ying; Wang, Pan; Wang, Xiao-Bing; Wang, Yu; LI Chen-Di

    2008-01-01

    We studied the Ehrlich ascetic tumor (EAT) cell line killing effects by ultrasound activating protoporphyrin Ⅸ (PPⅨ) and its mechamism. The cellular uptake and subcellular localization of protoporphyrin Ⅸ were estimated by fluorescence photometer and laser scanning confocal microscopy (LSCM) respectively. The trypan blue exclusion method was used to analyze the relative viability of EAT cells after ultrasonically activated protoporphyrin Ⅸ. Changes of ultra-microstructure of the treated cell...

  11. Differential effects of protoporphyrin and uroporphyrin on murine mast cells

    Lim, H.W.; Gigli, I.; Wasserman, S.I.

    1987-03-01

    To investigate the mechanisms responsible for the distinct cutaneous manifestations of erythropoietic protoporphyria and porphyria cutanea tarda, the effects of protoporphyrin (PP) and uroporphyrin (URO), the predominant porphyrins in the respective disease, on mast cells were examined. Release of preformed and generated mediators was assessed by the release of radioactivity from cells labeled with (/sup 3/H)serotonin and (/sup 14/C)arachidonic acid, respectively. Clinically relevant doses of PP (25-500 ng/ml) and 396-407 nm irradiation (3-16 X 10(2)J/m2) induced maximal net release of preformed mediators ,f 44.52 +/- 6.6 to 58.01 +/- 4.0% (mean +/- SE). In contrast, irradiation in the presence of URO (50-5000 ng/ml) resulted in less than 5% net release. (3H)Serotonin release induced by PP and irradiation was calcium-independent, and was not enhanced by phorbol 12-myristate 13-acetate, a known activator of protein kinase C. This release was suppressed by catalase, a scavenger of hydrogen peroxide. Furthermore, irradiation in the presence of PP, but not in the presence of URO, resulted in perturbation of cell membrane. Irradiation in the presence of PP also resulted in a maximal net release of generated mediators of 9.98 +/- 3.5% (mean +/- SE), whereas similar treatment in the presence of URO induced less than 0.5% net release. These results suggested that the burning, stinging, erythema, and edema experienced by patients with erythropoietic protoporphyria following sun exposure, and the lack of such findings in patients with porphyria cutanea tarda, may be explained, at least in part, by the differential effects of PP and URO on mast cells.

  12. Differential effects of protoporphyrin and uroporphyrin on murine mast cells

    To investigate the mechanisms responsible for the distinct cutaneous manifestations of erythropoietic protoporphyria and porphyria cutanea tarda, the effects of protoporphyrin (PP) and uroporphyrin (URO), the predominant porphyrins in the respective disease, on mast cells were examined. Release of preformed and generated mediators was assessed by the release of radioactivity from cells labeled with [3H]serotonin and [14C]arachidonic acid, respectively. Clinically relevant doses of PP (25-500 ng/ml) and 396-407 nm irradiation (3-16 X 10(2)J/m2) induced maximal net release of preformed mediators ,f 44.52 +/- 6.6 to 58.01 +/- 4.0% (mean +/- SE). In contrast, irradiation in the presence of URO (50-5000 ng/ml) resulted in less than 5% net release. [3H]Serotonin release induced by PP and irradiation was calcium-independent, and was not enhanced by phorbol 12-myristate 13-acetate, a known activator of protein kinase C. This release was suppressed by catalase, a scavenger of hydrogen peroxide. Furthermore, irradiation in the presence of PP, but not in the presence of URO, resulted in perturbation of cell membrane. Irradiation in the presence of PP also resulted in a maximal net release of generated mediators of 9.98 +/- 3.5% (mean +/- SE), whereas similar treatment in the presence of URO induced less than 0.5% net release. These results suggested that the burning, stinging, erythema, and edema experienced by patients with erythropoietic protoporphyria following sun exposure, and the lack of such findings in patients with porphyria cutanea tarda, may be explained, at least in part, by the differential effects of PP and URO on mast cells

  13. Combined iron sucrose and protoporphyrin treatment protects against ischemic and toxin-mediated acute renal failure.

    Zager, Richard A; Johnson, Ali C M; Frostad, Kirsten B

    2016-07-01

    Tissue preconditioning, whereby various short-term stressors initiate organ resistance to subsequent injury, is well recognized. However, clinical preconditioning of the kidney for protection against acute kidney injury (AKI) has not been established. Here we tested whether a pro-oxidant agent, iron sucrose, combined with a protoporphyrin (Sn protoporphyrin), can induce preconditioning and protect against acute renal failure. Mice were pretreated with iron sucrose, protoporphyrin, cyanocobalamin, iron sucrose and protoporphyrin, or iron sucrose and cyanocobalamin. Eighteen hours later, ischemic, maleate, or glycerol models of AKI were induced, and its severity was assessed the following day (blood urea nitrogen, plasma creatinine concentrations; post-ischemic histology). Agent impact on cytoprotective gene expression (heme oxygenase 1, hepcidin, haptoglobin, hemopexin, α1-antitrypsin, α1-microglobulin, IL-10) was assessed as renal mRNA and protein levels. AKI-associated myocardial injury was gauged by plasma troponin I levels. Combination agent administration upregulated multiple cytoprotective genes and, unlike single agent administration, conferred marked protection against each tested model of acute renal failure. Heme oxygenase was shown to be a marked contributor to this cytoprotective effect. Preconditioning also blunted AKI-induced cardiac troponin release. Thus, iron sucrose and protoporphyrin administration can upregulate diverse cytoprotective genes and protect against acute renal failure. Associated cardiac protection implies potential relevance to both AKI and its associated adverse downstream effects. PMID:27165818

  14. Corrosion behavior of magnesium and magnesium alloys

    I.M.Baghni; WU Yin-shun(吴荫顺); LI Jiu-qing(李久青); ZHANG Wei(张巍)

    2004-01-01

    The automotive industry has crossed the threshold from using magnesium alloys in interior applications such as instrument panels and steering wheels to unprotected environment such as oil pan, cylinder head and wheels. The expanding territory of magnesium leads to new challenges: mainly environmental degradation of the alloys used and how they can be protected. The present critical review is aimed at understanding the corrosion behavior of magnesium and magnesium alloys in industrial and marine environments, and the effect of microstructure, additive elements and inhibitors on the corrosion mechanism.

  15. Protoporphyrin IX-induced structural and functional changes in human red blood cells, haemoglobin and myoglobin

    Susmita Sil; Tania Bose; Dibyendu Roy; Abhay Sankar Chakraborti

    2004-09-01

    Protoporphyrin IX and its derivatives are used as photosensitizers in the photodynamic therapy of cancer. Protoporphyrin IX penetrates into human red blood cells and releases oxygen from them. This leads to a change in the morphology of the cells. Spectrophotometric studies reveal that protoporphyrin IX interacts with haemoglobin and myoglobin forming ground state complexes. For both proteins, the binding affinity constant decreases, while the possible number of binding sites increases, as the aggregation state of the porphyrin is increased. The interactions lead to conformational changes of both haemoglobin and myoglobin as observed in circular dichroism studies. Upon binding with the proteins, protoporphyrin IX releases the heme-bound oxygen from the oxyproteins, which is dependent on the stoichiometric ratios of the porphyrin: protein. The peroxidase activities of haemoglobin and myoglobin are potentiated by the protein-porphyrin complexation. Possible mechanisms underlying the relation between the porphyrin-induced structural modifications of the heme proteins and alterations in their functional properties have been discussed. The findings may have a role in establishing efficacy of therapeutic uses of porphyrins as well as in elucidating their mechanisms of action as therapeutic agents.

  16. Diagnostic utility of zinc protoporphyrin to detect iron deficiency in Kenyan pregnant women

    Mwangi, M.N.; Maskey, S.; Andang'o, P.E.A.; Shinali, N.K.; Roth, J.M.; Trijsburg, L.; Mwangi, A.M.

    2014-01-01

    Iron-deficient erythropoiesis results in excess formation of zinc protoporphyrin (ZPP), which can be measured instantly and at low assay cost using portable haematofluorometers. ZPP is used as a screening marker of iron deficiency in individual pregnant women and children, but also to assess populat

  17. The location of protoporphyrin in the eggshell of brown-shelled eggs.

    Samiullah, S; Roberts, J R

    2013-10-01

    Protoporphyrin has been identified as the main eggshell pigment in brown-shelled eggs. However, there has been some uncertainty concerning the distribution of the pigment within the shell (and cuticle) in brown-shelled eggs. Most previous studies have suggested that the bulk of the shell pigment is deposited in the cuticle of the shell. The present study measured the levels of protoporphyrin in intact eggshells and in shells from which the cuticle had been removed, using eggs from flocks at 3 different ages. This enabled the calculation of the relative amount of protoporphyrin in the calcareous eggshell and the cuticle layer of the eggshell. The majority of the protoporphyrin pigment was located in the calcareous part of the eggshell (80-87%) with a minority contained within the cuticle (13-20%). These findings suggest that studies focused on maintenance of shell color in brown-shelled eggs need to consider the stage of egg formation at which the reduction in pigment deposition is occurring. PMID:24046428

  18. The effect of protoporphyrin on histamine secretion by rat peritoneal mast cells: a dual phototoxic reaction

    Protoporphyrin-induced phototoxicity in rat peritoneal mast cells was manifested either by inhibition of 48/80-stimulated histamine secretion or by cell lysis. At a protoporphyrin concentration of 100 ng/ml, histamine secretion was completely inhibited after 30 min illumination. After initiation, the inhibited state progressed in the dark, and was irreversible; however, it did not develop into cell lysis. Cell lysis was evoked by increasing the light intensity between 180-950 W/m2, using a light source with emission maxima in the 350-470 nm region. Dual phototoxic effects could also be demonstrated in erythrocytes. Increased resistance to osmotic lysis was seen under moderate illumination conditions, and decreased resistance and cell lysis were seen under severe conditions. In the absence of protoporphyrin, the effect of light alone on mast cells was similar to protoporphyrin-phototoxicity, although the light intensities required were higher both for inhibition (60-130 W/m2) and lysis (280-950 W/m2). The data therefore indicate that certain cell functions can be specifically disrupted by phototoxic reactions that are not cytotoxic; however, phototoxic reactions that lead to severe membrane protein denaturation and cell lysis also occur. The manifestation of these dual effects depends on the intensity of illumination in the 350-470 nm region. (author)

  19. Choline Magnesium Trisalicylate

    Choline magnesium trisalicylate is used to relieve the pain, tenderness, inflammation (swelling), and stiffness caused by arthritis and painful ... used to relieve pain and lower fever. Choline magnesium trisalicylate is in a class of nonsteroidal anti- ...

  20. Nutrition and magnesium absorption.

    Brink, E.J.

    1992-01-01

    The influence of various nutrients present in dairy products and soybean-based products on absorption of magnesium has been investigated. The studies demonstrate that soybean protein versus casein lowers apparent magnesium absorption in rats through its phytate component. However, true magnesium absorption was neither affected by soybean protein in the diet nor by supplemental phytate. The inhibitory influence of soybean protein and phytate on apparent magnesium absorption was found to be cau...

  1. Magnesium and Space Flight

    Smith, Scott M.; Zwart, Sara R.

    2016-01-01

    Magnesium is an essential nutrient for muscle, cardiovascular, and bone health on Earth, and during space flight. We sought to evaluate magnesium status in astronauts before, during, and after space missions, in 43 astronauts (34 male, 9 female) on 4-6 month space flight missions. We also studied individuals participating in a ground analog of space flight, (head-down tilt bed rest, n=27, 35 +/- 7 y). We evaluated serum concentration and 24-hour urinary excretion of magnesium along with estimates of tissue magnesium status from sublingual cells. Serum magnesium increased late in flight, while urinary magnesium excretion was higher over the course of 180-d space missions. Urinary magnesium increased during flight but decreased significantly at landing. Neither serum nor urinary magnesium changed during bed rest. For flight and bed rest, significant correlations existed between the area under the curve of serum and urinary magnesium and the change in total body bone mineral content. Tissue magnesium concentration was unchanged after flight and bed rest. Increased excretion of magnesium is likely partially from bone and partially from diet, but importantly, it does not come at the expense of muscle tissue stores. While further study is needed to better understand the implications of these findings for longer space exploration missions, magnesium homeostasis and tissue status seem well maintained during 4- to 6-month space missions.

  2. Nutrition and magnesium absorption.

    Brink, E.J.

    1992-01-01

    The influence of various nutrients present in dairy products and soybean-based products on absorption of magnesium has been investigated. The studies demonstrate that soybean protein versus casein lowers apparent magnesium absorption in rats through its phytate component. However, true magnesium abs

  3. Magnesium and Space Flight

    Scott M. Smith

    2015-12-01

    Full Text Available Magnesium is an essential nutrient for muscle, cardiovascular, and bone health on Earth, and during space flight. We sought to evaluate magnesium status in 43 astronauts (34 male, 9 female; 47 ± 5 years old, mean ± SD before, during, and after 4–6-month space missions. We also studied individuals participating in a ground analog of space flight (head-down-tilt bed rest; n = 27 (17 male, 10 female, 35 ± 7 years old. We evaluated serum concentration and 24-h urinary excretion of magnesium, along with estimates of tissue magnesium status from sublingual cells. Serum magnesium increased late in flight, while urinary magnesium excretion was higher over the course of 180-day space missions. Urinary magnesium increased during flight but decreased significantly at landing. Neither serum nor urinary magnesium changed during bed rest. For flight and bed rest, significant correlations existed between the area under the curve of serum and urinary magnesium and the change in total body bone mineral content. Tissue magnesium concentration was unchanged after flight and bed rest. Increased excretion of magnesium is likely partially from bone and partially from diet, but importantly, it does not come at the expense of muscle tissue stores. While further study is needed to better understand the implications of these findings for longer space exploration missions, magnesium homeostasis and tissue status seem well maintained during 4–6-month space missions.

  4. Magnesium and the Athlete.

    Volpe, Stella Lucia

    2015-01-01

    Magnesium is the fourth most abundant mineral and the second most abundant intracellular divalent cation in the body. It is a required mineral that is involved in more than 300 metabolic reactions in the body. Magnesium helps maintain normal nerve and muscle function, heart rhythm (cardiac excitability), vasomotor tone, blood pressure, immune system, bone integrity, and blood glucose levels and promotes calcium absorption. Because of magnesium's role in energy production and storage, normal muscle function, and maintenance of blood glucose levels, it has been studied as an ergogenic aid for athletes. This article will cover the general roles of magnesium, magnesium requirements, and assessment of magnesium status as well as the dietary intake of magnesium and its effects on exercise performance. The research articles cited were limited from those published in 2003 through 2014. PMID:26166051

  5. Magnesium Metabolism and its Disorders

    Swaminathan, R.

    2003-01-01

    Magnesium is the fourth most abundant cation in the body and plays an important physiological role in many of its functions. Magnesium balance is maintained by renal regulation of magnesium reabsorption. The exact mechanism of the renal regulation is not fully understood. Magnesium deficiency is a common problem in hospital patients, with a prevalence of about 10%. There are no readily available and easy methods to assess magnesium status. Serum magnesium and the magnesium tolerance test are ...

  6. Magnesium in depression.

    Serefko, Anna; Szopa, Aleksandra; Wlaź, Piotr; Nowak, Gabriel; Radziwoń-Zaleska, Maria; Skalski, Michał; Poleszak, Ewa

    2013-01-01

    Magnesium is one of the most essential mineral in the human body, connected with brain biochemistry and the fluidity of neuronal membrane. A variety of neuromuscular and psychiatric symptoms, including different types of depression, was observed in magnesium deficiency. Plasma/serum magnesium levels do not seem to be the appropriate indicators of depressive disorders, since ambiguous outcomes, depending on the study, were obtained. The emergence of a new approach to magnesium compounds in medical practice has been seen. Apart from being administered as components of dietary supplements, they are also perceived as the effective agents in treatment of migraine, alcoholism, asthma, heart diseases, arrhythmias, renal calcium stones, premenstrual tension syndrome etc. Magnesium preparations have an essential place in homeopathy as a remedy for a range of mental health problems. Mechanisms of antidepressant action of magnesium are not fully understood yet. Most probably, magnesium influences several systems associated with development of depression. The first information on the beneficial effect of magnesium sulfate given hypodermically to patients with agitated depression was published almost 100 years ago. Numerous pre-clinical and clinical studies confirmed the initial observations as well as demonstrated the beneficial safety profile of magnesium supplementation. Thus, magnesium preparations seem to be a valuable addition to the pharmacological armamentarium for management of depression. PMID:23950577

  7. Magnesium and Osteoporosis

    Ferda Özdemir

    2004-03-01

    Full Text Available Osteoporosis (OP is a condition of bone fragility resulting from micro-architectural deterioration and decreased bone mass. OP depends on the interaction of genetic, hormonal, environmental and nutritional factors. Chronic low intakes of vitamin D and possibly magnesium, zinc, fluoride and vitamins K, B12, B6 and folic acid may predispose to osteoporosis. Magnesium is a mineral needed by every cell of your body. It helps maintain normal muscle and nerve function, keeps heart rhythm steady, and bones strong. Mg serves as co-factors for enzymes that help build bone matrix. Magnesium deficiency occurs due to excessive loss of magnesium in urine, gastrointestinal system disorders that cause a loss of magnesium or limit magnesium absorption, or a chronic low intake of magnesium. Signs of magnesium deficiency include confusion, disorientation, loss of appetite, depression, muscle contractions and cramps, tingling, numbness, abnormal heart rhythms, coronary spasm, and seizures. Magnesium deficiency alters calcium metabolism and the hormones that regulates calcium. Several studies have suggested that magnesium supplementation may improve bone mineral density and prevent fractures.

  8. Magnesium Cermets and Magnesium-Beryllium Alloys

    The paper describes some results of work on the development of magnesium-magnesium oxide cermets and of super heat-resistant magnesiumberyllium alloys produced by powder metallurgical methods. The introduction of even a minute quantity of finely dispersed magnesium oxide into magnesium results in a strengthening of the material, the degree of which increases with increased magnesium oxide concentration, although variation of this concentration within the limits of 0.3 to 5 wt.% has a comparatively slight effect on the corresponding variation in the short-term strength over the whole range of temperatures investigated. At 20oC, in the case of the cermets, σβ = 28 to 31 kg/mm2 and δ = 3 .5 to 4.5%; at 500oC σβ = 2.6 to 3.2 kg/mm2 and δ =30 to 40%. The positive effect of the finely dispersed oxide phase is particularly evident in protracted tests. For magnesium cermets, σ (300)/100 = 2.2 kg/mm2. Characteristic of the mixtures is the high thermal stability of the strength properties, linked chiefly with the thermodynamic stability of the strength-giving oxide phase in the metal matrix. The use of powder metallurgical methods has yielded super heat-resistant magnesium-beryllium alloys containing heightened concentrations of beryllium (PMB alloys). In their strength characteristics PMB alloys are close to Mg-MgO cermets, but the magnesium-beryllium alloys have a degree and duration of resistance to high temperature oxidation which exceeds the corresponding qualities of the magnesium alloys at present known. Thus, in air of 580oC, PMB alloys with 2 to 5% beryllium maintain a high resistance to oxidation for a period of over 12000 to 14000 h. This long-term heat resistance is chiefly a result of the amount of beryllium in the alloy, and increases with increasing beryllium content. PMB alloys are also marked by high resistance to short bursts of overheating. Magnesium cermets and magnesium-beryllium alloys, with their enhanced high-temperature stability, are capable

  9. The local atomic structure of di-alanine amino acid derivative of protoporphyrin IX

    The photophysical and photochemical properties of photosensitizers bearing potential for photodynamic diagnosis (PDD) and treatment (PDT) of malignant tissues strictly depend on the details of their chemical processing. In this work, the x-ray absorption spectroscopy (XAFS) and electron spin resonance (ESR) techniques were applied to determine the nearest neighbourhood of iron in the di-alanine amino acid derivative of protoporphyrin IX (L-alanine diprotoporphyrinate). The investigated compound is a technological precursor for novel-class, highly water-soluble protoporphyrin IX-based photosensitizers, which have potential for applications in PDD and PDT and have just entered phase I clinical trials. Knowing the chemical content and exact atomic structures of the technological precursor, as well as of the high-purity final product, which all might contain some contamination, is a prerequisite for preparing photosensitizers for preliminary clinical tests

  10. The local atomic structure of di-alanine amino acid derivative of protoporphyrin IX

    Walczak, M S [Institute of Physics PAS, Aleja Lotnikow 32/46, 02-668 Warsaw (Poland); Lawniczak-Jablonska, K [Institute of Physics PAS, Aleja Lotnikow 32/46, 02-668 Warsaw (Poland); Sienkiewicz, A [Institute of Physics PAS, Aleja Lotnikow 32/46, 02-668 Warsaw (Poland); Czuba, M [Institute of Optoelectronics MUT, ulica Stefana Kaliskiego 2, 00-908 Warsaw (Poland); Klepka, M [Institute of Physics PAS, Aleja Lotnikow 32/46, 02-668 Warsaw (Poland); Graczyk, A [Institute of Optoelectronics MUT, ulica Stefana Kaliskiego 2, 00-908 Warsaw (Poland)

    2007-07-18

    The photophysical and photochemical properties of photosensitizers bearing potential for photodynamic diagnosis (PDD) and treatment (PDT) of malignant tissues strictly depend on the details of their chemical processing. In this work, the x-ray absorption spectroscopy (XAFS) and electron spin resonance (ESR) techniques were applied to determine the nearest neighbourhood of iron in the di-alanine amino acid derivative of protoporphyrin IX (L-alanine diprotoporphyrinate). The investigated compound is a technological precursor for novel-class, highly water-soluble protoporphyrin IX-based photosensitizers, which have potential for applications in PDD and PDT and have just entered phase I clinical trials. Knowing the chemical content and exact atomic structures of the technological precursor, as well as of the high-purity final product, which all might contain some contamination, is a prerequisite for preparing photosensitizers for preliminary clinical tests.

  11. The magnesium chelation step in chlorophyll biosynthesis

    Weinstein, J.D.

    1991-01-01

    The biogenesis of energy transducing membranes requires the coordinate synthesis of prosthetic groups, proteins and lipids. Two of the major prosthetic groups, chlorophyll and heme, share a common biosynthetic pathway that diverges at the point of metal insertion into protoporphyrin IX. Insertion of iron leads to heme, while insertion of magnesium leads to chlorophyll. The Mg-chelatase from intact cucumber chloroplasts has been characterized with regard to substrate specificity, regulation, ATP requirement, and a requirement for intact chloroplasts. Mg-chelatase was isolated from maize, barley and peas and characterized in order to circumvent the intact chloroplast requirement of cucumber Mg-chelatase. Pea Mg-chelatase activity is higher than cucumber Mg-chelatase activity, and lacks the requirement for intact chloroplasts. Studies on isolated pea Mg-chelatase have shown more cofactors are required for the reaction than are seen with ferrochelatase, indicating a greater opportunity for regulatory control of this pathway. Two of the cofactors are proteins, and there appears to be a requirement for a protease-sensitive component which is outside the outer envelope. We are developing a continuous spectrophotometric assay for Mg-chelatase activity, and an assay for free heme which has shown heme efflux from intact chloroplasts. 18 refs. (MHB)

  12. Structure of cobalt protoporphyrin chloride and its dimer, observation and DFT modeling.

    de la Lande, Aurélien; Ha-Thi, Minh-Huong; Chen, Shufeng; Soep, Benoît; Shafizadeh, Niloufar

    2016-06-22

    In this article we present a joint study by time-of-flight mass spectroscopy and density functional theory of cobalt protoporphyrin dimer complexes. The main novelty of the experimental part is to reveal the formation of porphyrin dimers that eventually include a chlorine atom. Density functional theory calculations have been performed to shed light on the structural and electronic properties of monomers and dimers that may be formed experimentally. Various geometries of the monomers are analyzed in the two lowest spin states. The electronic structures are examined by means of population analysis relying on the iterative Hirshfeld scheme and the topological analyses of the electron localization function. It is shown that the cobalt ligand bond is purely ionic in the triplet states but shows a noticeable covalent character in the singlet state. Ionization potential of Co-protoporphyrin and binding energies of the chlorine ligand are also reported. Concerning the dimers, several association patterns are investigated for the chlorinated and non-chlorinated complexes. It is found that the structures of the most stable complexes involve four hydrogen bonds between the carboxylic acid moieties of the protoporphyrins. However other association modes are likely to be possible in the experiments. PMID:27270590

  13. Serum magnesium and irradiation

    Serum magnesium determinations were obtained on 10 dogs and 11 patients undergoing fractionated irradiation to the pelvis and lower abdomen. Five of the dogs received oral prednisone during irradiation. There was no significant change in magnesium concentration in either the control dogs or the patients, but there was a significant increase in stool frequency in both the dogs and patients. A significant increase in magnesium concentration was noted in the dogs receiving prednisone. It is concluded that radiation-induced diarrhea is not caused by reduced serum magnesium concentration

  14. Magnesium for Hydrogen Storage

    Vigeholm, B.; Kjøller, John; Larsen, Bent

    1980-01-01

    The reaction of hydrogen with commercially pure magnesium powder (above 99.7%) was investigated in the temperature range 250–400 °C. Hydrogen is readily sorbed above the dissociation pressure. During the initial exposure the magnesium powder sorbs hydrogen slowly below 400 °C but during the second...

