Struvite crystallization versus amorphous magnesium and calcium phosphate precipitation during the treatment of a saline industrial wastewater.

PubMed

Crutchik, D; Garrido, J M

2011-01-01

Struvite crystallization (MgNH(4)PO(4)·6H(2)O, MAP) could be an alternative for the sustainable and economical recovery of phosphorus from concentrated wastewater streams. Struvite precipitation is recommended for those wastewaters which have high orthophosphate concentration. However the presence of a cheap magnesium source is required in order to make the process feasible. For those wastewater treatment plants (WWTP) located near the seashore magnesium could be economically obtained using seawater. However seawater contains calcium ions that could interfere in the process, by promoting the precipitation of amorphous magnesium and calcium phosphates. Precipitates composition was affected by the NH(4)(+)/PO(4)(3-) molar ratio used. Struvite or magnesium and calcium phosphates were obtained when NH(4)(+)/PO(4)(3-) was fixed at 4.7 or 1.0, respectively. This study demonstrates that by manipulating the NH(4)(+)/PO(4)(3-) it is possible to obtain pure struvite crystals, instead of precipitates of amorphous magnesium and calcium phosphates. This was easily performed by using either raw or secondary treated wastewater with different ammonium concentrations.

Phosphate Adsorption from Membrane Bioreactor Effluent Using Dowex 21K XLT and Recovery as Struvite and Hydroxyapatite

PubMed Central

Nur, Tanjina; Loganathan, Paripurnanda; Kandasamy, Jaya; Vigneswaran, Saravanamuthu

2016-01-01

Discharging phosphate through wastewaters into waterways poses a danger to the natural environment due to the serious risks of eutrophication and health of aquatic organisms. However, this phosphate, if economically recovered, can partly overcome the anticipated future scarcity of phosphorus (P) resulting from exhaustion of natural phosphate rock reserves. An experiment was conducted to determine the efficiency of removing phosphate from a membrane bioreactor effluent (pH 7.0–7.5, 20, 35 mg phosphate/L) produced in a water reclamation plant by adsorption onto Dowex 21K XLT ion exchange resin and recover the phosphate as fertilisers. The data satisfactorily fitted to Langmuir adsorption isotherm with a maximum adsorption capacity of 38.6 mg·P/g. The adsorbed phosphate was quantitatively desorbed by leaching the column with 0.1 M NaCl solution. The desorbed phosphate was recovered as struvite when ammonium and magnesium were added at the molar ratio of phosphate, ammonium and magnesium of 1:1:1 at pH 9.5. Phosphate was also recovered from the desorbed solution as hydroxyapatite precipitate by adding calcium hydroxide to the solution at a phosphate to calcium molar ratio of 1:2 at pH 7.0. The P contents of struvite and hydroxyapatite produced were close to those of the respective commercial phosphate fertilisers. PMID:26950136

40 CFR 180.930 - Inert ingredients applied to animals; exemptions from the requirement of a tolerance.

Code of Federal Regulations, 2014 CFR

2014-07-01

... di- and monohydrogen phosphate esters and the corresponding ammonium, calcium, magnesium, monoethanolamine, potassium, sodium and zinc salts of the phosphate esters; minimum oxyethylene content averages 2..., density control agent Benzoic acid Preservative for formulations 2-Bromo-2-nitro-1,3-propanediol (CAS Reg...

40 CFR 180.930 - Inert ingredients applied to animals; exemptions from the requirement of a tolerance.

Code of Federal Regulations, 2011 CFR

2011-07-01

... without polyoxypropylene, mixture of di- and monohydrogen phosphate esters and the corresponding ammonium, calcium, magnesium, monoethanolamine, potassium, sodium and zinc salts of the phosphate esters; minimum..., density control agent Benzoic acid Preservative for formulations 2-Bromo-2-nitro-1,3-propanediol (CAS Reg...

Laboratory experiments on simultaneous removal of K and P from synthetic and real urine for nutrient recycle by crystallization of magnesium-potassium-phosphate-hexahydrate in a draft tube and baffle reactor.

PubMed

Xu, Kangning; Wang, Chengwen; Wang, Xiaoxue; Qian, Yi

2012-06-01

The simultaneous removal of K and P from urine for nutrient recycling by crystallization of magnesium potassium phosphate hexahydrate (MPP) in a laboratory-scale draft tube and baffle reactor (DTBR) is investigated. Results show that mixing speed and hydraulic retention time are important operating factors that influence crystallization and crystal settlement. Slurry should be discharged at a crystal retention time of 11 h to maintain fluidity in the reactor. Further applications of the DTBR using real urine (pretreated by ammonia stripping and diluted five times) showed that 76% K and 68% P were recycled to multi-nutrient products. The crystals collected were characterized and confirmed mainly as a mixture of magnesium ammonium phosphate hexahydrate, MPP, and magnesium sodium phosphate heptahydrate. Results indicate that the DTBR effectively achieved the simultaneous recycling of K and P from urine to multi-nutrient products through MPP crystallization. Copyright © 2012 Elsevier Ltd. All rights reserved.

40 CFR 180.930 - Inert ingredients applied to animals; exemptions from the requirement of a tolerance.

Code of Federal Regulations, 2013 CFR

2013-07-01

...-hydroxypolyoxyethylene polymer with or without polyoxypropylene, mixture of di- and monohydrogen phosphate esters and the corresponding ammonium, calcium, magnesium, monoethanolamine, potassium, sodium and zinc salts of the phosphate... Reg. No. 7727-43-7) Carrier, density control agent Benzoic acid Preservative for formulations 2-Bromo...

40 CFR 180.930 - Inert ingredients applied to animals; exemptions from the requirement of a tolerance.

Code of Federal Regulations, 2012 CFR

2012-07-01

...-hydroxypolyoxyethylene polymer with or without polyoxypropylene, mixture of di- and monohydrogen phosphate esters and the corresponding ammonium, calcium, magnesium, monoethanolamine, potassium, sodium and zinc salts of the phosphate..., density control agent Benzoic acid Preservative for formulations 2-Bromo-2-nitro-1,3-propanediol (CAS Reg...

Chemical composition and binary mixture of human urinary stones using FT-Raman spectroscopy method.

PubMed

Selvaraju, R; Raja, A; Thiruppathi, G

2013-10-01

In the present study the human urinary stones were observed in their different chemical compositions of calcium oxalate monohydrate, calcium oxalate dihydrate, calcium phosphate, struvite (magnesium ammonium phosphate), uric acid, cystine, oxammite (ammonium oxalate monohydrate), natroxalate (sodium oxalate), glushinkite (magnesium oxalate dihydrate) and moolooite (copper oxalate) were analyzed using Fourier Transform-Raman (FT-Raman) spectroscopy. For the quantitative analysis, various human urinary stone samples are used for ratios calculation of binary mixtures compositions such as COM/COD, HAP/COD, HAP/COD, Uric acid/COM, uric acid/COD and uric acid/HAP. The calibration curve is used for further analysis of binary mixture of human urinary stones. For the binary mixture calculation the various intensities bands at 1462 cm(-1) (I(COM)), 1473 cm(-1) (I(COD)), 961 cm(-1) (I(HAP)) and 1282 cm(-1) (I(UA)) were used. Copyright © 2013 Elsevier B.V. All rights reserved.

Recovery of nitrogen from saponification wastewater by struvite precipitation.

PubMed

Huang, Haiming; Xiao, Xianming; Yang, Liping; Yan, Bo

2010-01-01

In general, saponification wastewater produced from the separation process of rare-earth elements contains high ammonium concentration. In this study, a series of experiments were conducted to investigate the parameters to enhance the struvite precipitation potential for ammonium removal from the wastewater having an ammonium concentration of 4,100 mg/L. Experimental results showed that increasing the dose and grain size of pre-formed struvite, which was added as the seeding material in struvite reaction, could increase ammonium removal. The removal efficiency increased 7.6% when the dose of pre-formed struvite with crystal grain size range of 0.098-0.150 mm increased from 0 g/L to 60 g/L. Additionally, struvite precipitation was tested with the intermittent addition of magnesium and phosphate to utilize the struvite crystals formed during the reaction process as the seeding material for the subsequent reaction. The results revealed that intermittently adding magnesium 7 times effectively enhanced ammonium removal by around 8%, which was equivalent to that of using pre-formed struvite as the seeding material. Furthermore, the chemical composition of the struvite recovered with intermittent addition of magnesium was characterized, showing the struvite could be used as fertilizer. An economic evaluation indicated that intermittent addition of magnesium 7 times can save 13.4% cost for recovering per kg NH(4)(+) compared to that of bulk addition.

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

PubMed

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

2011-09-01

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

A combined qualitative and quantitative procedure for the chemical analysis of urinary calculi

PubMed Central

Hodgkinson, A.

1971-01-01

A better understanding of the physico-chemical principles underlying the formation of calculus has led to a need for more precise information on the chemical composition of stones. A combined qualitative and quantitative procedure for the chemical analysis of urinary calculi which is suitable for routine use is presented. The procedure involves five simple qualitative tests followed by the quantitative determination of calcium, magnesium, inorganic phosphate, and oxalate. These data are used to calculate the composition of the stone in terms of calcium oxalate, apatite, and magnesium ammonium phosphate. Analytical results and derived values for five representative types of calculi are presented. PMID:5551382

Waffle production: influence of batter ingredients on sticking of waffles at baking plates-Part II: effect of fat, leavening agent, and water.

PubMed

Huber, Regina; Schoenlechner, Regine

2017-05-01

Fresh egg waffles are continuously baked in tunnel baking ovens in industrial scale. Waffles that partly or fully stick to the baking plates cause significant product loss and increased costs. The aim of this study was, therefore, to investigate the effect of different recipe ingredients on the sticking behavior of waffles. In this second part, ingredients investigated were different leavening agents (sodium acid pyrophosphate, ammonium bicarbonate, magnesium hydroxide carbonate, or monocalcium phosphate), different fat sources (rapeseed oil, cocos fat, butter, or margarine), and different water sources (tap water 12°dH and distilled water). Within the different types of fats, solid fats with high amount of short-chain fatty acids (cocos fat or butter) decreased the number of sticking waffles compared to liquid oils (rapeseed oil). Regarding leavening agents, magnesium hydroxide carbonate and ammonium bicarbonate were superior to sodium acid pyrophosphate or monocalcium phosphate. Between the two water sources, effects were small.

In Vivo Evaluation of Chemical Composition of Eight Types of Urinary Calculi Using Spiral Computerized Tomography in a Chinese Population.

PubMed

Huo, Jun; Liu, Zhong-Yuan; Wang, Ke-Feng; Xu, Zhen-Qun

2015-09-01

This study was conducted to evaluate the chemical composition of eight types of urinary calculi using spiral computerized tomography (CT) in vivo. From October 2011 to February 2013, upper urinary tract calculi were obtained from 122 patients in the department of urinary surgery of the First Affiliated Hospital of Soochow University. All patients were scanned with a 64-detector row helical CT scanner using 6.50 mm collimation before ureterorenoscopy. Data from the preoperative spiral CT scans and postoperative chemical composition of urinary calculi were collected. The chemical composition analysis indicates that there were five types of pure calculi and three types of mixed calculi, including 39 calcium oxalate calculi, 12 calcium phosphate calculi, 10 calcium carbonate calculi, 8 magnesium ammonium phosphate calculi, 6 carbonated apatite, 21 uric acid/ammonium urate calculi, 10 uric acid/calcium oxalate calculi, and 16 calcium oxalate/calcium phosphate calculi. There were significant differences in the mean CT values among the five types of pure calculi (P < 0.001). Furthermore, we also observed significant differences in the mean CT values among three types of mixed calculi (P < 0.001). Significant differences in the mean CT values were also found among eight types of urinary calculi (P < 0.001). However, no statistically significant difference was observed between the mean CT values of magnesium ammonium phosphate calculi and uric acid/calcium oxalate calculi (P = 0.262). Our findings suggest that spiral CT could be a promising tool for determining the chemical composition of upper urinary tract calculi. © 2014 Wiley Periodicals, Inc.

Bacillus stearothermophilus sporulation response to different composition media.

PubMed

Penna, T C; Machoshvili, I A; Taqueda, M E; Ferraz, C A

1998-01-01

To evaluate the effectiveness of 11 commonly used ingredients to improve Bacillus stearothermophilus ATCC 7953 sporulation, with high spore yields in a short period of incubation, 32 composition media were set up by a fractional factorial 2IV11-6 design at two levels: D-glucose (0.018-0.25%), L-glutamic acid (0.040-0.10%), yeast extract (0.050-0.40%), peptone (0.30-0.50%), sodium chloride (0.001-1.0%), magnesium sulfate (0.001-0.20%), ammonium phosphate (0.010-0.035%), potassium phosphate monobasic (0.050-0.25%), calcium chloride (0.001-0.05%), ferrous sulfate (0.0003-0.002%), manganese sulfate (0.001-0.50%). The largest variation on Log10 CFU response took place due to sodium chloride main effect, by changing it from low to high levels. Magnesium sulfate, calcium chloride, and ferrous sulfate were split and exerted no detectable main effect influence on sporulation. Setting up two 16 runs for sodium chloride effect, in each of which the remainder levels were kept constant, other components contribution was studied. At low sodium chloride, best average 7.25 Log10 CFU yielded by fastening yeast extract and peptone at high level, and remainders at low level. Considering high level of sodium chloride, peptone, yeast extract and ammonium phosphate kept at high level and remainders at low level confirmed the best sporulation yield. Adjusted models evidenced a strong influence of joint yeast/peptone effect, associated to ammonium phosphate contributing positively. The reduced incubation period from 15 days to 3-6 days at 62 degrees C was attained for all 32 experimental runs.

Recovery of phosphorous from industrial waste water by oxidation and precipitation.

PubMed

Ylmén, Rikard; Gustafsson, Anna M K; Camerani-Pinzani, Caterina; Steenari, Britt-Marie

2017-07-03

This paper describes the development of a method for recovery of phosphorous from one of the waste waters at an Akzo Nobel chemical plant in Ale close to Göteborg. It was found that it is possible to transform the phosphorous in the waste water to a saleable product, i.e. a slowly dissolving fertilizer. The developed process includes oxidation of phosphite to phosphate with hydrogen peroxide and heat. The phosphate is then precipitated as crystalline struvite (ammonium magnesium phosphate) by the addition of magnesium chloride. The environmental impacts of the new method were compared with those of the current method using life cycle assessment. It was found that the methodology developed in this project was an improvement compared with the current practice regarding element resource depletion and eutrophication. However, the effect on global warming would be greater with the new method. There could however be several ways to decrease the global warming effect. Since most of the carbon dioxide emissions come from the production of magnesium chloride from carbonates, changing to utilization of a magnesium chloride from desalination of seawater or from recycling of PVC would decrease the carbon footprint significantly.

Evaluation and thermodynamic calculation of ureolytic magnesium ammonium phosphate precipitation from UASB effluent at pilot scale.

PubMed

Desmidt, E; Ghyselbrecht, K; Monballiu, A; Verstraete, W; Meesschaert, B D

2012-01-01

The removal of phosphate as magnesium ammonium phosphate (MAP, struvite) has gained a lot of attention. A novel approach using ureolytic MAP crystallization (pH increase by means of bacterial ureases) has been tested on the anaerobic effluent of a potato processing company in a pilot plant and compared with NuReSys(®) technology (pH increase by means of NaOH). The pilot plant showed a high phosphate removal efficiency of 83 ± 7%, resulting in a final effluent concentration of 13 ± 7 mg · L(-1) PO(4)-P. Calculating the evolution of the saturation index (SI) as a function of the remaining concentrations of Mg(2+), PO(4)-P and NH(4)(+) during precipitation in a batch reactor, resulted in a good estimation of the effluent PO(4)-P concentration of the pilot plant, operating under continuous mode. X-ray diffraction (XRD) analyses confirmed the presence of struvite in the small single crystals observed during experiments. The operational cost for the ureolytic MAP crystallization treating high phosphate concentrations (e.g. 100 mg · L(-1) PO(4)-P) was calculated as 3.9 € kg(-1) P(removed). This work shows that the ureolytic MAP crystallization, in combination with an autotrophic nitrogen removal process, is competitive with the NuReSys(®) technology in terms of operational cost and removal efficiency but further research is necessary to obtain larger crystals.

Statistical media design for efficient polyhydroxyalkanoate production in Pseudomonas sp. MNNG-S.

PubMed

Saranya, V; Rajeswari, V; Abirami, P; Poornimakkani, K; Suguna, P; Shenbagarathai, R

2016-07-03

Polyhydroxyalkanoate (PHA) is a promising polymer for various biomedical applications. There is a high need to improve the production rate to achieve end use. When a cost-effective production was carried out with cheaper agricultural residues like molasses, traces of toxins were incorporated into the polymer, which makes it unfit for biomedical applications. On the other hand, there is an increase in the popularity of using chemically defined media for the production of compounds with biomedical applications. However, these media do not exhibit favorable characteristics such as efficient utilization at large scale compared to complex media. This article aims to determine the specific nutritional requirement of Pseudomonas sp. MNNG-S for efficient production of polyhydroxyalkanoate. Response surface methodology (RSM) was used in this study to statistically design for PHA production based on the interactive effect of five significant variables (sucrose; potassium dihydrogen phosphate; ammonium sulfate; magnesium sulfate; trace elements). The interactive effects of sucrose with ammonium sulfate, ammonium sulfate with combined potassium phosphate, and trace element with magnesium sulfate were found to be significant (p < .001). The optimization approach adapted in this study increased the PHA production more than fourfold (from 0.85 g L(-1) to 4.56 g L(-1)).

Study on Release Characteristics and Recovery of Nitrogen and Phosphorus during the Anaerobic Fermentation of Excess Sludge

NASA Astrophysics Data System (ADS)

Qin, Yuqian; Hu, Shulong

2018-01-01

Ammonia nitrogen and phosphate are produced from activated excess sludge under anaerobic conditions,and will cause eutrophication upon release to the environment. A study of sludge from a eutrophication was carried out, to obtain knowledge of the nitrogen and phosphorus release patterns of the excess sludge during anaerobic fermentation and the recycling efficiency of both nitrogen and phosphorus, by adding magnesium salt and alkali solution to the supernatant liquors. The results showed that the concentration of ammonia nitrogen and phosphate of the supernatant liquors continued to increase during the process of anaerobic digestion, and both reached a maximum in 12 days, at 41.56mg / L and 47.02 mg / L respectively. By adding magnesium salt to the supernatant with c(Mg): c(P) = 1.1:1, adjusting pH value to 9.0 ∼ 9.5, phosphorus recovery rate reached up to 95.0%, while the recovery rate of ammonia was 47.4%, resulting in the formation of a sediment of magnesium ammonium phosphate, or MAP, which may he used as a high-quality fertilizer.

Degradation processes of reinforced concretes by combined sulfate–phosphate attack

DOE Office of Scientific and Technical Information (OSTI.GOV)

Secco, Michele, E-mail: michele.secco@unipd.it; Department of Civil, Environmental and Architectural Engineering; Lampronti, Giulio Isacco, E-mail: gil21@cam.ac.uk

2015-02-15

A novel form of alteration due to the interaction between hydrated cement phases and sulfate and phosphate-based pollutants is described, through the characterization of concrete samples from an industrial reinforced concrete building. Decalcification of the cement matrices was observed, with secondary sulfate and phosphate-based mineral formation, according to a marked mineralogical and textural zoning. Five alteration layers may be detected: the two outermost layers are characterized by the presence of gypsum–brushite solid solution phases associated with anhydrous calcium sulfates and phosphates, respectively, while a progressive increase in apatite and ammonium magnesium phosphates is observable in the three innermost layers, associatedmore » with specific apatite precursors (brushite, octacalcium phosphate and amorphous calcium phosphate, respectively). The heterogeneous microstructural development of secondary phases is related to the chemical, pH and thermal gradients in the attacked cementitious systems, caused by different sources of pollutants and the exposure to the sun's radiation.« less

21 CFR 184.1434 - Magnesium phosphate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Magnesium phosphate. 184.1434 Section 184.1434... Listing of Specific Substances Affirmed as GRAS § 184.1434 Magnesium phosphate. (a) Magnesium phosphate includes both magnesium phosphate, dibasic, and magnesium phosphate, tribasic. Magnesium phosphate, dibasic...

21 CFR 184.1434 - Magnesium phosphate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Magnesium phosphate. 184.1434 Section 184.1434... Listing of Specific Substances Affirmed as GRAS § 184.1434 Magnesium phosphate. (a) Magnesium phosphate includes both magnesium phosphate, dibasic, and magnesium phosphate, tribasic. Magnesium phosphate, dibasic...

21 CFR 184.1434 - Magnesium phosphate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Magnesium phosphate. 184.1434 Section 184.1434... Listing of Specific Substances Affirmed as GRAS § 184.1434 Magnesium phosphate. (a) Magnesium phosphate includes both magnesium phosphate, dibasic, and magnesium phosphate, tribasic. Magnesium phosphate, dibasic...

21 CFR 184.1434 - Magnesium phosphate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Magnesium phosphate. 184.1434 Section 184.1434 Food... Specific Substances Affirmed as GRAS § 184.1434 Magnesium phosphate. (a) Magnesium phosphate includes both magnesium phosphate, dibasic, and magnesium phosphate, tribasic. Magnesium phosphate, dibasic (MgHPO4·3H2O...

21 CFR 184.1434 - Magnesium phosphate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Magnesium phosphate. 184.1434 Section 184.1434... GRAS § 184.1434 Magnesium phosphate. (a) Magnesium phosphate includes both magnesium phosphate, dibasic, and magnesium phosphate, tribasic. Magnesium phosphate, dibasic (MgHPO4·3H2O, CAS Reg. No. 7782-0975...

Vaginal Calculus in a Woman With Mixed Urinary Incontinence and Vaginal Mesh Exposure.