  15. Photosensitization of experimental hepatocellular carcinoma with protoporphyrin synthesized from administered δaminolevulinic acid. Studies with cultured cells and implanted tumors

    Background/Aims: Photodynamic therapy using porphyrins or related compounds and laser light is an investigational treatment for neoplasms. The aim of this study was to establish whether this might be applicable for hepatocellular carcinoma using protoporphyrin synthesized in the tissue from administered δ-aminolevulinic acid. Methods: We measured porphyrin accumulation in normal rat hepatocytes and Morris hepatoma cells in culture, and in subcutaneously implanted hepatomas and other tissues of the rat after administration of δ-aminolevulinic acid, and assessed cell and tissue damage after application of laser light. Results: Porphyrin accumulation after δ-aminolevulinic acid was added to the medium was greater and continued to increase for a longer period of time in hepatoma cells than in hepatocytes (1337±42 vs 513±31 fluorescence units/cell at 8 h, means±SE, p<0.001). After intraperitoneal injection of δaminolevulinic acid to rats with subcutaneously growing hepatomas, porphyrin content in tumor and liver was similar at 4 h but was higher in tumor at 6 h. Laser light caused necrosis of normal and malignant liver cells in culture and subcutaneous hepatomas in vivo. Conclusions: We conclude from these in vitro and in vivo studies that porphyrin accumulation after administration of δaminolevulinic acid in this hepatoma is substantial and time dependent, and delivery of laser light locally can cause tumor photosensitization and necrosis. (au) 41 refs

  16. Magnesium deficiency: what's our status?

    Low magnesium intake has been implicated in a broad range of cardiometabolic conditions, including diabetes, hypertension, and cardiovascular disease. Dietary magnesium and total body magnesium status have a widely-used but imperfect biomarker in serum magnesium. Despite serum magnesium’s limitation...

  17. Comparison of protoporphyrin IX content and related gene expression in the tissues of chickens laying brown-shelled eggs.

    Li, Guangqi; Chen, Sirui; Duan, Zhongyi; Qu, Lujiang; Xu, Guiyun; Yang, Ning

    2013-12-01

    Protoporphyrin IX (PpIX), an immediate precursor of heme, is the main pigment resulting in the brown coloration of eggshell. The brownness and uniformity of the eggshell are important marketing considerations. In this study, 9 chickens laying darker brown shelled eggs and 9 chickens laying lighter brown shelled eggs were selected from 464 individually caged layers in a Rhode Island Red pureline. The PpIX contents were measured with a Microplate Reader at the wavelength of 412 nm and were compared in different tissues of the 2 groups. Although no significant difference in serum, bile, and excreta was found between the 2 groups, PpIX content in the shell gland and eggshell of the darker group was higher than in those of the lighter group, suggesting that PpIX was synthesized in the shell gland. We further determined the expression levels of 8 genes encoding enzymes involved in the heme synthesis and transport in the liver and shell gland at 6 h postoviposition by quantitative PCR. The results showed that expression of aminolevulinic acid synthase-1 (ALAS1) was higher in the liver of hens laying darker brown shelled eggs, whereas in the shell gland the expression levels of ALAS1, coproporphyrinogen oxidase (CPOX), ATP-binding cassette family members ABCB7 and ABCG2, and receptor for feline leukemia virus, subgroup C (FLVCR) were significantly higher in the hens laying darker brown shelled eggs. Our results demonstrated that hens laying darker brown shelled eggs could deposit more PpIX onto the eggshell and the brownness of the eggshell was dependent on the total quantity of PpIX in the eggshell. More heme was synthesized in the liver and shell gland of hens laying darker brown shelled eggs than those of hens laying lighter brown shelled eggs. High expression level of ABCG2 might facilitate the accumulation of PpIX in the shell gland. PMID:24235220

  18. Magnesium Aluminate Spinel

    Yu Lingyan

    2012-01-01

    1 ScopeThis standard specifies the terms, definitions,classifications,technical requirements,test methods,inspection rules, packing, marking, transportation,storage,and quality certificate of magnesium aluminate spinel.

  19. Magnesium blood test

    Magnesium - blood ... A blood sample is needed. ... When the needle is inserted to draw blood, some people feel slight pain. Others feel a prick or stinging. Afterward, there may be some throbbing or a slight bruise. This soon ...

  20. Magnesium and Osteoporosis

    Ferda Özdemir; Meliha Rodoplu

    2004-01-01

    Osteoporosis (OP) is a condition of bone fragility resulting from micro-architectural deterioration and decreased bone mass. OP depends on the interaction of genetic, hormonal, environmental and nutritional factors. Chronic low intakes of vitamin D and possibly magnesium, zinc, fluoride and vitamins K, B12, B6 and folic acid may predispose to osteoporosis. Magnesium is a mineral needed by every cell of your body. It helps maintain normal muscle and nerve function, keeps heart rhythm steady...

  1. Protoporphyrin Treatment Modulates Susceptibility to Experimental Autoimmune Encephalomyelitis in miR-155-Deficient Mice.

    Jinyu Zhang

    Full Text Available We previously identified heme oxygenase 1 (HO-1 as a specific target of miR-155, and inhibition of HO-1 activity restored the capacity of miR-155-/- CD4+ T cells to promote antigen-driven inflammation after adoptive transfer in antigen-expressing recipients. Protoporphyrins are molecules recognized for their modulatory effect on HO-1 expression and function. In the present study, we investigated the effect of protoporphyrin treatment on the development of autoimmunity in miR-155-deficient mice. MiR-155-mediated control of HO-1 expression in promoting T cell-driven chronic autoimmunity was confirmed since HO-1 inhibition restored susceptibility to experimental autoimmune encephalomyelitis (EAE in miR-155-deficient mice. The increased severity of the disease was accompanied by an enhanced T cell infiltration into the brain. Taken together, these results underline the importance of miR-155-mediated control of HO-1 expression in regulating the function of chronically-stimulated T cells in EAE.

  2. Electrodeposition of magnesium and magnesium/aluminum alloys

    Mayer, A.

    1988-01-21

    Electrolytes and plating solutions for use in processes for electroplating and electroforming pure magnesium and alloys of aluminum and magnesium and also electrodeposition processes. An electrolyte of this invention is comprised of an alkali metal fluoride or a quaternary ammonium halide, dimethyl magnesium and/or diethyl magnesium, and triethyl aluminum and/or triisobutyl aluminum. An electrolyte may be dissolved in an aromatic hydrocarbon solvent to form a plating solution. The proportions of the component compounds in the electrolyte are varied to produce essentially pure magnesium or magnesium/aluminum alloys having varying selected compositions.

  3. Combustion and extinction of magnesium fires

    The studies made in France on magnesium combustion and extinguishing means are associated at the nuclear fuel of the graphite-gas reactor. Safety studies are made for ameliorate our knowledge on: - magnesium combustion - magnesium fire propagation - magnesium fire extinguishing

  4. Radiation-induced radicals in hydrated magnesium sulfate

    Radiation-induced free radicals in hydrated magnesium sulfate, which are thought to be present on the surface of Europa, one of the Jovian moons, have been studied by electron spin resonance (ESR). ESR signals of both atomic hydrogen (H·) at g = 2.0023 and sulfite radical (SO3−·) at g = 2.0029 are observed in epsomite (MgSO4·7H2O) and in quenched samples of magnesium sulfate solutions, after gamma-ray irradiation at 77 K. Atomic hydrogen disappears at temperatures above 90 K. The sulfite radical starts to decay above 190 K in the quenched sample of 10% magnesium sulfate solution, whereas in epsomite, it is stable even at 260 K. The sulfite radical accumulates at low ambient temperatures, and is a promising candidate for estimating the age of hydrated magnesium sulfate, especially in extraterrestrial environments.

  5. Delta pH-dependent accumulation of tetracycline in Escherichia coli.

    A. Yamaguchi; Ohmori, H; Kaneko-Ohdera, M; Nomura, T.; Sawai, T

    1991-01-01

    The effects of ionophores on tetracycline accumulation in Escherichia coli cells were investigated in the presence of polymyxin B nonapeptide. Accumulation was inhibited by nigericin but not by valinomycin. Tetracycline accumulation was stimulated by decreasing the pH of the medium and inhibited by the addition of magnesium ions. These results indicated that tetracycline enters cells through diffusion as a protonated form (TH2) and is accumulated as a membrane-impermeable magnesium-tetracycli...

  6. Egg-Citing! Isolation of Protoporphyrin IX from Brown Eggshells and Its Detection by Optical Spectroscopy and Chemiluminescence

    Dean, Michelle L.; Miller, Tyson A.; Bruckner, Christian

    2011-01-01

    A simple and cost-effective laboratory experiment is described that extracts protoporphyrin IX from brown eggshells. The porphyrin is characterized by UV-vis and fluorescence spectroscopy. A chemiluminescence reaction (peroxyoxalate ester fragmentation) is performed that emits light in the UV region. When the porphyrin extract is added as a fluor…

  7. Acúmulo de nutrientes em frutos de cafeeiro em quatro altitudes de cultivo: cálcio, magnésio e enxofre Nutrient accumulation in coffee fruits at four plantations altitude: calcium, magnesium and sulfur

    Bruno Galvêas Laviola

    2007-12-01

    Full Text Available As curvas de acúmulo de nutrientes em frutos permitem estimar sua exportação, bem como as épocas de maior demanda. Estudou-se o acúmulo de MS, Ca, Mg e S em frutos de Coffea arabica (L. da antese à maturação em quatro altitudes, bem como a variação na concentração dos elementos em folhas dos ramos produtivos. O experimento foi constituído da variedade de cafeeiro Catuaí IAC 44 cultivada a 720, 800, 880 e 950 m de altitude, no município de Martins Soares-MG. O delineamento experimental foi inteiramente ao acaso, com três repetições, usando-se um esquema de parcela subdividida no tempo. O aumento da altitude influenciou o ciclo reprodutivo do cafeeiro, pois houve demanda de maior tempo para formação dos frutos. No estádio de expansão rápida, a percentagem de acúmulo de MS, Ca, Mg e S foi maior na altitude de 720 m, comparada, principalmente, à de 950 m. A TMAD (taxa máxima de acúmulo diário no estádio de granação-maturação apresentou tendência de ser mais tardia com a elevação da altitude. O consumo de nutrientes pelos frutos, assim como o enchimento de grãos, é mais crítico em condições de menor altitude, já que a planta necessita completar esses processos em menor espaço de tempo. De modo geral, na altitude de 720 m ocorreu maior competição fruto/folha pela partição de Ca, Mg e S.Crurves of fruit nutrient accumulation are tools for estimating the peaks of nutrient demand and the nutrient export form the soil. The accumulation of dry matter (DM, Ca, Mg and S was studied in fruits of Coffea arabica (L. in the period between anthesis and maturation at four altitudes of cultivation, as well as the variation in the leaf content of the elements in productive branches. The experiment consisted of the coffee variety Catuaí IAC 44 cultivated at 720, 800, 880 and 950 m above sea level (asl, in Martins Soares-MG. The experimental design was entirely randomized with tree replications using a split-plot in time

  8. 21 CFR 184.1434 - Magnesium phosphate.

    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...

  9. INVESTIGATION OF MAGNESIUM ALLOYS MACHINABILITY

    Berat Barıs BULDUM

    2013-01-01

    Full Text Available Magnesium is the lightest structural metal. Magnesium alloys have a hexagonal lattice structure, which affects the fundamental properties of these alloys. Plastic deformation of the hexagonal lattice is more complicated than in cubic latticed metals like aluminum, copper and steel. Magnesium alloy developments have traditionally been driven by industry requirements for lightweight materials to operate under increasingly demanding conditions. Magnesium alloys have always been attractive to designers due to their low density, only two thirds that of aluminium and its alloys [1]. The element and its alloys take a big part of modern industry needs. Especially nowadays magnesium alloys are used in automotive and mechanical (trains and wagons manufacture, because of its lightness and other features. Magnesium and magnesium alloys are the easiest of all metals to machine, allowing machining operations at extremely high speed. All standard machining operations such as turning, drilling, milling, are commonly performed on magnesium parts.

  10. Aluminum Hydroxide and Magnesium Hydroxide

    Aluminum Hydroxide, Magnesium Hydroxide are antacids used together to relieve heartburn, acid indigestion, and upset stomach. They ... They combine with stomach acid and neutralize it. Aluminum Hydroxide, Magnesium Hydroxide are available without a prescription. ...

  11. INVESTIGATION OF MAGNESIUM ALLOYS MACHINABILITY

    Berat Barıs BULDUM; Aydın SIK; Iskender OZKUL

    2013-01-01

    Magnesium is the lightest structural metal. Magnesium alloys have a hexagonal lattice structure, which affects the fundamental properties of these alloys. Plastic deformation of the hexagonal lattice is more complicated than in cubic latticed metals like aluminum, copper and steel. Magnesium alloy developments have traditionally been driven by industry requirements for lightweight materials to operate under increasingly demanding conditions. Magnesium alloys have always been attra...

  12. Elevation of blood levels of zinc protoporphyrin by radiomimetic drugs and friend leukemia virus

    Sublethal doses of whole-body irradiation induced the elevation of zinc protoporphyrin (ZPP). Experiments were conducted to determine if recovery from radiomimetic drugs also resulted in elevation of ZPP. Daily injections with hydroxyurea and other cytotoxic drugs for 10 days caused ZPP elevation and a dose of radiation too low to cause ZPP elevation by itself caused ZPP elevation when hydroxyurea was administered prior to irradiation. Friend leukemia virus also brought about an elevation of ZPP. However, not all factors that increased erythropoiesis brought about ZPP elevation. The elevated erythropoiesis in response to hypoxia and the enhanced erythropoiesis that followed administration of folic acid to folic acid-deficient mice was not accompanied by ZPP elevation. (orig.)

  13. Pain during photodynamic therapy is associated with protoporphyrin IX fluorescence and fluence rate

    Wiegell, S.R.; Skiveren, J.; Philipsen, P.A.;

    2008-01-01

    protoporphyrin IX (PpIX) fluorescence, lesion type, lesion preparation and lesion localization. Methods Twenty-six patients with actinic keratoses (AKs) in different localizations and 34 patients with facial acne vulgaris were treated with methyl aminolaevulinate-PDT. Patients with acne were illuminated using......) patients with acne had a pain score of 6 [interquartile range (IQR) 5-7] compared with 8 (IQR 6-10) when using a fluence rate of 68 mW cm(-2) (P = 0.018). After correcting the pain score for PpIX fluorescence no differences in pain scores were found between first and second acne treatment, locations of AK...... lesions or between the two types of lesions. Conclusions Pain during PDT was correlated with the PpIX fluorescence in the treatment area prior to illumination. Pain was reduced using a lower fluence rate during PDT of acne Udgivelsesdato: 2008/4...

  14. Spectroscopic study of protoporphyrin IX zinc(II) encapsulated in sol-gel glass

    Zaitoun, Mohammed A.

    2005-06-01

    Previous studies indicated that the organization of native porphyrins and their intentionally designated derivatives in solid substrates is of current interest because of the biological and practical importance of these compounds. In this paper, we report herein for the first time the incorporation of a functionalized diacid, protoporphyrin IX Zn(II) (Zn-pp-IX), successfully in a silica based transparent organic-inorganic hybrid material by choosing proper alkoxy silane containing amino-group via the sol-gel method. The entrapped guest was diagnosed using UV-vis sectrophotometry, emission spectroscopy, and infrared spectrometry; the properties of the encapsulated porphyrin were compared to those of the compound in solution. The results indicate that Zn-pp-IX is well distributed and homogeneously in the glass.

  15. Enhanced cellular uptake of protoporphyrine IX/linolenic acid-conjugated spherical nanohybrids for photodynamic therapy.

    Lee, Hye-In; Kim, Young-Jin

    2016-06-01

    Protoporphyrin IX (PpIX) has wide applications in photodynamic diagnosis and photodynamic therapy (PDT) in many human diseases. However, poor water solubility and cancer cell localization limit its direct application for PDT. We improved the water-solubility and cellular internalization of PpIX to enhance PDT efficacy by developing biocompatible PpIX/linolenic acid-conjugated polyhedral oligomeric silsesquioxane (PPLA) nanohybrids. The resulting PPLA nanohybrids exhibited a quasi-spherical shape with a size of laser irradiation was detected by photoluminescence emission. Fluorescence-activated cell sorting (FACS) analysis displayed higher cellular internalization of PPLA compared with free PpIX. In addition, PPLA nanohybrids exhibited significantly reduced dark-toxicity and a high phototoxicity mostly because of apoptotic cell death against human gastric cancer cells. These results imply that the PPLA nanohybrid system may be applicable in PDT. PMID:26954084

  16. Extraction of protoporphyrin disodium and its inhibitory effects on HBV-DNA

    Chao-Pin Li; Li-Fa Xu; Qun-Hong Liu; Chao Zhang; Jian Wang; Yu-Xia Zhu

    2004-01-01

    AIM: To explore an ideal method for extracting protoporphyrin disodium (PPN) from unanticoagulated animal blood, and to study the inhibitory effects of PPN on HBV-DNA duplication and its cytotoxicity to 2.2.15 cell strain.METHODS: Protoporphyrin methyl ester and other intermediate products were prepared with protoheme separated from protein hydrolysates of coagulated animal blood, which were finally made into PPN and detected quantitatively with an ultraviolet fluorescent analyzer.Ten μg/ml, 20 μg/ml, 40 μg/ml, 80 μg/ml and 160 μg/ml of PPN-aqueous solution were added into culture medium for 2.2.15 cells respectively. Eight days later, the drug concentration in supernatant from the culture medium was detected when inhibition rate of HBeAg, cell Survival rate when inhibition rate of HBeAg was 50% (ID50), and when survival cells in experimental group were 50% of those in control group (CD50), and the therapeutic index (TI) was also detected. PPN with different concentration of 10 μg/ml,20 μg/ml, 40 μg/ml, 80 μg/ml and 160 μg/ml was respectively mixed and cultivated with HepG2 2.2.15 cell suspension,and then the inhibition of PPN against HBV-DNA was judged by PCR.RESULTS: The extract of henna crystal was identified to be PPN. When the concentrations of PPN were 160 μg/ml and 80 μg/ml, the inhibition rates of HBeAg were 89.8% and 82.4%, and the cell survival rates were 98.7% and 99.2%.CONCLUSION: It is suggested that PPN can be extracted from unanticoagulated animal blood. PPN can inhibit HBV-DNA expression and duplication ih vitro, and has no cytotoxicity to liver cells. Further study and application of PPN are warranted.

  17. The developing strategy of Chinese magnesium and magnesium alloy

    ZUO; Tie-yong; DU; Wen-bo

    2005-01-01

    The status and developing strategy of Chinese magnesium industry are summarized in the present paper. The output and export of Chinese magnesium ingot have rapidly increased in the recent ten years, but the magnesium products with high value, such as the wrought magnesium alloys, and their applications are insufficient. Chinese magnesium industry should develop toward the direction of large scale, specialization and collectivization in the future. The enterprises should enhance the level of management and reinforce the international competing ability with the help of governmental policies.

  18. FOCUS ON MAGNESIUM BASED DRUGS

    I. I. Esenova

    2016-01-01

    Full Text Available Magnesium deficiency in the organism is one of the most common human deficiency states. The prevalence of magnesium deficiency is about 15%, and suboptimal magnesium level is observed more than in 30% of people in the general population. Clinical signs of hypomagnesaemia are observed in 40% of patients in general care hospitals, in 70% of patients - in intensive care units, and magnesium deficiency occurs in 90% of patients with acute coronary syndrome. Magnesium metabolic disorders in the organism accelerate significantly development of complications of coronary heart disease, hypertension, type 2 diabetes, asthma and a number of neurological and psychiatric diseases. The value of this macro in the body is well studied, and its daily need is identified depending on age and sex. It is known that magnesium intake with the food does not cover an organism need. It is a rationale for preventive and therapeutic use of magnesium based drugs in various diseases. Organic salts of magnesium are recommended for these purposes. Magnesium metabolic disorders, approaches to pharmacotherapeutic correction of magnesium deficiency, advantages of magnesium salts of orotic acid are reviewed.

  19. eEF1A1 binds and enriches protoporphyrin IX in cancer cells in 5-aminolevulinic acid based photodynamic therapy

    Fan, Zhichao; Cui, Xiaojun; Wei, Dan; Liu, Wei; Li, Buhong; He, Hao; Ye, Huamao; Zhu, Naishuo; Wei, Xunbin

    2016-05-01

    Photodynamic therapy (PDT) with protoporphyrin IX (PpIX), which is endogenously derived from 5-aminolevulinic acid (5-ALA) or its derivatives, is a promising modality for the treatment of both pre-malignant and malignant lesions. However, the mechanisms of how ALA-induced PpIX selectively accumulated in the tumors are not fully elucidated. Here we discovered that eukaryotic translation elongation factor 1 alpha 1 (eEF1A1) interacted with PpIX (with an affinity constant of 2.96 × 106 M‑1). Microscopy imaging showed that ALA-induced PpIX was co-localized with eEF1A1 in cancer cells. eEF1A1 was found to enrich ALA-induced PpIX in cells by competitively blocking the downstream bioavailability of PpIX. Taken together, our study discovered eEF1A1 as a novel photosensitizer binding protein, which may play an essential role in the enrichment of ALA-induced PpIX in cancer cells during PDT. These suggested eEF1A1 as a molecular marker to predict the selectivity and efficiency of 5-ALA based PDT in cancer therapy.

  20. The magnesium chelation step in chlorophyll biosynthesis. Annual technical progress report for 1994

    Weinstein, J.

    1994-02-01

    Mg-chelatase catalyses the first step unique to chlorophyll synthesis, namely the insertion of magnesium into protoporphyrin IX. When pea (Pisum sativum L., cv. Spring) chloroplasts are lysed in a buffer lacking magnesium and the thylakoids removed by centrifugation, the remaining mixture of light membranes and soluble proteins (LM/S) has high Mg-chelatase activity. Several lines of evidence are presented to show that the magnesium insertion catalysed by this preparation is a two-step reaction consisting of activation followed by magnesium chelation. An activated state of Mg-chelatase is achieved by preincubating LM/S with ATP. The activated state is observed as the elimination of the approximately 6 min lag in the rate of magnesium chelation upon addition of the prophyrin substrate. The activity of LM/S assayed at low protein concentrations can be greatly enhanced by preincubating at high protein concentrations (12 mg/ml is optimal). This activation effect requires the presence of both LM and S fractions, as well as ATP. Both steps require ATP, but at different concentrations; the first step is optimal at > 0.5 mM (EC{sub 50} = 0.3 mM) and the second step is optimal at 0.3 mM (EC{sub 50} < 0.2 mM). ATP in the first step could be replaced by ATP{gamma}S; this analog could not sustain activity in the second step. This activated state was stable for at least 30 min at room temperature, but chilling of preincubated LM/S on ice for 30 min caused an almost complete loss of the activated state.

  1. Mechanisms and regulation of renal magnesium transport.

    Houillier, Pascal

    2014-01-01

    Magnesium's most important role is in the release of chemical energy. Although most magnesium is stored outside of the extracellular fluid compartment, the regulated value is blood magnesium concentration. Cellular magnesium and bone magnesium do not play a major role in the defense of blood magnesium concentration; the major role is played by the kidney, where the renal tubule matches the urinary magnesium excretion and the net entry of magnesium into the extracellular fluid. In the kidney, magnesium is reabsorbed in the proximal tubule, the thick ascending limb of the loop of Henle, and the distal convoluted tubule. Magnesium absorption is mainly paracellular in the proximal tubule and in the thick ascending limb of the loop of Henle, whereas it is transcellular in the distal convoluted tubule. Several hormones and extracellular magnesium itself alter the distal tubular handling of magnesium, but the hormone(s) regulating extracellular magnesium concentration remains unknown. PMID:24512082

  2. Ion induced dissociation of tetraphenyl iron(III) porphyrin chloride and electron-capture induced dissociation of protoporphyrin IX ions

    We performed experiments concerning the fragmentation of different porphyrin molecules. Multi-ionisation and ion-induced fragmentation of FeTPPCl''q''+ (q = 1 to 4) have been studied in slow collisions with multiply charged ions. We have shown also electron-capture induced dissociation of protoporphyrin cations, where two electrons in two successive have been captured in order to convert it to the corresponding even-electron anions. All fragmentation processes are discussed in terms of charge mobility.

  3. Magnesium for Hydrogen Storage

    Pedersen, Allan Schrøder; Kjøller, John; Larsen, B.;

    1983-01-01

    A study of the hydrogenation characteristics of fine magnesium powder during repeated cycling has been performed using a high-pressure microbalance facility. No effect was found from the cycling regarding kinetics and storage capacity. The reaction rate of the absorption process was fast at tempe......A study of the hydrogenation characteristics of fine magnesium powder during repeated cycling has been performed using a high-pressure microbalance facility. No effect was found from the cycling regarding kinetics and storage capacity. The reaction rate of the absorption process was fast...... at temperatures around 600 K and above, but the reversed reaction showed somewhat slower kinetics around 600 K. At higher temperatures the opposite was found. The enthalpy and entropy change by the hydrogenation, derived from pressure-concentration isotherms, agree fairly well with those reported earlier....

  4. Molecular mechanisms of the killing effects on Ehrlich ascites tumor cells by sono-chemical-activated protoporphyrin

    LIU Quan-Hong, XIAO Li-Na

    2008-10-01

    Full Text Available We studied the Ehrlich ascetic tumor (EAT cell line killing effects by ultrasound activating protoporphyrin Ⅸ (PPⅨ and its mechamism. The cellular uptake and subcellular localization of protoporphyrin Ⅸ were estimated by fluorescence photometer and laser scanning confocal microscopy (LSCM respectively. The trypan blue exclusion method was used to analyze the relative viability of EAT cells after ultrasonically activated protoporphyrin Ⅸ. Changes of ultra-microstructure of the treated cells were examined by transmission electron microscopy.Mitochondrial membrane potential(MMP, intracellular reactive oxygen species (ROS levels, and the level of lipid peroxidation were determined by Rhodamine 123, 2′,7′- dichlorodihydrofluorescin diacetate (DCFH-DA and thiobarbituric acid reaction method respectively. Results showed that there is a selective uptake and retention of the PPⅨ in tumor cells. CLSM revealed that PPⅨ localize mainly in the mitochondria. In the ultrasound plus PPⅨ group, the survival rate of cells was significantly lower. The ultra-microstructural damage of treated cells was the most remarkable, the loss of mitochondria membrane potential was the most noticeable, levels of ROS and lipid peroxides were remarkably increased. These results indicate that there is significant synergistic killing effect with ultrasound activating PPⅨ. The decreased mitochondria membrane potential and the increased level of lipid peroxidation in the ultrasound plus PPⅨ group may be associated with reactive oxygen species. In summary, reactive oxygen species might be involved in mediating the killing effect of EAT cells in SDT [Acta Zoologica Sinica 54(5: 846– 854, 2008

  5. Magnesium oxychloride cement concrete

    A K Misra; Renu Mathur

    2007-06-01

    The scope of magnesium oxychloride (MOC) cement in concrete works has been evaluated. MOC cement concrete compositions of varying strengths having good placing and finishing characteristics were prepared and investigated for their compressive and flexural strengths, -values, abrasion resistance etc. The durability of MOC concrete compositions against extreme environmental conditions viz. heating–cooling, freezing–thawing, wetting–drying and penetration and deposition of salts etc were investigated. The results reveal that MOC concrete has high compressive strength associated with high flexural strength and the ratio of compressive to flexural strength varies between 6 and 8. The elastic moduli of the compositions studied are found to be 23–85 GPa and the abrasion losses between 0.11 and 0.20%. While alternate heating–cooling cycles have no adverse effect on MOC concrete, it can be made durable against freezing–thawing and the excessive exposure to water and salt attack by replacing 10% magnesium chloride solution by magnesium sulphate solution of the same concentration.

  6. Magnesium as Biodegradable Implant Material

    2008-01-01

    Drawbacks associated with permanent metallic implants lead to the search for degradable metallic biomaterials. Magnesium alloys have been highly considered as Mg has a high biocorrosion potential and is essential to bodies. In this study, corrosion behaviour of pure magnesium and magnesium alloy AZ31 in both static and dynamic physiological conditions (Hank's solution) has been investigated. It is found that the materials degrade fast at beginning, then stabilize after 5 days of immersion. High purity in th...

  7. Low brain magnesium in migraine

    Brain magnesium was measured in migraine patients and control subjects using in vivo 31-Phosphorus Nuclear Magnetic Resonance Spectroscopy. pMg and pH were calculated from the chemical shifts between Pi, PCr and ATP signals. Magnesium levels were low during a migraine attack without changes in pH. We hypothesize that low brain magnesium is an important factor in the mechanism of the migraine attack

  8. Mineral of the month: magnesium

    Kramer, Deborah A.

    2005-01-01

    Magnesium, often confused with last month’s mineral of the month manganese, is valued primarily because of its light weight and high strength-to-weight ratio. Magnesium is the eighth most abundant element and constitutes about 2 percent of the Earth’s crust. It is the third most plentiful element dissolved in seawater, with a concentration averaging 0.13 percent. Magnesium is found in over 60 minerals, and also is recovered from seawater, wells, and lake brines and bitterns.

  9. Activity of Gallium Meso- and Protoporphyrin IX against Biofilms of Multidrug-Resistant Acinetobacter baumannii Isolates.

    Chang, David; Garcia, Rebecca A; Akers, Kevin S; Mende, Katrin; Murray, Clinton K; Wenke, Joseph C; Sanchez, Carlos J

    2016-01-01

    Acinetobacter baumannii is a challenging pathogen due to antimicrobial resistance and biofilm development. The role of iron in bacterial physiology has prompted the evaluation of iron-modulation as an antimicrobial strategy. The non-reducible iron analog gallium(III) nitrate, Ga(NO₃)₃, has been shown to inhibit A. baumannii planktonic growth; however, utilization of heme-iron by clinical isolates has been associated with development of tolerance. These observations prompted the evaluation of iron-heme sources on planktonic and biofilm growth, as well as antimicrobial activities of gallium meso- and protoporphyrin IX (Ga-MPIX and Ga-PPIX), metal heme derivatives against planktonic and biofilm bacteria of multidrug-resistant (MDR) clinical isolates of A. baumannii in vitro. Ga(NO₃)₃ was moderately effective at reducing planktonic bacteria (64 to 128 µM) with little activity against biofilms (≥512 µM). In contrast, Ga-MPIX and Ga-PPIX were highly active against planktonic bacteria (0.25 to 8 µM). Cytotoxic effects in human fibroblasts were observed following exposure to concentrations exceeding 128 µM of Ga-MPIX and Ga-PPIX. We observed that the gallium metal heme conjugates were more active against planktonic and biofilm bacteria, possibly due to utilization of heme-iron as demonstrated by the enhanced effects on bacterial growth and biofilm formation. PMID:26999163

  10. Cobalt Protoporphyrin Upregulates Cyclooxygenase-2 Expression Through a Heme Oxygenase-Independent Mechanism.

    Lin, Hsiao-Yun; Tsai, Chon-Haw; Lin, Chingju; Yeh, Wei-Lan; Tsai, Cheng-Fang; Chang, Pei-Chun; Wu, Ling-Hsuan; Lu, Dah-Yuu

    2016-09-01

    Cobalt protoporphyrin (CoPP) is a potent HO-1 inducer and generally known to be an antioxidant in various cell types. Little is known about the CoPP-induced cyclooxygenase-2 (COX-2) expression and its downstream signaling in microglial cells. In current study, CoPP caused concentration- and time-dependent increases in COX-2 expression in microglial cells. Furthermore, activation of apoptosis signal-regulating kinase (ASK) 1/MAP kinase involved in CoPP-induced COX-2 expression in microglia. CoPP also induced P2X7 receptor activation, and treatment of P2X7 inhibitors effectively reduced CoPP-induced COX-2 expression. Protein inhibitor of activated STAT (PIAS) 1 is reported to be involved in modulating anti-inflammatory response through negative regulation of transcription factors. Interestingly, treatment with CoPP markedly induced PIAS1 degradation which is regulated by PI3K, Akt, and glycogen synthase kinase 3α/β (GSK3α/β) signaling pathways. These results suggest that CoPP induces COX-2 expression through activating P2X7 receptors and ASK1/MAP kinases as well as PIAS1 degradation signaling pathways. Our study provides a new insight into the regulatory effect of CoPP on neuroinflammation in microglial cells. PMID:26255181

  11. Metallation of protoporphyrins used as fluorescent chemo sensor for imidazole recognition

    Metalloporphyrin Complexes play significant roles in many biological and catalytic systems. The diversity of their functions is due in part to the variety of metals that bind in the pocket of the porphyrin ring system. Two kinds of metalloporphyrin derivatives, Cu (II) and Zn (II) protoporphyrins (PP) were microscale synthesized and characterized by spectroscopic methods and magnetic measurements. A PP ligand bound to each metal center in a tetradentate fashion including four amine nitrogen atoms in the equatorial planes. These complexes were found to recognize imidazolyl groups of histidine and histamine derivatives as guest molecules by coordination and additional non-covalent interactions. These added analytes displace the selective fluorescent indicator, which when released to the solution displays its full fluorescence. Thus, analyte recognition is signaled by the sharp appearance of the fluorescence of the indicators. The binding affinities to histidine and histamine were investigated and accounted for different complexation properties. Moreover, we demonstrated that careful choice of a fluorescent indicator with tuned affinity toward the receptor can provide discrimination in sensing of a desired substrate and the role that the metal coordination plays on the hypochromic shift and loss of fluorescence distincted characteristics of hypsoporphyrins were also discussed. (author)

  12. [Lead poisoning in the school-aged child: results of a screening program using zinc protoporphyrin].

    Villalbí, J R; Estany, J; Dalmau, J; Sales, C; Gadea-Carrera, E; Pascual-Benes, A

    1987-07-01

    The results of a zinc-protoporphyrin (ZPP) screening in 1983 among first-grade schoolchildren in Hospitalet de Llobregat (Catalonia, Spain) are presented. Tap water in this industrial city comes from the Llobregat river and is extremely hard, with an excessive level of salts. At this time, Spanish gasoline had high levels of lead. The purpose of the study was to evaluate the effect of environmental pollution on subclinical lead poisoning. These were 428 children in the study, 67% of those eligible. Causes for non participation were being absent from school on the screening day or lack of parental consent for participation in the study. Only in two children levels of ZPP above 40 theta g/100 ml were found; both cases had iron deficiency anemia with low blood lead levels. Mean ZPP levels were somewhat higher in the Collblanc district, which suffers higher air pollution from street traffic, and in children living in houses built before 1940. The relevance and implications of these findings are discussed. PMID:3662252

  13. White light-informed optical properties improve ultrasound-guided fluorescence tomography of photoactive protoporphyrin IX

    Flynn, Brendan P.; DSouza, Alisha V.; Kanick, Stephen C.; Davis, Scott C.; Pogue, Brian W.

    2013-04-01

    Subsurface fluorescence imaging is desirable for medical applications, including protoporphyrin-IX (PpIX)-based skin tumor diagnosis, surgical guidance, and dosimetry in photodynamic therapy. While tissue optical properties and heterogeneities make true subsurface fluorescence mapping an ill-posed problem, ultrasound-guided fluorescence-tomography (USFT) provides regional fluorescence mapping. Here USFT is implemented with spectroscopic decoupling of fluorescence signals (auto-fluorescence, PpIX, photoproducts), and white light spectroscopy-determined bulk optical properties. Segmented US images provide a priori spatial information for fluorescence reconstruction using region-based, diffuse FT. The method was tested in simulations, tissue homogeneous and inclusion phantoms, and an injected-inclusion animal model. Reconstructed fluorescence yield was linear with PpIX concentration, including the lowest concentration used, 0.025 μg/ml. White light spectroscopy informed optical properties, which improved fluorescence reconstruction accuracy compared to the use of fixed, literature-based optical properties, reduced reconstruction error and reconstructed fluorescence standard deviation by factors of 8.9 and 2.0, respectively. Recovered contrast-to-background error was 25% and 74% for inclusion phantoms without and with a 2-mm skin-like layer, respectively. Preliminary mouse-model imaging demonstrated system feasibility for subsurface fluorescence measurement in vivo. These data suggest that this implementation of USFT is capable of regional PpIX mapping in human skin tumors during photodynamic therapy, to be used in dosimetric evaluations.

  14. Evaluation of Sonochemiluminescence in a Phantom in the Presence of Protoporphyrin IX Conjugated to Nanoparticles

    When a liquid is irradiated with high-intensity and low-frequency ultrasound, acoustic cavitation occurs and there are some methods to determine and quantify this phenomenon. The existing methods for performing these experiments include sonochemiluminescence and chemical dosimetric methods. The particles in a liquid decrease the ultrasonic intensity threshold needed for cavitation onset. In this study, a new nano conjugate made up of Protoporphyrin IX and gold nanoparticles, i.e., Au-PpIX was used to provide nucleation sites for cavitation. The nonradiative relaxation time of PpIX in the presence of GNPs is longer than the similar time for PpIX without GNPs. This effect can be used in medical diagnostic and therapeutic applications. The acoustic cavitation activity was investigated studying integrated sonochemiluminescence signal in the wavelength range of 400-500 nm in polyacrylamide gel phantom containing luminol using a cooled CCD spectrometer at different intensities of 1 MHz ultrasound. In order to confirm these results, a chemical dosimetric method was utilized, too. sonochemiluminescence signal level in gel phantom containing Au-PpIX was higher than the other phantoms. These results have been confirmed by the chemical dosimetric data. This finding can be related to the existence of PpIX as a sensitizer and GNPs as cavitation nuclei. In other words, nanoparticles have acted as the sites for cavitation and have increased the cavitation rate. Another theory is that activation of PpIX has produced more free radicals and has enhanced the sonochemiluminescence signal level.

  15. Activity of Gallium Meso- and Protoporphyrin IX against Biofilms of Multidrug-Resistant Acinetobacter baumannii Isolates

    David Chang

    2016-03-01

    Full Text Available Acinetobacter baumannii is a challenging pathogen due to antimicrobial resistance and biofilm development. The role of iron in bacterial physiology has prompted the evaluation of iron-modulation as an antimicrobial strategy. The non-reducible iron analog gallium(III nitrate, Ga(NO33, has been shown to inhibit A. baumannii planktonic growth; however, utilization of heme-iron by clinical isolates has been associated with development of tolerance. These observations prompted the evaluation of iron-heme sources on planktonic and biofilm growth, as well as antimicrobial activities of gallium meso- and protoporphyrin IX (Ga-MPIX and Ga-PPIX, metal heme derivatives against planktonic and biofilm bacteria of multidrug-resistant (MDR clinical isolates of A. baumannii in vitro. Ga(NO33 was moderately effective at reducing planktonic bacteria (64 to 128 µM with little activity against biofilms (≥512 µM. In contrast, Ga-MPIX and Ga-PPIX were highly active against planktonic bacteria (0.25 to 8 µM. Cytotoxic effects in human fibroblasts were observed following exposure to concentrations exceeding 128 µM of Ga-MPIX and Ga-PPIX. We observed that the gallium metal heme conjugates were more active against planktonic and biofilm bacteria, possibly due to utilization of heme-iron as demonstrated by the enhanced effects on bacterial growth and biofilm formation.

  16. Marine resources chemistry of magnesium. Magnesium no kaiyo shigen kagaku

    1993-05-18

    Marine water body covers 71% of the earth surface, and has an average depth of about 3700 m. This huge marine water body contains magnesium of 1300 ppm on average in its water. This paper describes research and development related to high-purity sea water magnesium oxide that could be produced from these marine resources. Effects of impurities in sea water, particularly removal of calcium and boron are the important subject for studying high-purity sea water magnesium oxide. This paper describes results of developing a decarbonation pretreatment method for reducing calcium impurities and an alkaline method to reduce boron impurities. Most methods of manufacturing magnesium from sea water in an industrial scale change magnesium hydroxide precipitated from sea water into MgCl2, and electrolyze it to obtain metallic magnesium. The paper shows results of the development of a method to recover magnesium hydroxide and basic magnesium carbonate using the lime-ammonium circulation process that uses salt making bittern as a raw material. 6 refs., 7 figs.

  17. Locus: 14516 [

    Full Text Available At.22023 A. thaliana + S: NC_003075 NC_003075 Arabidopsis thaliana magnesium -protoporphyrin O-me ... thyltransferase, putative / magnesium -protoporphyrin IX methyltransferase, putative (At4 ...

  18. Magnesium Hall Thruster

    Szabo, James J.

    2015-01-01

    This Phase II project is developing a magnesium (Mg) Hall effect thruster system that would open the door for in situ resource utilization (ISRU)-based solar system exploration. Magnesium is light and easy to ionize. For a Mars- Earth transfer, the propellant mass savings with respect to a xenon Hall effect thruster (HET) system are enormous. Magnesium also can be combusted in a rocket with carbon dioxide (CO2) or water (H2O), enabling a multimode propulsion system with propellant sharing and ISRU. In the near term, CO2 and H2O would be collected in situ on Mars or the moon. In the far term, Mg itself would be collected from Martian and lunar regolith. In Phase I, an integrated, medium-power (1- to 3-kW) Mg HET system was developed and tested. Controlled, steady operation at constant voltage and power was demonstrated. Preliminary measurements indicate a specific impulse (Isp) greater than 4,000 s was achieved at a discharge potential of 400 V. The feasibility of delivering fluidized Mg powder to a medium- or high-power thruster also was demonstrated. Phase II of the project evaluated the performance of an integrated, highpower Mg Hall thruster system in a relevant space environment. Researchers improved the medium power thruster system and characterized it in detail. Researchers also designed and built a high-power (8- to 20-kW) Mg HET. A fluidized powder feed system supporting the high-power thruster was built and delivered to Busek Company, Inc.

  19. Optical storage by magnesium; Optisches Speichern von Magnesium

    Riedmann, Matthias

    2010-07-15

    source of cold atoms. A los of trapped atoms in the T-MOT can be observed with light of the wavelength 532 nm and is attributed to photoionization of the excited state (3s3d) {sup 3}D{sub 3}. The ionization cross section for this process is measured to be {sigma}{sub ion} (3s3d {sup 3}D{sub 3}, 532 nm) = 1,2 x 10{sup -22} m{sup 2}. This photoionization process is also possible with light at the magic wavelength. In contrast, 1064 nm light cannot drive this photoionization due to too low photon energy. As part of the work presented in this dissertation, the optical trapping of magnesium could be demonstrated for the first time with a dipole trap at this wavelength. A continuous loading scheme was developed with the two-stage magneto-optical trap. This makes the accumulation of atoms in the state (3s3p){sup 3}P{sub 0} in the optical dipole trap possible. During loading, only few atoms are stored in the magneto-optical traps at any time. This reduces atom losses due to inelastic collisions and the limitation of density by reabsorption of photons. These two processes often limit the loading efficiency of optical dipole traps in similar experiments with alkali atoms. In this way, 10{sup 5} atoms at a temperature of below 100 {mu}K can be loaded into the dipole trap. This number is limited by inelastic collisions of trapped atoms in the state (3s3p){sup 3}P{sub 0}. The atoms stored in the dipole trap were transferred to a second dipole trap and an optical lattice at the wavelength 532 nm. This method can also be used for a future transfer to an optical lattice at the magic wavelength. (orig.)

  20. Magnesium in Prevention and Therapy

    Gröber, Uwe; Schmidt, Joachim; Kisters, Klaus

    2015-01-01

    Magnesium is the fourth most abundant mineral in the body. It has been recognized as a cofactor for more than 300 enzymatic reactions, where it is crucial for adenosine triphosphate (ATP) metabolism. Magnesium is required for DNA and RNA synthesis, reproduction, and protein synthesis. Moreover, magnesium is essential for the regulation of muscular contraction, blood pressure, insulin metabolism, cardiac excitability, vasomotor tone, nerve transmission and neuromuscular conduction. Imbalances in magnesium status—primarily hypomagnesemia as it is seen more common than hypermagnesemia—might result in unwanted neuromuscular, cardiac or nervous disorders. Based on magnesium’s many functions within the human body, it plays an important role in prevention and treatment of many diseases. Low levels of magnesium have been associated with a number of chronic diseases, such as Alzheimer’s disease, insulin resistance and type-2 diabetes mellitus, hypertension, cardiovascular disease (e.g., stroke), migraine headaches, and attention deficit hyperactivity disorder (ADHD). PMID:26404370

  1. Evaluation of Sonochemiluminescence in a Phantom in the Presence of Protoporphyrin IX Conjugated to Nanoparticles

    Ahmad Shanei

    2012-03-01

    Full Text Available Introduction When a liquid is irradiated with high-intensity and low-frequency ultrasound, acoustic cavitation occurs and there are some methods to determine and quantify this phenomenon. The existing methods for performing these experiments include sonochemiluminescence (SCL and chemical dosimetric methods. The particles in a liquid decrease the ultrasonic intensity threshold needed for cavitation onset. In this study, a new nanoconjugate made up of Protoporphyrin IX (PpIX and gold nanoparticles (GNP, i.e., Au-PpIX was used to provide nucleation sites for cavitation. The nonradiative relaxation time of PpIX in the presence of GNPs is longer than the similar time for PpIX without GNPs. This effect can be used in medical diagnostic and therapeutic applications. Materials and Methods The acoustic cavitation activity was investigated studying integrated SCL signal in the wavelength range of 400-500 nm in polyacrylamide gel phantom containing luminol using a cooled CCD spectrometer at different intensities of 1 MHz ultrasound. In order to confirm these results, a chemical dosimetric method was utilized, too. Results SCL signal level in gel phantom containing Au-PpIX was higher than the other phantoms. These results have been confirmed by the chemical dosimetric data. Conclusion This finding can be related to the existence of PpIX as a sensitizer and GNPs as cavitation nuclei. In other words, nanoparticles have acted as the sites for cavitation and have increased the cavitation rate. Another theory is that activation of PpIX has produced more free radicals and has enhanced the SCL signal level.

  2. Influence of heme oxygenase-1 expression on immune liver fibrosis induced by cobalt protoporphyrin in rats

    Fei Wang; Zhi-Jun Duan; Ying-Jie Sun

    2009-01-01

    AIM: To investigate the effect of heme oxygenase-1 (HO-1) expression on immune liver fibrosis induced by cobalt protoporphyrin (CoPP) in rats. METHODS: An immune liver fibrosis model of rat was established by administering human serum albumin (HSA). The rats were divided into CoPP, liver fibrosis and normal control groups. Rats in the CoPP group received intraperitoneal CoPP concurrently with HSA. Expression of HO-1 protein was observed by Western blotting and immunohistochemistry. Hematoxylin and eosin (HE) staining was performed to assess fibrosis proliferation and distribution, proliferation extent of fibroblasts, and alterations in hepatocytes and inflammatory cells. Type Ⅰ and Ⅲ collagens were detected with Van Gieson's (VG) staining and Foot's reticular fiber staining, respectively. In addition, spindle-shaped cells existing at perisinusoidal locations beyond portal and septa areas were investigated with HE staining.RESULTS: Western blotting and immunohistochemistry showed that the expression of HO-1 protein was higher in the CoPP group than in the liver fibrosis group (P < 0.05). Compared with the liver fibrosis group, the serological index of hepatic fibrosis in the CoPP group decreased significantly (P < 0.05). HE, VG and Foot's staining revealed that administration of CoPP reduced the extent of hepatic fibrosis. The levels of serological indicators and the number of spindle-shaped cells at perisinuous locations beyond the portal and septa areas were reduced in the CoPP group. Only a few inflammatory cells were seen around the portal areas and central veins in the CoPP group. CONCLUSION: Increased endogenous HO-1 may suppress liver fibrosis by protecting liver cells,inhibiting inflammatory cell infiltration and hepatic stellate cell transformation.

  3. Hierarchical coassembly of DNA–triptycene hybrid molecular building blocks and zinc protoporphyrin IX

    Kumari, Rina; Singh, Sumit; Monisha, Mohan; Bhowmick, Sourav; Roy, Anindya

    2016-01-01

    Summary Herein, we describe the successful construction of composite DNA nanostructures by the self-assembly of complementary symmetrical 2,6,14-triptycenetripropiolic acid (TPA)–DNA building blocks and zinc protoporphyrin IX (Zn PpIX). DNA–organic molecule scaffolds for the composite DNA nanostructure were constructed through covalent conjugation of TPA with 5′-C12-amine-terminated modified single strand DNA (ssDNA) and its complementary strand. The repeated covalent conjugation of TPA with DNA was confirmed by using denaturing polyacrylamide gel electrophoresis (PAGE), reverse-phase high-performance liquid chromatography (RP-HPLC) and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF). The biologically relevant photosensitizer Zn PpIX was used to direct the hybridization-mediated self-assembly of DNA–TPA molecular building blocks as well as a model guest molecule within the DNA–TPA supramolecular self-assembly. The formation of fiber-like composite DNA nanostructures was observed. Native PAGE, circular dichroism (CD) and atomic force microscopy (AFM) have been utilized for analyzing the formation of DNA nanofibers after the coassembly. Computational methods were applied to discern the theoretical dimension of the DNA–TPA molecular building block of the nanofibers. A notable change in photocatalytic efficiency of Zn PpIX was observed when it was inside the TPA–DNA scaffold. The significant increase in ROS generation by Zn PpIX when trapped in this biocompatible DNA–TPA hybrid nanofiber may be an effective tool to explore photodynamic therapy (PDT) applications as well as photocatalytic reactions.

  4. DNA Damage and Cell Cycle Arrest Induced by Protoporphyrin IX in Sarcoma 180 Cells

    Qing Li

    2013-09-01

    Full Text Available Background: Porphyrin derivatives have been widely used in photodynamic therapy as effective sensitizers. Protoporphyrin IX (PpIX, a well-known hematoporphyrin derivative component, shows great potential to enhance light induced tumor cell damage. However, PpIX alone could also exert anti-tumor effects. The mechanisms underlying those direct effects are incompletely understood. This study thus investigated the putative mechanisms underlying the anti-tumor effects of PpIX on sarcoma 180 (S180 cells. Methods: S180 cells were treated with different concentrations of PpIX. Following the treatment, cell viability was evaluated by the 3-(4, 5- dimethylthiazol-2-yl-2, 5-diphenyltetrazoliumbromide (MTT assay; Disruption of mitochondrial membrane potential was measured by flow cytometry; The trans-location of apoptosis inducer factor (AIF from mitochondria to nucleus was visualized by confocal laser scanning microscopy; DNA damage was detected by single cell gel electrophoresis; Cell cycle distribution was analyzed by DNA content with flow cytometry; Cell cycle associated proteins were detected by western blotting. Results: PpIX (≥ 1 µg/ml significantly inhibited proliferation and reduced viability of S180 cells in a dose-dependent manner. PpIX rapidly and significantly triggered mitochondrial membrane depolarization, AIF (apoptosis inducer factor translocation from mitochondria to nucleus and DNA damage, effects partially relieved by the specific inhibitor of MPTP (mitochondrial permeability transition pore. Furthermore, S phase arrest and upregulation of the related proteins of P53 and P21 were observed following 12 and 24 h PpIX exposure. Conclusion: PpIX could inhibit tumor cell proliferation by induction of DNA damage and cell cycle arrest in the S phase.

  5. Ultrasound-assisted synthesis of magnesium hydroxide nanoparticles from magnesium.

    Baidukova, Olga; Skorb, Ekaterina V

    2016-07-01

    Acoustic cavitation in water provides special kinetic and thermodynamic conditions for chemical synthesis and nanostructuring of solids. Using cavitation phenomenon, we obtained magnesium hydroxide from pure magnesium. This approach allows magnesium hydroxide to be synthesized without the requirement of any additives and non-aqueous solvents. Variation of sonochemical parameters enabled a total transformation of the metal to nanosized brucite with distinct morphology. Special attention is given to the obtaining of platelet-shaped, nanometric and de-agglomerated powders. The products of the synthesis were characterized by transmission electron microscopy (TEM), electron diffraction (ED), scanning electron microscopy (SEM) and X-ray diffraction (XRD). PMID:26964968

  6. 21 CFR 184.1443 - Magnesium sulfate.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Magnesium sulfate. 184.1443 Section 184.1443 Food... Specific Substances Affirmed as GRAS § 184.1443 Magnesium sulfate. (a) Magnesium sulfate (MgSO4·7H2O, CAS... magnesium oxide, hydroxide, or carbonate with sulfuric acid and evaporating the solution to...

  7. Mineral resource of the month: magnesium

    Kramer, Deborah A.

    2012-01-01

    Magnesium is the eighthmost abundant element in Earth’s crust, and the second-most abundant metal ion in seawater. Although magnesium is found in more than 60 minerals, only brucite, dolomite, magnesite and carnallite are commercially important for their magnesium content. Magnesium and its compounds also are recovered from seawater, brines found in lakes and wells, and bitterns (salts).

  8. 21 CFR 184.1431 - Magnesium oxide.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Magnesium oxide. 184.1431 Section 184.1431 Food and... Substances Affirmed as GRAS § 184.1431 Magnesium oxide. (a) Magnesium oxide (MgO, CAS Reg. No. 1309-48-4... powder (light) or a relatively dense white powder (heavy) by heating magnesium hydroxide or...