PubMed

Winkelman, William D; Rabban, Joseph T; Korn, Abner P

2016-01-01

Vaginal calculi are extremely rare and are most commonly encountered in the setting of an urethrovaginal or vesicovaginal fistula. We present a case of a 72-year-old woman with mixed urinary incontinence and vaginal mesh exposure incidentally found to have a large vaginal calculus. We removed the calculus surgically and analyzed the components. Results demonstrated the presence of ammonium-magnesium phosphate hexahydrate and carbonate apatite.

Study of the recovery of phosphorus from struvite precipitation in supernatant line from anaerobic digesters of sludge.

PubMed

Xavier, Luciano Dias; Cammarota, Magali Christe; Yokoyama, Lídia; Volschan Junior, Isaac

2014-01-01

The goal of this work was to study the effective recovery of phosphorus from the supernatant of anaerobic digestion of sewage sludge by precipitation as struvite. The formation of struvite is envisioned as a promising process for nutrient removal and subsequent recovery, thus providing a strong incentive for its implementation, since the sewage is a renewable source of phosphorus. Struvite precipitation was obtained by controlled addition of Mg(OH)2 or MgCl2. We evaluated the removal of ammonia and phosphate under equimolar conditions of magnesium and magnesium stoichiometric excess of 100 to 200% relative to the limiting reagent, under a stirring speed of 300 rpm at pH 8, 9 and 10. The best condition was MgCl2 in 1:1 molar ratio to phosphate, considering the stoichiometric ratio [PO4(3-)]:[NH4(+)] of 0.13 (presented by raw sample). The results show the best cost-benefit ratio, removal of phosphate of 90.6% and ammonium removal of 29%, resulting in 23 mg l(-1) PO4(3-) and 265 mg l(-1) NH4(+) concentration in effluent.

Evaluation of Musa (Paradisiaca Linn. cultivar)--"Puttubale" stem juice for antilithiatic activity in albino rats.

PubMed

Prasad, K V; Bharathi, K; Srinivasan, K K

1993-10-01

The fresh juice of Musa stem (Puttubale) was tested for its antilithiatic activity. Zinc discs were implanted in the urinary bladder of albino rats to induce urolithiasis. The stones formed were mainly of magnesium ammonium phosphate with traces of calcium oxalate. Musa stem juice (3 mL/rat/day orally) was found to be effective in reducing the formation and also in dissolving the pre-formed stones.

Capacity and mechanisms of ammonium and cadmium sorption on different wetland-plant derived biochars.

PubMed

Cui, Xiaoqiang; Hao, Hulin; Zhang, Changkuan; He, Zhenli; Yang, Xiaoe

2016-01-01

The objective of this study was to investigate the relationship between Cd(2+)/NH4(+) sorption and physicochemical properties of biochars produced from different wetland plants. Biochars from six species of wetland plants (i.e., Canna indica, Pennisetum purpureum Schum, Thalia dealbata, Zizania caduciflora, Phragmites australis and Vetiveria zizanioides) were obtained at 500°C and characterized, and their sorption for ammonium and cadmium was determined. There were significant differences in elemental composition, functional groups and specific surface area among the biochars derived from different wetland plant species. Sorption of ammonium and cadmium on the biochars could be described by a pseudo second order kinetic model, and the simple Langmuir model fits the isotherm data better than the Freundlich or Temkin model. The C. indica derived biochar had the largest sorption capacity for NH4(+) and Cd(2+), with a maximum sorption of 13.35 and 125.8mgg(-1), respectively. P. purpureum Schum derived biochar had a similar maximum sorption (119.3mgg(-1)) for Cd(2+). Ammonium sorption was mainly controlled by cation exchange, surface complexation with oxygen-containing functional groups and the formation of magnesium ammonium phosphate compounds, whereas for Cd(2+) sorption, the formation of cadmium phosphate precipitates, cation exchange and binding to oxygen-containing groups were the major possible mechanisms. In addition, the sorption of ammonium and cadmium was not affected by surface area and microporosity of the biochars. Copyright © 2015 Elsevier B.V. All rights reserved.

Effects of three kinds of organic acids on phosphorus recovery by magnesium ammonium phosphate (MAP) crystallization from synthetic swine wastewater.

PubMed

Song, Yonghui; Dai, Yunrong; Hu, Qiong; Yu, Xiaohua; Qian, Feng

2014-04-01

P recovery from swine wastewater has become a great concern as a result of the high demand for P resources and its potential eutrophication effects on water ecosystems. The method of magnesium ammonium phosphate (MAP) crystallization was used to recover P from simulated swine wastewater, and the effects of three organic acids (citric acid, succinic acid and acetic acid) on P removal efficiency and rate at different pH values were investigated. The results indicated that the P removal efficiency was worst affected by citric acid in the optimal pH range of 9.0-10.5, followed by succinic acid and acetic acid, and the influencing extent of organic acids decreased with the increasing pH value. Due to the complexation between organic acid and Mg(2+)/NH4(+), all of three organic acids could inhibit the P removal rate at the beginning of the reaction, which showed positive correlation between the inhibition effects and the concentration of organic acids. The high concentration of citric acid could completely suppress the MAP crystallization reaction. Moreover, citric acid and succinic acid brought obvious effects on the morphology of the crystallized products. The experimental results also demonstrated that MAP crystals could be obtained in the presence of different kinds and concentrations of organic acids. Copyright © 2013 Elsevier Ltd. All rights reserved.

Magnesium modifies the association between serum phosphate and the risk of progression to end-stage kidney disease in patients with non-diabetic chronic kidney disease.

PubMed

Sakaguchi, Yusuke; Iwatani, Hirotsugu; Hamano, Takayuki; Tomida, Kodo; Kawabata, Hiroaki; Kusunoki, Yasuo; Shimomura, Akihiro; Matsui, Isao; Hayashi, Terumasa; Tsubakihara, Yoshiharu; Isaka, Yoshitaka; Rakugi, Hiromi

2015-10-01

It is known that magnesium antagonizes phosphate-induced apoptosis of vascular smooth muscle cells and prevents vascular calcification. Here we tested whether magnesium can also counteract other pathological conditions where phosphate toxicity is involved, such as progression of chronic kidney disease (CKD). We explored how the link between the risk of CKD progression and hyperphosphatemia is modified by magnesium status. A post hoc analysis was run in 311 non-diabetic CKD patients who were divided into four groups according to the median values of serum magnesium and phosphate. During a median follow-up of 44 months, 135 patients developed end-stage kidney disease (ESKD). After adjustment for relevant clinical factors, patients in the lower magnesium-higher phosphate group were at a 2.07-fold (95% CI: 1.23-3.48) risk for incident ESKD and had a significantly faster decline in estimated glomerular filtration rate compared with those in the higher magnesium-higher phosphate group. There were no significant differences in the risk of these renal outcomes among the higher magnesium-higher phosphate group and both lower phosphate groups. Incubation of tubular epithelial cells in high phosphate and low magnesium medium in vitro increased apoptosis and the expression levels of profibrotic and proinflammatory cytokine; these changes were significantly suppressed by increasing magnesium concentration. Thus, magnesium may act protectively against phosphate-induced kidney injury.

New agent to treat elevated phosphate levels: magnesium carbonate/calcium carbonate tablets.

PubMed

Meyer, Caitlin; Cameron, Karen; Battistella, Marisa

2012-01-01

In summary, Binaphos CM, a magnesium carbonate/calcium carbonate combination phosphate binder, is marketed for treating elevated phosphate levels in dialysis patients. Although studies using magnesium/calcium carbonate as a phosphate binder are short term with small numbers of patients, this phosphate binder has shown some promising results and may provide clinicians with an alternative for phosphate binding. Using a combination phosphate binder may reduce pill burden and encourage patient compliance. In addition to calcium and phosphate, it is imperative to diligently monitor magnesium levels in patients started on this medication, as magnesium levels may increase with longer duration of use. Additional randomized controlled trials are necessary to evaluate long-term efficacy and safety of this combination phosphate binder.

Phosphates (V) recovery from phosphorus mineral fertilizers industry wastewater by continuous struvite reaction crystallization process.

PubMed

Hutnik, Nina; Kozik, Anna; Mazienczuk, Agata; Piotrowski, Krzysztof; Wierzbowska, Boguslawa; Matynia, Andrzej

2013-07-01

Continuous DT MSMPR (Draft Tube Mixed Suspension Mixed Product Removal) crystallizer was provided with typical wastewater from phosphorus mineral fertilizers industry (pH < 4, 0.445 mass % of PO4(3-), inorganic impurities presence), dissolved substrates (magnesium and ammonium chlorides) and solution alkalising the environment of struvite MgNH4PO4·6H2O reaction crystallization process. Research ran in constant temperature 298 K assuming stoichiometric proportions of substrates or 20% excess of magnesium ions. Influence of pH (8.5-10) and mean residence time (900-3600 s) on product size distribution, its chemical composition, crystals shape, size-homogeneity and process kinetics was identified. Crystals of mean size ca. 25-37 μm and homogeneity CV 70-83% were produced. The largest crystals, of acceptable homogeneity, were produced using 20% excess of magnesium ions, pH 9 and mean residence time 3600 s. Under these conditions nucleation rate did not exceed 9 × 10(7) 1/(s m(3)) according to SIG (Size Independent Growth) MSMPR kinetic model. Linear crystal growth rate was 4.27 × 10(-9) m/s. Excess of magnesium ions influenced struvite reaction crystallization process yield advantageously. Concentration of phosphate(V) ions decreased from 0.445 to 9.2 × 10(-4) mass %. This can be regarded as a very good process result. In product crystals, besides main component - struvite, all impurities from wastewater were detected analytically. Copyright © 2013 Elsevier Ltd. All rights reserved.

Crystallization efficiencies of inorganic polyphosphate oligomers reacted with magnesium and calcium cations using anion-exchange chromatography with particulate formation-laser scattering detector.

PubMed

Ando, Masaki; Imadzu, Sakiyo; Kitagawa, Shinya; Ohtani, Hajime

2010-08-06

A particulate formation-laser scattering detector (PFLSD) was developed and used for evaluating the crystallization efficiency of inorganic polyphosphates (PPs) that reacted with either magnesium or calcium cations. As the solutions for reactive crystallization, 0.5 M ammonium buffer (pH 9.6) containing either 0.15 M MgCl(2) or 0.15 M CaCl(2) (MAP: magnesium ammonium phosphate and HAP: hydroxyapatite solution) were used. In the case of mono- and diphosphate (P1 and P2), the significant dependences of the particulate formation efficiency on various types of both P1/P2 and MAP/HAP reaction solutions were observed with the direct sample injection mode. The PFLSD was hyphenated with the anion-exchange chromatography and the dependence of the particulate formation efficiency on the polymerization degree (n(p)) of PP oligomers, separated chromatographically, was evaluated sequentially. The significant suppression of the particulate formation for PP oligomers was clearly confirmed, i.e., the MAP and HAP reaction solutions did not produce the particulates of the PP oligomers having an n(p) value of more than 3 and 5, respectively. As the overall tendency, the particulate formation efficiency in the case of the HAP solution was superior to that in the case of the MAP solution. Copyright 2010 Elsevier B.V. All rights reserved.

Data on snow chemistry of the Cascade-Sierra Nevada Mountains

USGS Publications Warehouse

Laird, L.B.; Taylor, Howard E.; Lombard, R.E.

1986-01-01

Snow chemistry data were measured for solutes found in snow core samples collected from the Cascade-Sierra Nevada Mountains from late February to mid-March 1983. The data are part of a study to assess geographic variations in atmospheric deposition in Washington, Oregon, and California. The constituents and properties include pH and concentrations of hydrogen ion, calcium, magnesium, sodium, potassium, chloride, sulfate, nitrate, fluoride, phosphate, ammonium, iron, aluminum, manganese, copper, cadmium, lead, and dissolved organic carbon. Concentrations of arsenic and bromide were below the detection limit. (USGS)

Effect of surface treatment on the corrosion properties of magnesium-based fibre metal laminate

NASA Astrophysics Data System (ADS)

Zhang, X.; Zhang, Y.; Ma, Q. Y.; Dai, Y.; Hu, F. P.; Wei, G. B.; Xu, T. C.; Zeng, Q. W.; Wang, S. Z.; Xie, W. D.

2017-02-01

The surface roughness, weight of phosphating film and wettability of magnesium alloy substrates after abrasion and phosphating treatment were investigated in this work. The interfacial bonding and corrosion properties of a magnesium-based fibre metal laminate (MgFML) were analysed. The results showed that the wettability of the magnesium alloy was greatly influenced by the surface roughness, and the rough surface possessed a larger surface energy and better wettability. The surface energy and wettability of the magnesium alloy were significantly improved by the phosphating treatment. After phosphating for 5 min, a phosphating film with a double-layer structure was formed on the magnesium substrate, and the weight of the phosphating film and the surface energy reached their maximum values. The surface energies of the phosphated substrate after abrasion with #120 and #3000 grit abrasive papers were 84.31 mJ/m2 and 83.65 mJ/m2, respectively. The wettability of the phosphated magnesium was significantly better than the abraded magnesium. The phosphated AZ31B sheet had a better corrosion resistance than the abraded AZ31B sheet within short times. The corrosion resistance of the magnesium alloy was greatly increased by being composited with glass fibre/epoxy prepregs.

40 CFR 180.910 - Inert ingredients used pre- and post-harvest; exemptions from the requirement of a tolerance.

Code of Federal Regulations, 2010 CFR

2010-07-01

... formulation Surfactant α-Alkyl(C6-C15)-ω-hydroxypoly(oxyethylene)sulfate, and its ammonium, calcium, magnesium... Alkyl (C8-C18) sulfate and its ammonium, calcium, isopropylamine, magnesium, potassium, sodium, and zinc..., 93917-76-1, 5297-93-8, 94266-36-1, 1002-89-7) Surfactant Ammonium stearate Surfactant Ammonium sulfate...

Effect of dosing time on the ammonium nitrogen disinhibition in autothermal thermophilic aerobic digestion for sewage sludge by chemical precipitation.

PubMed

Xu, Changwen; Yuan, Haiping; Lou, Ziyang; Zhang, Guofang; Gong, Junzhe; Zhu, Nanwen

2013-12-01

Magnesium ammonium phosphate (MAP) precipitation was introduced to remove ammonium nitrogen (NH4(+)-N) in autothermal thermophilic aerobic digestion (ATAD) in this study. The dosing time of MgCl2 · 6H2O and NaH2PO4 · 2H2O will influence the removal efficiency of ammonium nitrogen greatly, and the time interval of 2nd, 7th, 12th day were chosen in ATAD process. The lowest NH4(+)-N concentration was found in the 2nd day dosing digester, and 38.37% of VS removal rate was obtained after 12 days digestion, which achieved stabilization 9 days earlier than the non-dosing digester. It revealed that removal of ammonium nitrogen could accelerate the sludge stabilization process. Meanwhile, 49.30% of VS removal rate was found in the 2nd day dosing digester in the 21st day, much higher than that in the non-dosing digester, the 7th day dosing digester, and the 12th day dosing digester, with the corresponding value of 38.37%, 38.38% and 37.04%, respectively. Copyright © 2013 Elsevier Ltd. All rights reserved.

21 CFR 582.5434 - Magnesium phosphate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5434 Magnesium phosphate. (a) Product. Magnesium phosphate (di- and tribasic). (b...

21 CFR 582.5434 - Magnesium phosphate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5434 Magnesium phosphate. (a) Product. Magnesium phosphate (di- and tribasic). (b...

21 CFR 582.5434 - Magnesium phosphate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5434 Magnesium phosphate. (a) Product. Magnesium phosphate (di- and tribasic). (b...

21 CFR 582.5434 - Magnesium phosphate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5434 Magnesium phosphate. (a) Product. Magnesium phosphate (di- and tribasic). (b...

21 CFR 582.5434 - Magnesium phosphate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5434 Magnesium phosphate. (a) Product. Magnesium phosphate (di- and tribasic). (b...

Role of magnesium on the biomimetic deposition of calcium phosphate

NASA Astrophysics Data System (ADS)

Sarma, Bimal K.; Sarma, Bikash

2016-10-01

Biomimetic depositions of calcium phosphate (CaP) are carried out using simulated body fluid (SBF), calcifying solution and newly developed magnesium containing calcifying solution. Calcium phosphate has a rich phase diagram and is well known for its excellent biocompatibility and bioactivity. The most common phase is hydroxyapatite (HAp), an integral component of human bone and tooth, widely used in orthopedic and dental applications. In addition, calcium phosphate nanoparticles show promise for the targeted drug delivery. The doping of calcium phosphate by magnesium, zinc, strontium etc. can change the protein uptake by CaP nanocrystals. This work describes the role of magnesium on the nucleation and growth of CaP on Ti and its oxide substrates. X-ray diffraction studies confirm formation of HAp nanocrystals which closely resemble the structure of bone apatite when grown using SBF and calcifying solution. It has been observed that magnesium plays crucial role in the nucleation and growth of calcium phosphate. A low magnesium level enhances the crystallinity of HAp while higher magnesium content leads to the formation of amorphous calcium phosphate (ACP) phase. Interestingly, the deposition of ACP phase is rapid when magnesium ion concentration in the solution is 40% of calcium plus magnesium ions concentration. Moreover, high magnesium content alters the morphology of CaP films.

Phosphorus recovery as struvite from eutropic waters by XDA-7 resin.

PubMed

Li, Huanwen; Ye, Zhiping; Lin, Ying; Wang, Fengying

2012-01-01

Phosphorus releases into aquatic environment and its subsequent contribution to eutrophication have resulted in a widespread global pollution issue. However, phosphorus is a non-renewable source. The potential supplies of phosphorus are decreasing worldwide. Therefore, removal and recovery of phosphorus from the eutropic waters is important, emergent and necessary. In this research, experiments for recovering phosphate from eutropic waters by anion exchange combined with struvite precipitation were conducted. The results indicated that the prepared XDA-7 resin was an effective adsorbent for phosphate. The adsorption isotherm of XDA-7 resin was found to be a modified Freundlich type. The maximum phosphate adsorption (20.9 mg/g) occurred in the pH range of 6.0-8.0. Phosphate adsorbed on the XDA-7 resin was effectively desorbed with 8% NaCl solution, and the resin was able to be regenerated with 3% NaClO and 4% NaOH solutions. Phosphate desorbed from the resin was recovered as magnesium ammonium phosphate (struvite). The obtained struvite was analyzed by acid dissolution method, scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR). The struvite precipitate was found to be 75.8% in purity, a high-value fertilizer.

The Effect of Stone Composition on the Efficacy of Retrograde Intrarenal Surgery: Kidney Stones 1 - 3 cm in Diameter.

PubMed

Xue, Yuquan; Zhang, Peng; Yang, Xiaojie; Chong, Tie

2015-05-01

The goal of this study was to analyze the effect of stone composition on the efficacy of retrograde intrarenal surgery (RIRS) with kidney stones of 1-3 cm, 1-2 cm, and 2-3 cm in diameter. We undertook a retrospective analysis of 74 patients with kidney stones who underwent RIRS. The patients were divided into two groups based on stone composition: Group I (n=47) (calcium oxalate monohydrate and calcium phosphate) was the hard to fragment stone group and group II (n=27) (calcium oxalate dihydrate, magnesium ammonium phosphate, and uric acid) was the easy to fragment stone group. Forty-six patients with kidney stones 1 to 2 cm in diameter were divided into group A (n=30) (smaller than 20 mm, hard to fragment stones) and group B (n=16) (smaller than 20 mm, easy to fragment stones). Twenty-eight patients with stones 2 to 3 cm in diameter were divided into group C (n=17) (larger than 20 mm, hard to fragment stones) and group D (n=11) (larger than 20 mm, easy-to-crush stones). The stone clearance rates of group I and group II were 66.0% and 88.9%, respectively (P<0.05). The stone clearance rates of group A and group B were 73.3% and 100% (P<0.05). The stone clearance rates of group C and group D were 52.9% and 72.7%, respectively. Stone composition has a significant impact on the efficacy of RIRS in the management of 1 to 3 cm kidney stones. For 2-3 cm calcium oxalate dihydrate stones, uric acid stones, and magnesium ammonium phosphate stones, the outcome of RIRS treatment was relatively good, and RIRS is recommended.

Determination of phosphorus fertilizer soil reactions by Raman and synchrotron infrared microspectroscopy.

PubMed

Vogel, Christian; Adam, Christian; Sekine, Ryo; Schiller, Tara; Lipiec, Ewelina; McNaughton, Don

2013-10-01

The reaction mechanisms of phosphate-bearing mineral phases from sewage sludge ash-based fertilizers in soil were determined by Raman and synchrotron infrared microspectroscopy. Different reaction mechanisms in wet soil were found for calcium and magnesium (pyro-) phosphates. Calcium orthophosphates were converted over time to hydroxyapatite. Conversely, different magnesium phosphates were transformed to trimagnesium phosphate. Since the magnesium phosphates are unable to form an apatite structure, the plant-available phosphorus remains in the soil, leading to better growth results observed in agricultural pot experiments. The pyrophosphates also reacted very differently. Calcium pyrophosphate is unreactive in soil. In contrast, magnesium pyrophosphate quickly formed plant-available dimagnesium phosphate.

Effect of Oestrogen on Altering the Serum and Urinary Levels of Calcium, Phosphate and Magnesium in Hysterectomised Women Compared to Natural Menopausal South Indian Women: A Case Control Study.