  9. Magnesium Oxide Induced Metabolic Alkalosis in Cattle

    Ogilvie, T. H.; Butler, D G; Gartley, C J; Dohoo, I R

    1983-01-01

    A study was designed to compare the metabolic alkalosis produced in cattle from the use of an antacid (magnesium oxide) and a saline cathartic (magnesium sulphate). Six, mature, normal cattle were treated orally with a magnesium oxide (MgO) product and one week later given a comparable cathartic dose of magnesium sulphate (MgSO4).

  10. Lattice Dynamics of Magnesium

    A group theoretical analysis of modes of vibrations in hexagonal close-packed lattices has been made. The results have been used to classify the phonons at some special points in the Brillouin zone and factorized the secular determinant. Dispersion relations for phonons in magnesium along the two symmetry directions [0001] and [0110] have been measured (at room temperature) more accurately than reported earlier. The measurements have been made using a triple-axis spectrometer and a ''window filter'' spectrometer, both operated in the ''constant-Q'' mode. The results are compared with calculations based on three- and four-neighbour axially symmetric models. It is observed that the four-neighbour model gives a reasonably good description of the data. Even better agreement is obtained with a four-neighbour tensor force model. The force constants derived from the experiment have been used to compute the frequency distribution. (author)

  11. SERUM MAGNESIUM IN ACUTE MYOCARDIAL INFARCTION

    Nambakam Tanuja; Girish P

    2015-01-01

    BACKGROUND: In myocardial infarction, there occurs functional deficit of available magnesium due to trapping of free magnesium in adipocytes. Magnesium has been implicated in the pathogenesis of acute myocardial infarction and its complications. Magnesium ions are considered essential for the maintenance of functional integrity of myocardium. The serum magnesium concentration was found to have g reat significance in acute myocardial infarction. The present study was un...

  12. Conserved Chloroplast Open-reading Frame ycf54 Is Required for Activity of the Magnesium Protoporphyrin Monomethylester Oxidative Cyclase in Synechocystis PCC 6803

    Hollingshead, S.; Kopečná, Jana; Jackson, P. J.; Canniffe, D. P.; Davidson, P. A.; Dickman, M. J.; Sobotka, Roman; Hunter, C. N.

    2012-01-01

    Roč. 287, č. 33 (2012), s. 27823-27833. ISSN 0021-9258 R&D Projects: GA ČR GAP501/10/1000; GA MŠk(CZ) ED2.1.00/03.0110 Institutional support: RVO:61388971 Keywords : CHLOROPHYLL ISOCYCLIC RING * RHODOBACTER-SPHAEROIDES * SP PCC-6803 Subject RIV: CE - Biochemistry Impact factor: 4.651, year: 2012

  13. Effect of magnesium deficiency on renal magnesium and calcium transport in the rat.

    Carney, S L; Wong, N L; Quamme, G A; Dirks, J.H.

    1980-01-01

    Recollection of micropuncture experiments were performed on acutely thyroparathyroidectomized rats rendered magnesium deficient by dietary deprivation. Urinary magnesium excretion fell from a control of 15 to 3% of the filtered load after magnesium restriction. The loop of Henle, presumably the thick ascending limb, was the major modulator for renal magnesium homeostasis. The transport capacity for magnesium, however, was less in deficient rats than control animals. Absolute magnesium reabsor...

  14. Zinc protoporphyrin IX, a heme oxygenase-1 inhibitor, demonstrates potent antitumor effects but is unable to potentiate antitumor effects of chemotherapeutics in mice

    HO-1 participates in the degradation of heme. Its products can exert unique cytoprotective effects. Numerous tumors express high levels of HO-1 indicating that this enzyme might be a potential therapeutic target. In this study we decided to evaluate potential cytostatic/cytotoxic effects of zinc protoporphyrin IX (Zn(II)PPIX), a selective HO-1 inhibitor and to evaluate its antitumor activity in combination with chemotherapeutics. Cytostatic/cytotoxic effects of Zn(II)PPIX were evaluated with crystal violet staining and clonogenic assay. Western blotting was used for the evaluation of protein expression. Flow cytometry was used to evaluate the influence of Zn(II)PPIX on the induction of apoptosis and generation of reactive oxygen species. Knock-down of HO-1 expression was achieved with siRNA. Antitumor effects of Zn(II)PPIX alone or in combination with chemotherapeutics were measured in transplantation tumor models. Zn(II)PPIX induced significant accumulation of reactive oxygen species in tumor cells. This effect was partly reversed by administration of exogenous bilirubin. Moreover, Zn(II)PPIX exerted potent cytostatic/cytotoxic effects against human and murine tumor cell lines. Despite a significant time and dose-dependent decrease in cyclin D expression in Zn(II)PPIX-treated cells no accumulation of tumor cells in G1 phase of the cell cycle was observed. However, incubation of C-26 cells with Zn(II)PPIX increased the percentage of cells in sub-G1 phase of the cells cycle. Flow cytometry studies with propidium iodide and annexin V staining as well as detection of cleaved caspase 3 by Western blotting revealed that Zn(II)PPIX can induce apoptosis of tumor cells. B16F10 melanoma cells overexpressing HO-1 and transplanted into syngeneic mice were resistant to either Zn(II)PPIX or antitumor effects of cisplatin. Zn(II)PPIX was unable to potentiate antitumor effects of 5-fluorouracil, cisplatin or doxorubicin in three different tumor models, but significantly

  15. Combination photodynamic therapy using 5-fluorouracil and aminolevulinate enhances tumor-selective production of protoporphyrin IX and improves treatment efficacy of squamous skin cancers and precancers

    Maytin, Edward V.; Anand, Sanjay

    2016-03-01

    In combination photodynamic therapy (cPDT), a small-molecule drug is used to modulate the physiological state of tumor cells prior to giving aminolevulinate (ALA; a precursor for protoporphyrin IX, PpIX). In our laboratory we have identified three agents (methotrexate, 5-fluorouracil, and vitamin D) that can enhance therapeutic effectiveness of ALAbased photodynamic therapy for cutaneous squamous cell carcinoma (SCC). However, only one (5-fluorouracil; 5-FU) is FDA-approved for skin cancer management. Here, we describe animal and human studies on 5-FU mechanisms of action, in terms of how 5-FU pretreatment leads to enhanced PpIX accumulation and improves selectivity of ALA-PDT treatment. In A431 subcutaneous tumors in mice, 5-FU changed expression of heme enzyme (upregulating coproporphyrinogen oxidase, and down-regulating ferrochelatase), inhibited tumor cell proliferation (Ki-67), enhanced differentiation (E-cadherin), and led to strong, tumor-selective increases in apoptosis. Interestingly, enhancement of apoptosis by 5-FU correlated strongly with an increased accumulation of p53 in tumor cells that persisted for 24 h post- PDT. In a clinical trial using a split-body, bilaterally controlled study design, human subjects with actinic keratoses (AK; preneoplastic precursors of SCC) were pretreated on one side of the face, scalp, or forearms with 5-FU cream for 6 days, while the control side received no 5-FU. On the seventh day, the levels of PpIX in 4 test lesions were measured by noninvasive fluorescence dosimetry, and then all lesions were treated with PDT using methyl-aminolevulinate (MAL) and red light (635 nm). Relative amounts of PpIX were found to be increased ~2-fold in 5-FU pretreated lesions relative to controls. At 3 months after PDT, the overall clinical response to PDT (reduction in lesion counts) was 2- to 3-fold better for the 5-FU pretreated lesions, a clinically important result. In summary, 5-FU is a useful adjuvant to aminolevulinate-based PDT

  16. Effect of oxygen on the hydrogenation properties of magnesium films

    Ostenfeld, Christopher Worsøe; Chorkendorff, Ib

    2006-01-01

    The effect of magnesium oxide on the magnesium and hydrogen desorption properties of magnesium films have been investigated. We find that by capping metallic magnesium films with oxide overlayers the apparent desorption energy of magnesium is increased from 146 kJ/mol to 314 kJ/mol. The results...... are discussed in light of previous investigations of ball-milled magnesium powders....

  17. Distribution of protoporphyrin IX in Bowen's disease and basal cell carcinomas treated with topical 5-aminolaevulinic acid

    Roberts, David J.; Stables, G. I.; Ash, D. V.; Brown, Stanley B.

    1995-03-01

    We have used ultra-low light level fluorescence microscopy to examine the suggestion that the relatively poor response of human basal cell carcinomas (BCC) to topical 5-aminolaevulinic acid (ALA)-based photodynamic therapy (PDT) arises from limited drug penetration into the lesion. The distribution of ALA-induced protoporphyrin IX (PpIX) in human BCC and Bowen's disease was examined and, in almost all cases, was found to be most intense in those regions of tumor immediately adjacent to the dermis. This distribution was independent of tumor type, and did not appear to be affected by tumor depth in the skin. It is suggested that ALA penetration may not limit the efficacy of ALA-PDT in the treatment of BCC. Failure of superficial ALA-based PDT in basal cell carcinoma may, instead, be related to the histological structure of this type of lesion.

  18. Magnesium removal in the electrolytic zinc industry

    Booster, J.L.

    2003-01-01

    Electrolytic zinc plants need to take measures to control the magnesium content in their process liquors, because the natural magnesium bleed does not balance the input from concentrates. Presently used methods are environmentally unfriendly (due to the production of large amounts of waste gypsum) or expensive. Therefore, an alternative process route is explored in which magnesium is removed from zinc electrolyte by selective precipitation of magnesium fluoride (sellaite). As standard applica...

  19. Solid-state rechargeable magnesium battery

    Shao, Yuyan; Liu, Jun; Liu, Tianbiao; Li, Guosheng

    2016-09-06

    Embodiments of a solid-state electrolyte comprising magnesium borohydride, polyethylene oxide, and optionally a Group IIA or transition metal oxide are disclosed. The solid-state electrolyte may be a thin film comprising a dispersion of magnesium borohydride and magnesium oxide nanoparticles in polyethylene oxide. Rechargeable magnesium batteries including the disclosed solid-state electrolyte may have a coulombic efficiency .gtoreq.95% and exhibit cycling stability for at least 50 cycles.

  20. A Search for Magnesium in Europa's Atmosphere

    Horst, Sarah M.; Brown, Michael E.

    2013-01-01

    Europa's tenuous atmosphere results from sputtering of the surface. The trace element composition of its atmosphere is therefore related to the composition of Europa's surface. Magnesium salts are often invoked to explain Galileo Near Infrared Mapping Spectrometer spectra of Europa's surface, thus magnesium may be present in Europa's atmosphere. We have searched for magnesium emission in the Hubble Space Telescope Faint Object Spectrograph archival spectra of Europa's atmosphere. Magnesium wa...

  1. Magnesium sulphate for fetal neuroprotection

    Bickford, Celeste D; Magee, Laura A; Mitton, Craig;

    2013-01-01

    BACKGROUND: The aim of this study was to assess the cost-effectiveness of administering magnesium sulphate to patients in whom preterm birth at ... sensitivity analyses were used to compare the administration of magnesium sulphate with the alternative of no treatment. Two separate cost perspectives were utilized in this series of analyses: a health system and a societal perspective. In addition, two separate measures of effectiveness were utilized: cases...... of cerebral palsy (CP) averted and quality-adjusted life years (QALYs). RESULTS: From a health system and a societal perspective, respectively, a savings of $2,242 and $112,602 is obtained for each QALY gained and a savings of $30,942 and $1,554,198 is obtained for each case of CP averted when magnesium...

  2. Magnesium and related low alloys

    In the first part the authors examine the comparative corrosion of commercial magnesium, of a magnesium-zirconium alloy (0,4 per cent ≤ Zr ≤ 0,7 per cent) of a ternary magnesium-zinc-zirconium alloy (0,8 per cent ≤ Zn ≤ 1,2 per cent) and of english 'Magnox type' alloys, in dry carbon dioxide-free air, in damp carbon dioxide-free air, and in dry and damp carbon dioxide, at temperatures from 300 to 600 deg. C. In the second part the structural stability of these materials is studied after annealings, of 10 to 1000 hours at 300 to 450 deg. C. Variations in grain after these heat treatments and mechanical stretching properties at room temperature are presented. Finally various creep rate and life time diagrams are given for these materials, for temperatures ranging from 300 to 450 deg. C. (author)

  3. 21 CFR 582.5431 - Magnesium oxide.

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Magnesium oxide. 582.5431 Section 582.5431 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5431 Magnesium oxide. (a) Product. Magnesium oxide. (b) Conditions of use. This...

  4. 21 CFR 582.5443 - Magnesium sulfate.

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Magnesium sulfate. 582.5443 Section 582.5443 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5443 Magnesium sulfate. (a) Product. Magnesium sulfate. (b) Conditions of use....

  5. 21 CFR 582.1431 - Magnesium oxide.

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Magnesium oxide. 582.1431 Section 582.1431 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1431 Magnesium oxide. (a) Product. Magnesium oxide. (b) Conditions of use. This substance...

  6. 21 CFR 201.71 - Magnesium labeling.

    2010-04-01

    ... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Magnesium labeling. 201.71 Section 201.71 Food and... LABELING Labeling Requirements for Over-the-Counter Drugs § 201.71 Magnesium labeling. (a) The labeling of over-the-counter (OTC) drug products intended for oral ingestion shall contain the magnesium...

  7. 76 FR 69284 - Pure Magnesium From China

    2011-11-08

    ... COMMISSION Pure Magnesium From China Determination On the basis of the record \\1\\ developed in the subject... order on pure magnesium from China would be likely to lead to continuation or recurrence of material... USITC Publication 4274 (October 2011), entitled Pure Magnesium from China: Investigation No....

  8. 21 CFR 582.5434 - Magnesium phosphate.

    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)....

  9. Magnesium, Inflammation, and Obesity in Chronic Disease

    About 60% of U.S. adults do not consume the Estimated Average Intake for magnesium, but widespread pathological conditions attributed to magnesium deficiency have not been reported. However, low magnesium status has been associated with numerous pathological conditions characterized as having a chr...

  10. Magnesium Diboride Current Leads

    Panek, John

    2010-01-01

    A recently discovered superconductor, magnesium diboride (MgB2), can be used to fabricate conducting leads used in cryogenic applications. Dis covered to be superconducting in 2001, MgB2 has the advantage of remaining superconducting at higher temperatures than the previously used material, NbTi. The purpose of these leads is to provide 2 A of electricity to motors located in a 1.3 K environment. The providing environment is a relatively warm 17 K. Requirements for these leads are to survive temperature fluctuations in the 5 K and 11 K heat sinks, and not conduct excessive heat into the 1.3 K environment. Test data showed that each lead in the assembly could conduct 5 A at 4 K, which, when scaled to 17 K, still provided more than the required 2 A. The lead assembly consists of 12 steelclad MgB2 wires, a tensioned Kevlar support, a thermal heat sink interface at 4 K, and base plates. The wires are soldered to heavy copper leads at the 17 K end, and to thin copper-clad NbTi leads at the 1.3 K end. The leads were designed, fabricated, and tested at the Forschungszentrum Karlsruhe - Institut foer Technische Physik before inclusion in Goddard's XRS (X-Ray Spectrometer) instrument onboard the Astro-E2 spacecraft. A key factor is that MgB2 remains superconducting up to 30 K, which means that it does not introduce joule heating as a resistive wire would. Because the required temperature ranges are 1.3-17 K, this provides a large margin of safety. Previous designs lost superconductivity at around 8 K. The disadvantage to MgB2 is that it is a brittle ceramic, and making thin wires from it is challenging. The solution was to encase the leads in thin steel tubes for strength. Previous designs were so brittle as to risk instrument survival. MgB2 leads can be used in any cryogenic application where small currents need to be conducted at below 30 K. Because previous designs would superconduct only at up to 8 K, this new design would be ideal for the 8-30 K range.

  11. Synthesis of Environmentally Friendly Magnesium Linoleate Detergent

    Wang Yonglei; Li Haiyun; Fang Hongxia; Ni Zhifei; Zhao Lele

    2014-01-01

    This paper mainly covers a method for preparing a highly alkaline magnesium linoleate solution with a total base number (TBN) value of 328 mg KOH/g using linoleic acid as the biodegradable raw material, which can substitute for traditional lubricant detergents as an environmentally friendly detergent. Reaction conditions, including the molar ratio of magnesium oxide to linoleic acid, the molar ratio of methanol to magnesium oxide, the carbonation temperature, the molar ratio of water to magnesium oxide, the lfow rate of CO2 gas and the duration for injection of CO2 to magnesium oxide sys-tem, were optimized.

  12. LOW DOSE MAGNESIUM SULPHATE REGIME FOR ECLAMPSIA

    Bangal V

    2009-09-01

    Full Text Available Pre- eclampsia is one of the commonest medical complications seen during pregnancy. It contributes significantly to maternal and perinatal morbidity and mortality. Dr.J.A.Pritchard in 1955, introduced magnesium sulphate for control of convulsions in eclampsia and is used worldwide. Considering the low body mass index of indian women, a low dose magnesium sulphate regime has been introduced by some authors. Present study was carried out at tertiary care centre in rural area. Fifty cases of eclampsia were randomly selected to find out the efficacy of low dose magnesium sulphate regime to control eclamptic convulsions. Maternal and perinatal outcome and magnesium toxicity were analyzed. It was observed that 86% cases responded to initial intravenous dose of 4 grams of 20% magnesium sulphate . Eight percent cases, who got recurrence of convulsion, were controlled by additional 2 grams of 20% magnesium sulphate. Six percent cases required shifting to standard Pritchard regime, as they did not respond to low dose magnesium sulphate regime. The average total dose of magnesium sulphate required for control of convulsions was 20 grams ie. 54.4% less than that of standard Pritchard regime. The maternal and perinatal morbidity and mortality in the present study werecomparable to those of standard Pritchard regime. The study did not find a single case of magnesium related toxicity with low dose magnesium sulphate regime. Low dose magnesium sulphate regime was found to be safe and effective in eclampsia.

  13. Forming of magnesium alloy microtubes in the fabrication of biodegradable stents

    Lixiao Wang

    2014-10-01

    Full Text Available Magnesium alloys have, in recent years, been recognized as highly promising biodegradable materials, especially for vascular stent applications. Forming of magnesium alloys into high-precision thin-wall tubes has however presented a technological barrier in the fabrication of vascular stents, because of the poor workability of magnesium at room temperature. In the present study, the forming processes, i.e., hot indirect extrusion and multi-pass cold drawing were used to fabricate seamless microtubes of a magnesium alloy. The magnesium alloy ZM21 was selected as a representative biomaterial for biodegradable stent applications. Microtubes with an outside diameter of 2.9 mm and a wall thickness of 0.2 mm were successfully produced at the fourth pass of cold drawing without inter-pass annealing. Dimensional evaluation showed that multi-pass cold drawing was effective in correcting dimensional non-uniformity arising from hot indirect extrusion. Examinations of the microstructures of microtubes revealed the generation of a large number of twins as a result of accumulated work hardening at the third and fourth passes of cold drawing, corresponding to the significantly raised forming forces. The work demonstrated the viability of the forming process route selected for the fabrication of biodegradable magnesium alloy microtubes.

  14. Electrochemical investigations of magnesium in DMEM with biodegradable polycaprolactone coating as corrosion barrier

    Degner, Julia; Singer, Ferdinand; Cordero, Luis; Boccaccini, Aldo R.; Virtanen, Sannakaisa

    2013-10-01

    Magnesium and its alloys are being increasingly investigated as biodegradable metallic implant materials. However, the high corrosion rate and accumulation of hydrogen gas upon degradation prevent the clinical application of many magnesium based materials. Applying polymer or ceramic coatings is a popular approach to improve the corrosion behaviour of magnesium and its alloys. In the current research, a biodegradable polymer film of polycaprolactone (PCL) is prepared in different concentrations by spin coating, in order to influence the corrosion behaviour of 99.9% pure magnesium. The resulting polymer coating was qualified by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and tape-test according to ASTM D3359-09 to measure the adhesion strength of the coating on the substrate. Furthermore, coated and uncoated specimens were stored up to 30 days at 37 ̊C in DMEM. The corrosion behaviour was investigated by polarization curves. The PCL-films were found to be uniform and without pores, but they show a low adhesion strength on the substrate. Nevertheless, remarkable improvement of the corrosion resistance of magnesium substrate can be obtained by the polymer films, depending on the film thickness and exposition time. In summary, coating magnesium with PCL is a promising method to tailor the degradation behaviour for biomedical applications.

  15. Electrochemical investigations of magnesium in DMEM with biodegradable polycaprolactone coating as corrosion barrier

    Degner, Julia; Singer, Ferdinand [Department of Materials Science, WW4-LKO, University of Erlangen-Nuremberg, Martenstr. 7, 91058 Erlangen (Germany); Cordero, Luis; Boccaccini, Aldo R. [Department of Materials Science, WW7-BioMat, University of Erlangen-Nuremberg, Cauerstr. 6, 91058 Erlangen (Germany); Virtanen, Sannakaisa, E-mail: Virtanen@ww.uni-erlangen.de [Department of Materials Science, WW4-LKO, University of Erlangen-Nuremberg, Martenstr. 7, 91058 Erlangen (Germany)

    2013-10-01

    Magnesium and its alloys are being increasingly investigated as biodegradable metallic implant materials. However, the high corrosion rate and accumulation of hydrogen gas upon degradation prevent the clinical application of many magnesium based materials. Applying polymer or ceramic coatings is a popular approach to improve the corrosion behaviour of magnesium and its alloys. In the current research, a biodegradable polymer film of polycaprolactone (PCL) is prepared in different concentrations by spin coating, in order to influence the corrosion behaviour of 99.9% pure magnesium. The resulting polymer coating was qualified by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and tape-test according to (ASTM D3359-09) to measure the adhesion strength of the coating on the substrate. Furthermore, coated and uncoated specimens were stored up to 30 days at 37 {sup o}C in DMEM. The corrosion behaviour was investigated by polarization curves. The PCL-films were found to be uniform and without pores, but they show a low adhesion strength on the substrate. Nevertheless, remarkable improvement of the corrosion resistance of magnesium substrate can be obtained by the polymer films, depending on the film thickness and exposition time. In summary, coating magnesium with PCL is a promising method to tailor the degradation behaviour for biomedical applications.

  16. Electrochemical investigations of magnesium in DMEM with biodegradable polycaprolactone coating as corrosion barrier

    Magnesium and its alloys are being increasingly investigated as biodegradable metallic implant materials. However, the high corrosion rate and accumulation of hydrogen gas upon degradation prevent the clinical application of many magnesium based materials. Applying polymer or ceramic coatings is a popular approach to improve the corrosion behaviour of magnesium and its alloys. In the current research, a biodegradable polymer film of polycaprolactone (PCL) is prepared in different concentrations by spin coating, in order to influence the corrosion behaviour of 99.9% pure magnesium. The resulting polymer coating was qualified by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and tape-test according to (ASTM D3359-09) to measure the adhesion strength of the coating on the substrate. Furthermore, coated and uncoated specimens were stored up to 30 days at 37 oC in DMEM. The corrosion behaviour was investigated by polarization curves. The PCL-films were found to be uniform and without pores, but they show a low adhesion strength on the substrate. Nevertheless, remarkable improvement of the corrosion resistance of magnesium substrate can be obtained by the polymer films, depending on the film thickness and exposition time. In summary, coating magnesium with PCL is a promising method to tailor the degradation behaviour for biomedical applications.

  17. Bidentate RNA–magnesium clamps: On the origin of the special role of magnesium in RNA folding

    Petrov, Anton S.; Bowman, Jessica C.; Harvey, Stephen C.; Williams, Loren Dean

    2011-01-01

    Magnesium plays a special role in RNA function and folding. Although water is magnesium's most common first-shell ligand, the oxyanions of RNA have significant affinity for magnesium. Here we provide a quantum mechanical description of first-shell RNA–magnesium and DNA–magnesium interactions, demonstrating the unique features that characterize the energetics and geometry of magnesium complexes within large folded RNAs. Our work focuses on bidentate chelation of magnesium by RNA or DNA, where ...

  18. Protoporphyrin IX formation and photobleaching in different layers of normal human skin

    Togsverd-Bo, Katrine; Idorn, Luise W; Philipsen, Peter A;

    2012-01-01

    human skin was tape-stripped and incubated with 20% methylaminolevulinate (MAL) or 20% hexylaminolevulinate (HAL) for 3 h. Fluorescence microscopy quantified PpIX accumulation in epidermis, superficial, mid and deep dermis, down to 2 mm. PpIX photobleaching by light-emitting diode (LED, 632 nm, 18 and......Topical photodynamic therapy (PDT) is used for various skin disorders, and selective targeting of specific skin structures is desirable. The objective was to assess accumulation of PpIX fluorescence and photobleaching within skin layers using different photosensitizers and light sources. Normal...... 37 J/cm(2)), intense pulsed light (IPL, 500-650 nm, 36 and 72 J/cm(2)) and long-pulsed dye laser (LPDL, 595 nm, 7.5 and 15 J/cm(2)) was measured using fluorescence photography and microscopy. We found higher PpIX fluorescence intensities in epidermis and superficial dermis in HAL-incubated skin than...

  19. Struvite precipitation and phosphorus removal using magnesium sacrificial anode.

    Kruk, Damian J; Elektorowicz, Maria; Oleszkiewicz, Jan A

    2014-04-01

    Struvite precipitation using magnesium sacrificial anode as the only source of magnesium is presented. High-purity magnesium alloy cast anode was found to be very effective in recovery of high-quality struvite from water solutions and from supernatant of fermented waste activated sludge from a wastewater treatment plant that does not practice enhanced biological phosphorus removal. Struvite purity was strongly dependent on the pH and the electric current density. Optimum pH of the 24 mM phosphorus and 46 mM ammonia solution (1:1.9 P:N ratio) was in the broad range between 7.5 and 9.3, with struvite purity exceeding 90%. Increasing the current density resulted in elevated struvite purity. No upper limits were observed in the studied current range of 0.05-0.2 A. Phosphorus removal rate was proportional to the current density and comparable for tests with water solutions and with the supernatant from fermented sludge. The highest P-removal rate achieved was 4.0 mg PO4-P cm(-2) h(-1) at electric current density of 45 A m(-2). Initial substrate concentrations affected the rate of phosphorus removal. The precipitated struvite accumulated in bulk liquid with significant portions attached to the anode surface from which regular detachment occurred. PMID:24387911

  20. Poly(L-histidine-tagged 5-aminolevulinic acid prodrugs: new photosensitizing precursors of protoporphyrin IX for photodynamic colon cancer therapy

    Johnson RP

    2012-05-01

    Full Text Available Renjith P Johnson,1* Chung-Wook Chung,2* Young-Il Jeong,2 Dae Hwan Kang,2 Hongsuk Suh,3 Il Kim,11WCU Centre for Synthetic Polymer Bioconjugate Hybrid Materials, Department of Polymer Science and Engineering, Pusan National University, Pusan, 2National Research and Development Center for Hepatobiliary Cancer, Pusan National University, Yangsan Hospital, Yangsan, Gyeongnam, 3Department of Chemistry and Chemistry Institute for Functional Materials, Pusan National University, Pusan, Korea*These authors contributed equally to this workBackground: 5-Aminolevulinic acid (ALA and its derivatives have been widely used in photodynamic therapy. The main drawback associated with ALA-based photodynamic therapy (ALA-PDT and ALA fluorescence diagnosis results from the hydrophilic nature of ALA and lack of selectivity for tumor versus nontumor cells. The application of certain triggers, such as pH, into conventional sensitizers for controllable 1O2 release is a promising strategy for tumor-targeted treatment.Methods: A series of pH-sensitive ALA-poly(L-histidine [p(L-Hisn] prodrugs were synthesized via ring opening polymerization of 1-benzyl-N-carboxy-L-histidine anhydride initiated by the amine hydrochloride group of ALA itself. As an alternative to ALA for PDT, the synthesized prodrugs were used to treat a cultured human colon cancer HCT116 cell line under different pH conditions. The effect of ALA-p(L-Hisn derivatives was evaluated by monitoring the fluorescence intensity of protoporphyrin IX, and measuring the cell survival rate after suitable light irradiation.Results: The cytotoxicity and dark toxicity of ALA and synthesized ALA-p(L-His derivatives in HEK293T and HCT116 cells in the absence of light at pH 7.4 and 6.8 shows that the cell viability was relatively higher than 100%. ALA-p(L-Hisn showed high phototoxicity and selectivity in different pH conditions compared with ALA alone. Because the length of the histidine chain increases in the ALA

  1. Magnesium deficiency and cardiovascular diseases: time to act

    E. I. Trisvetova

    2014-01-01

    Progression of cardiovascular disease is often caused by a deficiency of magnesium in the human body. Magnesium belongs to the necessary vital macronutrients providing many physiological and pathological reactions and is involved in the constructive, energy, electrolyte metabolism. Correction of magnesium deficiency is realized using magnesium-containing drugs, for example magnesium orotate, having pleiotropic effects due to independent metabolic activity of orotic acid.

  2. Calcium and magnesium silicate hydrates

    Deep geological disposals are planed to discard long-lived intermediate-level and high-level radioactive wastes. Clay-based geological barriers are expected to limit the ingress of groundwater and to reduce the mobility of radioelements. In the interaction zone between the cement and the clay based material alteration can occur. Magnesium silicate hydrates (M-S-H) have been observed due to the reaction of magnesium sulfate containing groundwater with cements or in the interaction zone between low-pH type cement and clays. M-S-H samples synthesized in the laboratory showed that M-S-H has a variable composition within 0.7 ≤ Mg/Si ≤ 1.5. TEM/EDS analyses show an homogeneous gel with no defined structure. IR and 29Si NMR data reveal a higher polymerization degree of the silica network in M-S-H compared to calcium silicate hydrates (C-S-H). The presence of mainly Q3 silicate tetrahedrons in M-S-H indicates a sheet like or a triple-chain silica structure while C-S-H is characterised by single chain-structure. The clear difference in the silica structure and the larger ionic radius of Ca2+ (1.1 Angstrom) compared to Mg2+ (0.8 Angstrom) make the formation of an extended solid solution between M-S-H and C-S-H gel improbable. In fact, the analyses of synthetic samples containing both magnesium and calcium in various ratios indicate the formation of separate M-S-H and C-S-H gels with no or very little uptake of magnesium in CS-H or calcium in M-S-H

  3. Substrate and method for the formation of continuous magnesium diboride and doped magnesium diboride wire

    Suplinskas, Raymond J.; Finnemore, Douglas; Bud'ko, Serquei; Canfield, Paul

    2007-11-13

    A chemically doped boron coating is applied by chemical vapor deposition to a silicon carbide fiber and the coated fiber then is exposed to magnesium vapor to convert the doped boron to doped magnesium diboride and a resultant superconductor.

  4. Preparation and characterization of porous magnesium materials

    LIU Xi-qin; LIU Zi-li; ZHANG Xiao-hong; FENG Jun-dong; YU Ta-xi

    2006-01-01

    The proper spacer material and the preparation technology for biological compatible porous magnesium materials were explored by the powder metallurgy method, and microstructures, porosity and mechanical properties of sintered porous magnesium were investigated. The results show that compared with spacer materials of NH4CO3, NH3Cl and carbamide, NH4CO3 is the best one for preparation of sintered porous magnesium, and the worst one is NH3Cl. The isolated blind pores are formed mainly by the particle interval of the magnesium powders. Adding spacer material favors the formation of open pores, while has little contribution to the formation of blind pores. The overall porosity and porosity of open pore of the sintered porous magnesium increase with the increase of added spacer material, while decrease with the increase of the molding stress. The mechanical properties of sintered porous magnesium increase with decreasing addition of spacer material and increasing molding stress.

  5. Lightweight Heat Pipes Made from Magnesium

    Rosenfeld, John N.; Zarembo, Sergei N.; Eastman, G. Yale

    2010-01-01

    Magnesium has shown promise as a lighter-weight alternative to the aluminum alloys now used to make the main structural components of axially grooved heat pipes that contain ammonia as the working fluid. Magnesium heat-pipe structures can be fabricated by conventional processes that include extrusion, machining, welding, and bending. The thermal performances of magnesium heat pipes are the same as those of equal-sized aluminum heat pipes. However, by virtue of the lower mass density of magnesium, the magnesium heat pipes weigh 35 percent less. Conceived for use aboard spacecraft, magnesium heat pipes could also be attractive as heat-transfer devices in terrestrial applications in which minimization of weight is sought: examples include radio-communication equipment and laptop computers.

  6. Sensitization and photodynamic therapy of esophageal,duodenal, and colonic tumors with 5-aminolaevulinic acid (ALA) induced protoporphyrin IX (PPIX)

    Mlkvy, Peter; Messmann, Helmut; Regula, Jaroslaw; Conio, M.; Pauer, M.; Millson, Charles E.; MacRobert, Alexander J.; Bown, Stephen G.

    1995-03-01

    Five aminolaevulinic acid (ALA) is a promising agent for PDT sensitization as it can be given orally and only causes skin photosensitivity for 1 - 2 days. In fluorescence and photodynamic studies 26 patients with benign and malignant gastrointestinal tumors (M 17, F 9; mean age 79) were given 30 - 60 mg ALA orally (single or divided doses) and biopsies taken of tumor and normal tissue at 1 - 24 hours for fluorescence microscopy. With 30 mg/kg, highest protoporphyrin IX (PPIX) levels were seen in oesophagus, duodenum and less in colon, but without tumor selectivity. Better tumor selectivity was seen in the colon after 60 mg/kg (5:1). Six patients had transient rises in transaminases and five mild nausea. Sixteen patients were later treated (after further ALA) with red light (628 nm, bare fiber or diffuser, 50 - 100 J at 50 mW at each site). All but two showed subsequent necrosis, but only 0.5 - 1.5 mm depth. PDT with ALA is simple, safe, and promising for tumors in the GI tract. Modification of treatment parameters may make it suitable for larger lesions.

  7. Photophysical studies of tin(IV)-protoporphyrin: Potential phototoxicity of a chemotherapeutic agent proposed for the prevention of neonatal jaundice

    The strongly light-absorbing metalloporphyrin tin(IV)-protoporphyrin IX (SnPP) is currently being considered as a chemotherapeutic agent for preventing severe hyperbilirubinemia in newborns, a condition usually treated by phototherapy with visible light. To assess the potential phototoxicity of SnPP the authors studied the photophysics of the drug in aqueous and nonaqueous solutions using laser flash photolysis and pulse radiolysis. Quantum yields for formation of triplet-state excited SnPP were measured, along with triplet lifetimes and extinction coefficients. In addition, they measured quantum yields for the SnPP-photosensitized formation of singlet oxygen in MeO2H and in 2H2O containing cetyltrimethylammonium bromide, using a time-resolved luminescence technique. Quantum yields for formation of triplet SnPP from monomeric ground-state SnPP are high, and triplet lifetimes are long. SnPP-photosensitized formation of singlet oxygen in aqueous and nonaqueous solvents was confirmed by the detection of the characteristic luminescence at 1270 nm. These observations suggest that cutaneous photosensitivity arising from singlet-oxygen damage is likely to be an undesirable side-effect of SnPP therapy

  8. Role of Cellular Magnesium in Human Diseases

    Long, Samantha; Romani, Andrea MP

    2014-01-01

    Magnesium is required for many of the major organs to function and plays a crucial role in human and mammalian physiology. Magnesium is essential for the structure of bones and teeth, acts as a cofactor for more than 300 enzymes in the body, including binding to ATP for kinase reactions, and affects permeability of excitable membranes and neuromuscular transmission. Despite these essential roles, much is still unknown about magnesium physiology and homeostasis. Currently, nutritionists believ...

  9. Status of Research on Magnesium Oxide Backfill

    PAPENGUTH,HANS W.; KRUMHANSL,JAMES L.; BYNUM,R. VANN; WANG,YIFENG; KELLY,JOHN W.; ANDERSON,HOWARD; NOWAK,E. JAMES

    2000-07-31

    For the WIPP, chemical and physical characteristics of MgO suggest it to be the most beneficial backfill choice, particularly because it has the ability to buffer the aqueous chemical conditions to control actinide volubility. In the current experimental program, the authors are developing a technical basis for taking credit for the complete set of attributes of MgO in geochemical, hydrogeological, and geomechanical technical areas, resulting in an improved conceptual model for the WIPP such as the following. Water uptake by MgO will delay the development of mobile actinides and gas generation by microbes and corrosion. Reduced gas generation will reduce or even eliminate spallings releases. As MgO hydrates, it swells, reducing porosity and permeability, which will inhibit gas flow in the repository, in turn reducing spallings releases. Hydration will also result in a self-sealing mechanism by which water uptake and swelling of MgO adjacent to a groundwater seep cuts off further seepage. Reaction with some groundwaters will produce cementitious materials, which will help to cement waste particles or produce a cohesive solid mass. Larger particles are less likely to be entrained in a spallings release. If sufficient water eventually accumulates in a repository to support microbial gas generation, magnesium carbonate cements will form; also producing good cohesion and strength.

  10. Status of Research on Magnesium Oxide Backfill

    For the WIPP, chemical and physical characteristics of MgO suggest it to be the most beneficial backfill choice, particularly because it has the ability to buffer the aqueous chemical conditions to control actinide volubility. In the current experimental program, the authors are developing a technical basis for taking credit for the complete set of attributes of MgO in geochemical, hydrogeological, and geomechanical technical areas, resulting in an improved conceptual model for the WIPP such as the following. Water uptake by MgO will delay the development of mobile actinides and gas generation by microbes and corrosion. Reduced gas generation will reduce or even eliminate spallings releases. As MgO hydrates, it swells, reducing porosity and permeability, which will inhibit gas flow in the repository, in turn reducing spallings releases. Hydration will also result in a self-sealing mechanism by which water uptake and swelling of MgO adjacent to a groundwater seep cuts off further seepage. Reaction with some groundwaters will produce cementitious materials, which will help to cement waste particles or produce a cohesive solid mass. Larger particles are less likely to be entrained in a spallings release. If sufficient water eventually accumulates in a repository to support microbial gas generation, magnesium carbonate cements will form; also producing good cohesion and strength

  11. Low Temperature Synthesis of Magnesium Aluminate Spinel

    The low-temperature synthesis of magnesium-aluminum spinel is carried out by a method of thermal decomposition in combined precipitated hydrates. The fine material of magnesium-aluminium spinel with average size of coherent dispersion's area 4...5 nanometers is obtained. Magnesium-aluminum spinel and initial hydrates were investigated by methods of the differential thermal analysis, the x-ray phase analysis and measurements of weight loss during the dehydration and thermal decomposition. It is established that synthesis of magnesium-aluminum spinel occurs at temperature 300 degree C by method of the x-ray phase analysis

  12. Magnesium growth in magnesium deuteride thin films during deuterium desorption

    Checchetto, R., E-mail: riccardo.checchetto@unitn.it [Dipartimento di Fisica and CNISM, Università di Trento, Via Sommarive 14, I-38123 Trento (Italy); Miotello, A. [Dipartimento di Fisica and CNISM, Università di Trento, Via Sommarive 14, I-38123 Trento (Italy); Mengucci, P.; Barucca, G. [Dipartimento di Fisica e Ingegneria dei Materiali e del Territorio, Università Politecnica delle Marche, I-60131 Ancona (Italy)

    2013-12-15

    Highlights: ► Highly oriented Pd-capped magnesium deuteride thin films. ► The MgD{sub 2} dissociation was studied at temperatures not exceeding 100 °C. ► The structure of the film samples was analyzed by XRD and TEM. ► The transformation is controlled by the re-growth velocity of the Mg layers. ► The transformation is thermally activated, activation energy value of 1.3 ± 0.1 eV. -- Abstract: Pd- capped nanocrystalline magnesium thin films having columnar structure were deposited on Si substrate by e-gun deposition and submitted to thermal annealing in D{sub 2} atmosphere to promote the metal to deuteride phase transformation. The kinetics of the reverse deuteride to metal transformation was studied by Thermal Desorption Spectroscopy (TDS) while the structure of the as deposited and transformed samples was analyzed by X-rays diffraction and Transmission Electron Microscopy (TEM). In Pd- capped MgD{sub 2} thin films the deuteride to metal transformation begins at the interface between un-reacted Mg and transformed MgD{sub 2} layers. The D{sub 2} desorption kinetics is controlled by MgD{sub 2}/Mg interface effects, specifically the re-growth velocity of the Mg layers. The Mg re-growth has thermally activated character and shows an activation energy value of 1.3 ± 0.1 eV.

  13. Exoelectron emission from magnesium surfaces

    Klar, F.; Bansmann, J.; Glaefeke, H.; Fitting, H.-J.; Meiwes-Broer, K.-H.

    1999-12-01

    Clean magnesium surfaces were created by evaporating Mg onto silicon wafers. When exposing the Mg surface to a low oxygen partial pressure, an exoelectron emission (EEE) is observed after a time delay of the order of several hours after evaporation. On a much shorter time scale, similar effects in exoemission from Mg and alkali metals have been observed previously. The results are discussed within a 'potential emission' model of exoelectrons during oxygen capture at the pure Mg surface, but extending the model by including an escape mechanism. A macroscopic quantitative description of the model is given, which is in good agreement with our measurements.

  14. Magnesium removal in the electrolytic zinc industry

    Booster, J.L.

    2003-01-01

    Electrolytic zinc plants need to take measures to control the magnesium content in their process liquors, because the natural magnesium bleed does not balance the input from concentrates. Presently used methods are environmentally unfriendly (due to the production of large amounts of waste gypsum) o

  15. Magnesium Hydride for Load Levelling Energy Storage

    Vigeholm, B.

    Some of the magnesium properties essential to the applicability of the reaction Mg+H2⇆MgH2 as a hydrogen storage system have been investigated. Three magnesium powders with particle size smaller than 50 μm average diameter were cycled, over 31, 71 and 151 cycles respectively, at 675K (400°C...

  16. Magnesium improves hydrogen production by a novel fermentative hydrogen-producing bacterial strain B49

    WANG Xiang-jing; REN Nan-qi; XIANG Wen-sheng

    2005-01-01

    Batch experiments were conducted to investigate the effects of magnesium on glucose metabolism, including growth and hydrogen-producing capacity of fermentative hydrogen-producing bacterial strain B49. These abilities were enhanced with an increase in magnesium concentration. At the end of fermentation from 10 g/L ratio of ethanol amount (mg/L) to acetate amount (mg/L) was 1.1, and the accumulated hydrogen volume hydrogen volume was increased to 2 360. 5 mL H2/L culture, the ratio of ethanol amount (mg/L) to acetate amount (mg/L) was increased to 1.3 and polysaccharide was decreased to 2. 5 mg/L. Moreover, the magnesium solution addition to the medium at different fermentation times affected hydrogen-producing ability. However,the later the addition time was postponed, the less the effect was on hydrogen evolution. Further experiments confirmed the enhancement was dependent on magnesium ions and not on the other inorganic ions such as SO42- or Cl-, which constituted the magnesium salts.

  17. Dual effects of protoporphyrin and long wave ultraviolet light on histamine release from rat peritoneal and cutaneous mast cells

    In this study we investigated the effects of long wave ultraviolet light (UVA) and various doses of protoporphyrin (PP) on the release of histamine from rat peritoneal and cutaneous mast cells. We also correlated these results with morphologic characteristics and viability of the cells. PP at a dose of 30 ng/ml plus UVA-induced negligible histamine release from rat peritoneal mast cells (RPMC), but was able to suppress the ability of the cells to release histamine in response to subsequent exposure to the calcium ionophore A23187, compound 48/80, or the combination of Ag and IgE. This functional change was associated with an increase in cell size, and cell lysis that gradually occurred during 24 h in culture. PP at a dose of 3 ng/ml plus UVA also significantly inhibited secretogogue-induced histamine release from rat peritoneal mast cells, but this dose was not associated with significant changes in morphology or viability. These various effects of PP plus UVA were also observed with mast cell preparations obtained by the enzymatic dispersion of rat skin. The suppression of secretogogue-induced histamine release in rat peritoneal mast cells treated with PP (3 ng/ml) and UVA could not be reversed by culturing the cells in the dark for 24 h in the absence of PP. Unlike the direct cytotoxic histamine releasing action of high doses of PP plus UVA, the suppressive effect of low PP doses could not be inhibited by catalase, but could be reduced by the absence of calcium. Our results indicate that PP plus UVA has dual effects on mast cells, apparently involving distinct mechanisms. This implies the possibility that PP and UVA at appropriate doses could be used in photochemotherapy of mast cell-mediated skin diseases

  18. Improved cytotoxicity testing of magnesium materials

    Fischer, Janine, E-mail: janine.fischer@hzg.de [Helmholtz-Zentrum Geesthacht, Institute of Materials Research, Department for Structural Research on Macromolecules, Max-Planck Str. 1, D - 21502 Geesthacht (Germany); Proefrock, Daniel [Helmholtz-Zentrum Geesthacht, Institute for Coastal Research, Department for Marine Bioanalytical Chemistry, Max-Planck Str. 1, D - 21502 Geesthacht (Germany); Hort, Norbert [Helmholtz-Zentrum Geesthacht, Institute of Materials Research, Department for Magnesium Processing, Max-Planck Str. 1, D - 21502 Geesthacht (Germany); Willumeit, Regine; Feyerabend, Frank [Helmholtz-Zentrum Geesthacht, Institute of Materials Research, Department for Structural Research on Macromolecules, Max-Planck Str. 1, D - 21502 Geesthacht (Germany)

    2011-06-25

    Metallic magnesium (Mg) and its alloys are highly suitable for medical applications as biocompatible and biodegradable implant materials. Magnesium has mechanical properties similar to bone, stimulates bone regeneration, is an essential non-toxic element for the human body and degrades completely within the body environment. In consequence, magnesium is a promising candidate as implant material for orthopaedic applications. Protocols using the guideline of current ISO standards should be carefully evaluated when applying them for the characterization of the cytotoxic potential of degradable magnesium materials. For as-cast material we recommend using 10 times more extraction medium than recommended by the ISO standards to obtain reasonable results for reliable cytotoxicity rankings of degradable materials in vitro. In addition primary isolated human osteoblasts or mesenchymal stem cells should be used to test magnesium materials.

  19. Improved cytotoxicity testing of magnesium materials

    Metallic magnesium (Mg) and its alloys are highly suitable for medical applications as biocompatible and biodegradable implant materials. Magnesium has mechanical properties similar to bone, stimulates bone regeneration, is an essential non-toxic element for the human body and degrades completely within the body environment. In consequence, magnesium is a promising candidate as implant material for orthopaedic applications. Protocols using the guideline of current ISO standards should be carefully evaluated when applying them for the characterization of the cytotoxic potential of degradable magnesium materials. For as-cast material we recommend using 10 times more extraction medium than recommended by the ISO standards to obtain reasonable results for reliable cytotoxicity rankings of degradable materials in vitro. In addition primary isolated human osteoblasts or mesenchymal stem cells should be used to test magnesium materials.

  20. Imparting passivity to vapor deposited magnesium alloys

    Wolfe, Ryan C.

    Magnesium has the lowest density of all structural metals. Utilization of low density materials is advantageous from a design standpoint, because lower weight translates into improved performance of engineered products (i.e., notebook computers are more portable, vehicles achieve better gas mileage, and aircraft can carry more payload). Despite their low density and high strength to weight ratio, however, the widespread implementation of magnesium alloys is currently hindered by their relatively poor corrosion resistance. The objective of this research dissertation is to develop a scientific basis for the creation of a corrosion resistant magnesium alloy. The corrosion resistance of magnesium alloys is affected by several interrelated factors. Among these are alloying, microstructure, impurities, galvanic corrosion effects, and service conditions, among others. Alloying and modification of the microstructure are primary approaches to controlling corrosion. Furthermore, nonequilibrium alloying of magnesium via physical vapor deposition allows for the formation of single-phase magnesium alloys with supersaturated concentrations of passivity-enhancing elements. The microstructure and surface morphology is also modifiable during physical vapor deposition through the variation of evaporation power, pressure, temperature, ion bombardment, and the source-to-substrate distance. Aluminum, titanium, yttrium, and zirconium were initially chosen as candidates likely to impart passivity on vapor deposited magnesium alloys. Prior to this research, alloys of this type have never before been produced, much less studied. All of these metals were observed to afford some degree of corrosion resistance to magnesium. Due to the especially promising results from nonequilibrium alloying of magnesium with yttrium and titanium, the ternary magnesium-yttrium-titanium system was investigated in depth. While all of the alloys are lustrous, surface morphology is observed under the scanning

  1. Magnesium supplement in pregnancy-induced hypertension: effects on maternal and neonatal magnesium and calcium homeostasis

    Rudnicki, M; Frølich, A; Fischer-Rasmussen, W

    1991-01-01

    The objective of this study was to evaluate the effect of low dose magnesium supplement upon maternal and fetal serum levels of mineral status in pregnancies complicated with hypertension (PIH). Twenty-five patients with PIH agreed to participate and were randomly allocated, in a double-blind man......The objective of this study was to evaluate the effect of low dose magnesium supplement upon maternal and fetal serum levels of mineral status in pregnancies complicated with hypertension (PIH). Twenty-five patients with PIH agreed to participate and were randomly allocated, in a double......-blind manner, either to intravenous magnesium for 2 days followed by oral magnesium (n = 12) until delivery or placebo (n = 13). In women supplemented with magnesium the level of magnesium increased from 0.74 to 1.02 mmol/l during the first 24 h of inclusion and simultaneously we observed an increased urinary...... loss of magnesium. Serum level and the urinary excretion of magnesium returned to pretreatment level at delivery. Maternal magnesium supplement increased the concentrations of magnesium in umbilical cord and neonatal blood 1 day after delivery. Serum ionized calcium did not change during the study...

  2. Urinary and plasma magnesium and risk of ischemic heart disease

    Joosten, Michel M.; Gansevoort, Ron T.; Mukamal, Kenneth J.; van der Harst, Pim; Geleijnse, Johanna M.; Feskens, Edith J. M.; Navis, Gerjan; Bakker, Stephan J. L.

    2013-01-01

    Background: Previous studies on dietary magnesium and risk of ischemic heart disease (IHD) have yielded inconsistent results, in part because of a lack of direct measures of actual magnesium uptake. Urinary excretion of magnesium, an indicator of dietary magnesium uptake, might provide more consiste

  3. Magnesium Therapy for Intractable Ventricular Tachyarrhythmias in Normomagnesemic Patients

    Iseri, Lloyd T.; Chung, Peter; Tobis, Jonathan

    1983-01-01

    Intractable ventricular tachyarrhythmia associated with hypomagnesemia responds well to magnesium given intravenously. Two patients with recurrent ventricular tachycardia and ventricular fibrillation associated with normal serum magnesium levels and resistant to treatment with potassium chloride, lidocaine and bretylium tosylate responded dramatically to the administration of magnesium sulfate. A third patient in whom the serum magnesium level was unknown also showed dramatic response to magn...

  4. Radioactive {sup 210}Po in magnesium supplements

    Struminska-Parulska, Dagmara Ida [Gdansk Univ. (Poland). Environmental Chemistry and Radiochemistry Chair

    2016-08-01

    The aim of this pioneer study was to determine polonium {sup 210}Po in the most popular magnesium supplements in Poland and estimate the possible related dose assessment to the consumers. The analyzed magnesium pharmaceutics contained organic or inorganic magnesium compounds; some from natural sources. The objectives of this research were to investigate the naturally occurring {sup 210}Po activity concentrations in magnesium supplements, find the correlations between {sup 210}Po concentration in medicament and magnesium chemical form, and calculate the effective radiation dose connected to analyzed magnesium supplement consumption. The highest {sup 210}Po activity concentrations were determined in mineral tablets made from sedimentary rocks, namely dolomite - 3.84 ± 0.15 mBq g{sup -1} (sample Mg17). The highest annual radiation dose from {sup 210}Po taken with 1 tablet of magnesium supplement per day or with 400 mg of pure Mg daily would come from sample Mg17 (dolomite) - 1.35 ± 0.5 and 8.44 ± 0.33 μSv year{sup -1} respectively.

  5. Monitoring Biodegradation of Magnesium Implants with Sensors

    Zhao, Daoli; Wang, Tingting; Guo, Xuefei; Kuhlmann, Julia; Doepke, Amos; Dong, Zhongyun; Shanov, Vesselin N.; Heineman, William R.