PubMed

Sonu, Yeldose; Avinash, S S; Sreekantha; Arun Kumar, K; Malathi, M; Shivashankara, A R

2016-07-01

Given the paucity of studies conducted to know the effect of suddenness and earlier onset of endocrinological changes associated with hysterectomy, on the serum and urinary levels of calcium, magnesium and phosphate the present study was conducted to compare the levels of calcium, magnesium and phosphate in serum and urine of hysterectomised and natural menopausal south Indian women. This is a cross-sectional observational study. The study included three groups of 30 healthy premenopausal, 30 early surgical menopausal and 30 natural post menopausal women. Women suffering from any endocrine disease were excluded. Analysis was performed in serum and urine sample. The levels of calcium, magnesium and phosphate in serum and calcium/creatinine, magnesium/creatinine and phosphate/creatinine ratio were estimated in urine by spectrophotometric method. Hysterectomised women (serum calcium: 8.7 ± 0.09 mg/dl; urine calcium/creatinine: 0.16 ± 0.02) have significantly low serum calcium (p < 0.001) and high urinary calcium/creatinine (p = 0.002) ratio and post menopausal women (serum magnesium: 2.1 ± 0.03; serum phosphate: 4.4 ± 0.16; urinary calcium/creatinine: 0.17 ± 0.02; urinary magnesium/creatinine: 0.09 ± 0.01) have significantly high serum magnesium (p = 0.016), serum phosphate (p = 0.043) and high urinary calcium/creatinine (p = 0.002), magnesium/creatinine ratio (p = 0.025) compared to healthy pre menopausal women. Post menopausal women (serum calcium: 9.1 ± 0.08) have significantly high serum calcium and phosphate compared to hysterectomised women (serum phosphate: 3.93 ± 0.11). Hysterectomised women have significantly low serum calcium, oestrogen and high urinary calcium/creatinine ratio compared to healthy premenopausal women and low serum calcium and low serum phosphate compared to natural postmenopausal women. Natural postmenopausal women had low serum oestrogen and high serum magnesium, serum phosphate, urinary calcium creatinine ratio and urinary magnesium creatinine ratio compared to healthy premenopausal women.

Struvite urolithiasis in a litter of miniature Schnauzer dogs.

PubMed

Klausner, J S; Osborne, C A; O'Leary, T P; Gebhart, R N; Griffith, D P

1980-05-01

Magnesium ammonium phosphate calculi developed in the urinary bladders and urethras of four of five offspring of Miniature Schnauzer parents with recurrent struvite urolithiasis. Calculi were detected by radiograhy when the dogs were 12 to 15 months old. Males and females were affected. A significant number of urease-producing staphylococci were identified in the urine of three of four dogs before urolith formation, and in one dog after urolith formation. The dogs were evaluated until they were 26 months old. Serum concentrations of calcium, phosphorus, and magnesium were inside usual limits throughout the study. Abnormalities that might predispose to urinary tract infection were not identified by radiography or necropsy studies. In one dog, bladder calculi recurred after surgical removal of multiple cystoliths. In another, urethral obstruction and acute generalized pyelonephritis induced a lethal uremic crisis. Gross and microscopic lesions, detected after necropsy of all dogs with uroliths, were typical of bacterial infection.

Ammonium, Nitrate, and Phosphate Sorption to and Solute Leaching from Biochars Prepared from Corn Stover ( L.) and Oak Wood ( spp.).

PubMed

Hollister, C Colin; Bisogni, James J; Lehmann, Johannes

2013-01-01

Biochar (BC) was evaluated for nitrogen (N) and phosphorus (P) removal from aqueous solution to quantify its nutrient pollution mitigation potential in agroecosystems. Sorption isotherms were prepared for solutions of ammonium (NH), nitrate (NO), and phosphate (PO-P) using BC of corn ( L.) and oak ( spp.) feedstock, each pyrolyzed at 350 and 550°C highest treatment temperature (HTT). Sorption experiments were performed on original BC as well as on BC that went through a water extraction pretreatment (denoted WX-BC). Ammonium sorption was observed for WX-Oak-BC and WX-Corn-BC, and Freundlich model linearization showed that a 200°C increase in HTT resulted in a 55% decrease in * values for WX-Oak-BC and a 69% decrease in * for WX-Corn-BC. Nitrate sorption was not observed for any BC. Removing metals by water extraction from WX-Oak-350 and WX-Oak-550 resulted in a 25 to 100% decrease in phosphate removal efficiency relative to original Oak-350 and Oak-550, respectively. No PO-P sorption was observed using any Corn-BC. Calcium (Ca) leached from BC produced at 550°C was 63 and 104% higher than from BC produced at 350°C for corn and oak, respectively. Leaching of P was two orders of magnitude lower in WX-Oak-BC than in WX-Corn-BC, concurrent with similar difference in magnesium (Mg). Nitrate and NH leaching from consecutive water extractions of all tested BCs was mostly below detection limits. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

21 CFR 181.29 - Stabilizers.

Code of Federal Regulations, 2012 CFR

2012-04-01

... glycerophosphate. Calcium phosphate. Calcium hydrogen phosphate. Calcium oleate. Calcium acetate. Calcium carbonate. Calcium ricinoleate. Calcium stearate. Disodium hydrogen phosphate. Magnesium glycerophosphate. Magnesium...

21 CFR 181.29 - Stabilizers.

Code of Federal Regulations, 2010 CFR

2010-04-01

... glycerophosphate. Calcium phosphate. Calcium hydrogen phosphate. Calcium oleate. Calcium acetate. Calcium carbonate. Calcium ricinoleate. Calcium stearate. Disodium hydrogen phosphate. Magnesium glycerophosphate. Magnesium...

21 CFR 181.29 - Stabilizers.

Code of Federal Regulations, 2011 CFR

2011-04-01

... glycerophosphate. Calcium phosphate. Calcium hydrogen phosphate. Calcium oleate. Calcium acetate. Calcium carbonate. Calcium ricinoleate. Calcium stearate. Disodium hydrogen phosphate. Magnesium glycerophosphate. Magnesium...

21 CFR 181.29 - Stabilizers.

Code of Federal Regulations, 2013 CFR

2013-04-01

... glycerophosphate. Calcium phosphate. Calcium hydrogen phosphate. Calcium oleate. Calcium acetate. Calcium carbonate. Calcium ricinoleate. Calcium stearate. Disodium hydrogen phosphate. Magnesium glycerophosphate. Magnesium...

Changes in serum magnesium and phosphate in older hospitalised patients--correlation with muscle strength and risk factors for refeeding syndrome.

PubMed

Henderson, S; Boyce, F; Sumukadas, D; Witham, M D

2010-12-01

To evaluate changes in serum magnesium and phosphate over time in hospitalised older patients, examine whether such changes were associated with changes in muscle strength, and assess whether risk factors for refeeding syndrome were associated with falls in serum magnesium and phosphate. Community dwelling patients aged 70 and over, admitted to a specialist Medicine for the Elderly assessment unit were included in a prospective study. Weight, height, triceps skinfold thickness and mid arm circumference were recorded at baseline. Serum magnesium and phosphate was measured on admission, and at days 1, 2, 3, 5, 7, 10, 14, 21, 28 after admission, along with handgrip and quadriceps strength measured in the non-dominant limbs using a portable dynamometer. 43 patients were recruited with a mean age of 83.8 years (SD 7.5). 58% were female. Mean baseline serum magnesium and phosphate levels were 0.89 mmol/L and 1.07 mmol/L respectively. 10/43 patients had a fall in serum magnesium of at least 0.2 mmol/l from baseline and 20/43 had a similar fall in phosphate. No correlation was shown between these changes in electrolytes and muscle strength. Regression analyses did not show that risk factors for refeeding syndrome were associated with falls in electrolyte levels. Changes in serum magnesium and phosphate levels do not correlate with changes in muscle strength in older hospitalised patients. Risk factors for refeeding syndrome did not predict falls in serum phosphate or magnesium.

Use of magnesium as a drug in chronic kidney disease

PubMed Central

Wilkie, Martin

2012-01-01

From chronic kidney disease (CKD) Stage 4 onwards, phosphate binders are needed in many patients to prevent the development of hyperphosphataemia, which can result in disturbed bone and mineral metabolism, cardiovascular disease and secondary hyperparathyroidism. In this review, we re-examine the use of magnesium-containing phosphate binders for patients with CKD, particularly as their use circumvents problems such as calcium loading, aluminum toxicity and the high costs associated with other agents of this class. The use of magnesium hydroxide in the 1980s has been superseded by magnesium carbonate, as the hydroxide salt was associated with poor gastrointestinal tolerability, whereas studies with magnesium carbonate show much better gastrointestinal profiles. The use of combined magnesium- and calcium-based phosphate binder regimens allows a reduction in the calcium load, and magnesium and calcium regimen comparisons show that magnesium may be as effective a phosphate binder as calcium. A large well-designed trial has recently shown that a drug combining calcium acetate and magnesium carbonate was non-inferior in terms of lowering serum phosphate to sevelamer-HCl and had an equally good tolerability profile. Because of the high cost of sevelamer and lanthanum carbonate, the use of magnesium carbonate could be advantageous and drug acquisition cost savings would compensate for the cost of introducing routine magnesium monitoring, if this is thought to be necessary and not performed anyway. Moreover, given the potential cost savings, it may be time to re-investigate magnesium-containing phosphate binders for CKD patients with further well-designed clinical research using vascular end points. PMID:26069822

Electrothermal atomic absorption spectrometric determination of copper in nickel-base alloys with various chemical modifiers*1

NASA Astrophysics Data System (ADS)

Tsai, Suh-Jen Jane; Shiue, Chia-Chann; Chang, Shiow-Ing

1997-07-01

The analytical characteristics of copper in nickel-base alloys have been investigated with electrothermal atomic absorption spectrometry. Deuterium background correction was employed. The effects of various chemical modifiers on the analysis of copper were investigated. Organic modifiers which included 2-(5-bromo-2-pyridylazo)-5-(diethylamino-phenol) (Br-PADAP), ammonium citrate, 1-(2-pyridylazo)-naphthol, 4-(2-pyridylazo)resorcinol, ethylenediaminetetraacetic acid and Triton X-100 were studied. Inorganic modifiers palladium nitrate, magnesium nitrate, aluminum chloride, ammonium dihydrogen phosphate, hydrogen peroxide and potassium nitrate were also applied in this work. In addition, zirconium hydroxide and ammonium hydroxide precipitation methods have also been studied. Interference effects were effectively reduced with Br-PADAP modifier. Aqueous standards were used to construct the calibration curves. The detection limit was 1.9 pg. Standard reference materials of nickel-base alloys were used to evaluate the accuracy of the proposed method. The copper contents determined with the proposed method agreed closely with the certified values of the reference materials. The recoveries were within the range 90-100% with relative standard deviation of less than 10%. Good precision was obtained.

Magnesium prevents phosphate-induced vascular calcification via TRPM7 and Pit-1 in an aortic tissue culture model.

PubMed

Sonou, Tomohiro; Ohya, Masaki; Yashiro, Mitsuru; Masumoto, Asuka; Nakashima, Yuri; Ito, Teppei; Mima, Toru; Negi, Shigeo; Kimura-Suda, Hiromi; Shigematsu, Takashi

2017-06-01

Previous clinical and experimental studies have indicated that magnesium may prevent vascular calcification (VC), but mechanistic characterization has not been reported. This study investigated the influence of increasing magnesium concentrations on VC in a rat aortic tissue culture model. Aortic segments from male Sprague-Dawley rats were incubated in serum-supplemented high-phosphate medium for 10 days. The magnesium concentration in this medium was increased to demonstrate its role in preventing VC, which was assessed by imaging and spectroscopy. The mineral composition of the calcification was analyzed using Fourier transform infrared (FTIR) spectroscopic imaging, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) mapping. Magnesium supplementation of high-phosphate medium dose-dependently suppressed VC (quantified as aortic calcium content), and almost ablated it at 2.4 mm magnesium. The FTIR images and SEM-EDX maps indicated that the distribution of phosphate (as hydroxyapatite), phosphorus and Mg corresponded with calcium content in the aortic ring and VC. The inhibitory effect of magnesium supplementation on VC was partially reduced by 2-aminoethoxy-diphenylborate, an inhibitor of TRPM7. Furthermore, phosphate transporter-1 (Pit-1) protein expression was increased in tissues cultured in HP medium and was gradually-and dose dependently-decreased by magnesium. We conclude that a mechanism involving TRPM7 and Pit-1 underpins the magnesium-mediated reversal of high-phosphate-associated VC.

Effects of Magnesium on the Phosphate Toxicity in Chronic Kidney Disease: Time for Intervention Studies.

PubMed

Sakaguchi, Yusuke; Hamano, Takayuki; Isaka, Yoshitaka

2017-02-06

Magnesium, an essential mineral for human health, plays a pivotal role in the cardiovascular system. Epidemiological studies in the general population have found an association between lower dietary magnesium intake and an elevated risk of cardiovascular events. In addition, magnesium supplementation was shown to improve blood pressure control, insulin sensitivity, and endothelial function. The relationship between magnesium and cardiovascular prognosis among patients with chronic kidney disease (CKD) has been increasingly investigated as it is becoming evident that magnesium can inhibit vascular calcification, a prominent risk of cardiovascular events, which commonly occurs in CKD patients. Cohort studies in patients receiving dialysis have shown a lower serum magnesium level as a significant risk for cardiovascular mortality. Interestingly, the cardiovascular mortality risk associated with hyperphosphatemia is alleviated among those with high serum magnesium levels, consistent with in vitro evidence that magnesium inhibits high-phosphate induced calcification of vascular smooth muscle cells. Furthermore, a harmful effect of high phosphate on the progression of CKD is also attenuated among those with high serum magnesium levels. The potential usefulness of magnesium as a remedy for phosphate toxicity should be further explored by future intervention studies.

Effects of Magnesium on the Phosphate Toxicity in Chronic Kidney Disease: Time for Intervention Studies

PubMed Central

Sakaguchi, Yusuke; Hamano, Takayuki; Isaka, Yoshitaka

2017-01-01

Magnesium, an essential mineral for human health, plays a pivotal role in the cardiovascular system. Epidemiological studies in the general population have found an association between lower dietary magnesium intake and an elevated risk of cardiovascular events. In addition, magnesium supplementation was shown to improve blood pressure control, insulin sensitivity, and endothelial function. The relationship between magnesium and cardiovascular prognosis among patients with chronic kidney disease (CKD) has been increasingly investigated as it is becoming evident that magnesium can inhibit vascular calcification, a prominent risk of cardiovascular events, which commonly occurs in CKD patients. Cohort studies in patients receiving dialysis have shown a lower serum magnesium level as a significant risk for cardiovascular mortality. Interestingly, the cardiovascular mortality risk associated with hyperphosphatemia is alleviated among those with high serum magnesium levels, consistent with in vitro evidence that magnesium inhibits high-phosphate induced calcification of vascular smooth muscle cells. Furthermore, a harmful effect of high phosphate on the progression of CKD is also attenuated among those with high serum magnesium levels. The potential usefulness of magnesium as a remedy for phosphate toxicity should be further explored by future intervention studies. PMID:28178182

Assessment of source-based nitrogen removal alternatives in leather tanning industry wastewater.

PubMed

Zengin, G; Olmez, T; Doğruel, S; Kabdaşli, I; Tünay, O

2002-01-01

Nitrogen is an important parameter of leather tanning wastewaters. Magnesium ammonium phosphate (MAP) precipitation is a chemical treatment alternative for ammonia removal. In this study, a detailed source-based wastewater characterisation of a bovine leather tannery was made and nitrogen speciation as well as other basic pollutant parameter values was evaluated. This evaluation has led to definition of alternatives for source-based MAP treatment. MAP precipitation experiments conducted on these alternatives have yielded over 90% ammonia removal at pH 9.5 and using stoichiometric doses. Among the alternatives tested liming-deliming and bating-washing was found to be the most advantageous providing 71% ammonia removal.

Serum phosphate and magnesium in children recovering from severe acute undernutrition in Ethiopia: an observational study.

PubMed

Hother, Anne-Louise; Girma, Tsinuel; Rytter, Maren J H; Abdissa, Alemseged; Ritz, Christian; Mølgaard, Christian; Michaelsen, Kim F; Briend, André; Friis, Henrik; Kæstel, Pernille

2016-11-05

Children with severe acute malnutrition (SAM) have increased requirements for phosphorus and magnesium during recovery. If requirements are not met, the children may develop refeeding hypophosphatemia and hypomagnesemia. However, little is known about the effect of current therapeutic diets (F-75 and F-100) on serum phosphate (S-phosphate) and magnesium (S-magnesium) in children with SAM. Prospective observational study, with measurements of S-phosphate and S-magnesium at admission, prior to rehabilitation phase and at discharge in children aged 6-59 months admitted with SAM to Jimma Hospital, Ethiopia. Due to shortage of F-75, 25 (35 %) children were stabilized with diluted F-100 (75 kcal/100 ml). Of 72 children enrolled, the mean age was 32 ± 14 months, and edema was present in 50 (69 %). At admission, mean S-phosphate was 0.92 ± 0.34 mmol/L, which was low compared to normal values, but increased to 1.38 ± 0.28 mmol/L at discharge, after on average 16 days. Mean S-magnesium, at admission, was 0.95 ± 0.23 mmol/L, and increased to 1.13 ± 0.17 mmol/L at discharge. At discharge, 18 (51 %) children had S-phosphate below the normal range, and 3 (9 %) had S-phosphate above. Most children (83 %) had S-magnesium above normal range for children. Both S-phosphate and S-magnesium at admission were positively associated with serum albumin (S-albumin), but not with anthropometric characteristics or co-diagnoses. Using diluted F-100 for stabilization was not associated with lower S-phosphate or S-magnesium. Hypophosphatemia was common among children with SAM at admission, and still subnormal in about half of the children at discharge. This could be problematic for further recovery as phosphorus is needed for catch-up growth and local diets are likely to be low in bioavailable phosphorus. The high S-magnesium levels at discharge does not support that magnesium should be a limiting nutrient for growth in the F-100 diet. Although diluted F-100 (75 kcal/100 mL) is not designed for stabilizing children with SAM, it did not seem to cause lower S-phosphate than in children fed F-75.

The influence of phosphate, calcium and magnesium on matrix Gla-protein and vascular calcification: a systematic review.

PubMed

Houben, E; Neradova, A; Schurgers, L J; Vervloet, Marc

2016-01-01

Vitamin K-dependent matrix Gla protein (MGP) is a key inhibitor of vascular calcification (VC). MGP is synthesized by chondrocytes and vascular smooth muscle cells (VSMC) and the absence or inactivity of MGP results in excessive calcification of both growth plate and vasculature. Apart from its vitamin K dependency little is known about other factors that influence MGP metabolism. Phosphate, calcium and magnesium are involved in bone mineralization and play an important role in VC. In this review we provide a summary of the effect of phosphate, calcium, and magnesium on MGP metabolism. Elevated phosphate and calcium levels promote VC, in part by increasing the release of matrix vesicles (MV) that under the influence of calcium and phosphate become calcification competent. Phosphate and calcium simultaneously induce an upregulation of MGP protein and gene expression, which possibly inhibits calcification. Elevated phosphate levels did not change MGP protein levels in MV. On the contrary, elevated calcium concentrations caused a decrease of MGPloading in MV, which might in part explainthe calcifying effects of MV. Magnesium is a known inhibitor of VC. However, magnesium has been shown to have an inhibitory effect on MGP synthesis induced through downregulation of the calcium-sensing receptor and hereby causing a decrease in calcium induced MGP upregulation. There might also be stimulatory effect of magnesium on MGP in which the TRPM7 channel is involved. In conclusion there is a clear interaction between MGP and phosphate, calcium and magnesium. The upregulation of MGP by phosphate and calcium might be a cellular response that possibly results in the mitigation of VC.

Phosphate-dependent glutaminase in enterocyte mitochondria and its regulation by ammonium and other ions.

PubMed

Masola, B; Zvinavashe, E

2003-06-01

The effects of ammonium and other ions on phosphate dependent glutaminase (PDG) activity in intact rat enterocyte mitochondria were investigated. Sulphate and bicarbonate activated the enzyme in absence and presence of added phosphate. In presence of 10 mM phosphate, ammonium at concentrations <1 mM inhibited the enzyme. This inhibition was reversed by increased concentration of phosphate or sulphate. The inhibition of PDG by ammonium in presence of 10 mM phosphate was biphasic with respect to glutamine concentration, its effect being through a lowering of V(max) at glutamine concentration of

Phosphate conversion coating reduces the degradation rate and suppresses side effects of metallic magnesium implants in an animal model.

PubMed

Rahim, Muhammad Imran; Tavares, Ana; Evertz, Florian; Kieke, Marc; Seitz, Jan-Marten; Eifler, Rainer; Weizbauer, Andreas; Willbold, Elmar; Jürgen Maier, Hans; Glasmacher, Birgit; Behrens, Peter; Hauser, Hansjörg; Mueller, Peter P

2017-08-01

Magnesium alloys have promising mechanical and biological properties for the development of degradable implants. However, rapid implant corrosion and gas accumulations in tissue impede clinical applications. With time, the implant degradation rate is reduced by a highly biocompatible, phosphate-containing corrosion layer. To circumvent initial side effects after implantation it was attempted to develop a simple in vitro procedure to generate a similarly protective phosphate corrosion layer. To this end magnesium samples were pre-incubated in phosphate solutions. The resulting coating was well adherent during routine handling procedures. It completely suppressed the initial burst of corrosion and it reduced the average in vitro magnesium degradation rate over 56 days almost two-fold. In a small animal model phosphate coatings on magnesium implants were highly biocompatible and abrogated the appearance of gas cavities in the tissue. After implantation, the phosphate coating was replaced by a layer with an elemental composition that was highly similar to the corrosion layer that had formed on plain magnesium implants. The data demonstrate that a simple pre-treatment could improve clinically relevant properties of magnesium-based implants. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1622-1635, 2017. © 2016 Wiley Periodicals, Inc.