    2016-04-01

    Magnesium and its alloys exhibit properties such as high strength, light weight, and in vivo corrosion that make them promising candidates for the development of biodegradable metallic implant materials for bone repair, stents and other medical applications. Sensors have been used to monitor the corrosion of magnesium and its alloys by measuring the concentrations of the following corrosion products: magnesium ions, hydroxyl ions and hydrogen gas. The corrosion characterization system with home-made capillary pH and Mg2+ microsensors has been developed for real-time detection of magnesium corrosion in vitro. A hydrogen gas sensor was used to monitor the corrosion of magnesium by measuring the concentration of the hydrogen gas reaction product in vivo. The high permeability of hydrogen through skin allows transdermal monitoring of the biodegradation of a magnesium alloy implanted beneath the skin by detecting hydrogen gas at the skin surface. The sensor was used to map hydrogen concentration in the vicinity of an implanted magnesium alloy.

  6. Magnesium supplement in pregnancy-induced hypertension. A clinicopathological study

    Rudnicki, M; Junge, Jette; Frølich, A;

    1990-01-01

    as a double-blind randomized controlled study in which 11 women were allocated to magnesium and 7 to placebo treatment. The treatment comprised a 48-hour intravenous magnesium/placebo infusion followed by daily oral magnesium/placebo intake until one day after delivery. Magnesium supplement increased birth....... There was no significant difference when the magnesium group, the placebo group and the control group were compared separately. The present study suggests that magnesium supplement has a beneficial effect on fetal growth in pregnancy-induced hypertension. With regard to the light and electron microscopic changes we were...... unable to demonstrate any significant difference between the magnesium, placebo and control groups....

  7. On the hydrogenation mechanism in magnesium I

    Pedersen, A.S.; Kjøller, John; Larsen, Bent;

    1985-01-01

    The first time hydriding of spherical magnesium particles covered by a thin oxide layer and sieve-fractionated into narrow size distributions within the range 40–90 μm was followed by microgravimetry. The size distributions of the fractions were determined by semiautomatic image analysis. The hyd......The first time hydriding of spherical magnesium particles covered by a thin oxide layer and sieve-fractionated into narrow size distributions within the range 40–90 μm was followed by microgravimetry. The size distributions of the fractions were determined by semiautomatic image analysis...... generalizing results from the hydriding of magnesium powders....

  8. (n, γ)-radiolysis of magnesium iodate

    The initial retention of thermal neutron irradiated magnesium iodate tetrahydrate was found to be 47% and increased to 54% for the dehydrated salt. The post irradiation isothermal annealing followed the characteristic pattern both in hydrated and dehydrated salts; the rate of increase in retention in the hydrated salt being faster than in the dehydrated form. At an annealing temperature of 453 K, 100% retention was achieved by the hydrated salt but the corresponding value for the dehydrated magnesium iodate was not higher than 88%. The role of water of crystallization in the retention studies of magnesium iodate is discussed. (author)

  9. Magnesium doping of boron nitride nanotubes

    Legg, Robert; Jordan, Kevin

    2015-06-16

    A method to fabricate boron nitride nanotubes incorporating magnesium diboride in their structure. In a first embodiment, magnesium wire is introduced into a reaction feed bundle during a BNNT fabrication process. In a second embodiment, magnesium in powder form is mixed into a nitrogen gas flow during the BNNT fabrication process. MgB.sub.2 yarn may be used for superconducting applications and, in that capacity, has considerably less susceptibility to stress and has considerably better thermal conductivity than these conventional materials when compared to both conventional low and high temperature superconducting materials.

  10. Boron Clusters as Highly Stable Magnesium-Battery Electrolytes**

    Carter, Tyler J; Mohtadi, Rana; Arthur, Timothy S; Mizuno, Fuminori; Zhang, Ruigang; Shirai, Soichi; Kampf, Jeff W.

    2014-01-01

    Boron clusters are proposed as a new concept for the design of magnesium-battery electrolytes that are magnesium-battery-compatible, highly stable, and noncorrosive. A novel carborane-based electrolyte incorporating an unprecedented magnesium-centered complex anion is reported and shown to perform well as a magnesium-battery electrolyte. This finding opens a new approach towards the design of electrolytes whose likelihood of meeting the challenging design targets for magnesium-battery electro...

  11. Intestinal absorption of magnesium from food and supplements.

    Fine, K D; Santa Ana, C A; Porter, J L; Fordtran, J S

    1991-01-01

    The purpose of this study was to measure magnesium absorption over the wide range of intakes to which the intestine may be exposed from food and/or magnesium-containing medications. Net magnesium absorption was measured in normal subjects after they ingested a standard meal supplemented with 0, 10, 20, 40, and 80 mEq of magnesium acetate. Although absorption increased with each increment in intake, fractional magnesium absorption fell progressively (from 65% at the lowest to 11% at the highes...

  12. The reference range of serum, plasma and erythrocyte magnesium

    Suzanna Immanuel

    2006-12-01

    Full Text Available The interest in the clinical importance of serum magnesium level has just recently begun with the analysis and findings of abnormal magnesium level in cardiovascular, metabolic and neuromuscular disorder. Although the serum level does not reflect the body magnesium level, but currently, only serum magnesium determination is widely used. Erythrocyte magnesium is considered more sensitive than serum magnesium as it reflects intracellular magnesium status. According to NCCLS (National Committee for Clinical Laboratory Standards every laboratory is recommended to have its own reference range for the tests it performs, including magnesium determination. The reference range obtained is appropriate for the population and affected by the method and technique. This study aimed to find the reference range of serum and plasma magnesium and also intracellular magnesium i.e. erythrocyte magnesium by direct method, and compare the results of serum and plasma magnesium. Blood was taken from 114-blood donor from Unit Transfusi Darah Daerah (UTDD Budhyarto Palang Merah Indonesia (PMI DKI Jakarta, consisted of 57 male and 57 female, aged 17 – 65 years, clinically healthy according to PMI donor criteria. Blood was taken from blood set, collected into 4 ml vacuum tube without anticoagulant for serum magnesium determination and 3 ml vacuum tube with lithium heparin for determination of erythrocyte and plasma magnesium Determination of magnesium level was performed with clinical chemistry auto analyzer Hitachi 912 by Xylidil Blue method colorimetrically. This study showed no significant difference between serum and heparinized plasma extra cellular magnesium. The reference range for serum or plasma magnesium was 1.30 – 2.00 mEq/L and for erythrocyte magnesium was 4.46 - 7.10 mEq/L. (Med J Indones 2006; 15:229-35Keywords: Reference range, extracellular magnesium, intracellular magnesium

  13. Regulation of magnesium balance: lessons learned from human genetic disease

    de Baaij, Jeroen H. F.; Hoenderop, Joost G. J.; Bindels, René J. M.

    2012-01-01

    Magnesium (Mg2+) is the fourth most abundant cation in the body. Thus, magnesium homeostasis needs to be tightly regulated, and this is facilitated by intestinal absorption and renal excretion. Magnesium absorption is dependent on two concomitant pathways found in both in the intestine and the kidneys: passive paracellular transport via claudins facilitates bulk magnesium absorption, whereas active transcellular pathways mediate the fine-tuning of magnesium absorption. The identification of g...

  14. Development and validation of simple titrimetric method for the determination of magnesium content in esomeprazole magnesium

    R N Haddadin

    2011-01-01

    Full Text Available A simple and inexpensive titrimetric method for the determination of magnesium ion in esomeprazole magnesium raw material was developed and validated according to International Conference on Harmonization guidelines and the United States Pharmacopoeia. The method depends on complex formation between EDTA and magnesium ion. The method was proven to be valid, equivalent and useful as an alternative method to the current pharmacopeial methods that are based on atomic absorption spectrometry.

  15. A multidisciplinary study on magnesium

    Radić-Perić Jelena

    2012-01-01

    Full Text Available During plasma electrolytic oxidation of a magnesium alloy (96% Mg, 3% Al, 1% Zn we obtained a luminescence spectrum in the wave number range between 19 950 and 20 400 cm-1. The broad peak with clearly pronounced structure was assigned to the v’-v” = 0 sequence of the B 1Σ+ → X 1Σ+ electronic transition of MgO. Quantum-mechanical perturbative approach was applied to extract the form of the potential energy curves for the electronic states involved in the observed spectrum, from the positions of spectral bands. These potential curves, combined with the results of quantum-chemical calculations of the electric transition moment, were employed in subsequent variational calculations to obtain the Franck-Condon factors and transition moments for the vibrational transitions observed. Comparing the results of these calculations with the measured intensity distribution within the spectrum we derived relative population of the upper electronic state vibration levels. This enabled us to estimate the plasma temperature. Additionally, the temperature was determined by analysis of the recorded A 2Σ+ (v’ = 0 - X 2П (v” = 0 emission spectrum of OH. The composition of plasma containing magnesium, oxygen, and hydrogen under assumption of local thermal equilibrium was calculated in the temperature range up to 12 000 K and for pressures of 105, 106, 107, and 108 Pa, in order to explain the appearance of the observed spectral features and to contribute to elucidation of processes taking place during the electrolytic oxidation of Mg. [Projekat Ministarstva nauke Republike Srbije, br. 172040

  16. Modifier activity of the protoporphyrin IX of the clastogenic damage induced by gamma radiation in Drosophila melanogaster

    It has been demonstrated that the copper sodium chlorophyllin (CCS) it is a potent inhibitor of the one genetic damage induced by physical or chemical agents in systems like: bacteria, Drosophila, rainbow trout and mammals. Nevertheless it has been observed that under certain conditions it promotes it. In the laboratory of Drosophila of the ININ evidences have been obtained that the CCS increases the percentage of lethal embryonic dominant and post-embryonic induced by gamma radiation. One of the probable causes of this effect promoter, is the oxidizer stress that it could cause the metallic center of the CCS. The objective of this investigation it was the evaluation of the inhibitory action of the protoporphyrin IX (PP-IX) of the genetic damage induced by gamma radiation in the germinal line of Drosophila melanogaster. For such effect it was used the lethal dominant test by means of two protocols: one in the one that the PP-IX or CCS was administered to the females and the other one to the males. Females of genotype y/y and males of the canton-S stump were used. In both cases the males were treated with 40 Gy of gamma radiation. Its were count the embryonic lethal dominant (L-E) and those post-embryonic (L-PE) of the F1. The results indicated that after the one pretreatment with PP-IX to the crossed females with males treaties increase the percentage of L-E (P ≤ 0.001) and it diminished that of L-PE (P ≤ 0.001) compared with the sucrose control more radiation, however when it was pretreated with CCS also it was observed an increment in the percentage of L-E (P ≤ 0.001), but it doesn't present effect on that of L-PE. In contrast, when the males were pretreated, it was observed that the PP-IX tends to increase those L-E, but diminished the L-PE (P ≤ 0.05), however when it was pretreated with CCS was observed that increased the percentage of L-E (P ≤ 0.001) but diminished that of L-PE (P ≤ 0.001). It was concluded that none of the two pigments act as

  17. Action of the protoporphyrin-Ix (Pp-Ix) in the life period of Drosophila mutants deficient in endogenous antioxidants

    The human being is daily exposed to free radicals or reactive oxygen species (Ros), as a result of the breathing and the interactions with xenobiotics that can cause irreversible lesions in molecules and cellular structures and that they are associated to diseases like the cancer, neuro degenerative and to the acceleration of the normal process of aging. Fortunately, to reduce the damaging effect of the Ros the cell has endogenous antioxidant systems constituted by antioxidant enzymes as: the superoxide dismutase (Sod), the catalase (Cat), and the glutathione peroxidase and reductase. Even, when these systems are not enough, we find to the exogenous antioxidants that cooperate in the balance of the Ros, as the porphyrins that include to the chlorophyllin, the hemin and the bilirubin among others. The protoporphyrin-Ix (Pp-Ix) is a tetra pyrrole without metallic center with antimutagenic and antioxidant activity similar to that of the chlorophyllin. However, is also known that their over-expression has toxic effects, because induces Ros. In Drosophila melanogaster, recently was found that the Pp-Ix have dual action anti and persistent mutagenic. One of their possible mechanism to act like mutagen is through the Ros induction. To evaluate this possibility and based in that the increase in the Ros levels can accelerate the aging process, in the present work the Pp-Ix role was evaluated, in the life period of Drosophila melanogaster strains deficient in Sod and Cat, sensitive to radiation or oxidative stress (rad, whd and flr3) and a wild one as control (C-S). Females and males of each strain were treated chronically for separate with sucrose or Pp-Ix and every 15 days a group of each sex was irradiated with 10 Gy of gamma rays. The results indicated that the chronic treatment with Pp-Ix and in combination with radiation, increased the life period of the C-S strain. The Sod strain had a contrary effect and this effect was pronounced with the combined treatment of Pp

  18. Assessing environmental impact of magnesium production using Pidgeon process in China

    GAO Feng; NIE Zuo-ren; WANG Zhi-hong; GONG Xian-zheng; ZUO Tie-yong

    2008-01-01

    Based on the practice of magnesium production in China,a quantitative evaluation of the environment impact was carried out according to the theory and framework of life cycle assessment (LCA) study.The major gaseous pollutants including CO2,SO2,NOx,CH4,HF and particulates were calculated.The accumulative environmental performances of different energy use strategies and the characterization results,including abiotic depletion potential (ADP),global warming potential (GWP),acidification potential (AP) and human-toxicity potential (HTP) were compared.The results show that the direct emission of fuel combustion in the process is the major contributor to the pollutants emission of magnesium production.Global warming potential and acidification potential make the main contribution to the accumulative environmental impact.The different fuel use strategies in the practice of magnesium production cause much different impacts on the environmental performance.The accumulative environmental impact of coal burned directly is the highest,and that of producer-gas comes to the next,while that of coke-oven gas is the lowest.

  19. Study on crystal transformation process of magnesium carbonate hydrate based on salt lake magnesium resource utilization

    Du, Juan; Chen, Zhen; WU, Yu-Long; YANG, Ming-De

    2013-01-01

    The crystal transformation process of magnesium carbonate hydrate by the reaction of magnesium sulfate (MgSO4) with ammonium carbonate [(NH4)2CO3] was investigated. MgSO4 is one of the main magnesium resources of the Lop Nur salt lake in the Xinjiang Autonomous Region of China. Magnesium carbonate hydrates with different chemical compositions were prepared. The transformation process of the 2 crystals, MgSO4 and (NH4)2CO3, was analyzed by Raman spectroscopy, and the associated chang...

  20. Development of Magnesium-Insertion Positive Electrode for Rechargeable Magnesium Batteries

    Huatang YUAN; Lifang JIAO; Jiansheng CAO; Xiusheng LIU; Ming ZHAO; Yongmei WANG

    2004-01-01

    Magnesium-based rechargeable batteries might be an interesting future alternative to lithium-based batteries. It is so far well known that Mg2+ ion insertion into ion-transfer hosts proceeds slowly compared with Li+, so it is necessary to realize fast Mg2+ transport in the host in addition to other requirements as practical cathode materials for magnesium batteries. Positive electrode materials based on inorganic transition-metal oxides, sulfides, and borides are the only ones used up to now to insert magnesium ions. In this paper, the available results of research on materials suitable as possible, for secondary magnesium batteries, are reviewed.

  1. Recycling of magnesium drive train components

    Daniel FEGHNER; Carsten BLAWERT; Norbert HORT; Karl Ulrich KAINER

    2009-01-01

    With the development of new heat resistant magnesium alloys, the automotive industry has introduced several parts to the drive train. The rising number of large magnesium components will result in a higher quantity of automotive post consumer scrap. It was the aim of this work to find a reasonable alloy system for the recycling of these magnesium drive train components. A matrix of potential recy-cling alloys based on the magnesium alloy AM50 was prepared via permanent mould casting. The ma-terials were investigated via tensile testing, creep tests and salt spray tests. Three alloys were selected for processing via high pressure die casting and the tests were repeated on the new materials. A promising system for recycling has been isolated and will be investigated more deeply for the influence of impurities.

  2. Recycling of magnesium drive train components

    Daniel; FECHNER; Carsten; BLAWERT; Norbert; HORT; Karl; Ulrich; KAINER

    2009-01-01

    With the development of new heat resistant magnesium alloys, the automotive industry has introduced several parts to the drive train. The rising number of large magnesium components will result in a higher quantity of automotive post consumer scrap. It was the aim of this work to find a reasonable alloy system for the recycling of these magnesium drive train components. A matrix of potential recy-cling alloys based on the magnesium alloy AM50 was prepared via permanent mould casting. The materials were investigated via tensile testing, creep tests and salt spray tests. Three alloys were selected for processing via high pressure die casting and the tests were repeated on the new materials. A promising system for recycling has been isolated and will be investigated more deeply for the influence of impurities.

  3. Processing magnesium alloys by severe plastic deformation

    Figueiredo, Roberto B.; Aguilar, Maria Teresa P.; Cetlin, Paulo Roberto; Langdon, Terence G.

    2014-08-01

    The use of severe plastic deformation techniques for processing magnesium alloys has moved from the early difficulties of processing to a stage of tailoring the best properties of these materials. The present paper reviews processing, structure and mechanical properties characterization. It is shown that ultrafine-grained structures are obtained in magnesium alloys processed by multiple passes of Equal-Channel Angular Pressing at moderate temperatures. Ultrafine-grained structures are also obtained by room temperature processing by High- Pressure Torsion. The ultrafine-grained structures increase strength and introduce excellent superplastic capabilities in many magnesium alloys. Moreover, processing magnesium alloys by severe plastic deformation leads to the development of anisotropy in mechanical behavior.

  4. Magnesium and anabolic hormones in older men

    Maggio, M.; Ceda, G.P.; F. Lauretani; Cattabiani, C.; Avantaggiato, E.; Morganti, S.; Ablondi, F.; Bandinelli, S.; Dominguez, L. J.; M. Barbagallo; Paolisso, G.; Semba, R D; Ferrucci, L.

    2011-01-01

    Optimal nutritional and hormonal statuses are determinants of successful ageing. The age associated decline in anabolic hormones such as testosterone and insulin-like growth factor 1 (IGF-1) is a strong predictor of metabolic syndrome, diabetes and mortality in older men. Studies have shown that magnesium intake affects the secretion of total IGF-1 and increase testosterone bioactivity. This observation suggests that magnesium can be a modulator of the anabolic/catabolic equilibrium disrupted...

  5. Immunological Response to Biodegradable Magnesium Implants

    Pichler, Karin; Fischerauer, Stefan; Ferlic, Peter; Martinelli, Elisabeth; Brezinsek, Hans-Peter; Uggowitzer, Peter J.; Löffler, Jörg F.; Weinberg, Annelie-Martina

    2014-04-01

    The use of biodegradable magnesium implants in pediatric trauma surgery would render surgical interventions for implant removal after tissue healing unnecessary, thereby preventing stress to the children and reducing therapy costs. In this study, we report on the immunological response to biodegradable magnesium implants—as an important aspect in evaluating biocompatibility—tested in a growing rat model. The focus of this study was to investigate the response of the innate immune system to either fast or slow degrading magnesium pins, which were implanted into the femoral bones of 5-week-old rats. The main alloying element of the fast-degrading alloy (ZX50) was Zn, while it was Y in the slow-degrading implant (WZ21). Our results demonstrate that degrading magnesium implants beneficially influence the immune system, especially in the first postoperative weeks but also during tissue healing and early bone remodeling. However, rodents with WZ21 pins showed a slightly decreased phagocytic ability during bone remodeling when the degradation rate reached its maximum. This may be due to the high release rate of the rare earth-element yttrium, which is potentially toxic. From our results we conclude that magnesium implants have a beneficial effect on the innate immune system but that there are some concerns regarding the use of yttrium-alloyed magnesium implants, especially in pediatric patients.

  6. Accumulation of radiation damage in spinel crystals: Quantitative analysis and interpretation of RBS/C data

    Accumulation of radiation damage in magnesium aluminate spinel was studied using the Rutherford Backscattering/Channelling (RBS/C) technique. The possibilities offered by Monte-Carlo simulations of RBS/C spectra for the analysis of the disorder induced in spinel crystals by low and high energy ions are presented. A new model of damage accumulation based on the concept of multi-step destabilization of the crystal structure was developed and allowed us to correctly reproduce the experimental data

  7. The role of magnesium in the electrochemical behaviour of 5XXX aluminium-magnesium alloys

    Flores Ramirez, J.R.

    2006-01-01

    An investigation concerning the effects of magnesium on the intergranular corrosion susceptibility of AA5XXX aluminium alloys was carried out. In the present work, magnesium is found to be highly mobile in the bulk metal as well as in the aluminium oxide. This mobility is also found to be dependent

  8. Silane coatings doped with corrosion inhibitors for protection of plasma-anodized magnesium and magnesium alloy

    Darwich, S.; Lampke, T.; Alisch, G.; Dietrich, D. [Chemnitz Univ. of Technology (Germany). Inst. of Materials Science and Engineering

    2010-07-01

    Magnesium, with or without an additionally-formed oxide layer, shows enhanced corrosion resistance after immersion to form a silane coating. In the case of plasma anodised magnesium, pores similar to those occurring in anodised aluminium, are found. These pores can be impregnated with silane, thus providing increased corrosion resistance. (orig.)

  9. A review: Hot topics on magnesium technology in China

    Zhen-hua CHEN; Ji-hua CHEN

    2008-01-01

    Magnesium alloys have wide applications in automobiles, aerospace and so on due to many advan-tages, while a number of undesirable properties including poor corrosion resistance, inferior creep resistance and bad plastic processing ability have hindered their applica-tions. Creep-resistant magnesium alloy design, plastic processing of magnesium alloys and rapid solidification processing of magnesium alloys have become the hot topics in magnesium technology. Other than these, surface modification as well as laser beam welding are also involved. The research progress and development in mag-nesium technology in China are reviewed in the paper.

  10. Production of Magnesium by Vacuum Aluminothermic Reduction with Magnesium Aluminate Spinel as a By-Product

    Wang, Yaowu; You, Jing; Peng, Jianping; Di, Yuezhong

    2016-03-01

    The Pidgeon process currently accounts for 85% of the world's magnesium production. Although the Pidgeon process has been greatly improved over the past 10 years, such production still consumes much energy and material and creates much pollution. The present study investigates the process of producing magnesium by employing vacuum aluminothermic reduction and by using magnesite as material and obtaining magnesium aluminate spinel as a by-product. The results show that compared with the Pidgeon process, producing magnesium by vacuum aluminothermic reduction can save materials by as much as 50%, increase productivity up to 100%, and save energy by more than 50%. It can also reduce CO2 emission by up to 60% and realize zero discharge of waste residue. Vacuum aluminothermic reduction is a highly efficient, low-energy-consumption, and environmentally friendly method of producing magnesium.

  11. Production of Magnesium by Vacuum Aluminothermic Reduction with Magnesium Aluminate Spinel as a By-Product

    Wang, Yaowu; You, Jing; Peng, Jianping; Di, Yuezhong

    2016-06-01

    The Pidgeon process currently accounts for 85% of the world's magnesium production. Although the Pidgeon process has been greatly improved over the past 10 years, such production still consumes much energy and material and creates much pollution. The present study investigates the process of producing magnesium by employing vacuum aluminothermic reduction and by using magnesite as material and obtaining magnesium aluminate spinel as a by-product. The results show that compared with the Pidgeon process, producing magnesium by vacuum aluminothermic reduction can save materials by as much as 50%, increase productivity up to 100%, and save energy by more than 50%. It can also reduce CO2 emission by up to 60% and realize zero discharge of waste residue. Vacuum aluminothermic reduction is a highly efficient, low-energy-consumption, and environmentally friendly method of producing magnesium.

  12. Magnesium and type 2 diabetes

    Mario; Barbagallo; Ligia; J; Dominguez

    2015-01-01

    Type 2 diabetes is frequently associated with both extracellular and intracellular magnesium(Mg) deficits. A chronic latent Mg deficit or an overt clinical hypomagnesemia is common in patients with type 2 diabetes, especially in those with poorly controlled glycemic profiles. Insulinand glucose are important regulators of Mg metabolism. Intracellular Mg plays a key role in regulating insulin action, insulin-mediated-glucose-uptake and vascular tone. Reduced intracellular Mg concentrations result in a defective tyrosine-kinase activity, postreceptorial impairment in insulin action and worsening of insulin resistance in diabetic patients. A low Mg intake and an increased Mg urinary loss appear the most important mechanisms that may favor Mg depletion in patients with type 2 diabetes. Low dietary Mg intake has been related to the development of type 2 diabetes and metabolic syndrome. Benefits of Mg supplementation on metabolic profiles in diabetic patients have been found in most, but not all clinical studies and larger prospective studies are needed to support the potential role of dietary Mg supplementation as a possible public health strategy in diabetes risk. The aim of this review is to revise current evidence on the mechanisms of Mg deficiency in diabetes and on the possible role of Mg supplementation in the prevention and management of the disease.

  13. Hole centres in magnesium oxide

    When magnesium oxide crystals are exposed to ionizing radiation the electron-loss (hole) centres are normally identified as O·- ions. In this paper, I examine the EPR evidence for this, and compare the data with those for the hole centres in alkali- halides (VK centres). The latter are clearly σ* radical anions, such as F.-F-.The analogous centre in MgO is O.-O3-, which does not seem to have been considered. The results compare well, suggesting that the O·- centres are really O.-O3- radicals. In particular, the 17O data for the oxygen centre and the 19F data for F2·- give similar estimates of the 2s and 2p character of the orbitals on oxygen and fluorine, suggesting that the spin-density on oxygen is ca. 50%. The exception is the direction of the principal axes of these centres, which are quite different from each other. It is suggested that the primary hole-centres in MgO migrate by electron transfer to neighbouring cation vacancies where they are stable, and that at these sites the (1, 0, 0) directions are most favourable for σ- bonding

  14. Borosilicate glass alteration driven by magnesium carbonates

    Highlights: ► We studied borosilicate glass/hydromagnesite interaction. ► Magnesium silicate precipitation increases glass alteration. ► Geochemical modeling allows to quantify the alteration mechanisms involved. - Abstract: The alteration of simplified synthetic glass, representative of the French reference nuclear glass R7T7, in presence of hydromagnesite has been experimentally investigated and modeled. Magnesium in solution is known to potentially enhance glass alteration; nuclear glass clayed host rocks contain magnesium and can dissolve to maintain the concentration of magnesium in solution. For modeling purposes, it was suitable to study a simple system. Hydromagnesite was therefore chosen as a simple model mineral in order to check the influence of an Mg-rich mineral on glass alteration. Since the models use thermodynamic and kinetic parameters measured in pure water and pH-buffered solutions, changing the solution composition or adding minerals is a key step towards the validation of the modeling assumptions before using the model for predictive purposes. Experiments revealed that glass alteration is enhanced in presence of hydromagnesite. Modeling was performed using the GRAAL model implemented within the CHESS/HYTEC reactive transport code. Modeling proved useful both for explaining the mechanisms involved and quantifying the impact on glass alteration: Mg coming from hydromagnesite dissolution reacts with Si provided by the glass in order to form magnesium silicates. This reaction decreases the pH down to neutral conditions where magnesium silicates are more soluble than at the natural alkali pH imposed by glass or hydromagnesite dissolution. The driving force of the magnesium silicate precipitation is eventually the interdiffusion of alkali within the altered amorphous glass layer as this mechanism consumes protons. The model’s ability to describe the concentrations of elements in solution and formed solids whatever the glass

  15. Final report on the safety assessment of aluminum silicate, calcium silicate, magnesium aluminum silicate, magnesium silicate, magnesium trisilicate, sodium magnesium silicate, zirconium silicate, attapulgite, bentonite, Fuller's earth, hectorite, kaolin, lithium magnesium silicate, lithium magnesium sodium silicate, montmorillonite, pyrophyllite, and zeolite.

    Elmore, Amy R

    2003-01-01

    This report reviews the safety of Aluminum, Calcium, Lithium Magnesium, Lithium Magnesium Sodium, Magnesium Aluminum, Magnesium, Sodium Magnesium, and Zirconium Silicates, Magnesium Trisilicate, Attapulgite, Bentonite, Fuller's Earth, Hectorite, Kaolin, Montmorillonite, Pyrophyllite, and Zeolite as used in cosmetic formulations. The common aspect of all these claylike ingredients is that they contain silicon, oxygen, and one or more metals. Many silicates occur naturally and are mined; yet others are produced synthetically. Typical cosmetic uses of silicates include abrasive, opacifying agent, viscosity-increasing agent, anticaking agent, emulsion stabilizer, binder, and suspending agent. Clay silicates (silicates containing water in their structure) primarily function as adsorbents, opacifiers, and viscosity-increasing agents. Pyrophyllite is also used as a colorant. The International Agency for Research on Cancer has ruled Attapulgite fibers >5 microm as possibly carcinogenic to humans, but fibers Hectorite was nonirritating to the skin of rabbits in a Draize primary skin irritation study. Magnesium Aluminum Silicate and Sodium Magnesium Silicate caused minimal eye irritation in a Draize eye irritation test. Bentonite caused severe iritis after injection into the anterior chamber of the eyes of rabbits and when injected intralamellarly, widespread corneal infiltrates and retrocorneal membranes were recorded. In a primary eye irritation study in rabbits, Hectorite was moderately irritating without washing and practically nonirritating to the eye with a washout. Rats tolerated a single dose of Zeolite A without any adverse reaction in the eye. Calcium Silicate had no discernible effect on nidation or on maternal or fetal survival in rabbits. Magnesium Aluminum Silicate had neither a teratogenic nor adverse effects on the mouse fetus. Female rats receiving a 20% Kaolin diet exhibited maternal anemia but no significant reduction in birth weight of the pups was

  16. Magnesium production by carbothermic reduction in vacuum

    Yang Tian

    2015-06-01

    Full Text Available In present work, we investigate production of magnesium by carbothermic reduction under vacuum conditions. The process was divided into two parts, one is reduction process, and the other one is condensation process. The experimental results revealed that during reduction process, the gas–solid reaction between MgO and CO was not occurred at a temperature and pressure of 1723 K and 30–100 Pa respectively. So the main reduction reaction was MgO(s + C(s = Mg(g + CO(g (under vacuum and reaction type belonged to solid–solid reaction. In Condensation Process, according to a contrast and analysis, the condensation quality of magnesium is associated with CO concentration. The resultant product C was formed and it followed magnesium vapor condensation which prevents mutual combination of two metal droplets to forms the compact condensation produces. Therefore, in order to compact morphological forms of magnesium crystal whiskers, we must control the technical conditions and find the method to separate the magnesium vapor and carbon monoxide. That's the key factor to get better crystalline structure.

  17. Post traumatic tetanus and role magnesium sulphate

    Tetanus is a life threatening disease. Reported mortality for tetanus is 15-39%. Conventional treatment includes heavy sedation and artificial ventilation. Complications resulting from long term heavy sedation and artificial ventilation contribute to 60% of the total mortality caused by tetanus. In this study magnesium sulphate was used to reduce the need for sedation and artificial ventilation. Objectives of this prospective study were to determine the role of magnesium sulphate in post traumatic tetanus. The study was carried out in surgical Intensive Care at Pakistan Institute of Medical Sciences (PIMS), Islamabad from Jan 2004 to Dec 2007. Forty-four patients presented during this period and 33 patients were included in the study. All patients had tracheostomy done within 48 hours. Every patient was started Magnesium Sulphate therapy for control of spasms after sending baseline investigations. Patients were given ventilatory support when needed. All data was entered in well structured proforma. SPSS-10 was used to analyse data. Thirty-three patients were included in the study and all patients were given magnesium sulphate. Out of these, 45.5% cases were grade 4 tetanus, 73.6% and 63.3% cases did not require artificial ventilation and additional sedation respectively, 51.1% patients remained free of complications of tetanus. Overall mortality was 30.3%. Use of Magnesium Sulphate is safe and reduces the need for sedation and artificial ventilation in high grade tetanus thus contributing to survival benefit in adult post-traumatic tetanus cases. (author)

  18. The initial oxidation of magnesium

    Kurth, M.

    2004-07-01

    Pure Magnesium samples have been oxidised in an UHV chamber under controlled conditions. Pressure range was 10{sup -10} Torr to 10{sup -7} Torr, temperature range was 273 K to 435 K. The samples have then been investigated with XPS, Ellipsometry and HERDA. Additionally, furnace oxidations at 750 Torr and 673 K have been carried out and investigated with XPS. From the XPS measurements data concerning layer thickness, composition, oxidation state and binding state have been gained. The ellipsometrie measurements yielded additional data concerning layer thickness as well as the size of the band gap of the developing oxide. With the HERDA measurements, the oxygen content within the oxide layer has been determined yielding additional information about composition and layer thickness. The layer thickness as a function of time have then been modelled with a kinetic growth model of Fromhold and Cook. For the refinement of the XPS data concerning layer thickness and composition, the pronounced plasmon excitations that occur in magnesium have been determined with two different procedures which have been developed in the methodical part of this work. The layer thickness and composition values have thus been corrected. Results: Two oxidation stages could be identified: a strong increase for the first few Langmuirs (1L = 1s x 10{sup -6} Torr), followed by a saturation'' region which was about 1.2 nm to 1.5 nm in magnitude. XPS and ellipsometry results have thereby been in very good agreement. The composition of the developing oxide showed a clear deviation from stoichiometric MgO, mainly caused by an oxygen deficiency; this deficiency has also been confirmed with the HERDA measurements. The Mg/O ratio as a function of layer thickness showed a continous decay starting from very high values for the thinnest layers (>{proportional_to}2.5) down to a saturation value of about 1.4, even for larger layer thicknesses gained with the furnace oxidations. The determination of

  19. Combustion Synthesis of Magnesium Aluminate

    Kale, M. A.; Joshi, C. P.; Moharil, S. V.

    2011-10-01

    In the system MgO-Al2O3, three compounds MgAl2O4, MgAl6O10 (also expressed as- Mg0.4Al2.4O4) and MgAl26O40 are well known. Importance of the first two is well established. Magnesium aluminate (MgAl2O4) spinel is a technologically important material due to its interesting thermal properties. The MgAl2O4 ceramics also find application as humidity sensors. Apart from the luminescence studies, the interest in MgAl2O4 is due to various applications such as humidity-sensing and PEM fuel cells, TL/OSL dosimetry of the ionizing radiations, white light source. Interest in the MgAl6O10 has aroused due to possible use as a substrate for GaN growth. Attempt was made to synthesize these compounds by the combustion synthesis using metal nitrates as oxidizer and urea as a fuel. Compounds MgAl2O4 and MgAl6O10 were formed in a single step, while MgAl26O40 was not formed by this procedure. Activation of MgAl6O10 by rare earth ions like Ce3+, Eu3+ and Tb3+ and ns2 ion Pb2+ could be achieved. Excitation bands for MgAl6O10 are at slightly shorter wavelengths compared to those reported for MgAl2O4.

  20. Magnesium diboride: one year on

    Last January physicists discovered that an innocuous compound that had been sitting on the shelf for decades was, in fact, a record-breaking intermetallic superconductor. At the end of 2000 superconductivity in metal alloys and compounds appeared to remain trapped by a glass ceiling. Over the previous 10 years the temperature at which certain oxide-based compounds - such as bismuth strontium calcium copper oxide and mercury barium calcium copper oxide - lost their resistance to electric current had soared to well over 100 K. Meanwhile, the transition temperature, Tc, for carbon-based materials, including alkali-doped carbon-60 compounds, had risen close to the boiling point of liquid nitrogen (77 K). During the same period, however, the superconducting transition temperature of intermetallic compounds (materials made solely of metals and metal-like elements) remained close to 20 K - as it had been since the mid-1960s. By February 2001 everything had totally changed. It was as if a firecracker had gone off in the tidy little ant hill of superconductivity research. For the first few months of 2001, groups all over the world raced to understand the properties of a new intermetallic superconductor. The substance that everyone was scrambling to buy or make, the substance that was causing this grand commotion, was magnesium diboride (Mg B2). This seemingly innocuous binary compound, which had been present in many labs for over half a century, had been discovered to superconduct just below 40 K. Even though we already know an amazing amount about Mg B2, our knowledge of superconductivity in this compound is only one year old. There is therefore the very real potential to improve its critical properties. In a similar vein, it is almost certain that our understanding of this extreme example of intermetallic superconductivity will greatly improve over the next few years and may even reveal other extreme superconductors. (U.K.)

  1. Alkalization is responsible for antibacterial effects of corroding magnesium.

    Rahim, Muhammad Imran; Eifler, Rainer; Rais, Bushra; Mueller, Peter P

    2015-11-01

    Magnesium alloys are presently investigated as potential medical implant materials for temporary applications. Magnesium has been reported to have antibacterial activities and could therefore be used to prevent antibiotic treatment-resistant bacterial implant infections. For characterizing the effects of magnesium on infectious bacteria, bioluminescent S. aureus or P. aeruginosa were employed. The proliferation of both types of bacteria was suppressed in the presence of metallic magnesium and also in aqueous magnesium corrosion extracts. Of the two soluble corrosion products, magnesium ions were well tolerated while antibacterial activities correlated with increased pH levels of the supernatants. The alkaline pH alone was sufficient for the antibacterial effects which were completely abolished when the pH of the corrosion supernatants was neutralized. These results demonstrate that pH increases are necessary and sufficient for the antibacterial activity of metallic magnesium. In an animal model magnesium implants showed an enhanced but variable resistance to bacterial colonization. PMID:25974048

  2. Histamine release from rodent and human mast cells induced by protoporphyrin and ultraviolet light: studies of the mechanism of mast-cell activation in erythropoietic protoporphyria

    We report that protoporphyrin (PP) and ultraviolet light (UVA) induces histamine release from rat peritoneal mast cells, mouse bone marrow mast cells and human cutaneous mast cells in a dose- and temperature-dependent manner. The mast-cell activation was associated with loss of membrane integrity and inhibited by the hydrogen peroxide scavenger, catalase. Histamine release was independent of extracellular calcium in the rodent mast cells, but was markedly reduced in the absence of calcium in human cells. These findings indicate that PP and UVA induce mast-cell-mediator release by a process that may involve hydrogen peroxide formation. There appear to be differences in response to PP and UVA between rodent and human mast cells. (author)

  3. The periodontal pathogen Porphyromonas gingivalis harnesses the chemistry of the mu-oxo bishaem of iron protoporphyrin IX to protect against hydrogen peroxide.

    Smalley, J W; Birss, A J; Silver, J

    2000-02-01

    The major haem component in the black pigment of Porphyromonas gingivalis is the mu-oxo bishaem of iron protoporphyrin IX and formation and cell-surface binding of this haem species is proposed as an extracellular buffer against reactive oxidants [Smalley, J.W. et al. (1998) Biochem. J. 331, 681-685]. P. gingivalis cells grown in the presence of the mu-oxo bishaem were protected against H(2)O(2) compared to control cells grown without it. When added to the growth medium, soluble mu-oxo bishaem inactivated H(2)O(2) and supported cell growth. Cells carrying a surface layer of mu-oxo bishaem were less susceptible to peroxidation by H(2)O(2). Cell-surface haems were slowly destroyed during reaction with H(2)O(2). Binding of mu-oxo bishaem by P. gingivalis may aid survival during neutrophil attack through inactivation of hydrogen peroxide. PMID:10650220

  4. Sequence Classification: 751791 [

    Full Text Available TMB Non-TMH Non-TMB TMB Non-TMB TMB >gi|15234905|ref|NP_194238.1| magnesium -protoporphyrin O-met ... hyltransferase, putative / magnesium -protoporphyrin IX methyltransferase, putative || h ...

  5. Sequence Classification: 751792 [

    Full Text Available TMB Non-TMH Non-TMB TMB Non-TMB TMB >gi|30686748|ref|NP_849438.1| magnesium -protoporphyrin O-met ... hyltransferase, putative / magnesium -protoporphyrin IX methyltransferase, putative || h ...

  6. Sequence Classification: 751793 [

    Full Text Available TMB Non-TMH Non-TMB TMB Non-TMB TMB >gi|30686750|ref|NP_849439.1| magnesium -protoporphyrin O-met ... hyltransferase, putative / magnesium -protoporphyrin IX methyltransferase, putative || h ...

  7. Magnesium salts as compounds of the preparation of magnesium oxide from Tunisian natural brines

    Behij Souheil

    2013-01-01

    Full Text Available Magnesium oxide is one of the most important magnesium compounds used in industry. The production of MgO is often done from calcined magnesium carbonate or from natural magnesium saline solutions (sea water and brines. In the case of these solutions, magnesium oxide is precipitated after the addition of a strong base (eg. Ammonia. Magnesium hydroxide is calcined after its separation from the excess resulting from the strong base through filtration. Thus, magnesia qualities may differ depending on several physical parameters and particularly on the nature of the compound. Consequently, two different compounds were selected: magnesium chloride and magnesium sulphate which can be recovered from Tunisian natural brines. Three physical factors were considered: calcination temperatures, precipitation temperatures and calcination time of Mg(OH2. The decomposition of Mg(OH2 was investigated by DTA/TGA. Mass losses vary in the range (23.0%-29.9%. Starting decomposition temperatures are between 362°C and 385°C. The MgO produced from MgSO4 under 1000°C within 48 hours of calcination time and with 40°C as a reaction temperature for Mg(OH2 shows a good crystallinity and is of a cristallyte size of 86.3 nm and has a specific surface area equal to 16.87 m2g-1. Finally, morphological differences between MgO agglomerates at different temperatures were observed by SEM. Consequently, magnesium sulphate as precursor for preparing MgO is selected.

  8. Magnesium Borate Synthesis by Microwave Energy: A New Method

    Azmi Seyhun Kipcak; Emek Moroydor Derun; Sabriye Piskin

    2013-01-01

    Magnesium borates are one of the major groups of boron minerals that have important properties such as high heat and corrosion resistances and high coefficients of elasticity. In this study, magnesium borate minerals are synthesized using boric acid and magnesium oxide with a new method of microwave, and the synthesized minerals are characterized by various analysis techniques. The results show that pure, “magnesium borate hydrate” minerals are obtained at the end of various steps. The charac...

  9. Low intracellular magnesium in patients with acute pancreatitis and hypocalcemia.

    Ryzen, E; Rude, R K

    1990-01-01

    To determine the role of magnesium deficiency in the pathogenesis of hypocalcemia in acute pancreatitis, we measured magnesium levels in serum and in peripheral blood mononuclear cells in 29 patients with acute pancreatitis, 14 of whom had hypocalcemia and 15 of whom had normal calcium levels. Only six patients had overt hypomagnesemia (serum magnesium less than 0.70 mmol per liter [1.7 mg per dl]). The mean serum magnesium concentration in hypocalcemic patients was not significantly lower th...

  10. Magnesium in CKD: more than a calcification inhibitor?

    Floege, Jürgen

    2014-01-01

    Magnesium fulfils important roles in multiple physiological processes. Accordingly, a tight regulation of magnesium homeostasis is essential. Dysregulated magnesium serum levels, in particular hypomagnesaemia, are common in patients with chronic kidney disease (CKD) and have been associated with poor clinical outcomes. In cell culture studies as well as in clinical situations magnesium levels were associated with vascular calcification, cardiovascular disease and altered bone-mineral metaboli...

  11. Magnesium sulfate administration in subarachnoid hemorrhage.

    Suarez, Jose I

    2011-09-01

    Magnesium offers theoretic vascular and neuroprotective benefits for patients with subarachnoid hemorrhage. An electronic literature search was conducted to identify original research studies describing intravenous magnesium treatment in patients with SAH published in English between January 1990 and October 2010. Seventeen articles were identified and reviewed, including one phase III randomized-controlled clinical trial and six phase II randomized-controlled trials. Study quality was low for most of the included studies, with the phase III trial considered to be of moderate quality. Due to inconsistently reported benefits and the occurrence of side effects, phase II data suggested that intravenous magnesium for SAH provided either no overall net benefit or uncertain trade-offs. Benefit was likewise not supported in the single phase III clinical trial. PMID:21748496

  12. Solid-state rechargeable magnesium batteries

    Chusid, O.; Gofer, Y.; Gizbar, H.; Vestfrid, Y.; Levi, E.; Aurbach, D. [Department of Chemistry, Bar-Ilan University, Ramat-Gan 52900 (Israel); Riech, I. [Ortal Magnesium Diecasting Ltd, Kibbutz Neve Ur 10875 (Israel)

    2003-04-17

    The development of all solid-state rechargeable magnesium battery systems is reported, with components that are environmentally friendly and relatively simple in their structure and preparation. As anodes, magnesium alloys containing Zn and Al are used, and the cathode is the chevrel phase, Mo{sub 6}S{sub 8}, which can insert two magnesium atoms per unit (Mg{sub 2}Mo{sub 6}S{sub 8}, 122 mA h g{sup -1}). The solid electrolyte is a gel comprising polyvinylidene difluoride, Mg(AlCl{sub 2}EtBt){sub 2} complex salt, and tetraglyme as a plasticizer. These batteries are found to function well in a temperature range of 0-80 C with a voltage range of 1.3-0.8V. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

  13. Calcium accumulation characterization in the aerobic granules cultivated in a continuous-flow airlift bioreactor.

    Zhou, Dandan; Liu, Mengyuan; Gao, Linlin; Shao, Chunyan; Yu, Jie

    2013-06-01

    Limited work has been done on the accumulation characterization of Ca(2+) in aerobic granules that are cultivated in a continuous-flow bioreactor. In this work, the contribution of Ca(2+) to the biogranulation in a continuous flow airlift fluidized bed (CAFB) reactor has been studied. The spatial distribution and form of calcium in the granules were investigated by scanning electron microscopy-mapping, energy dispersive X-ray and X-ray diffraction (XRD). Calcium was located throughout the Ca-rich granules, rather than accumulating in the center of the granules of the sequencing batch reactor. Furthermore, CaCO3 was detected as the main crystalline mineral form of the calcium. Calcium augmentation of the inflow promoted the accumulation of magnesium in the granules in the CAFB. The magnesium was presented as Ca7Mg2P6O24 according to XRD analyses. PMID:23436127

  14. Laser surface treatment of cast magnesium alloys

    L.A. Dobrzański

    2009-02-01

    Full Text Available Purpose: The goal of this work was to investigate influence of laser treatment on structure and properties MCMgAl3Zn1, MCMgAl6Zn1, MCMgAl9Zn1 and MCMgAl12Zn1 cast magnesium alloys.Design/methodology/approach: Tests were made on the experimental MCMgAl3Zn1 MCMgAl6Zn1 MCMgAl9Zn1 and MCMgAl12Zn1 casting magnesium alloys. Laser treatment was made using the Rofin DL020 HPDL high power diode laser in the argon shield gas cover with the technique of the continuous powder supply to the remelted pool area.Findings: Investigations of the surface layers carried out confirm that laser treatment of the surface layer of the Mg-Al-Zn casting magnesium alloys is feasible using the HPDL high power diode laser ensuring better properties compared to alloys properties after the regular heat treatment after employing the relevant process parameters. Occurrences were found based on the metallographic examinations of the remelted zone (RZ and the heat affected zone (HAZ in alloyed surface layer of the investigated casting magnesium alloy.Research limitations/implications: This investigation presents different laser power and in this research was used two powders, namely tungsten-, and titanium carbide.Practical implications: Reinforcing the surface of cast magnesium alloys by adding TiC and WC particles is such a possible way to achieve the possibilities of the laser melt injection process, which is a potential technique to produce a Metal-Matrix Composite (MMC layer in the top layer of a metal workpiece.Originality/value: The originality of this work is applying of High Power Diode Laser for alloying of magnesium alloy using hard particles like tungsten- and titanium carbide.

  15. Mechanistic Study of Magnesium Carbonate Semibatch Reactive Crystallization with Magnesium Hydroxide and CO2

    Han, B.; Qu, H. Y.; Niemi, H.;

    2014-01-01

    This work investigates semibatch precipitation of magnesium carbonate at ambient temperature and pressure using Mg(OH)(2) and CO2 as starting materials. A thermal analysis method was developed that reflects the dissolution rate of Mg(OH)(2) and the formation of magnesium carbonate. The method...... the liquid and solid phases. A stirring rate of 650 rpm was found to be the optimum speed as the flow rate of CO2 was 1 L/min. Precipitation rate increased with gas flow rate, which indicates that mass transfer of CO2 plays a critical role in this precipitation case. Magnesium carbonate trihydrate...

  16. New development of anodizing process of magnesium alloys

    BAI Li-qun; LI Di

    2004-01-01

    Magnesium alloy, a kind of environment-friendly material with promising and excellent properties, is a good choice for a number of applications. The research and development of anodizing on magnesium alloys and its application situation are reviewed, and the anodizing development trend on magnesium alloys is summarized.

  17. Magnesium retention in 12 to 48 month-old children

    In adults, adaptation to changes in magnesium intake is largely due to changes in fractional magnesium absorption and urinary magnesium excretion. We sought to examine whether these homeostatic mechanisms also occur in young children. Children, 12–48 m old, were studied (n=30). They were adapted to ...

  18. 40 CFR 721.9513 - Modified magnesium silicate polymer (generic).

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Modified magnesium silicate polymer... Specific Chemical Substances § 721.9513 Modified magnesium silicate polymer (generic). (a) Chemical... as modified magnesium silicate polymer (PMN P-98-604) is subject to reporting under this section...

  19. Synthesis and thermal stability of tetrahydrofuranate of magnesium borohydride

    Present article is devoted to synthesis and thermal stability of tetrahydrofuranate of magnesium borohydride. The thermal stability of tetrahydrofuranate of magnesium borohydride was studied. The character of thermal process passing was defined. The possibility of de solvation of initial sample was considered. The possibility of obtaining of not solvated magnesium borohydride was considered as well.

  20. Magnesium Intake and Prevalence of Metabolic Syndrome in Older Adults

    Higher dietary intake of magnesium (Mg) may protect against development of type 2 diabetes. The aim of this study was to examine the association between dietary magnesium intake and metabolic syndrome risk factors in elderly men and women. We examined cross-sectional associations between magnesium i...

  1. Mobility of cations in magnesium aluminate spinel

    Martinelli, J.R.; Sonder, E.; Weeks, R.A.; Zuhr, R.A.

    1986-04-15

    Transport of cations in magnesium aluminate spinel due to an applied electric field at approximately 1000 /sup 0/C has been measured by observing changes in elemental concentrations near the cathode and anode surfaces using ion backscattering techniques. The results indicate that magnesium ions are the mobile species at 1000 /sup 0/C and that these ions combine with ambient oxygen at the cathode surface to form a MgO layer. Quantitative interpretation of the data leads to the conclusion that the ionic transference number of spinel becomes approximately 0.5 after treatment in an electric field.

  2. Mobility of cations in magnesium aluminate spinel

    Transport of cations in magnesium aluminate spinel due to an applied electric field at approximately 1000 0C has been measured by observing changes in elemental concentrations near the cathode and anode surfaces using ion backscattering techniques. The results indicate that magnesium ions are the mobile species at 1000 0C and that these ions combine with ambient oxygen at the cathode surface to form a MgO layer. Quantitative interpretation of the data leads to the conclusion that the ionic transference number of spinel becomes approximately 0.5 after treatment in an electric field

  3. Mobility of cations in magnesium aluminate spinel

    Martinelli, J. R.; Sonder, E.; Weeks, R. A.; Zuhr, R. A.

    1986-04-01

    Transport of cations in magnesium aluminate spinel due to an applied electric field at approximately 1000 °C has been measured by observing changes in elemental concentrations near the cathode and anode surfaces using ion backscattering techniques. The results indicate that magnesium ions are the mobile species at 1000 °C and that these ions combine with ambient oxygen at the cathode surface to form a MgO layer. Quantitative interpretation of the data leads to the conclusion that the ionic transference number of spinel becomes approximately 0.5 after treatment in an electric field.

  4. Creep processes in magnesium metal matrix composites

    Sklenička, Václav; Kuchařová, Květa; Svoboda, M.; Kvapilová, Marie; Lukáč, P.