Study of the Thermal Properties and the Fire Performance of Flame Retardant-Organic PCM in Bulk Form

PubMed Central

Palacios, Anabel; De Gracia, Alvaro

2018-01-01

The implementation of organic phase change materials (PCMs) in several applications such as heating and cooling or building comfort is an important target in thermal energy storage (TES). However, one of the major drawbacks of organic PCMs implementation is flammability. The addition of flame retardants to PCMs or shape-stabilized PCMs is one of the approaches to address this problem and improve their final deployment in the building material sector. In this study, the most common organic PCM, Paraffin RT-21, and fatty acids mixtures of capric acid (CA), myristic acid (MA), and palmitic acid (PA) in bulk, were tested to improve their fire reaction. Several flame retardants, such as ammonium phosphate, melamine phosphate, hydromagnesite, magnesium hydroxide, and aluminum hydroxide, were tested. The properties of the improved PCM with flame retardants were characterized by thermogravimetric analyses (TGA), the dripping test, and differential scanning calorimetry (DSC). The results for the dripping test show that fire retardancy was considerably enhanced by the addition of hydromagnesite (50 wt %) and magnesium hydroxide (50 wt %) in fatty acids mixtures. This will help the final implementation of these enhanced PCMs in building sector. The influence of the addition of flame retardants on the melting enthalpy and temperatures of PCMs has been evaluated. PMID:29329212

46 CFR 148.220 - Ammonium nitrate-phosphate fertilizers.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 5 2012-10-01 2012-10-01 false Ammonium nitrate-phosphate fertilizers. 148.220 Section... § 148.220 Ammonium nitrate-phosphate fertilizers. (a) This section applies to the stowage and... nitrate and containing a maximum of 0.4 percent total added combustible material or containing a maximum...

46 CFR 148.220 - Ammonium nitrate-phosphate fertilizers.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 5 2014-10-01 2014-10-01 false Ammonium nitrate-phosphate fertilizers. 148.220 Section... § 148.220 Ammonium nitrate-phosphate fertilizers. (a) This section applies to the stowage and... nitrate and containing a maximum of 0.4 percent total added combustible material or containing a maximum...

46 CFR 148.220 - Ammonium nitrate-phosphate fertilizers.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 5 2013-10-01 2013-10-01 false Ammonium nitrate-phosphate fertilizers. 148.220 Section... § 148.220 Ammonium nitrate-phosphate fertilizers. (a) This section applies to the stowage and... nitrate and containing a maximum of 0.4 percent total added combustible material or containing a maximum...

46 CFR 148.220 - Ammonium nitrate-phosphate fertilizers.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 5 2011-10-01 2011-10-01 false Ammonium nitrate-phosphate fertilizers. 148.220 Section... § 148.220 Ammonium nitrate-phosphate fertilizers. (a) This section applies to the stowage and... nitrate and containing a maximum of 0.4 percent total added combustible material or containing a maximum...

Disinhibition of the ammonium nitrogen in autothermal thermophilic aerobic digestion for sewage sludge by chemical precipitation.

PubMed

Yuan, Haiping; Xu, Changwen; Zhu, Nanwen

2014-10-01

Magnesium ammonium phosphate (MAP) precipitation was introduced to remove ammonium nitrogen (NH4(+)-N) in autothermal thermophilic aerobic digestion (ATAD) in this study by addition of MgCl2 · 6H2O and NaH2PO4 · 2H2O. The results showed that the lowest NH4(+)-N concentration was found in the D2 digester after 2nd day dosing treatment and 38.12% of VS removal efficiency was obtained after 15 days ATAD treatment. Sludge stabilization was achieved in the D2 digester 6 days earlier than the non-dosing digester when 8.7 g/L MgCl2 · 6H2O and 6.7 g/L NaH2PO4 · 2H2O were added into the digester. Furthermore, the highest VS removal efficiency of 40.03% was observed after 21 days digestion in D2 digesters. Therefore, MAP precipitation was an effective method for the ammonium nitrogen disinhibition when 8.7 g/L MgCl2 · 6H2O and 6.7 g/L NaH2PO4 · 2H2O were added into on the 2nd day after the digester startup. Copyright © 2014 Elsevier Ltd. All rights reserved.

Metal cation controls phosphate release in the myosin ATPase.

PubMed

Ge, Jinghua; Huang, Furong; Nesmelov, Yuri E

2017-11-01

Myosin is an enzyme that utilizes ATP to produce a conformational change generating a force. The kinetics of the myosin reverse recovery stroke depends on the metal cation complexed with ATP. The reverse recovery stroke is slow for MgATP and fast for MnATP. The metal ion coordinates the γ phosphate of ATP in the myosin active site. It is accepted that the reverse recovery stroke is correlated with the phosphate release; therefore, magnesium "holds" phosphate tighter than manganese. Magnesium and manganese are similar ions in terms of their chemical properties and the shell complexation; hence, we propose to use these ions to study the mechanism of the phosphate release. Analysis of octahedral complexes of magnesium and manganese show that the partial charge of magnesium is higher than that of manganese and the slightly larger size of manganese ion makes its ionic potential smaller. We hypothesize that electrostatics play a role in keeping and releasing the abstracted γ phosphate in the active site, and the stronger electric charge of magnesium ion holds γ phosphate tighter. We used stable myosin-nucleotide analog complex and Raman spectroscopy to examine the effect of the metal cation on the relative position of γ phosphate analog in the active site. We found that in the manganese complex, the γ phosphate analog is 0.01 nm further away from ADP than in the magnesium complex. We conclude that the ionic potential of the metal cation plays a role in the retention of the abstracted phosphate. © 2017 The Protein Society.

Magnesium and Calcium in Isolated Cell Nuclei

PubMed Central

Naora, H.; Naora, H.; Mirsky, A. E.; Allfrey, V. G.

1961-01-01

The calcium and magnesium contents of thymus nuclei have been determined and the nuclear sites of attachment of these two elements have been studied. The nuclei used for these purposes were isolated in non-aqueous media and in sucrose solutions. Non-aqueous nuclei contain 0.024 per cent calcium and 0.115 per cent magnesium. Calcium and magnesium are held at different sites. The greater part of the magnesium is bound to DNA, probably to its phosphate groups. Evidence is presented that the magnesium atoms combined with the phosphate groups of DNA are also attached to mononucleotides. There is reason to believe that those DNA-phosphate groups to which magnesium is bound, less than 1/10th of the total, are metabolically active, while those to which histones are attached seem to be inactive. PMID:13727745

Impurities Removal in Seawater to Optimize the Magnesium Extraction

NASA Astrophysics Data System (ADS)

Natasha, N. C.; Firdiyono, F.; Sulistiyono, E.

2017-02-01

Magnesium extraction from seawater is promising way because magnesium is the second abundant element in seawater and Indonesia has the second longest coastline in the world. To optimize the magnesium extraction, the impurities in seawater need to be eliminated. Evaporation and dissolving process were used in this research to remove the impurities especially calcium in seawater. Seawater which has been evaporated from 100 ml to 50 ml was dissolved with variations solution such as oxalic acid and ammonium bicarbonate. The solution concentration is 100 g/l and it variations are 2 ml, 4 ml, 6 ml, 8 ml, 10 ml, 20 ml, 30 ml, 40 ml and 50 ml. This step will produce precipitate and filtrate then it will be analysed to find out the result of this process. The precipitate was analysed by X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM) but the filtrate was analysed by Inductively Coupled Plasma (ICP). XRD analysis shows that calcium oxalate and calcium carbonate were formed and ICP analysis shows that the remaining calcium in seawater using oxalic acid is about 0.01% and sodium 0.14% but when using ammonium bicarbonate the remaining calcium is 2.5% and sodium still more than 90%. The results show that both oxalic acid and ammonium bicarbonate can remove the impurities but when using oxalic acid, not only the impurities but also magnesium was precipitated. The conclusion of this research is the best solution to remove the impurities in seawater without precipitate the magnesium is using ammonium bicarbonate.

Effect of Mg(2+) doping on beta-alpha phase transition in tricalcium phosphate (TCP) bioceramics.

PubMed

Frasnelli, Matteo; Sglavo, Vincenzo M

2016-03-01

The beta to alpha transition in tricalcium phosphate (TCP) bioceramics containing different amount of magnesium was studied in the present work. Mg-doped TCP powder was obtained by solid-state reaction starting from pure calcium carbonate, ammonium phosphate dibasic and magnesium oxide powders. The β to α transformation temperature was identified by dilatometric and thermo-differential analyses. Small pellets produced by uniaxial pressing samples were employed to study the influence of Mg(2+) on the transition kinetic, after sintering at 1550°C and subsequent slow or fast cooling down to room temperature. The evolution of β- and α-TCP crystalline phases during each thermal treatment was determined by X-ray powder diffraction analysis combined with Rietveld method-based software An annealing treatment, suitable to reconvert metastable α phase to the more clinically suitable β phase, was also investigated. It is shown that the presence of magnesium within the TCP lattice strongly influences the kinetic of the β⇆α phase transition, promoting the spontaneous α→β reconversion even upon fast cooling, or slowing down the β→α transition during heating. Similarly, it allows the α→β transformation in TCP sintered components by optimized annealing treatment at 850°C. This work concerns the effect of Mg(2+) doping on the β→α phase reconstructive transition in tricalcium phosphate (TCP), one of the most important bio-resorbable materials for bone tissue regeneration. The transition occurs upon the sintering process and is has been shown to be strongly irreversible upon cooling, leading to technological issues such as poor mechanical properties and excessive solubility due to the presence of metastable α-phase. This paper points out the kinetic contribution of Mg(2+) on the spontaneous α→β reconversion also upon fast cooling (i.e. quenching). Moreover, an annealing treatment has been shown to be beneficial to remove the retained α-phase in sintered TCP components, the presence of Mg promoting the reconversion process. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Simultaneous removal of ammonium and phosphate by alkaline-activated and lanthanum-impregnated zeolite.

PubMed

He, Yinhai; Lin, Hai; Dong, Yingbo; Liu, Quanli; Wang, Liang

2016-12-01

Simultaneous ammonium and phosphate removal characteristics and mechanism, as well as the major influencing factors, such as pH, temperature and co-existing ions, onto NaOH-activated and lanthanum-impregnated zeolite (NLZ) were investigated. The phosphate adsorption increases from 0.2 mg g -1 for natural zeolite up to 8.96 mg g -1 for NLZ, while only a slight decrease on the ammonium adsorption capacity from 23.9 mg g -1 for NaOH-activated zeolite to 21.2 mg g -1 for NLZ was observed. The ammonium and phosphate adsorption showed little pH dependence in the range from pH 3 to 7, while it decreased sharply with the pH increased above pH 7. Adsorption of ammonium and phosphate could be well described by the pseudo-second-order model and the process was mainly governed by intra-particle diffusion. The Langmuir and Freundlich model can be acceptably applied to fit the experimental data, which suggested that adsorption was caused by both the monolayer and homogeneous coverage at specific and equal affinity sites available NLZ. The underlying mechanism for the specific adsorption of phosphate by NLZ was revealed with the aid of SEM-EDS, XPS, and FTIR analysis, and the formation of (LaO)(OH)PO 2 was verified to be the dominant pathway for selective phosphate adsorption by lanthanum-impregnated zeolite. While the removal mechanism of ammonium could be well interpreted by SEM-EDS, FTIR and ICP analysis, and ion-exchange was expected to be the main removal process for ammonium. The results indicate that NLZ could efficiently and simultaneously remove low concentration of ammonium and phosphate from contaminated waters. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effects of surface treatments and bonding types on the interfacial behavior of fiber metal laminate based on magnesium alloy

NASA Astrophysics Data System (ADS)

Zhang, Xi; Ma, Quanyang; Dai, Yu; Hu, Faping; Liu, Gang; Xu, Zouyuan; Wei, Guobing; Xu, Tiancai; Zeng, Qingwen; Xie, Weidong

2018-01-01

Fiber metal laminates based on magnesium alloys (MgFML) with different surface treatments and different bonding types were tested and analyzed. By using dynamic contact angle measurement and scanning electron microscopy (SEM), it was found that phosphating treatment can significantly improve the surface energy and wettability of magnesium alloy, and the surface energy of phosphated magnesium alloy was approximately 50% higher than that of abraded-only magnesium alloy. The single cantilever beam (SCB) test showed that the interfacial fracture energies of directly bonded MgFMLs based on abraded-only magnesium and abraded + phosphated magnesium were 650 J/m2 and 1030 J/m2, respectively, whereas the interfacial fracture energies of indirectly bonded MgFMLs were 1650 J/m2 and 2260 J/m2, respectively. Phosphating treatment and modified polypropylene interleaf were observed to improve the tensile strength and interfacial fracture toughness of MgFML. In addition, the rougher surface was more conducive to enhance the bonding strength and interfacial fracture toughness of MgFML.

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

PubMed

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

2015-01-01

As biocompatible materials, magnesium phosphates have received a lot of attention for orthopedic applications. During the last decade multiple studies have shown advantages for magnesium phosphate such as lack of cytotoxicity, biocompatibility, strong mechanical properties, and high biodegradability. The present study investigates the role of Mg(+2) and Ca(+2) ions in the structure of magnesium phosphate and calcium phosphate nanoparticles. To directly compare the effect of Mg(+2) and Ca(+2) ions on structure of nanoparticles and their biological behavior, three groups of nanoparticles including amorphous magnesium phosphates (AMPs) which release Mg(+2), calcium magnesium phosphates (CMPs) which release Mg(+2) and Ca(+2), and hydroxyapatites (HAs) which release Ca(+2) were studied. SEM, TEM, XRD, and FTIR were used to evaluate the morphology, crystallinity, and chemical properties of the particles. AMP particles were homogeneous nanospheres, whereas CMPs were combinations of heterogeneous nanorods and nanospheres, and HAs which contained heterogeneous nanosphere particles. Cell compatibility was monitored in all groups to determine the cytotoxicity effect of particles on studied MC3T3-E1 preosteoblasts. AMPs showed significantly higher attachment rate than the HAs after 1 day and both AMPs and CMPs showed significantly higher proliferation rate when compared to HAs after 7days. Gene expression level of osteoblastic markers ALP, COL I, OCN, OPN, RUNX2 were monitored and they were normalized to GAPDH housekeeping gene. Beta actin expression level was monitored as the second housekeeping gene to confirm the accuracy of results. In general, AMPs and CMPs showed higher expression level of osteoblastic genes after 7 days which can further confirm the stimulating role of Mg(+2) and Ca(+2) ions in increasing the proliferation rate, differentiation, and mineralization of MC3T3-E1 preosteoblasts. Copyright © 2015 Elsevier B.V. All rights reserved.

Renal Control of Calcium, Phosphate, and Magnesium Homeostasis

PubMed Central

Chonchol, Michel; Levi, Moshe

2015-01-01

Calcium, phosphate, and magnesium are multivalent cations that are important for many biologic and cellular functions. The kidneys play a central role in the homeostasis of these ions. Gastrointestinal absorption is balanced by renal excretion. When body stores of these ions decline significantly, gastrointestinal absorption, bone resorption, and renal tubular reabsorption increase to normalize their levels. Renal regulation of these ions occurs through glomerular filtration and tubular reabsorption and/or secretion and is therefore an important determinant of plasma ion concentration. Under physiologic conditions, the whole body balance of calcium, phosphate, and magnesium is maintained by fine adjustments of urinary excretion to equal the net intake. This review discusses how calcium, phosphate, and magnesium are handled by the kidneys. PMID:25287933

Nitrogen recovery from a stabilized municipal landfill leachate.

PubMed

Di Iaconi, Claudio; Pagano, Michele; Ramadori, Roberto; Lopez, Antonio

2010-03-01

The present paper reports the results of an investigation aimed at evaluating the effectiveness of magnesium ammonium phosphate precipitation (MAP), commonly called struvite, for removing ammonia from a mature municipal landfill leachate. MAP precipitation was carried out at laboratory scale by adding phosphoric acid and magnesium oxide as external sources of phosphorus and magnesium, respectively, and regulating the pH at 9.0. The effect of Mg:NH(4):PO(3) ratio was studied. Due to the low solubility of MgO, a low ammonia removal efficiency (i.e. 67%), with a rather high residual concentration, was obtained when the stoichiometric molar ratio was applied. However, by doubling the amount of magnesium oxide (i.e. by using a molar ratio of 2:1:1), ammonia removal efficiency increased up to 95% with a residual concentration compatible with a successive biological treatment. The struvite produced in the present study showed a composition close to the theoretical one. Furthermore, the precipitate was characterized by a heavy metal content much lower than that of typical raw soil, excluding any concern about heavy metal contamination in the case of its use as a fertilizer. The economic analysis of the process showed that ammonia can be removed at a cost of 9.6 euro/kg NH(4)-N(removed). This value can be greatly reduced, however, if the value of the struvite produced is considered. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

Calcium phosphate coatings on magnesium alloys for biomedical applications: a review.

PubMed

Shadanbaz, Shaylin; Dias, George J

2012-01-01

Magnesium has been suggested as a revolutionary biodegradable metal for use as an orthopaedic material. As a biocompatible and degradable metal, it has several advantages over the permanent metallic materials currently in use, including eliminating the effects of stress shielding, improving biocompatibility concerns in vivo and improving degradation properties, removing the requirement of a second surgery for implant removal. The rapid degradation of magnesium, however, is a double-edged sword as it is necessary to control the corrosion rates of the materials to match the rates of bone healing. In response, calcium phosphate coatings have been suggested as a means to control these corrosion rates. The potential calcium phosphate phases and their coating techniques on substrates are numerous and can provide several different properties for different applications. The reactivity and low melting point of magnesium, however, require specific parameters for calcium phosphate coatings to be successful. Within this review, an overview of the different calcium phosphate phases, their properties and their behaviour in vitro and in vivo has been provided, followed by the current coating techniques used for calcium phosphates that may be or may have been adapted for magnesium substrates. Copyright © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Energetic Materials Laboratory

DTIC Science & Technology

2015-04-30

regolith simulants mixed with magnesium, supported by NASA. It has also been used for studies on combustion synthesis of magnesium silicide , a...ammonium dinitramide based monopropellant.  The laser flash apparatus has been used for thermal diffusivities measurements for magnesium silicide and

Reduced toxicological activity of cigarette smoke by the addition of ammonia magnesium phosphate to the paper of an electrically heated cigarette: subchronic inhalation toxicology.

PubMed

Moennikes, O; Vanscheeuwijck, P M; Friedrichs, B; Anskeit, E; Patskan, G J

2008-05-01

Cigarette smoke is a complex chemical mixture that causes a variety of diseases, such as lung cancer. With the electrically heated cigarette smoking system (EHCSS), temperatures are applied to the tobacco below those found in conventional cigarettes, resulting in less combustion, reduced yields of some smoke constituents, and decreased activity in some standard toxicological tests. The first generation of electrically heated cigarettes (EHC) also resulted in increased formaldehyde yields; therefore, a second generation of EHC was developed with ammonium magnesium phosphate (AMP) in the cigarette paper in part to address this increase. The toxicological activity of mainstream smoke from these two generations of EHC and of a conventional reference cigarette was investigated in two studies in rats: a standard 90-day inhalation toxicity study and a 35-day inhalation study focusing on lung inflammation. Many of the typical smoke exposure-related changes were found to be less pronounced after exposure to smoke from the second-generation EHC with AMP than to smoke from the first-generation EHC or the conventional reference cigarette, when compared on a particulate matter or nicotine basis. Differences between the EHC without AMP and the conventional reference cigarette were not as prominent. Overall, AMP incorporated in the EHC cigarette paper reduced the inhalation toxicity of the EHCSS more than expected based on the observed reduction in aldehyde yields.

Renal control of calcium, phosphate, and magnesium homeostasis.

PubMed

Blaine, Judith; Chonchol, Michel; Levi, Moshe

2015-07-07

Calcium, phosphate, and magnesium are multivalent cations that are important for many biologic and cellular functions. The kidneys play a central role in the homeostasis of these ions. Gastrointestinal absorption is balanced by renal excretion. When body stores of these ions decline significantly, gastrointestinal absorption, bone resorption, and renal tubular reabsorption increase to normalize their levels. Renal regulation of these ions occurs through glomerular filtration and tubular reabsorption and/or secretion and is therefore an important determinant of plasma ion concentration. Under physiologic conditions, the whole body balance of calcium, phosphate, and magnesium is maintained by fine adjustments of urinary excretion to equal the net intake. This review discusses how calcium, phosphate, and magnesium are handled by the kidneys. Copyright © 2015 by the American Society of Nephrology.

Effect of nitrogen source concentration on curdlan production by Agrobacterium sp. ATCC 31749 grown on prairie cordgrass hydrolysates.

PubMed

West, Thomas P

2016-01-01

The effect of nitrogen source concentration on the production of the polysaccharide curdlan by the bacterium Agrobacterium sp. ATCC 31749 from hydrolysates of prairie cordgrass was examined. The highest curdlan concentrations were produced by ATCC 31749 when grown on a medium containing a solids-only hydrolysate and the nitrogen source ammonium phosphate (2.2 mM) or on a medium containing a complete hydrolysate and 3.3 mM ammonium phosphate. The latter medium sustained a higher level of bacterial curdlan production than the former medium after 144 hr. Biomass production by ATCC 31749 was highest after 144 hr when grown on a medium containing a solids-only hydrolysate and 2.2 or 8.7 mM ammonium phosphate. On the medium containing the complete hydrolysate, biomass production by ATCC 31749 was highest after 144 hr when 3.3 mM ammonium phosphate was present. Bacterial biomass production after 144 hr was greater on the complete hydrolysate medium compared to the solids-only hydrolysate medium. Curdlan yield produced by ATCC 31749 after 144 hr from the complete hydrolysate medium containing 3.3 mM ammonium phosphate was higher than from the solids-only hydrolysate medium containing 2.2 mM ammonium phosphate.

A study of phosphate absorption by magnesium iron hydroxycarbonate.

PubMed

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

2009-10-21

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

Acoustic and mechanical properties of renal calculi: implications in shock wave lithotripsy.

PubMed

Chuong, C J; Zhong, P; Preminger, G M

1993-12-01

The acoustic and mechanical properties of renal calculi dictate how a stone interacts with the mechanical forces produced by shock wave lithotripsy; thus, these properties are directly related to the success of the treatment. Using an ultrasound pulse transmission technique, we measured both longitudinal and transverse (or shear) wave propagation speeds in nine groups of renal calculi with different chemical compositions. We also measured stone density using a pycnometer based on Archimedes' principle. From these measurements, we calculated wave impedance and dynamic mechanical properties of the renal stones. Calcium oxalate monohydrate and cystine stones had higher longitudinal and transverse wave speeds, wave impedances, and dynamic moduli (bulk modulus, Young's modulus, and shear modulus), suggesting that these stones are more difficult to fragment. Phosphate stones (carbonate apatite and magnesium ammonium phosphate hydrogen) were found to have lower values of these properties, suggesting they are more amenable to shock wave fragmentation. These data provide a physical explanation for the significant differences in stone fragility observed clinically.

Nutrient availability at Mer Bleue bog measured by PRSTM probes

NASA Astrophysics Data System (ADS)

Wang, M.; Moore, T. R.; Talbot, J.

2015-12-01

Bogs, covering ~0.7 million km2 in Canada, store a large amount of C and N. As nutrient deficient ecosystems, it's critical to examine the nutrient availabilities and seasonal dynamics. We used Plant Root Simulators (PRSTM) at Mer Bleue bog to provide some baseline data on nutrient availability and its variability. In particular, we focused on ammonium, nitrate, phosphate, calcium, magnesium and potassium, iron, sulphate and aluminum. We placed PRS probes at a depth of 5 - 15 cm in pristine plots and plots with long term N, P and K fertilization for 4 weeks and determined the availability of these nutrients, from spring through to fall. Probes were also placed beneath the water table in hummock and hollow microtopography and along a transect including part of the bog which had been drained through the creation of a ditch 80 years ago. The result showed that there was limited available ammonium, nitrate and phosphate in the bog, the seasonal variation of nutrient availabilities probably due to mineralization, an increase in the availability of some nutrients between different water table depths or as a result of drainage, and the relative availability of nutrients compared to the input from fertilization. We suggest that PRS probes could be a useful tool to examine nutrient availability and dynamics in wetlands, with careful consideration of installing condition, for example, proper exposure period, depth relative to water table etc.

Investigation of the effectiveness of nutrient release from sludge foam after hybrid pretreatment processes by IR analysis and EDX Quantification.

PubMed

Machnicka, Alicja; Grübel, Klaudiusz

2016-12-01

One of the problems in wastewater treatment technologies is the formation of foam/scum. It is thought that filamentous microorganisms are responsible for foam formation and foam elimination/destruction can be carried out by various methods, among which disintegration is included. Hybrid disintegration (chemical decomposition and hydrodynamic cavitation) of foam microorganisms results in the transfer of phosphates, ammonium nitrogen, magnesium and potassium from the foam solids into the liquid phase. Application of both methods as a hybrid pretreatment process caused an increase in the concentration of phosphates of about 650 mg [Formula: see text] L(-1) and ammonium nitrogen of about 30 mg [Formula: see text] L(-1). The concentration of Mg(2+) and K(+) in the solution increased from 6.8 and 26.1 mg Mg(2+) L(-1) to 32.2 and 82.2 mg K(+) L(-1), respectively. The presence of nutrients and metal cations in the solid phase of foam was acknowledged by EDX Quantification. The confirmation of physico-chemical changes and release of cellular matter as a result of cellular lysis (hybrid disintegration) was done by infrared analysis. It was demonstrated that the disintegration of foam permits the removal of a part of nutrients in the form of struvite.

Processes for making dense, spherical active materials for lithium-ion cells

DOEpatents

Kang, Sun-Ho [Naperville, IL; Amine, Khalil [Downers Grove, IL

2011-11-22

Processes are provided for making dense, spherical mixed-metal carbonate or phosphate precursors that are particularly well suited for the production of active materials for electrochemical devices such as lithium ion secondary batteries. Exemplified methods include precipitating dense, spherical particles of metal carbonates or metal phosphates from a combined aqueous solution using a precipitating agent such as ammonium hydrogen carbonate, sodium hydrogen carbonate, or a mixture that includes sodium hydrogen carbonate. Other exemplified methods include precipitating dense, spherical particles of metal phosphates using a precipitating agent such as ammonium hydrogen phosphate, ammonium dihydrogen phosphate, sodium phosphate, sodium hydrogen phosphate, sodium dihydrogen phosphate, or a mixture of any two or more thereof. Further provided are compositions of and methods of making dense, spherical metal oxides and metal phosphates using the dense, spherical metal precursors. Still further provided are electrodes and batteries using the same.

40 CFR 180.910 - Inert ingredients used pre- and post-harvest; exemptions from the requirement of a tolerance.

Code of Federal Regulations, 2011 CFR

2011-07-01

... formulation Surfactant α-Alkyl(C6-C15)-ω-hydroxypoly(oxyethylene)sulfate, and its ammonium, calcium, magnesium..., related adjuvants of surfactants Alkyl (C8-C18) sulfate and its ammonium, calcium, isopropylamine... stearate Surfactant Ammonium sulfate Solid diluent, carrier Ammonium thiosulfate Intensifier when used with...

40 CFR 721.10302 - Zinc ammonium phosphate (generic).

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Zinc ammonium phosphate (generic). 721.10302 Section 721.10302 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10302 Zinc ammonium...

40 CFR 721.10302 - Zinc ammonium phosphate (generic).

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Zinc ammonium phosphate (generic). 721.10302 Section 721.10302 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10302 Zinc ammonium...

40 CFR 721.10302 - Zinc ammonium phosphate (generic).

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Zinc ammonium phosphate (generic). 721.10302 Section 721.10302 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10302 Zinc ammonium...

Magnesium Counteracts Vascular Calcification: Passive Interference or Active Modulation?

PubMed

Ter Braake, Anique D; Shanahan, Catherine M; de Baaij, Jeroen H F

2017-08-01

Over the last decade, an increasing number of studies report a close relationship between serum magnesium concentration and cardiovascular disease risk in the general population. In end-stage renal disease, an association was found between serum magnesium and survival. Hypomagnesemia was identified as a strong predictor for cardiovascular disease in these patients. A substantial body of in vitro and in vivo studies has identified a protective role for magnesium in vascular calcification. However, the precise mechanisms and its contribution to cardiovascular protection remain unclear. There are currently 2 leading hypotheses: first, magnesium may bind phosphate and delay calcium phosphate crystal growth in the circulation, thereby passively interfering with calcium phosphate deposition in the vessel wall. Second, magnesium may regulate vascular smooth muscle cell transdifferentiation toward an osteogenic phenotype by active cellular modulation of factors associated with calcification. Here, the data supporting these major hypotheses are reviewed. The literature supports both a passive inorganic phosphate-buffering role reducing hydroxyapatite formation and an active cell-mediated role, directly targeting vascular smooth muscle transdifferentiation. However, current evidence relies on basic experimental designs that are often insufficient to delineate the underlying mechanisms. The field requires more advanced experimental design, including determination of intracellular magnesium concentrations and the identification of the molecular players that regulate magnesium concentrations in vascular smooth muscle cells. © 2017 American Heart Association, Inc.

Two-Dimensional Magnesium Phosphate Nanosheets Form Highly Thixotropic Gels That Up-Regulate Bone Formation.

PubMed

Laurenti, Marco; Al Subaie, Ahmed; Abdallah, Mohamed-Nur; Cortes, Arthur R G; Ackerman, Jerome L; Vali, Hojatollah; Basu, Kaustuv; Zhang, Yu Ling; Murshed, Monzur; Strandman, Satu; Zhu, Julian; Makhoul, Nicholas; Barralet, Jake E; Tamimi, Faleh

2016-08-10

Hydrogels composed of two-dimensional (2D) nanomaterials have become an important alternative to replace traditional inorganic scaffolds for tissue engineering. Here, we describe a novel nanocrystalline material with 2D morphology that was synthesized by tuning the crystallization of the sodium-magnesium-phosphate system. We discovered that the sodium ion can regulate the precipitation of magnesium phosphate by interacting with the crystal's surface causing a preferential crystal growth that results in 2D morphology. The 2D nanomaterial gave rise to a physical hydrogel that presented extreme thixotropy, injectability, biocompatibility, bioresorption, and long-term stability. The nanocrystalline material was characterized in vitro and in vivo and we discovered that it presented unique biological properties. Magnesium phosphate nanosheets accelerated bone healing and osseointegration by enhancing collagen formation, osteoblasts differentiation, and osteoclasts proliferation through up-regulation of COL1A1, RunX2, ALP, OCN, and OPN. In summary, the 2D magnesium phosphate nanosheets could bring a paradigm shift in the field of minimally invasive orthopedic and craniofacial interventions because it is the only material available that can be injected through high gauge needles into bone defects in order to accelerate bone healing and osseointegration.

Inhibitory effect of phosphates on magnesium lactate efflorescence formation in dry-fermented sausages.

PubMed

Walz, Felix H; Gibis, Monika; Schrey, Pia; Herrmann, Kurt; Reichert, Corina L; Hinrichs, Jörg; Weiss, Jochen

2017-10-01

This study aimed to prevent the phenomena of efflorescence formation on the surface of dry fermented sausages due to the complexation of efflorescence forming cations with phosphates. Efflorescence formation is a critical issue constituting a major quality defect, especially of dry fermented sausages. Different phosphates (di- and hexametaphosphate) were added (3.0g/kg) to the sausage batter. As a hypothesis, these additives should complex with one of the main efflorescence-causing substances such as magnesium. The formation of efflorescences was determined for dry fermented sausages without phosphate addition, with diphosphate, or hexametaphosphate addition during 8weeks of storage under modified atmosphere. The visual analyses of the sausage surface revealed high amounts of efflorescences for the control (42.2%) and for the sausages with added diphosphate (40.9%), whereas the sausages containing hexametaphosphate had significantly reduced amounts of efflorescence formation, showing only 11.9% efflorescences after 8weeks of storage. This inhibition was a result of strong complexation of hexametaphosphate with magnesium ions, thus preventing the diffusion of magnesium towards the sausage surface. This can be explained by the magnesium content on the sausage surface that increased by 163.9, 127.8, and 52.8% for the sausages without phosphate, diphosphate, and hexametaphosphate addition, respectively. The mass transport of lactate and creatine was not affected by phosphate addition. Isothermal titration calorimetry confirmed that, theoretically, 4.5g/kg of diphosphate or 2.8g/kg hexametaphosphate are required to complex 0.2g/kg magnesium ions naturally occurring in dry fermented sausages and, thus, the chosen overall phosphate concentration of 3.0g/kg was enough when adding hexametaphosphate, but not for diphosphate, to inhibit the efflorescence formation. Copyright © 2017 Elsevier Ltd. All rights reserved.

The influence of different pretreatment methods on biogas production from Jatropha curcas oil cake.

PubMed

Jabłoński, Sławomir Jan; Kułażyński, Marek; Sikora, Ilona; Łukaszewicz, Marcin

2017-12-01

Drought and pest resistance, together with high oil content in its seeds, make Jatropha curcas a good oil source for biodiesel. Oil cake from J. curcas is not suitable for animal feeding and thus may be profitably used for additional energy production by conversion into biogas; however, the anaerobic digestion process must be optimized to obtain good efficiency. We subjected oil cake to thermal and acidic pretreatment to deactivate protease inhibitors and partially hydrolyze phytate. We then digested the samples in batch conditions to determine the effects of pretreatment on biogas production. Thermal pretreatment changed the kinetics of anaerobic digestion and reduced protease inhibitor activity and the concentration of phytate; however, biogas production efficiency was not affected (0.281 m 3  kg -1 ). To evaluate the possibility of recirculating water for SSF hydrolysis, ammonium nitrogen recovery from effluent was evaluated by its precipitation in the form of struvite (magnesium ammonium phosphate).Concentration of ammonium ions was reduced by 53% (to 980 mg L -1 ). We propose a water-saving concept based on percolation of J. curcas cake using anaerobic digestion effluent and feeding that percolate into a methanogenic bioreactor. Copyright © 2016 Elsevier Ltd. All rights reserved.

Application of natural zeolite for phosphorus and ammonium removal from aqueous solutions.

PubMed

Karapinar, Nuray

2009-10-30

Removal of both nutrients ammonium and phosphorus by natural zeolite has been studied in lab scale by using a mechanically stirred batch system (1000 ml). Zeolite, a mean particle size of 13 microm, was used as an adsorbent for the removal of ammonium and then as a seed material for the precipitation of calcium phosphate. A relationship was established between the uptake of ammonium by zeolite and the ratio of initial ammonium concentration to zeolite dosage. Ammonium uptake of zeolite was almost completed within initial 5 min of adsorption period. There is no pronounced effect of zeolite and ammonium, neither positive nor negative on the amount of calcium phosphate precipitation. The extent of the precipitation of phosphate increased with rising pH. It was also observed that when the system was allowed to relax at constant pH (i.e. under relatively low super saturations), a certain lag time was noted to elapse at the onset of the precipitation. At the pH 7.2, the amount of initial fast precipitation within 5 min and total precipitation within 120 min were around 34% and 93%, respectively. Precipitation of calcium phosphate on to ammonium-loaded zeolite was achieved at low super saturations (< pH 7.5) through secondary nucleation and crystal growth, leading to an increase in particle size.

Properties of porous magnesium prepared by powder metallurgy.

PubMed

Čapek, Jaroslav; Vojtěch, Dalibor

2013-01-01

Porous magnesium-based materials are biodegradable and promising for use in orthopaedic applications, but their applications are hampered by their difficult fabrication. This work reports the preparation of porous magnesium materials by a powder metallurgy technique using ammonium bicarbonate as spacer particles. The porosity of the materials depended on the amount of ammonium bicarbonate and was found to have strong negative effects on flexural strength and corrosion behaviour. However, the flexural strength of materials with porosities of up to 28 vol.% was higher than the flexural strength of non-metallic biomaterials and comparable with that of natural bone. Copyright © 2012 Elsevier B.V. All rights reserved.

Fermentation of molasses using a thermotolerant yeast, Kluyveromyces marxianus IMB3: simplex optimisation of media supplements.

PubMed

Gough, S; Flynn, O; Hack, C J; Marchant, R

1996-09-01

The use of molasses as a substrate for ethanol production by the thermotolerant yeast Kluyveromyces marxianus var. marxianus was investigated at 45 degrees C. A maximum ethanol concentration of 7.4% (v/v) was produced from unsupplemented molasses at a concentration of 23% (v/v). The effect on ethanol production of increasing the sucrose concentration in 23% (v/v) molasses was determined. Increased sucrose concentration had a similar detrimental effect on the final ethanol produced as the increase in molasses concentration. This indicated that the effect may be due to increased osmotic activity as opposed to other components in the molasses. The optimum concentration of the supplements nitrogen, magnesium, potassium and fatty acid for maximum ethanol production rate was determined using the Nelder and Mead (Computer J 7:308-313, 1965) simplex optimisation method. The optimum concentration of the supplements were 0.576 g1(-1) magnesium sulphate, 0.288 g1(-1) potassium dihydrogen phosphate and 0.36% (v/v) linseed oil. Added nitrogen in the form of ammonium sulphate did not affect the ethanol production rate.

Inert Reassessment Document for Ammonium Nitrate

EPA Pesticide Factsheets

Magnesium nitrate is used in preservation. Other uses for magnesium nitrate include use as a catalyst in the manufacture of petrochemicals, as a densensitizer for lithographic plates and in pyrotechnics.

[Screening, identification and phosphate-solubilizing characteristics of phosphate-solubilizing bacteria strain D2 (Pantoea sp.)in rhizosphere of Pinus tabuliformis in iron tailings yard.

PubMed

Wang, Jun Juan; Yan, Ai Hua; Wang, Wei; Li, Ji Quan; Li, Yu Ling

2016-11-18

Two strains of phosphate-solubilizing bacteria were isolated from the rhizosphere of Pinus tabuliformis in iron tailings vegetation restoration areas in Malan Town, Qianan City, Hebei Pro-vince. The bacterial strain D2 with strong phosphate-solubilizing capacity was obtained via screening with plate and shake flask. Based on the morphology, physiology and biochemistry, and the sequence analysis of 16S rDNA, the D2 was identified as a member of Pantoea sp. A fermentation experiment was conducted to investigate the effect of carbon and nitrogen sources on the phosphate-solubilizing capacity of the strain D2; under different nitrogen sources, the organic acids in liquid culture, as well as their types and contents were determined by high performance liquid chromatography. The results showed that the strain D2 was capable of efficiently solubilizing tricalcium phosphate, and the highest value of available phosphorus was up to 392.13 mg·L -1 in liquid culture. The strain D2 displayed the strongest phosphate-solubilizing capability when glucose and ammonium sulfate were used as carbon and nitrogen sources in the culture media, respectively. Under varied nitrogen sources, the resulting organic acids and their types and contents were different. When the nitrogen source in culture media was ammonium sulfate, ammonium chloride, potassium nitrate, sodium nitrate or ammonium nitrate, all four organic acids, including oxalic acid, formic acid, acetic acid and citric acid, were produced. In addition, malic acid was uniquely produced when ammonium sulfate, ammonium chloride or ammonium nitrate was used as the nitrogen source. By Pearson's correlation analysis, a significant positive correlation between the acetic acid content and the available phosphorus content was found (r=0.886, P<0.05), suggesting that acetic acid produced by strain D2 played an important role in promoting inorganic phosphorus dissolution, which was most likely to be one of the important phosphate-solubilizing mechanisms of the strain.

Electrodeposition of magnesium and magnesium/aluminum alloys

DOEpatents

Mayer, Anton

1988-01-01

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.

Electrodeposition of magnesium and magnesium/aluminum alloys

DOEpatents

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.

Particle emission from heavy-duty engine fuelled with blended diesel and biodiesel.

PubMed

Martins, Leila Droprinchinski; da Silva Júnior, Carlos Roberto; Solci, Maria Cristina; Pinto, Jurandir Pereira; Souza, Davi Zacarias; Vasconcellos, Pérola; Guarieiro, Aline Lefol Nani; Guarieiro, Lílian Lefol Nani; Sousa, Eliane Teixeira; de Andrade, Jailson B

2012-05-01

In this study, particulate matter (PM) were characterized from a place impacted by heavy-duty vehicles (Bus Station) fuelled with diesel/biodiesel fuel blend (B3) in the city of Londrina, Brazil. Sixteen priority polycyclic aromatic hydrocarbons (PAH) concentrations were analyzed in the samples by their association with atmospheric PM, mass size distributions and major ions (fluorite, chloride, bromide, nitrate, phosphate, sulfate, nitrite, oxalate; fumarate, formate, succinate and acetate; lithium, sodium, potassium, magnesium, calcium and ammonium). Results indicate that major ions represented 21.2% particulate matter mass. Nitrate, sulfate, and ammonium, respectively, presented the highest concentration levels, indicating that biodiesel may also be a significant source for these ions, especially nitrate. Dibenzo[a,h]anthracene and indeno[1,2,3,-cd]pyrene were the main PAH found, and a higher fraction of PAH particles was found in diameters lower than 0.25 μm in Londrina bus station. The fine and ultrafine particles were dominant among the PM evaluated, suggesting that biodiesel decreases the total PAH emission. However, it does also increase the fraction of fine and ultrafine particles when compared to diesel.

Influence of aggressive ions on the degradation behavior of biomedical magnesium alloy in physiological environment.

PubMed

Xin, Yunchang; Huo, Kaifu; Tao, Hu; Tang, Guoyi; Chu, Paul K

2008-11-01

Various electrochemical approaches, including potentiodynamic polarization, open circuit potential evolution and electrochemical impedance spectroscopy (EIS), are employed to investigate the degradation behavior of biomedical magnesium alloy under the influence of aggressive ions, such as chloride, phosphate, carbonate and sulfate, in a physiological environment. The synergetic effects and mutual influence of these ions on the degradation behavior of Mg are revealed. Our results demonstrate that chloride ions can induce porous pitting corrosion. In the presence of phosphates, the corrosion rate decreases and the formation of pitting corrosion is significantly delayed due to precipitation of magnesium phosphate. Hydrogen carbonate ions are observed to stimulate the corrosion of magnesium alloy during the early immersion stage but they can also induce rapid passivation on the surface. This surface passivation behavior mainly results from the fast precipitation of magnesium carbonate in the corrosion product layer that can subsequently inhibit pitting corrosion completely. Sulfate ions are also found to stimulate magnesium dissolution. These results improve our understanding on the degradation mechanism of surgical magnesium in the physiological environment.

Computational Assessment of Potassium and Magnesium Ion Binding to a Buried Pocket in GTPase-Associating Center RNA

PubMed Central

2016-01-01

An experimentally well-studied model of RNA tertiary structures is a 58mer rRNA fragment, known as GTPase-associating center (GAC) RNA, in which a highly negative pocket walled by phosphate oxygen atoms is stabilized by a chelated cation. Although such deep pockets with more than one direct phosphate to ion chelation site normally include magnesium, as shown in one GAC crystal structure, another GAC crystal structure and solution experiments suggest potassium at this site. Both crystal structures also depict two magnesium ions directly bound to the phosphate groups comprising this controversial pocket. Here, we used classical molecular dynamics simulations as well as umbrella sampling to investigate the possibility of binding of potassium versus magnesium inside the pocket and to better characterize the chelation of one of the binding magnesium ions outside the pocket. The results support the preference of the pocket to accommodate potassium rather than magnesium and suggest that one of the closely binding magnesium ions can only bind at high magnesium concentrations, such as might be present during crystallization. This work illustrates the complementary utility of molecular modeling approaches with atomic-level detail in resolving discrepancies between conflicting experimental results. PMID:27983843

Computational Assessment of Potassium and Magnesium Ion Binding to a Buried Pocket in GTPase-Associating Center RNA.