    Brno: Ústav fyziky materiálů AV ČR, v. v. i., 2015 - (Dlouhý, A.; Kunz, L.). s. 216-216 ISBN 978-80-87434-07-9. [ICSMA-17 International Conference on the Strength of Materials /17./. 09.08.2015-14.08.2015, Brno] R&D Projects: GA MŠk(CZ) ED1.1.00/02.0068 Institutional support: RVO:68081723 Keywords : magnesium composites * magnesium alloy s * creep * reinforcement * interfacial microstructure * load transfer Subject RIV: JG - Metallurgy

  5. Effect of zinc protoporphyrin on carbon monoxide/heme oxygenase-1 system in rats subjected to recurrent febrile convulsion

    2007-01-01

    BACKGROUND: Studies on febrile convulsion (FC)-caused brain injury are disputed in many aspects.How FC cause nervous system injury in the developmental period and what are the characteristics of these pathological injury are unknown. The current studies have demonstrated that heme oxygenase-1 (HO-l) exerts effects on brain injury mainly by catalyzing hemoglobin to produce degradation products, and HO-1 not only has neuroprotective effects, but also has neurotoxic effects during the FC-caused brain injury. Study on the effect of zinc protoporphyrin (ZnPP) on brain injury is still in the stage of animal experiment.OBJECTIVE: To observe the effects of ZnPP on carbon monoxide (CO)/HO-1 system of rats subjected to FC, and to analyze the action pathway of ZnPP in brain protective effect.DESIGN: A randomized controlled animal experiment.SETTING: Department of Pediatrics, First Hospital Affiliated to Jiamusi University.MATERIALS: Sixty-five Wistar rats, of either gender, were involved in this study. They were randomized into normal control group( n =14, 37 ℃ water bath) and febrile treatment group (n =51, 44.5 ℃ hot water bath). Febrile treatment group was sub-divided into febrile non-convulsion group (FNC group, n =16) and FC group (n =35). FC group was further sub-divided into simple convulsion group (n =20) and ZnPP treatment group (n =15). HO-1 mRNA in situ hybridization kit was provided by Boster Bioengineering Co.,Ltd. ZnPP(dark brown powder) was the product of Jingmei Bioengineering Company.METHODS: This study was carried out in the postgraduate laboratory of Jiamusi University between January 2004 and January 2007. Rats in the febrile treatment group were placed in the 44.5 ℃ hot water bath box. If rats did not convulse in the water within 5 minutes, they were taken out, namely FNC group (n =16), and those, which were convulsed within 5 minutes, were taken out immediately when they presented such a phenomenon, namely FC group (n =35). Convulsion induction was

  6. On the precipitation of magnesium silicide in irradiated aluminum-magnesium alloys

    Thermal neutron irradiation of aluminium or its alloys causes the production of silicon by transmutation. In aluminium-magnesium alloys, the transmutation-produced silicon reacts with magnesium and forms small precipitates. The precipitation in irradiated Al-Mg alloys is similar to the early stage of aging in thermally treated Al-Mg-Si alloys. This study evidences the simultaneous generation of two crystallographically different precipitate types. On the basis of electron diffraction patterns, unit cell parameters are derived and compared with structures found in thermally aged alloys. One of the two precipitate types has an Mg2Si composition, while the other is an Al-Si-Mg intermetallic compound with high aluminium and silicon but low magnesium content. The formation of magnesium poor precipitates is important since it indicates that the threshold neutron fluence for grain boundary precipitation of silicon may be much higher than estimated in the past

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

    As biocompatible materials, magnesium phosphates have received a lot of attention for orthopedic applications. During the last decade multiple studies have shown advantages for magnesium phosphate such as lack of cytotoxicity, biocompatibility, strong mechanical properties, and high biodegradability. The present study investigates the role of Mg+2 and Ca+2 ions in the structure of magnesium phosphate and calcium phosphate nanoparticles. To directly compare the effect of Mg+2 and Ca+2 ions on structure of nanoparticles and their biological behavior, three groups of nanoparticles including amorphous magnesium phosphates (AMPs) which release Mg+2, calcium magnesium phosphates (CMPs) which release Mg+2 and Ca+2, and hydroxyapatites (HAs) which release Ca+2 were studied. SEM, TEM, XRD, and FTIR were used to evaluate the morphology, crystallinity, and chemical properties of the particles. AMP particles were homogeneous nanospheres, whereas CMPs were combinations of heterogeneous nanorods and nanospheres, and HAs which contained heterogeneous nanosphere particles. Cell compatibility was monitored in all groups to determine the cytotoxicity effect of particles on studied MC3T3-E1 preosteoblasts. AMPs showed significantly higher attachment rate than the HAs after 1 day and both AMPs and CMPs showed significantly higher proliferation rate when compared to HAs after 7 days. Gene expression level of osteoblastic markers ALP, COL I, OCN, OPN, RUNX2 were monitored and they were normalized to GAPDH housekeeping gene. Beta actin expression level was monitored as the second housekeeping gene to confirm the accuracy of results. In general, AMPs and CMPs showed higher expression level of osteoblastic genes after 7 days which can further confirm the stimulating role of Mg+2 and Ca+2 ions in increasing the proliferation rate, differentiation, and mineralization of MC3T3-E1 preosteoblasts. - Highlights: • Role of Mg2+ and Ca2+ ions in proliferation, and differentiation of

  8. Dechlorination of chlorophenols using magnesium-palladium bimetallic system

    Patel, Upendra D. [Centre of Environmental Science and Engineering, Indian Institute of Technology-Bombay, Mumbai 400076 (India)]. E-mail: upendra@iitb.ac.in; Suresh, Sumathi [Centre of Environmental Science and Engineering, Indian Institute of Technology-Bombay, Mumbai 400076 (India)]. E-mail: sumathis@iitb.ac.in

    2007-08-17

    Ninety-four percent removal of 10 mg L{sup -1} of pentachlorophenol (PCP) was achieved by treatment with 154.5 mM Mg{sup 0} and 0.063 mM K{sub 2}PdCl{sub 6} in the presence of 175 mM acetic acid in 1 h reaction time. Dechlorination of PCP was found to be sequential and phenol was identified as the end product along with accumulation of trace concentrations of tetra- and trichlorophenols. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) revealed that palladium in its metallic form (Pd{sup 0}) produced by reduction of Pd{sup 4+}, was spatially separated from magnesium granules when acid was included in the reaction. These colloidal palladium particles generated active reductive species of hydrogen and dechlorinated chlorophenols. In the absence of acid, the efficiency of dechlorination of PCP by Pd/Mg{sup 0} system was very low and chief mechanism of removal of the compound was through sorption onto solid surfaces. Thus, it was important to include acid in the system to: (a) facilitate corrosion of Mg{sup 0} and reduction of Pd{sup 4+} to Pd{sup 0}, (b) provision of protons to produce H{sub 2}, (c) retard formation of insoluble oxides and hydroxides that may deposit on the magnesium granules and sorb PCP and its partially dechlorinated products and. Application of 154.5 mM Mg{sup 0}/0.063 mM K{sub 2}PdCl{sub 6} on PCP, 2,4,5-trichlorophenol (TCP) and 2-chlorophenol (MCP) with organic chloride equivalence showed that the rate and extent of removal increased with decrease in number of chlorine atoms on phenol.

  9. Pharmacokinetic Profile of Oral Magnesium Hydroxide

    Dolberg, Mette Konow Bøgebjerg; Nielsen, Lars Peter; Dahl, Ronald

    2016-01-01

    Despite the presumption of a beneficial effect of magnesium (Mg) supplementation on various diseases, little is known concerning the pharmacokinetics of Mg hydroxide. This study was designed to provide a pharmacokinetic profile of Mg hydroxide after a single oral dose. Ten healthy male adults...

  10. 21 CFR 184.1428 - Magnesium hydroxide.

    2010-04-01

    ... Chemicals Codex, 3d Ed. (1981), p. 178, which is incorporated by reference. Copies are available from the... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Magnesium hydroxide. 184.1428 Section 184.1428 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD...

  11. Superconductivity of Magnesium Diboride: Theoretical Aspects

    Dahm, T.

    2004-01-01

    In this work we review our present understanding of superconductivity in Magnesium Diboride from the theoretical perspective as it evolves from band structure calculations. Particular emphasis is placed on two gap superconductivity. Some of its peculiar consequences are discussed, in particular upper critical field anisotropy and microwave conductivity.

  12. High grade magnesium from waste bittern

    The production of high grade magnesia for nuclear purposes from sea water by use of both aqueous and gaseous ammonia has been described. The effect of precipitating conditions on the settling rate and magnesium recovery, was thoroughly examined. Ammonia gas approach was recommended and justified

  13. Intravenous magnesium sulfate therapy in severe asthma

    Mohd. Al-Ajmi

    2007-01-01

    Full Text Available A 22-year-old female, known asthmatic since seven years, developed severe bronchospasm in the preop-erative period. Bronchospasm remained unresponsive to the inhaled beta-agonist plus anticholinergic, IV ami-nophylline and hydrocortisone but responded quickly with magnesium sulfate® ( PSI, KSA infusion 1.25gm in 100ml normal saline over 20 minutes and another 1.25 gm over next 30 minutes as the initial infusion showed improvement in her clinical symptoms. Within half an hour of administering the 1st infusion of magnesium sulfate (1.25 gm the respiratory rate started reducing, rhonchi became less, SpO 2 came upto 92% and re-mained always above 90%. Encouraged by this result IV magnesium sulfate 2.5 gm in 500 ml normal saline was infused over next 24 hours along with alternate salbutamol and ipratropium nebulization every 6 hourly. With this treatment regimen the patient became asymptomatic within next 24 hours with normal clinical parameters and FEV 1 value. Hence it may be concluded that IV magnesium sulfate can be considered for patients with acute severe asthma who do not respond to standard therapeutic medications.

  14. Processing aspects of magnesium alloy stent tube

    Werkhoven, R.J.; Sillekens, W.H.; Lieshout, J.B.J.M. van

    2011-01-01

    Biomedical applications are an emerging field of interest for magnesium technology, envisioning biodegradable implants that resorb in the human body after having cured a particular medical condition (such as artery clogging or bone fractures). This challenges research in a sense that the materials t

  15. Electron transfer in magnesium and zinc orthovanadate

    Electrophysical properties of magnesium and zinc orthovanadates were studied in wide range of temperatures and partial oxygen pressures. It is shown that these compounds represent mainly ionic conductors. Zn2+ ions are the carriers of ion current in zinc orthovanadate. Boundaries of electrolytic regions were determined

  16. Calcium, magnesium, and potassium in food

    The biochemical and physiological functions and consequences of deficient intakes, which show the nutritional importance of calcium, magnesium and potassium for humans, are reviewed. The dietary recommendations and food sources for these essential mineral elements for humans are presented. Factors t...

  17. In vivo study of degradable magnesium and magnesium alloy as bone implant

    HUANG Jingjing; REN Yibin; JIANG Yue; ZHANG Bingchun; YANG Ke

    2007-01-01

    In order to investigate the in vivo behavior of pure magnesium and AZ31B and the influence of mineralization induction ability,sample rods were implanted intramedullary into the femora of rabbits.After one and nine weeks,six animals from each group were sacrificed,respectively.Undecalcified cross-sections of implant were performed to observe bone-implant by scanning electron microscopy (SEM)and energy dispersive spectromicroscopy(EDS).The SEM/EDS evaluation showed that there is a thin layer of bone around magnesium and its alloy after nine-week implantation.The results further showed that the aluminum-zinc containing magnesium alloys AZ31B provided a slower degradation rate in vivo than the pure magnesium.At the locations where magnesium was resorbed,the deposition of new bone was found.The results indicate that magnesium is biocompatible,osteo-conductive and is a potential material for use as a degradable bone implant.

  18. Magnesium status and association with diabetes in the Taiwanese elderly.

    Wang, Jui-Line; Shaw, Ning-Sing; Yeh, Hsiang-Yu; Kao, Mei-Ding

    2005-01-01

    The average dietary intake of magnesium is below recommended dietary allowances in many affluent Western countries. Prolonged low magnesium intake tends to result in hypomagnesaemia which might increase the risk of chronic diseases in elderly people. A national population-based cross-sectional nutrition survey, the Elderly Nutrition and Health Survey in Taiwan (1999-2000), was used to investigate the magnesium status and association with diabetes in the Taiwanese elderly. Dietary magnesium intake was based on 24-hour dietary recalls. Blood biochemical parameters including plasma magnesium and blood glucose were also measured. Average magnesium intake was 250 mg in men and 216 mg in women, which is equivalent to 68-70% of relevant Taiwanese Dietary Reference Intakes. The mean plasma magnesium concentration was 0.903 mmol/L in men and 0.906 mmol/L in women. The prevalence of a plasma magnesium level of vegans had a significantly lower magnesium intake than ovo-lacto vegetarians and non-vegetarians. Diabetic men and women had significantly higher blood glucose levels than non-diabetics. The risk of diabetes was elevated 3.25 times at plasma magnesium levelsdeficiency, may not be sufficient to reduce the risk of diabetes in the elderly. Further prospective study is required to help explain the differential results between dietary and plasma magnesium levels. PMID:16169838

  19. Assessment of the magnesium primary production technology. Final report

    Flemings, M.C.; Kenney, G.B.; Sadoway, D.R.; Clark, J.P.; Szekely, J.

    1981-02-01

    At current production levels, direct energy savings achievable in primary magnesium production are 1.2 milliquads of energy per annum. Were magnesium to penetrate the automotive market to an average level of 50 pounds per vehicle, the resultant energy savings at the production stage would be somewhat larger, but the resulting savings in gasoline would conserve an estimated 325 milliquads of energy per year. The principal barrier to more widespread use of magnesium in the immediate future is its price. A price reduction of magnesium of 10% would lead to widespread conversion of aluminum die and permanent mold castings to magnesium. This report addresses the technology of electrolytic and thermic magnesium production and the economics of expanded magnesium production and use.

  20. Morphofunctional characteristics of fibroblasts (McCoy cell line) cultured with magnesium preparations

    L. V. Didenko; T. G. Borovaya; E. A. Kost; E A Ulubieva; A. V. Timofeeva; A. G. Avtandilov

    2015-01-01

    Aim. To study the effect of magnesium orotate, magnesium/pyridoxine combination and magnesium sulfate on fibroblast morphofunctional characteristics in cell culture of fibroblasts (McCoy line).Material and methods. The study of fibroblasts (McCoy line) with the addition of magnesium-containing preparations (magnesium orotate, magnesium/pyridoxine combination, magnesium sulphate) to the culture medium was performed using scanning and transmission electron microscopy.Results. When adding into t...

  1. Activated magnesium for hydrogen energy storage

    Hydrogen is the ideal means of storage, transport and conversion of energy for a comprehensive clean-energy concept because of its free emission. Hydrogen can be stored as an energy carrier in the form of gas, liquid, and in solid. Magnesium is the candidate material for on-board hydrogen storage in the form of solid metal hydride because of its safe and higher volumetric energy density, about 7.6 wt% of the metal. Previous experiment on the hydriding of magnesium with the particle size of <0.3 mm and <60 μm yields very poor hydrogen capacity due to the oxygen existence on the metal surface. To improve the hydrogen sorption properties, the magnesium with the particle size of <60 μm is activated by treating the metal with 0.15M NH4F solution for 1 hour. The hydriding experiment is conducted in a hydriding system that can be operated at a very high vacuum up to 1x10-7 mbar. Analyses on the experimental results of two cycles of hydriding show that the activated magnesium powder with the particle size of <60 mm absorbed hydrogen in the amount of 3.82 wt% of the metal in the first cycle, which increased to 5.15 wt% in the second cycle. The absorption process took respectively 312 and 221 seconds for the first and second cycle of hydriding. Experimental results show that the hydrogen capacity of the current experiment is still low likely due to the particle size of magnesium metal, i.e. it should be nano size. (author)

  2. Plastids and Carotenoid Accumulation.

    Li, Li; Yuan, Hui; Zeng, Yunliu; Xu, Qiang

    2016-01-01

    Plastids are ubiquitously present in plants and are the organelles for carotenoid biosynthesis and storage. Based on their morphology and function, plastids are classified into various types, i.e. proplastids, etioplasts, chloroplasts, amyloplasts, and chromoplasts. All plastids, except proplastids, can synthesize carotenoids. However, plastid types have a profound effect on carotenoid accumulation and stability. In this chapter, we discuss carotenoid biosynthesis and regulation in various plastids with a focus on carotenoids in chromoplasts. Plastid transition related to carotenoid biosynthesis and the different capacity of various plastids to sequester carotenoids and the associated effect on carotenoid stability are described in light of carotenoid accumulation in plants. PMID:27485226

  3. Chimpanzee accumulative stone throwing.

    Kühl, Hjalmar S; Kalan, Ammie K; Arandjelovic, Mimi; Aubert, Floris; D'Auvergne, Lucy; Goedmakers, Annemarie; Jones, Sorrel; Kehoe, Laura; Regnaut, Sebastien; Tickle, Alexander; Ton, Els; van Schijndel, Joost; Abwe, Ekwoge E; Angedakin, Samuel; Agbor, Anthony; Ayimisin, Emmanuel Ayuk; Bailey, Emma; Bessone, Mattia; Bonnet, Matthieu; Brazolla, Gregory; Buh, Valentine Ebua; Chancellor, Rebecca; Cipoletta, Chloe; Cohen, Heather; Corogenes, Katherine; Coupland, Charlotte; Curran, Bryan; Deschner, Tobias; Dierks, Karsten; Dieguez, Paula; Dilambaka, Emmanuel; Diotoh, Orume; Dowd, Dervla; Dunn, Andrew; Eshuis, Henk; Fernandez, Rumen; Ginath, Yisa; Hart, John; Hedwig, Daniela; Ter Heegde, Martijn; Hicks, Thurston Cleveland; Imong, Inaoyom; Jeffery, Kathryn J; Junker, Jessica; Kadam, Parag; Kambi, Mohamed; Kienast, Ivonne; Kujirakwinja, Deo; Langergraber, Kevin; Lapeyre, Vincent; Lapuente, Juan; Lee, Kevin; Leinert, Vera; Meier, Amelia; Maretti, Giovanna; Marrocoli, Sergio; Mbi, Tanyi Julius; Mihindou, Vianet; Moebius, Yasmin; Morgan, David; Morgan, Bethan; Mulindahabi, Felix; Murai, Mizuki; Niyigabae, Protais; Normand, Emma; Ntare, Nicolas; Ormsby, Lucy Jayne; Piel, Alex; Pruetz, Jill; Rundus, Aaron; Sanz, Crickette; Sommer, Volker; Stewart, Fiona; Tagg, Nikki; Vanleeuwe, Hilde; Vergnes, Virginie; Willie, Jacob; Wittig, Roman M; Zuberbuehler, Klaus; Boesch, Christophe

    2016-01-01

    The study of the archaeological remains of fossil hominins must rely on reconstructions to elucidate the behaviour that may have resulted in particular stone tools and their accumulation. Comparatively, stone tool use among living primates has illuminated behaviours that are also amenable to archaeological examination, permitting direct observations of the behaviour leading to artefacts and their assemblages to be incorporated. Here, we describe newly discovered stone tool-use behaviour and stone accumulation sites in wild chimpanzees reminiscent of human cairns. In addition to data from 17 mid- to long-term chimpanzee research sites, we sampled a further 34 Pan troglodytes communities. We found four populations in West Africa where chimpanzees habitually bang and throw rocks against trees, or toss them into tree cavities, resulting in conspicuous stone accumulations at these sites. This represents the first record of repeated observations of individual chimpanzees exhibiting stone tool use for a purpose other than extractive foraging at what appear to be targeted trees. The ritualized behavioural display and collection of artefacts at particular locations observed in chimpanzee accumulative stone throwing may have implications for the inferences that can be drawn from archaeological stone assemblages and the origins of ritual sites. PMID:26923684

  4. Physical properties of magnesium affected soils in Colombia

    Magnesium has some capacity to develop higher exchangeable sodium levels in clays and soil materials. The Mg+2 accumulation on the exchange complex of soils to a very high saturation levels affect their physical, chemical and biological properties. Colombia has a large area of these soils, located mainly in the main rivers valleys and in the Caribbean Region. In the Cauca River Valley there are about 117,000 hectares affected. There is a lack of information about the soil forming processes, the Mg+2 effects on soils, the type and source of compounds responsible for the magnesium enrichment, their relationship with the landscape and the way this accumulation occurs. To identify and quantify soil Mg+2 enriched areas over 2500 soil profiles from different landscape positions of the Cauca River Valley were studied. The information was processed to generate Mg-saturation maps, to identify the different soil profile types and to estimate the affected area. A topographic sequence from the alluvial inundation plain to the hills was used to explore the presence of diagnostic horizons and to determine the main soil characteristics and genetic, mineralogical or chemical evidences of soil forming processes. Two 180 kilometer transects parallel to the river were used to: a) study the type and source of Mg-compounds responsible for the Mg-enrichment and the way this accumulation occurs. b) the soil hydraulic properties like infiltration, saturated hydraulic conductivity and matrix potential at different depths were also measured. Samples of nine profiles were collected and the porosity and soil volume changes at different water content were examined. The program RETC was used for prediction of the hydraulic properties of non saturated soils. These properties involved the retention curve, the function of hydraulic conductivity and the diffusivity of the water in the soil. By grouping together the soil profiles, five main type of Mg-affected soils were identified as being

  5. Vibrational study of magnesium complexes and porphyrins

    In the course of chlorophyll investigations by vibrational spectroscopy, the magnesium complex Mg(NH3)6Cl2 was studied by infrared and Raman techniques and two porphyrin molecules, by resonance Raman scattering. For the hexa-ammine magnesium chloride, all vibrations predicted by group theory (internal and external vibrations) were observed; ligand orientations gives- the complex ion a D3d point group symmetry. Five isotopically substituted compounds were studied and a force constant calculation showed that the Mg-N bond has a value higher than most of those calculated for other divalent hexa-ammine metal ions. Two porphyrins were studied: the prophine and the meso-porphyrin IX dimethyl-ester.' Unexpected variations of vibrational bands intensities and depolarization ratios were recorded on changing the excitation wavelength. Three resonance levels were tentatively attributed to the presence of pure electronic transitions in band IV of the absorption spectra of these compounds. (author)

  6. Enhancements in Magnesium Die Casting Impact Properties

    David Schwam; John F. Wallace; Yulong Zhu; Srinath Viswanathan; Shafik Iskander

    2000-06-30

    The need to produce lighter components in transportation equipment is the main driver in the increasing demand for magnesium castings. In many automotive applications, components can be made of magnesium or aluminum. While being lighter, often times the magnesium parts have lower impact and fatigue properties than the aluminum. The main objective of this study was to identify potential improvements in the impact resistance of magnesium alloys. The most common magnesium alloys in automotive applications are AZ91D, AM50 and AM60. Accordingly, these alloys were selected as the main candidates for the study. Experimental quantities of these alloys were melted in an electrical furnace under a protective atmosphere comprising sulfur hexafluoride, carbon dioxide and dry air. The alloys were cast both in a permanent mold and in a UBE 315 Ton squeeze caster. Extensive evaluation of tensile, impact and fatigue properties was conducted at CWRU on permanent mold and squeeze cast test bars of AZ91, AM60 and AM50. Ultimate tensile strength values between 20ksi and 30ksi were obtained. The respective elongations varied between 25 and 115. the Charpy V-notch impact strength varied between 1.6 ft-lb and 5 ft-lb depending on the alloy and processing conditions. Preliminary bending fatigue evaluation indicates a fatigue limit of 11-12 ksi for AM50 and AM60. This is about 0.4 of the UTS, typical for these alloys. The microstructures of the cast specimens were investigated with optical and scanning electron microscopy. Concomitantly, a study of the fracture toughness in AM60 was conducted at ORNL as part of the study. The results are in line with values published in the literature and are representative of current state of the art in casting magnesium alloys. The experimental results confirm the strong relationship between aluminum content of the alloys and the mechanical properties, in particular the impact strength and the elongation. As the aluminum content increases from about 5

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

    Nabiyouni, Maryam, E-mail: maryam.nabiyouni@rockets.utoledo.edu [Department of Bioengineering, University of Toledo, Toledo, OH (United States); Ren, Yufu [Department of Mechanical, Industrial and Manufacturing Engineering, University of Toledo, Toledo, OH (United States); Bhaduri, Sarit B. [Department of Mechanical, Industrial and Manufacturing Engineering, University of Toledo, Toledo, OH (United States); Department of Surgery (Dentistry), University of Toledo, Toledo, OH (United States)

    2015-07-01

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

  8. Two-photon cooling of magnesium atoms

    Malossi, N.; Damkjær, S.; Hansen, P. L.;

    2005-01-01

    A two-photon mechanism for cooling atoms below the Doppler temperature is analyzed. We consider the magnesium ladder system (3s2)S01¿(3s3p)P11 at 285.2nm followed by the (3s3p)P11¿(3s3d)D21 transition at 880.7nm . For the ladder system quantum coherence effects may become important. Combined...

  9. Amalgam-chromatographic separation of magnesium isotopes

    Separation of magnesium isotopes within Mg(Hg)-MgI2 system (in dimethylformamide) is conducted under amalgam-chromatographic conditions. Separation maximal degree, that is (1.09), for 24 Mg and 26 Mg and separation coefficient (α = 1.0089±0.006) are determined. Light isotopes are found to concentrate in the amalgam. Technique of thermal conversion of flows within amalgam-dimethylformamide system is suggested on the basis of reversible reaction of Ca-Mg element exchange

  10. Accumulation of satellites

    Formation and evolution of circumplanetary satellite swarms are investigated. Characteristic times of various processes are estimated. The characteristic time for the accumulation of the bodies in the swarm was several orders of magnitude shorter than that of the planet, i.e. than the time of the replenishment of the material by the swarm (108 yr). The model of the accumulation of the swarm is constructed taking into account the increase of its mass due to trapping of heliocentrically moving particles and its decrease due to outfall of the inner part of the swarm onto the growing planet. The accumulation of circumplanetary bodies is also considered. The main features of the evolution of the swarm essentially depend on the size distribution of bodies in the swarm and in the zone of the planet and also on the degree of the concentration of the swarm mass toward the planet. If the sum of the exponents of the inverse power laws of these distributions is less than 7, the model of the transparent swarm developed in this paper should be preferred. When this sum is greater than 7, the model of opaque swarm suggested by A. Harris and W.M. Kaula is better. There is predominant trapping of small particles into the swarm due to their more frequent collisions. Optical thickness of the protoplanetary cloud in radial direction is estimated. It is shown that at the final stage of the planetary accumulation, the cloud was semitransparent in the region of terrestrial planets and volatile substances evaporated at collisions could be swept out from the outer parts of the satellite swarm by the solar wind