PubMed

Hayatshahi, Hamed S; Roe, Daniel R; Galindo-Murillo, Rodrigo; Hall, Kathleen B; Cheatham, Thomas E

2017-01-26

An experimentally well-studied model of RNA tertiary structures is a 58mer rRNA fragment, known as GTPase-associating center (GAC) RNA, in which a highly negative pocket walled by phosphate oxygen atoms is stabilized by a chelated cation. Although such deep pockets with more than one direct phosphate to ion chelation site normally include magnesium, as shown in one GAC crystal structure, another GAC crystal structure and solution experiments suggest potassium at this site. Both crystal structures also depict two magnesium ions directly bound to the phosphate groups comprising this controversial pocket. Here, we used classical molecular dynamics simulations as well as umbrella sampling to investigate the possibility of binding of potassium versus magnesium inside the pocket and to better characterize the chelation of one of the binding magnesium ions outside the pocket. The results support the preference of the pocket to accommodate potassium rather than magnesium and suggest that one of the closely binding magnesium ions can only bind at high magnesium concentrations, such as might be present during crystallization. This work illustrates the complementary utility of molecular modeling approaches with atomic-level detail in resolving discrepancies between conflicting experimental results.

Crystallization and precipitation of phosphate from swine wastewater by magnesium metal corrosion.

PubMed

Huang, Haiming; Liu, Jiahui; Jiang, Yang

2015-11-12

This paper presents a unique approach for magnesium dosage in struvite precipitation by Mg metal corrosion. The experimental results showed that using an air bubbling column filled with Mg metal and graphite pellets for the magnesium dosage was the optimal operation mode, which could significantly accelerate the corrosion of the Mg metal pellets due to the presence of graphite granules. The reaction mechanism experiments revealed that the solution pH could be used as the indicator for struvite crystallization by the process. Increases in the Mg metal dosage, mass ratio of graphite and magnesium metal (G:M) and airflow rate could rapidly increase the solution pH. When all three conditions were at 10 g L(-1), 1:1 and 1 L min(-1), respectively, the phosphate recovery efficiency reached 97.5%. To achieve a high level of automation for the phosphate recovery process, a continuous-flow reactor immersed with the graphite-magnesium air bubbling column was designed to harvest the phosphate from actual swine wastewater. Under conditions of intermittently supplementing small amounts of Mg metal pellets, approximately 95% of the phosphate could be stably recovered as struvite of 95.8% (±0.5) purity. An economic analysis indicated that the process proposed was technically simple and economically feasible.

Crystallization and precipitation of phosphate from swine wastewater by magnesium metal corrosion

PubMed Central

Huang, Haiming; Liu, Jiahui; Jiang, Yang

2015-01-01

This paper presents a unique approach for magnesium dosage in struvite precipitation by Mg metal corrosion. The experimental results showed that using an air bubbling column filled with Mg metal and graphite pellets for the magnesium dosage was the optimal operation mode, which could significantly accelerate the corrosion of the Mg metal pellets due to the presence of graphite granules. The reaction mechanism experiments revealed that the solution pH could be used as the indicator for struvite crystallization by the process. Increases in the Mg metal dosage, mass ratio of graphite and magnesium metal (G:M) and airflow rate could rapidly increase the solution pH. When all three conditions were at 10 g L–1, 1:1 and 1 L min–1, respectively, the phosphate recovery efficiency reached 97.5%. To achieve a high level of automation for the phosphate recovery process, a continuous-flow reactor immersed with the graphite-magnesium air bubbling column was designed to harvest the phosphate from actual swine wastewater. Under conditions of intermittently supplementing small amounts of Mg metal pellets, approximately 95% of the phosphate could be stably recovered as struvite of 95.8% (±0.5) purity. An economic analysis indicated that the process proposed was technically simple and economically feasible. PMID:26558521

Formation of chemically bonded ceramics with magnesium dihydrogen phosphate binder

DOEpatents

Wagh, Arun S.; Jeong, Seung-Young

2004-08-17

A new method for combining magnesium oxide, MgO, and magnesium dihydrogen phosphate to form an inexpensive compactible ceramic to stabilize very low solubility metal oxides, ashes, swarfs, and other iron or metal-based additives, to create products and waste forms which can be poured or dye cast, and to reinforce and strengthen the ceramics formed by the addition of fibers to the initial ceramic mixture.

Renal stone composition does not affect the outcome of percutaneous nephrolithotomy in children.

PubMed

Kaygısız, Onur; Türegün, Fethi Ahmet; Satar, Nihat; Özen, Ender; Toksöz, Serdar; Doğan, Hasan Serkan; Pişkin, Mehmet Mesut; İzol, Volkan; Sarıkaya, Şaban; Kılıçarslan, Hakan; Çiçek, Tufan; Öztürk, Ahmet; Tekgül, Serdar; Önal, Bülent

2018-05-14

We sought to investigate the association between renal stone composition and percutaneous nephrolithotomy outcomes in pediatric patients and define the characterization of the stone composition. The data of 1157 children who underwent percutaneous nephrolithotomy between 1991 and 2012 were retrieved from the multicenter database of the Turkish Pediatric Urology Society. The study population comprised 359 children (160 girls, 199 boys) with stone analyses. Patients were divided into five groups according to the stone composition [group 1: calcium oxalate; group 2: calcium phosphate; group 3: infection stones (magnesium ammonium phosphate, ammonium urate); group 4: cystine; group 5: uric acid, xanthine stones]. Patient characteristics, perioperative, postoperative, and stone characteristics were compared considering the stone composition. There were no significant differences between the groups concerning age, sex, side involved, preoperative hematocrit levels, and solitary renal unit. Patients with cystine stones were more likely to have a history of stone treatment. Groups 2 and 5 had mostly solitary stones. However, group 3 had staghorn stone more often, and group 4 frequently had multiple stones. Overall stone-free rate (79.4%) was similar among the groups. Although stone composition was related to blood transfusion and prolonged operative and fluoroscopy screening times on univariate analysis, it was not a significant predictor of them on multivariate analysis. Stone composition was not a predictor of outcomes of pediatric percutaneous nephrolithotomy. However, cystine and infection stones, which are larger and filled multiple calyxes due to the nature of stone forming, were more challenging cases that need multiple tracts.

Anatrophic nephrolithotomy for removal of staghorn or branched renal calculi.

PubMed

James, R; Novick, A C; Straffon, R A; Stewart, B H

1980-02-01

Forty anatrophic nephrolithotomies were performed in 38 patients between November, 1965, and December, 1977, to remove staghorn or branched renal calculi. Thirty-six (95 per cent) of the patients' preoperative urine cultures were infected, and postoperatively 35 of the cultures (88 per cent) were sterile. Magnesium ammonium phosphate calculi were present in the majority of patients (67 per cent). In 6 patients (15 per cent) transient nephrocutaneous fistulas developed. Thirty-six of the 40 renal units (90 per cent) had improved or stable intravenous pyelograms postoperatively. The patients had been followed for an average of twenty months (four to one hundred and twelve months). In 6 patients (15 per cent) recurrent renal calculi developed, and 3 patients (8 per cent) had residual calculi during this period.

Chemical ions affect survival of avian cholera organisms in pondwater

USGS Publications Warehouse

Price, J.I.; Yandell, B.S.; Porter, W.P.

1992-01-01

Avian cholera (Pasteurella multocida) is a major disease of wild waterfowl, but its epizootiology remains little understood. Consequently, we examined whether chemical ions affected survival of avian cholera organisms in water collected from the Nebraska Rainwater Basin where avian cholera is enzootic. We tested the response of P. multocida to ammonium (NH4), calcium (Ca), magnesium (Mg), nitrate (NO3), and ortho-phosphate (PO4) ions individually and in combination using a fractional factorial design divided into 4 blocks. High concentrations of Ca and Mg, singly or in combination, increased survival of P. multocida organisms (P < 0.001). We developed a survival index to predict whether or not specific ponds could be "problem" or "nonproblem" avian cholera sites based on concentrations of these ions in the water.

Methods for the collection of geochemical data from the sediments of the tidal Potomac River and estuary and data for 1978-1980

USGS Publications Warehouse

Goodwin, S.D.; Schultz, B.I.; Parkhurst, D.L.; Simon, N.S.; Callendar, Edward

1984-01-01

The chemical composition of bottom sediments and their associated pore waters from the tidal Potomac River and Estuary was studied from May 1978 through June 1980. Pore waters were routinely analyzed for pH, Eh, alkalinity, and concentrations of sulfide, sulfate, phosphate, carbon, ammonium, silica, iron, manganese, chloride, sodium, potassium, calcium, and magnesium. Porosity, weight loss on ignition, and carbon, nitrogen, and phosphorus contents were determined for the solid sediments. The range of salinity and chemical composition encountered in the estuary frequently necessitated modifications of standard methods of analysis. Therefore, the methods used, their modifications, and their limitations are presented in some detail. The appendix lists the data obtained from six sampling periods. (USGS)

Effect of salt nutrients on mannitol production by Lactobacillus intermedius NRRL B-3693.

PubMed

Saha, Badal C

2006-10-01

The effects of four salt nutrients (ammonium citrate, sodium phosphate, magnesium sulfate, and manganese sulfate) on the production of mannitol by Lactobacillus intermedius NRRL B-3693 in a simplified medium containing 300 g fructose, 5 g soy peptone, and 50 g corn steep liquor per liter in pH-controlled fermentation at 5.0 at 37 degrees C were evaluated using a fractional factorial design. Only manganese sulfate was found to be essential for mannitol production. Added manganese sulfate concentration of 0.033 g/l was found to support maximum production. The bacterium produced 200.6 +/- 0.2 g mannitol, 61.9 +/- 0.1 g lactic acid, and 40.4 +/- 0.3 g acetic acid from 300 g fructose per liter in 67 h.

A field method for the determination of calcium and magnesium in limestone and dolomite

USGS Publications Warehouse

Shapiro, Leonard; Brannock, Walter Wallace

1957-01-01

The method is an adaptation of a procedure described by Betz and Noll1 in 1950. Calcium and magnesium are determined by visual titration using Versene (disodium ethylenediamine tetraacetate) with Murexide (ammonium purpurate) as the indicator for calcium and Eriochrome Black T as the indicator for magnesium.

Synthesis and effectiveness of overbased magnesium and calcium petroleum sulfonates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fialkovskii, R.V.; Romanyutina, L.V.; Korbut, L.F.

Overbased sulfonate additives are widely used to improve the service properties of motor oils. This paper describes the preparation of an overbased magnesium sulfonate additive from MSG-8 oil and an investigation of its functional properties. In experiments, the solution of ammonium sulfate, fat diluted with I-20A oil to a 38% concentration, was heated and stirred continuously in the presence of water and excess magnesium oxide for a period of 4 h at 80-120/degree/C while stripping out the liberated ammonia with nitrogen. The resulting oil solution of magnesium sulfonate was dissolved in toluene. The toluene solution after cleanup was held undermore » vacuum to remove the solvent; the residue was an oil solution of overbased magnesium sulfonate. Their properties are tabulated. Comparative data are shown in Table 1 for a calcium sulfonate additive synthesized from the same intermediate (ammonium sulfate), using calcium hydroxide as the base. Test results on M-11 oil containing 5% of the magnesium or calcium additive are listed. It is shown that the magnesium additive gave better results from the calcium additive at the same concentration in terms of oxidation stability, corrosion properties, detergency, and dispersancy. 9 refs.« less

Urine Anion Gap to Predict Urine Ammonium and Related Outcomes in Kidney Disease.

PubMed

Raphael, Kalani L; Gilligan, Sarah; Ix, Joachim H

2018-02-07

Low urine ammonium excretion is associated with ESRD in CKD. Few laboratories measure urine ammonium, limiting clinical application. We determined correlations between urine ammonium, the standard urine anion gap, and a modified urine anion gap that includes sulfate and phosphate and compared risks of ESRD or death between these ammonium estimates and directly measured ammonium. We measured ammonium, sodium, potassium, chloride, phosphate, and sulfate from baseline 24-hour urine collections in 1044 African-American Study of Kidney Disease and Hypertension participants. We evaluated the cross-sectional correlations between urine ammonium, the standard urine anion gap (sodium + potassium - chloride), and a modified urine anion gap that includes urine phosphate and sulfate in the calculation. Multivariable-adjusted Cox models determined the associations of the standard urine anion gap and the modified urine anion gap with the composite end point of death or ESRD; these results were compared with results using urine ammonium as the predictor of interest. The standard urine anion gap had a weak and direct correlation with urine ammonium ( r =0.18), whereas the modified urine anion gap had a modest inverse relationship with urine ammonium ( r =-0.58). Compared with the highest tertile of urine ammonium, those in the lowest urine ammonium tertile had higher risk of ESRD or death (hazard ratio, 1.46; 95% confidence interval, 1.13 to 1.87) after adjusting for demographics, GFR, proteinuria, and other confounders. In comparison, participants in the corresponding standard urine anion gap tertile did not have higher risk of ESRD or death (hazard ratio, 0.82; 95% confidence interval, 0.64 to 1.07), whereas the risk for those in the corresponding modified urine anion gap tertile (hazard ratio, 1.32; 95% confidence interval, 1.03 to 1.68) approximated that of directly measured urine ammonium. Urine anion gap is a poor surrogate of urine ammonium in CKD unless phosphate and sulfate are included in the calculation. Because the modified urine anion gap merely estimates urine ammonium and requires five measurements, direct measurements of urine ammonium are preferable in CKD. Copyright © 2018 by the American Society of Nephrology.

Crystal Analysis of Multi Phase Calcium Phosphate Nanoparticles Containing Different amount of Magnesium

NASA Astrophysics Data System (ADS)

Gozalian, Afsaneh; Behnamghader, Ali Asghar; Moshkforoush, Arash

In this study, Mg doped hydroxyapatite [(Ca, Mg)10(PO4)6(OH)2] and β-tricalcium phosphate nanoparticles were synthesized via sol gel method. Triethyl phosphite, calcium nitrate tetrahydrate and magnesium nitrate hexahydrate were used as P, Ca and Mg precursors. The ratio of (Ca+Mg)/P and the amount of magnesium (x) were kept constant at 1.67 and ranging x = 0 up to 3 in molecular formula of Ca10-xMgx (PO4)6(OH)2, respectively. Phase composition and chemical structure were performed using X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR). Phase percentages, crystallite size, degree of crystallinity and lattice parameters were investigated. The presence of magnesium led to form the Mg doped tricalcium phosphate (β-TCMP) and Mg doped hydroxyapatite (Mg-HA). Based on the results of this study, lattice parameters, degree of crystallinity and crystallite size decreased with magnesium content. In addition, with increasing magnesium content, the amount of CaO phase decreased whereas the amount of MgO phase increased significantly. Obtained results can be used for new biomaterials design.

Electrochemical characteristics of calcium-phosphatized AZ31 magnesium alloy in 0.9 % NaCl solution.

PubMed

Hadzima, Branislav; Mhaede, Mansour; Pastorek, Filip

2014-05-01

Magnesium alloys suffer from their high reactivity in common environments. Protective layers are widely created on the surface of magnesium alloys to improve their corrosion resistance. This article evaluates the influence of a calcium-phosphate layer on the electrochemical characteristics of AZ31 magnesium alloy in 0.9 % NaCl solution. The calcium phosphate (CaP) layer was electrochemically deposited in a solution containing 0.1 M Ca(NO3)2, 0.06 M NH4H2PO4 and 10 ml l(-1) of H2O2. The formed surface layer was composed mainly of brushite [(dicalcium phosphate dihidrate (DCPD)] as proved by energy-dispersive X-ray analysis. The surface morphology was observed by scanning electron microscopy. Immersion test was performed in order to observe degradation of the calcium phosphatized surfaces. The influence of the phosphate layer on the electrochemical characteristics of AZ31, in 0.9 % NaCl solution, was evaluated by potentiodynamic measurements and electrochemical impedance spectroscopy. The obtained results were analysed by the Tafel-extrapolation method and equivalent circuits method. The results showed that the polarization resistance of the DCPD-coated surface is about 25 times higher than that of non-coated surface. The CaP electro-deposition process increased the activation energy of corrosion process.

Effects of Atrazine, Metolachlor, Carbaryl and Chlorothalonil on Benthic Microbes and Their Nutrient Dynamics

PubMed Central

Elias, Daniel; Bernot, Melody J.

2014-01-01

Atrazine, metolachlor, carbaryl, and chlorothalonil are detected in streams throughout the U.S. at concentrations that may have adverse effects on benthic microbes. Sediment samples were exposed to these pesticides to quantify responses of ammonium, nitrate, and phosphate uptake by the benthic microbial community. Control uptake rates of sediments had net remineralization of nitrate (−1.58 NO3 µg gdm−1 h−1), and net assimilation of phosphate (1.34 PO4 µg gdm−1 h−1) and ammonium (0.03 NH4 µg gdm−1 h−1). Metolachlor decreased ammonium and phosphate uptake. Chlorothalonil decreased nitrate remineralization and phosphate uptake. Nitrate, ammonium, and phosphate uptake rates are more pronounced in the presence of these pesticides due to microbial adaptations to toxicants. Our interpretation of pesticide availability based on their water/solid affinities supports no effects for atrazine and carbaryl, decreasing nitrate remineralization, and phosphate assimilation in response to chlorothalonil. Further, decreased ammonium and phosphate uptake in response to metolachlor is likely due to affinity. Because atrazine target autotrophs, and carbaryl synaptic activity, effects on benthic microbes were not hypothesized, consistent with results. Metolachlor and chlorothalonil (non-specific modes of action) had significant effects on sediment microbial nutrient dynamics. Thus, pesticides with a higher affinity to sediments and/or broad modes of action are likely to affect sediment microbes' nutrient dynamics than pesticides dissolved in water or specific modes of action. Predicted nutrient uptake rates were calculated at mean and peak concentrations of metolachlor and chlorothalonil in freshwaters using polynomial equations generated in this experiment. We concluded that in natural ecosystems, peak chlorothalonil and metolachlor concentrations could affect phosphate and ammonium by decreasing net assimilation, and nitrate uptake rates by decreasing remineralization, relative to mean concentrations of metolachlor and chlorothalonil. Our regression equations can complement models of nitrogen and phosphorus availability in streams to predict potential changes in nutrient dynamics in response to pesticides in freshwaters. PMID:25275369

Removal of phosphate from aqueous solution using magnesium-alginate/chitosan modified biochar microspheres derived from Thalia dealbata.

PubMed

Cui, Xiaoqiang; Dai, Xi; Khan, Kiran Yasmin; Li, Tingqiang; Yang, Xiaoe; He, Zhenli

2016-10-01

The objective of this study was to determine the feasibility of using magnesium-alginate/chitosan modified biochar microspheres to enhance removal of phosphate from aqueous solution. The introduction of MgCl2 substantially increased surface area of biochar (116.2m(2)g(-1)), and both granulation with alginate/chitosan and modification with magnesium improved phosphate sorption on the biochars. Phosphate sorption on the biochars could be well described by a simple Langmuir model, and the MgCl2-alginate modified biochar microspheres exhibited the highest phosphate sorption capacity (up to 46.56mgg(-1)). The pseudo second order kinetic model better fitted the kinetic data, and both the Yoon-Nelson and Thomas models were superior to other models in describing phosphate dynamic sorption. Precipitation with minerals and ligand exchange were the possible mechanisms of phosphate sorption on the modified biochars. These results imply that MgCl2-alginate modified biochar microspheres have potential as a green cost-effective sorbent for remediating P contaminated water environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

The use of chemical treatments for improved comminution of artificial stones.

PubMed

Heimbach, D; Kourambas, J; Zhong, P; Jacobs, J; Hesse, A; Mueller, S C; Delvecchio, F C; Cocks, F H; Preminger, G M

2004-05-01

The acoustic and mechanical properties of various stone compositions are significantly different and thus result in varying degrees of fragility. Consequently, results to shock wave lithotripsy (SWL) are influenced accordingly. We report the results of a study of fragility of various stone compositions, and the influence on each stone's baseline physical properties and fragility when exposed to various chemolytic solutions. Before SWL artificial stones of differing compositions were irrigated with various chemolytic solutions. Calcium oxalate monohydrate (COM) stones were treated with ethylenediaminetetraacetic acid (EDTA), stones composed of magnesium ammonium phosphate hydrogen were treated with hemiacidrin, and stones made of uric acid (UA) were treated with tromethamine. Synthetic urine served as a control for all stone groups. Using an ultrasound transmission technique, longitudinal wave propagation speed was measured in all groups of artificial stones. Stone density was also measured by using a pycnometer (based on Archimedes' principle). Based on these measurements transverse (shear) wave speed (assuming a constant Poisson's ratio), wave impedance and dynamic mechanical properties of the artificial stones were calculated. Moreover, the microhardness of these artificial stones was measured, and fragility testing using SWL with and without pretreatment with the previously mentioned chemolytic solutions, was performed. Wave speed, wave impedance, dynamic mechanical properties and microhardness of EDTA treated COM stones and tromethamine treated UA stones were found to decrease compared to untreated (synthetic urine) control groups. The suggestion that chemolytic pretreatment increases stone fragility was verified by the finding of increased stone comminution after SWL testing. Combining this medical pretreatment and SWL, the findings demonstrate a significant impact of various solvents on stone comminution, in particular EDTA treated COM stones, tromethamine treated UA stones and hemiacidrin treated magnesium ammonium phosphate hydrogen stones. These data suggest that by altering the chemical environment of the fluid surrounding the stones it is possible to increase the fragility of renal calculi in vitro. These results indicate that appropriate chemical treatments may provide a useful adjunctive modality for improving the efficacy of stone comminution during shock wave lithotripsy.

Phosphate-bonded calcium aluminate cements

DOEpatents

Sugama, Toshifumi

1993-01-01

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

Phosphate-bonded calcium aluminate cements

DOEpatents

Sugama, T.

1993-09-21

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

Kinetics Formulations for ICM-Lite: A Tool to Predict and Quantify Ecosystem Benefits in Aquatic Systems

DTIC Science & Technology

2015-07-01

Observed sediment-water fluxes. Ammonium , g m-2 d -1 Nitrate , g m-2 d -1 Phosphate, g m-2 d -1 SOD, g m-2 d -1 System 0.01 to 0.28 -0.04 to 0.1...defined substances are included, as well. Sediment-water fluxes of organic matter, ammonium , nitrate , phosphate, and dissolved oxygen are considered...preference. The preference depends on the abudance of ammonium and nitrate relative to the half-saturation concentration for algal ammonium uptake

Microwave assisted synthesis of amorphous magnesium phosphate nanospheres.

PubMed

Zhou, Huan; Luchini, Timothy J F; Bhaduri, Sarit B

2012-12-01

Magnesium phosphate (MgP) materials have been investigated in recent years for tissue engineering applications, attributed to their biocompatibility and biodegradability. This paper describes a novel microwave assisted approach to produce amorphous magnesium phosphate (AMP) in a nanospherical form from an aqueous solution containing Mg(2+) and HPO(4) (2-)/PO(4) (3-). Some synthesis parameters such as pH, Mg/P ratio, solution composition were studied and the mechanism of AMP precursors was also demonstrated. The as-produced AMP nanospheres were characterized and tested in vitro. The results proved these AMP nanospheres can self-assemble into mature MgP materials and support cell proliferation. It is expected such AMP has potential in biomedical applications.

Superposition model analysis of zero field splitting for Mn2+ in some host single crystals

NASA Astrophysics Data System (ADS)

Bansal, R. S.; Ahlawat, P.; Bharti, M.; Hooda, S. S.

2013-07-01

The Newman superposition model has been used to investigate the substitution of Mn2+ for Zn2+ site in ammonium tetra flurozincate dihydrate and for Co2+ site in cobalt ammonium phosphate hexahydrate and cobalt potassium phosphate hexahydrate single crystals. The calculated values of zero field splitting parameter b 2 0 at room temperature fit the experimental data with average intrinsic parameters overline{b}2 (F) = -0.0531 cm-1 for fluorine and overline{b}2 (O) = -0.0280 cm-1 for oxygen, taken t 2 = 7 for Mn2+ doped in ammonium tetra fluorozincate dihydrate single crystals. The values of overline{b}2 determined for Mn2+ doped in cobalt ammonium phosphate hexahydrate are -0.049 cm-1 for site I and -0.045 cm-1 for site II and in cobalt pottasium phosphate hexahydrate single crystals it is found to be overline{b}2 = -0.086 cm-1. We find close agreement between theoretical and experimental values of b 2 0.

Impact of a long-term fire retardant (Fire Trol 931) on the leaching of Ca, Mg, and K from a Mediterranean forest loamy soil.

PubMed

Michalopoulos, Charalampos; Koufopoulou, Sofia; Tzamtzis, Nikolaos; Pappa, Athina

2016-03-01

The present laboratory study was conducted in pot soil taken from forest. The leaching of calcium (Ca), magnesium (Mg), and potassium (K) (plant macronutrients) due to the application of a nitrogen phosphate-based long-term fire retardant (LTFR) (Fire Trol 931) was investigated. The concentrations of Ca(2+), Mg(2+), and K(+) were measured in the resulting leachates from pots with forest soil and pine tree alone and in combination with fire. Magnesium is a minor component of Fire Trol 931. The leaching of Ca(2+), Mg(2+), and K(+) from treated soils with the retardant pots was significantly greater than that from control pots. The leaching of Mg(2+) was found to be of small percentage of the initially applied Mg quantities. Fire Trol 931 application resulted in the leaching of Ca(2+), Mg(2+), and K(+) from a typical Mediterranean forest soil in pots, following the application of simulated annual precipitation probably due to ammonium (one of the major retardant components) soil deposition that mobilizes base cations from the soil. It seems that LTFR application may result in chemical leaching from the soil to the drainage water.

Blood Phosphorus and Magnesium Levels in 130 Elite Track and Field Athletes

PubMed Central

Malliaropoulos, Nikolaos; Tsitas, Kostas; Porfiriadou, Anthoula; Papalada, Agapi; R.Ames, Paul; Del Buono, Angelo; Lippi, Giuseppe; Maffulli, Nicola

2012-01-01

Purpose This study tested the clinical utility and relevance of serum phosphorus and magnesium as markers possibly useful to monitor training in athletes. Methods Phosphorus and magnesium serum concentrations of 130 elite track and field athletes (65 males and 65 females, age range 20-30 years) from the National Athletics Sports Medicine Center database in Thessaloniki, Greece were measured. Results Abnormal results were found in 61 (47%) athletes (32 men and 29 women). In male athletes, serum phosphate was higher than normal in 18% and decreased in 1.5%, whereas serum magnesium concentration was higher in 26%, and lower in 3%. Regarding female athletes, higher serum phosphate and magnesium levels were detected in 26% and 17% respectively, whereas decreased serum magnesium was found in 3%. The most common alterations were higher serum phosphate (29/61, 47%) and magnesium concentrations (28/61, 46%). Abnormalities of serum phosphorus and magnesium concentrations were detected in almost half of the athletes. Hyperphosphataemia and hypermagnesaemia were the most common abnormalities. Conclusion The reference intervals used for general population cannot be used for athletes. Given the lack of pathological manifestations, the physiopathological significance of these findings is uncertain. Further studies on the interpretation of reported ion concentrations in athletes should take in account the type of sport practiced and also the possible variations during the training and competition season. PMID:23785576

Magnesium-containing mixed coatings on zirconia for dental implants: mechanical characterization and in vitro behavior.

PubMed

Pardun, Karoline; Treccani, Laura; Volkmann, Eike; Streckbein, Philipp; Heiss, Christian; Gerlach, Juergen W; Maendl, Stephan; Rezwan, Kurosch

2015-07-01

An important challenge in the field of dental and orthopedic implantology is the preparation of implant coatings with bioactive functions that feature a high mechanical stability and at the same time mimic structural and compositional properties of native bone for a better bone ingrowth. This study investigates the influence of magnesium addition to zirconia-calcium phosphate coatings. The mixed coatings were prepared with varying additions of either magnesium oxide or magnesium fluoride to yttria-stabilized zirconia and hydroxyapatite. The coatings were deposited on zirconia discs and screw implants by wet powder spraying. Microstructure studies confirm a porous coating with similar roughness and firm adhesion not hampered by the coating composition. The coating morphology, mechanical flexural strength and calcium dissolution showed a magnesium content-dependent effect. Moreover, the in vitro results obtained with human osteoblasts reveal an improved biological performance caused by the presence of Mg(2+) ions. The magnesium-containing coatings exhibited better cell proliferation and differentiation in comparison to pure zirconia-calcium phosphate coatings. In conclusion, these results demonstrate that magnesium addition increases the bioactivity potential of zirconia-calcium phosphate coatings and is thus a highly suitable candidate for bone implant coatings. © The Author(s) 2015 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Macroscopic and microscopic variation in recovered magnesium phosphate materials: Implications for phosphorus removal processes and product re-use

USDA-ARS?s Scientific Manuscript database

Phosphorus (P) recovery and re-use will become increasingly important for water quality protection and sustainable nutrient cycling as environmental regulations become stricter and global P reserves decline. The objective of this study was to examine and characterize several magnesium phosphates re...

Parallel nano-assembling of a multifunctional GO/HapNP coating on ultrahigh-purity magnesium for biodegradable implants

NASA Astrophysics Data System (ADS)

Santos, C.; Piedade, C.; Uggowitzer, P. J.; Montemor, M. F.; Carmezim, M. J.

2015-08-01

This work reports the one-step fabrication of a novel coating on ultra high purity magnesium using a parallel nano assembling process. The multifunctional biodegradable surface was obtained by adding hydroxyapatite nanoparticles (HapNP) plus graphene oxide (GO). The coating was characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffractometer (XRD), micro-Raman spectroscopy. The thin phosphate coating (thickness of 1 μm) reveals a uniform coverage with cypress like structures. The incorporation of HapNP and GO promotes the hydrophilic behavior of the coating surface. The results revealed that the proposed coating can be used to tailor the surface properties such as wettability by adjusting the contents of HapNP and GO. The in vitro degradation rate of the coated magnesium suggests that the presence of HapNP and GO/HapNP in the phosphate coating decreased the current density compared to the single phosphate coating and uncoated magnesium. This study also reveals the HapNP/GO/phosphate coating induces apatite formation, showing suitable degradability that makes it a promising coating candidate for enhanced bone regeneration.

Diurnal shifts in co-distributions of sulfide and iron(II) and profiles of phosphate and ammonium in the rhizosphere of Zostera capricorni

NASA Astrophysics Data System (ADS)

Pagès, Anaïs; Welsh, David T.; Robertson, David; Panther, Jared G.; Schäfer, Jörg; Tomlinson, Rodger B.; Teasdale, Peter R.

2012-12-01

High resolution, two dimensional distributions of porewater iron(II) and sulfide were measured, using colourimetric DET (diffusive equilibration in a thin film) and DGT (diffusive gradients in a thin film) techniques, respectively, in Zostera capricorni colonised sediments under both light and dark conditions. Low resolution depth profiles of ammonium and phosphate were measured using conventional DET and DGT methods, respectively. Porewater iron(II) and sulfide distributions showed a high degree of spatial heterogeneity under both light and dark conditions, and distributions were characterised by a complex mosaic of sediment zones dominated by either iron(II) or sulfide. However, there was a clear shift in overall redox conditions between light and dark conditions. During light deployments, iron(II) and sulfide concentrations were generally low throughout the rhizosphere, apart from a few distinct "hotspots" of high concentration. Whereas during dark deployments, high concentrations of iron(II) were sometimes measured in the near surface sediments and sulfide depth distributions migrated towards the sediment surface. Profiles of porewater ammonium and phosphate demonstrated an increase in ammonium concentrations under dark compared to light conditions. Surprisingly, despite the large changes in iron(II) distributions between light and dark conditions, phosphate profiles remained similar, indicating that adsorption/release of phosphate by iron(III) hydr(oxide) mineral formation and reduction was not a major factor regulating porewater phosphate concentrations in these sediments or that phosphate uptake by the seagrass roots persisted during the dark period. Overall, the results demonstrate that the photosynthetic activity of the seagrass played a significant role in regulating sulfide, iron(II) and ammonium concentrations in the rhizosphere, due to rates of radial oxygen loss and ammonium uptake by the roots and rhizomes being lower under dark compared to light conditions. This cyclic production and reduction of iron(III) hydr(oxides) in the rhizosphere may act as a buffering system preventing sulfide accumulation.

Magnesium phosphate pentahydrate nanosheets: Microwave-hydrothermal rapid synthesis using creatine phosphate as an organic phosphorus source and application in protein adsorption.

PubMed

Qi, Chao; Zhu, Ying-Jie; Wu, Cheng-Tie; Sun, Tuan-Wei; Chen, Feng; Wu, Jin

2016-01-15

Magnesium phosphate materials have aroused interest of researchers in recent years and are promising for biomedical applications due to their good biocompatibility and biodegradability. In this work, we report the microwave-hydrothermal rapid synthesis of magnesium phosphate pentahydrate nanosheets (MPHSs) using biocompatible creatine phosphate as an organic phosphorus source. This method is facile, rapid, surfactant-free and environmentally friendly. The as-prepared MPHSs have an obvious pH-dependent dissolution performance which can be used as an ideal pH-responsive nanocarrier for drug and gene delivery. Moreover, the MPHSs have a good cytocompatibility and a high ability to promote osteoblast MC-3T3 adhesion and spreading, as well as a relatively high protein adsorption ability using hemoglobin (Hb) as a model protein. Thus, the MPHSs are promising for the applications in biomedical fields such as protein adsorption and bone regeneration. Copyright © 2015 Elsevier Inc. All rights reserved.

Optimization of date syrup for enhancement of the production of citric acid using immobilized cells of Aspergillus niger

PubMed Central

Mostafa, Yasser S.; Alamri, Saad A.

2012-01-01

Date syrup as an economical source of carbohydrates and immobilized Aspergillus niger J4, which was entrapped in calcium alginate pellets, were employed for enhancing the production of citric acid. Maximum production was achieved by pre-treating date syrup with 1.5% tricalcium phosphate to remove heavy metals. The production of citric acid using a pretreated medium was 38.87% higher than an untreated one that consumed sugar. The appropriate presence of nitrogen, phosphate and magnesium appeared to be important in order for citric acid to accumulate. The production of citric acid and the consumed sugar was higher when using 0.1% ammonium nitrate as the best source of nitrogen. The production of citric acid increased significantly when 0.1 g/l of KH2PO4 was added to the medium of date syrup. The addition of magnesium sulfate at the rate of 0.20 g/l had a stimulating effect on the production of citric acid. Maximum production of citric acid was obtained when calcium chloride was absent. One of the most important benefits of immobilized cells is their ability and stability to produce citric acid under a repeated batch culture. Over four repeated batches, the production of citric acid production was maintained for 24 days when each cycle continued for 144 h. The results obtained in the repeated batch cultivation using date syrup confirmed that date syrup could be used as a medium for the industrial production of citric acid. PMID:23961184

Association between Magnesium Disorders and Hypocalcemia following Thyroidectomy.

PubMed

Nellis, Jason C; Tufano, Ralph P; Gourin, Christine G

2016-09-01

To identify factors associated with postoperative hypocalcemia after thyroid surgery and to understand the relationship among hypocalcemia, length of hospitalization, and costs of care. Retrospective database analysis. Discharge data from the Nationwide Inpatient Sample for 620,744 patients who underwent thyroid surgery from 2001 to 2010 were analyzed through cross-tabulations and multivariate regression modeling. Hypocalcemia, length of stay, and costs were examined as dependent variables. Secondary independent variables included magnesium and phosphate metabolism disorders, vitamin D deficiency, menopause, sex, extent of surgery, malignancy, and surgeon volume. Hypocalcemia was reported in 6% of patients and was significantly more common for the following variables: women, age <65 years, patients from the Northeast, total thyroidectomy ± neck dissection patients, low-volume surgical care, malignancy, recurrent laryngeal nerve injury, and patients with disorders of magnesium or phosphate metabolism (P < .001). Magnesium and phosphate disorders were present in <1% of patients. Magnesium disorders were significantly more likely for patients with hypocalcemia (7%; P < .001), and hypocalcemia was present in 52% of patients with magnesium disorders (P < .001). On multiple logistic regression analysis, the odds of hypocalcemia were greatest for patients with magnesium disorders (odds ratio, 12.71; 95% confidence interval, 8.59-18.82). This relationship was not attenuated by high-volume surgical care. Hypocalcemia and magnesium disorders were both associated with increased length of stay and costs, with a greater effect for magnesium disorders than for hypocalcemia (P < .001). Disorders of magnesium metabolism are an independent risk factor for postthyroidectomy hypocalcemia and are associated with significantly increased costs and length of stay. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2016.

Biodegradation behavior of micro-arc oxidized AZ31 magnesium alloys formed in two different electrolytes

NASA Astrophysics Data System (ADS)

Seyfoori, A.; Mirdamadi, Sh.; Khavandi, A.; Raufi, Z. Seyed

2012-11-01

Degradation behavior of coated magnesium alloys is among most prominent factors for their biomedical applications. In this study, bio-corrosion behavior of micro-arc oxidized magnesium AZ31 alloys formed in silicate and phosphate baths was investigated in r-SBF medium. For this purpose polarization behavior and open circuit profile of the coated samples were achieved by electrochemical and immersion tests, respectively. Moreover, the morphology and composition of the coatings were evaluated before and after immersion test using scanning electron microscopy, X-ray diffraction and energy dispersive spectroscopy. The results showed that the phosphate film had better corrosion resistance and greater thickness than silicate film and, in turn, the lesser degradability in SBF solution, so that Ca2+ and PO43- containing compounds were more abundant on silicate film than phosphate film. Moreover phosphate film had greater surface roughness and lesser hydrophilic nature.

Calcium phosphate coating on magnesium alloy for modification of degradation behavior

NASA Astrophysics Data System (ADS)

Cui, Fu-zhai; Yang, Jing-xin; Jiao, Yan-peng; Yin, Qing-shui; Zhang, Yu; Lee, In-Seop

2008-06-01

Magnesium alloy has similar mechanical properties with natural bone, but its high susceptibility to corrosion has limited its application in orthopedics. In this study, a calcium phosphate coating is formed on magnesium alloy (AZ31) to control its degradation rate and enhance its bioactivity and bone inductivity. Samples of AZ31 plate were placed in the supersaturated calcification solution prepared with Ca(NO3)2, NaH2PO4 and NaHCO3, then the calcium phosphate coating formed. Through adjusting the immersion time, the thickness of uniform coatings can be changed from 10 to 20 μm. The composition, phase structure and morphology of the coatings were investigated. Bonding strength of the coatings and substrate was 2-4 MPa in this study. The coatings significantly decrease degradation rate of the original Mg alloy, indicating that the Mg alloy with calcium phosphate coating is a promising degradable bone material.

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

PubMed

McCarty, Mark F; DiNicolantonio, James J

2014-01-01

Increased fasting serum phosphate within the normal physiological range has been linked to increased cardiovascular risk in prospective epidemiology; increased production of fibroblast growth factor 23, and direct vascular effects of phosphate, may mediate this risk. Although dietary phosphate intake does not clearly influence fasting serum phosphate in individuals with normal renal function, increased phosphate intake can provoke a rise in fibroblast growth factor 23, and in diurnal phosphate levels, and hence may adversely influence vascular health. Dietary phosphate absorption can be moderated by emphasizing plant-based dietary choices (which provide phosphate in less bioavailable forms); avoidance of processed foods containing inorganic phosphate food additives; and by ingestion of phosphate-binder drugs, magnesium supplements, or niacin, which precipitate phosphate or suppress its gastrointestinal absorption. The propensity of dietary phosphate to promote vascular calcification may be opposed by optimal intakes of magnesium, vitamin K, and vitamin D; the latter should also counter the tendency of phosphate to elevate parathyroid hormone. Copyright © 2014 Elsevier Inc. All rights reserved.

30 CFR 75.1107-9 - Dry chemical devices; capacity; minimum requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Many dry chemical systems were originally designed for sodium bicarbonate before all-purpose chemical (ammonium phosphate) was shown to be more effective. Sodium bicarbonate is denser than ammonium phosphate; hence, for example, a 50-pound system designed for the sodium bicarbonate will hold slightly more by...

Magnesium Inhibits Wnt/β-Catenin Activity and Reverses the Osteogenic Transformation of Vascular Smooth Muscle Cells

PubMed Central

Montes de Oca, Addy; Guerrero, Fatima; Martinez-Moreno, Julio M.; Madueño, Juan A.; Herencia, Carmen; Peralta, Alan; Almaden, Yolanda; Lopez, Ignacio; Aguilera-Tejero, Escolastico; Gundlach, Kristina; Büchel, Janine; Peter, Mirjam E.; Passlick-Deetjen, Jutta; Rodriguez, Mariano; Muñoz-Castañeda, Juan R.

2014-01-01

Magnesium reduces vascular smooth muscle cell (VSMC) calcification in vitro but the mechanism has not been revealed so far. This work used only slightly increased magnesium levels and aimed at determining: a) whether inhibition of magnesium transport into the cell influences VSMC calcification, b) whether Wnt/β-catenin signaling, a key mediator of osteogenic differentiation, is modified by magnesium and c) whether magnesium can influence already established vascular calcification. Human VSMC incubated with high phosphate (3.3 mM) and moderately elevated magnesium (1.4 mM) significantly reduced VSMC calcification and expression of the osteogenic transcription factors Cbfa-1 and osterix, and up-regulated expression of the natural calcification inhibitors matrix Gla protein (MGP) and osteoprotegerin (OPG). The protective effects of magnesium on calcification and expression of osteogenic markers were no longer observed in VSMC cultured with an inhibitor of cellular magnesium transport (2-aminoethoxy-diphenylborate [2-APB]). High phosphate induced activation of Wnt/β-catenin pathway as demonstrated by the translocation of β-catenin into the nucleus, increased expression of the frizzled-3 gene, and downregulation of Dkk-1 gene, a specific antagonist of the Wnt/β-catenin signaling pathway. The addition of magnesium however inhibited phosphate-induced activation of Wnt/β-catenin signaling pathway. Furthermore, TRPM7 silencing using siRNA resulted in activation of Wnt/β-catenin signaling pathway. Additional experiments were performed to test the ability of magnesium to halt the progression of already established VSMC calcification in vitro. The delayed addition of magnesium decreased calcium content, down-regulated Cbfa-1 and osterix and up-regulated MGP and OPG, when compared with a control group. This effect was not observed when 2-APB was added. In conclusion, magnesium transport through the cell membrane is important to inhibit VSMC calcification in vitro. Inhibition of Wnt/β-catenin by magnesium is one potential intracellular mechanism by which this anti-calcifying effect is achieved. PMID:24586847

Electronic absorption spectrum of copper-doped magnesium potassium phosphate hexahydrate

NASA Astrophysics Data System (ADS)

Rao, S. N.; Sivaprasad, P.; Reddy, Y. P.; Rao, P. S.

1992-04-01

The optical absorption and EPR spectra of magnesium potassium phosphate hexahydrate (MPPH) doped with copper ions are recorded both at room and liquid nitrogen temperatures. The spectrum is characteristic of Cu2+ in tetragonal symmetry. The spin-Hamiltonian parameters and molecular orbital coefficients are evaluated. A correlation between EPR and optical absorption studies is drawn.

Microwave-assisted magnesium phosphate coating on the AZ31 magnesium alloy.

PubMed

Ren, Yufu; Babaie, Elham; Lin, Boren; Bhaduri, Sarit B

2017-08-18

Due to the combination of many unique properties, magnesium alloys have been widely recognized as suitable metallic materials for fabricating degradable biomedical implants. However, the extremely high degradation kinetics of magnesium alloys in the physiological environment have hindered their clinical applications. This paper reports for the first time the use of a novel microwave-assisted coating process to deposit magnesium phosphate (MgP) coatings on the Mg alloy AZ31 and improve its in vitro corrosion resistance. Newberyite and trimagnesium phosphate hydrate (TMP) layers with distinct features were fabricated at various processing times and temperatures. Subsequently, the corrosion resistance, degradation behavior, bioactivity and cytocompatibility of the MgP coated AZ31 samples were investigated. The potentiodynamic polarization tests reveal that the corrosion current density of the AZ31 magnesium alloy in simulated body fluid (SBF) is significantly suppressed by the deposited MgP coatings. Additionally, it is seen that MgP coatings remarkably reduced the mass loss of the AZ31 alloy after immersion in SBF for two weeks and promoted precipitation of apatite particles. The high viability of preosteoblast cells cultured with extracts of coated samples indicates that the MgP coatings can improve the cytocompatibility of the AZ31 alloy. These attractive results suggest that MgP coatings, serving as the protective and bioactive layer, can enhance the corrosion resistance and biological response of magnesium alloys.

40 CFR 721.5293 - Poly(oxy-1,2-ethanediyl), alpha-(9Z)-9-octadecenyl-.omega.-hydroxy-, phosphate, ammonium salt.

Code of Federal Regulations, 2010 CFR

2010-07-01

... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.5293 Poly(oxy-1,2-ethanediyl), alpha-(9Z)-9-octadecenyl-.omega.-hydroxy-, phosphate, ammonium salt. (a) Chemical substance and significant...

The Preparation, Characterization and Formation Mechanism of a Calcium Phosphate Conversion Coating on Magnesium Alloy AZ91D.

PubMed

Liu, Dong; Li, Yanyan; Zhou, Yong; Ding, Yigang

2018-05-28

The poor corrosion resistance of magnesium alloys is one of the main obstacles preventing their widespread usage. Due to the advantages of lower cost and simplicity in operation, chemical conversion coating has drawn considerable attention for its improvement of the corrosion resistance of magnesium alloys. In this study, a calcium phosphate coating was prepared on magnesium alloy AZ91D by chemical conversion. For the calcium phosphate coating, the effect of processing parameters on the microstructure and corrosion resistance was studied by scanning electron microscope (SEM) and electrochemical methods, and the coating composition was characterized by X-ray diffraction (XRD). The calcium phosphate coating was mainly composed of CaHPO₄·2H₂O (DCPD), with fewer cracks and pores. The coating with the leaf-like microstructure provided great corrosion resistance to the AZ91D substrate, and was obtained under the following conditions: 20 min, ambient temperature, and no stirring. At the same time, the role of NH₄H₂PO₄ as the coating-forming agent and the acidifying agent in the conversion process was realized, and the formation mechanism of DCPD was discussed in detail in this work.

Physiology of Calcium, Phosphate, Magnesium and Vitamin D.

PubMed

Allgrove, Jeremy

2015-01-01

The physiology of calcium and the other minerals involved in its metabolism is complex and intimately linked to the physiology of bone. Five principal humoral factors are involved in maintaining plasma concentrations of calcium, magnesium and phosphate and in coordinating the balance between their content in bone. The transmembrane transport of these elements is dependent on a series of complex mechanisms that are partly controlled by these hormones. The plasma concentration of calcium is initially sensed by a calcium-sensing receptor, which then sets up a cascade of events that initially determines parathyroid hormone secretion and eventually results in a specific action within the target organs, mainly bone and kidney. This chapter describes the physiology of these humoral factors and relates them to the pathological processes that give rise to disorders of calcium, phosphate and magnesium metabolism as well as of bone metabolism. This chapter also details the stages in the calcium cascade, describes the effects of calcium on the various target organs, gives details of the processes by which phosphate and magnesium are controlled and summarises the metabolism of vitamin D. The pathology of disorders of bone and calcium metabolism is described in detail in the relevant chapters. © 2015 S. Karger AG, Basel.

Forced-flow chromatographic determination of calcium and magnesium with continuous spectrophotometric detection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arguello, M.D.

1977-12-01

Modifications to the forced-flow chromatograph include a flow-through pH monitor to continuously monitor the pH of the final effluent and an active low-pass filter to eliminate noise in the spectrophotometric detector. All separations are performed using partially sulfonated XAD-2 as the ion exchanger. Elution of calcium and magnesium is accomplished using ammonium chloride and ethylenediammonium chloride solutions. Calcium and magnesium are detected by means of Arsenazo I and PAR-ZnEDTA color-forming reagents. Other metal ions are detected by means of PAR and Chromazurol S color-forming reagents. Calcium and magnesium distribution coefficients on partially sulfonated XAD-2 as functions of ammonium chloride andmore » ethylenediammonium chloride concentration are given together with distribution coefficients of other metal ions. Methods for the selective elution of interfering metal ions prior to the elution of calcium and magnesium are described. Beryllium and aluminum are selectively eluted with sulfosalicylic acid. Those elements forming anionic chloride complexes are selectively eluted with HCl-acetone. Nickel is selectively eluted with HCl-acetone-dimethylglyoxime. Synthetic samples containing calcium and magnesium, both alone and in combination with alkali metals, strontium, barium, beryllium, aluminum, transition metals, and rare earths, are analyzed. Hard water samples are analyzed for calcium and magnesium and the results compared to those obtained by EDTA titration, atomic absorption spectroscopy, and plasma emission spectroscopy. Several clinical serum samples are analyzed for calcium and magnesium and the results compared to those obtained by atomic absorption spectroscopy.« less

Influence of ethanol content in the precipitation medium on the composition, structure and reactivity of magnesium-calcium phosphate.

PubMed

Babaie, Elham; Zhou, Huan; Lin, Boren; Bhaduri, Sarit B

2015-08-01

Biocompatible amorphous magnesium calcium phosphate (AMCP) particles were synthesized using ethanol in precipitation medium from moderately supersaturated solution at pH10. Some synthesis parameters such as, (Mg+Ca):P, Mg:Ca ratio and different drying methods on the structure and stability of as-produced powder was studied and characterized using SEM, XRD and cell cytocompatibility. The results showed that depending on the Mg(2+) concentration, nano crystalline Struvite (MgNH4PO4·6H2O) can also be alternatively formed. However, the as-formed AMCP preserved its amorphous structure after 7 days of incubation in SBF for tested phosphate concentration, and equally ionic concentration of magnesium and calcium. Copyright © 2015 Elsevier B.V. All rights reserved.

Treatment and prevention of kidney stones: an update.

PubMed

Frassetto, Lynda; Kohlstadt, Ingrid

2011-12-01

The incidence of nephrolithiasis (kidney stones) is rising worldwide, especially in women and with increasing age. Kidney stones are associated with chronic kidney disease. Preventing recurrence is largely specific to the type of stone (e.g., calcium oxalate, calcium phosphate, cystine, struvite [magnesium ammonium phosphate]), and uric acid stones); however, even when the stone cannot be retrieved, urine pH and 24-hour urine assessment provide information about stone-forming factors that can guide prevention. Medications, such as protease inhibitors, antibiotics, and some diuretics, increase the risk of some types of kidney stones, and patients should be counseled about the risks of using these medications. Managing diet, medication use, and nutrient intake can help prevent the formation of kidney stones. Obesity increases the risk of kidney stones. However, weight loss could undermine prevention of kidney stones if associated with a high animal protein intake, laxative abuse, rapid loss of lean tissue, or poor hydration. For prevention of calcium oxalate, cystine, and uric acid stones, urine should be alkalinized by eating a diet high in fruits and vegetables, taking supplemental or prescription citrate, or drinking alkaline mineral waters. For prevention of calcium phosphate and struvite stones, urine should be acidified; cranberry juice or betaine can lower urine pH. Antispasmodic medications, ureteroscopy, and metabolic testing are increasingly being used to augment fluid and pain medications in the acute management of kidney stones.

40 CFR 418.10 - Applicability; description of the phosphate subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS FERTILIZER MANUFACTURING POINT SOURCE CATEGORY Phosphate...-process phosphoric acid, normal superphosphate, triple superphosphate and ammonium phosphate, except that...

40 CFR 418.10 - Applicability; description of the phosphate subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS FERTILIZER MANUFACTURING POINT SOURCE CATEGORY Phosphate...-process phosphoric acid, normal superphosphate, triple superphosphate and ammonium phosphate, except that...

Synthesis and characterization of struvite nano particles

NASA Astrophysics Data System (ADS)

Rathod, K. R.; Jogiya, B. V.; Chauhan, C. K.; Joshi, M. J.

2015-06-01

Struvite, Ammonium Magnesium Phosphate Hexahydrate [(AMPH) - (NH4)MgPO4.6(H2O)], is one of the fascinating inorganic phosphate minerals. Struvite is one of the components of the urinary stones. Struvite occurs as crystallites in urine and grows as a type of kidney stone. In this study, struvite nano particles were synthesized by wet chemical technique. The aqueous solutions containing dissolved Mg(CH3COO)2.4H2O and (NH4)H2PO4 mixed at the Mg/P molar ratio of 1.00. The synthesized struvite nano particles were characterized by XRD, FT-IR, Thermal Analysis and TEM. From XRD, crystal structure of the nano particle was found to be orthorhombic and crystalline size was found to be within 11 to 26 nm. The FT-IR spectrum for the struvite nano particles confirmed the presence of a water molecule and metal-oxygen stretching vibration, O-H stretching and bending, N-H bending and stretching, P-O bending and stretching vibrations. The Thermal Analysis was carried out from room temperature to 900°C. From TEM analysis, particle size was 23 to 30 nm. All the results were compared with bulk struvite.

Determination of phosphate phases in sewage sludge ash-based fertilizers by Raman microspectroscopy.

PubMed

Vogel, Christian; Adam, Christian; McNaughton, Don

2013-09-01

The chemical form of phosphate phases in sewage sludge ash (SSA)-based fertilizers was determined by Raman microspectroscopy. Raman mapping with a lateral resolution of 5 × 5 μm(2) easily detected different compounds present in the fertilizers with the help of recorded reference spectra of pure substances. Quartz and aluminosilicates showed Raman bands in the range of 450-520 cm(-1). Phosphates with apatite structure and magnesium triphosphate were determined at around 960 and 980 cm(-1), respectively. Furthermore, calcium/magnesium pyrophosphates were detected in some samples.

[Infrared spectrophotometry for crystalline composition of staghorn calculi].

PubMed

Ma, Kai; Huang, Xiao-bo; Xu, Qing-quan; Li, Jian-xing; Xiong, Liu-lin; Yang, Bo; Ye, Xiong-jun; Chen, Liang; Wang, Xiao-feng; Na, Yan-qun

2010-11-30

To provide theoretic rationales for treatment and prevention of staghorn calculi by analyzing stone composition and studying the relationship between stone and urinary tract infections. The clinical data of 51 staghorn calculi patients were analyzed retrospectively. The stone compositions were studied by infrared spectrophotometry. Six types of stone compositions were obtained. There were calcium oxalate monohydrate, calcium oxalate dehydrate, carbonate apatite, magnesium ammonium phosphate hexahydrate, uric acid and L-cystine. The majority of stones were of mixed compositions, pure stones were found in 15 cases (29.4%). Among all stones, calcium oxalate stones were found in 41 cases (80.4%) and uric stones in 10 cases (19.6%). Infectious stones were found in 26 cases (51.0%). Urinary tract infections were found in 40 (78.4%) patients and positive urine/stone culture was detected in 33 (64.7%) patients. With multiple crystalline compositions and etiological factors, the staghorn calculi are closely correlated with urinary tract infections.

Phonon assisted electronic transition in telluric acid ammonium phosphate single crystals

NASA Astrophysics Data System (ADS)

El-Muraikhi, M.; Kassem, M. E.; Al-Houty, L.

The effect of gamma-irradiation on the absorption optical spectra of telluric acid ammonium phosphate single crystals (TAAP) has been studied, in the wave length of 200-600 nm, for samples irradiated by various doses up to 10 Mrad. The results show that the electron phonon coupling constant increases with the irradiation dose.

Phosphorus doping a semiconductor particle

DOEpatents

Stevens, G.D.; Reynolds, J.S.

1999-07-20

A method of phosphorus doping a semiconductor particle using ammonium phosphate is disclosed. A p-doped silicon sphere is mixed with a diluted solution of ammonium phosphate having a predetermined concentration. These spheres are dried with the phosphorus then being diffused into the sphere to create either a shallow or deep p-n junction. A good PSG glass layer is formed on the surface of the sphere during the diffusion process. A subsequent segregation anneal process is utilized to strip metal impurities from near the p-n junction into the glass layer. A subsequent HF strip procedure is then utilized to removed the PSG layer. Ammonium phosphate is not a restricted chemical, is inexpensive, and does not pose any special shipping, handling, or disposal requirement. 1 fig.

Phosphorous doping a semiconductor particle

DOEpatents

Stevens, Gary Don; Reynolds, Jeffrey Scott

1999-07-20

A method (10) of phosphorus doping a semiconductor particle using ammonium phosphate. A p-doped silicon sphere is mixed with a diluted solution of ammonium phosphate having a predetermined concentration. These spheres are dried (16, 18), with the phosphorus then being diffused (20) into the sphere to create either a shallow or deep p-n junction. A good PSG glass layer is formed on the surface of the sphere during the diffusion process. A subsequent segregation anneal process is utilized to strip metal impurities from near the p-n junction into the glass layer. A subsequent HF strip procedure is then utilized to removed the PSG layer. Ammonium phosphate is not a restricted chemical, is inexpensive, and does not pose any special shipping, handling, or disposal requirement.

PERCHLORATE ENVIRONMENTAL CONTAMINATION: TOXICOLOGICAL REVIEW AND RISK CHARACTERIZATION (EXTERNAL REVIEW DRAFT) 2002

EPA Science Inventory

Perchlorate (ClO4-) is an anion that originates as a contaminant in ground water and surface waters when the salts of ammonium, potassium, magnesium, or sodium dissolve in water. One major source of contamination is the manufacture or improper disposal of ammonium perchlorate th...

Calcium, magnesium, and phosphate abnormalities in the emergency department.

PubMed

Chang, Wan-Tsu W; Radin, Bethany; McCurdy, Michael T

2014-05-01

Derangements of calcium, magnesium, and phosphate are associated with increased morbidity and mortality. These minerals have vital roles in the cellular physiology of the neuromuscular and cardiovascular systems. This article describes the pathophysiology of these mineral disorders. It aims to provide the emergency practitioner with an overview of the diagnosis and management of these disorders. Copyright © 2014 Elsevier Inc. All rights reserved.

Cord blood calcium, phosphate, magnesium, and alkaline phosphatase gestational age-specific reference intervals for preterm infants.

PubMed

Fenton, Tanis R; Lyon, Andrew W; Rose, M Sarah

2011-08-31

The objective was to determine the influence of gestational age, maternal, and neonatal variables on reference intervals for cord blood bone minerals (calcium, phosphate, magnesium) and related laboratory tests (alkaline phosphatase, and albumin-adjusted calcium), and to develop gestational age specific reference intervals based on infants without influential pathological conditions. Cross-sectional study. 702 babies were identified as candidates for this study in a regional referral neonatal unit. After exclusions (for anomalies, asphyxia, maternal magnesium sulfate administration, and death), relationships were examined between cord blood serum laboratory analytes (calcium, phosphate, magnesium, alkaline phosphatase, and albumin-adjusted calcium) with gestation age and also with maternal and neonatal variables using multiple linear regression. Infants with influential pathological conditions were omitted from the development of gestational age specific reference intervals for the following categories: 23-27, 28-31, 32-34, 35-36 and > 36 weeks. Among the 506 preterm and 54 terms infants included in the sample. Phosphate, magnesium, and alkaline phosphatase in cord blood serum decreased with gestational age, calcium increased with gestational age. Those who were triplets, small for gestational age, and those whose mother had pregnancy-induced hypertension were influential for most of the analytes. The reference ranges for the preterm infants ≥ 36 weeks were: phosphate 1.5 to 2.6 mmol/L (4.5 to 8.0 mg/dL), calcium: 2.1 to 3.1 mmol/L (8.3 to 12.4 mg/dL); albumin-adjusted calcium: 2.3 to 3.2 mmol/L (9.1 to 12.9 mg/dL); magnesium 0.6 to 1.0 mmol/L (1.4 to 2.3 mg/dL), and alkaline phosphatase 60 to 301 units/L. These data suggest that gestational age, as well as potentially pathogenic maternal and neonatal variables should be considered in the development of reference intervals for preterm infants.

Study on the influence of the decoking agent on the activity of limestone in wet flue gas desulfurization

NASA Astrophysics Data System (ADS)

Li, Qianjun; Xu, Dongyang; Wu, Yunxia; Yu, Jin

2017-01-01

Influence of the main components of decoking agent (magnesium nitrate, aluminum nitrate, copper nitrate, ammonium nitrate and actual decoking agent) on the activity of limestone is studied in laboratory by MET method. Results show that magnesium nitrate, ammonium nitrate and copper nitrate almost has no effect on the activity of limestone. With the concentration increasing, aluminum nitrate has an increasing inhibition on the dissolution of limestone. Fly ash has inhibition on dissolution of limestone due to the blockage of limestone pore by fly ash. The actual decoking agent has almost no effect on the limestone.

Study on pyrolysis characteristics of lignocellulosic biomass impregnated with ammonia source.

PubMed

Li, Kai; Zhu, Changpeng; Zhang, Liqiang; Zhu, Xifeng

2016-06-01

The current study presents the pyrolysis characteristics of rice husk impregnated with different kinds of ammonia source (ammonium acetate, urea, ammonium sulfate and ammonium dihydrogen phosphate) in a fixed bed reactor. The introduction of ammonia source in pyrolysis process achieved the conversation from carbonyl compounds to nitrogenous heterocyclic compounds. The liquid product of urea-impregnated biomass has higher content of nitrogenous heterocyclic compounds (8.35%) and phenols (30.4%). For ammonium sulfate and ammonium dihydrogen phosphate-impregnated biomass, the quantity of compounds in liquid products reduces remarkably, and the gas products are rich in CO and H2. All the solid products of pyrolysis have great potential application in biochar-based fertilizer and activated carbon for their high N content. Copyright © 2016 Elsevier Ltd. All rights reserved.

In situ synthesis of magnesium-substituted biphasic calcium phosphate and in vitro biodegradation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Tae-Wan; Lee, Hyeong-Shin; Kim, Dong-Hyun

Highlights: ► Mg–BCP were successfully prepared through in situ aqueous co-precipitation method. ► The amount of β-TCP phase was changed with the magnesium substitution level. ► The substitution of magnesium led to a decrease in the unit cell volume. ► Mg–BCP could be able to develop a new apatite phase on the surface faster than BCP. -- Abstract: In situ preparation of magnesium (Mg) substituted biphasic calcium phosphate (BCP) of hydroxyapatite (HAp)/β-tricalcium phosphate (β-TCP) were carried out through aqueous co-precipitation method. The concentrations of added magnesium were varied with the calcium in order to obtain constant (Ca + Mg)/P ratiosmore » of 1.602. X-ray diffraction (XRD) and Fourier transformed infrared (FTIR) spectroscopy were used to characterize the structure of synthesized magnesium substituted BCP powders. The results have shown that substitution of magnesium in the calcium deficient apatites revealed the formation of biphasic mixtures of different HAp/β-TCP ratios after heating at 1000 °C. The ratios of the formation of phase mixtures were dependent on the content of magnesium. After immersing in Hanks’ balanced salt solution (HBSS) for 1 week, 1 wt% magnesium substituted BCP powders were degraded and precipitation started to be formed with small granules consisting of number of flake-like crystal onto the surface of synthesized powders. On the other hand, in the case of pure BCP powders, the formation of new precipitates was detected after immersion in HBSS for 2 weeks. On the basis of these results, magnesium substituted BCP could be able to develop a new apatite phase on the surface in contact with physiological fluids faster than BCP does. In addition, the retention time to produce the new apatite phase in implantation operation for the BCP powder could be controlled by the amount of magnesium substitution.« less

Thermoelectrochemical system and method

DOEpatents

Ludwig, F.A.; Townsend, C.W.; Eliash, B.M.

1995-11-28

A thermal electrochemical system is described in which an electrical current is generated between a cathode immersed in a concentrated aqueous solution of phosphoric acid and an anode immersed in a molten salt solution of ammonium phosphate and monohydric ammonium phosphate. Reactants consumed at the electrodes during the electrochemical reaction are thermochemically regenerated and recycled to the electrodes to provide continuous operation of the system. 5 figs.

Environmental Acceptable Medium Caliber Ammunition Percussion Primers

DTIC Science & Technology

2008-05-01

the nanoparticles extremely hydrophobic. The alternative treatment of the solution was the addition of ammonium dihydrogen phosphate (ADP) to serve as...Ultrafine Aluminum Nanoparticles," LA-UR-04-2921. 49 ACRONYM LIST ADP Ammonium Dihydrogen Phosphate Al Aluminum ARDEC Armament Research Development and...Nitrocellulose Nd:Yag Neodymium -doped yttrium aluminum garnet NSWC-IH Naval Surface Warfare Center- Indian Head PAD Propellant actuated device PETN

Time and the crystallization of apatite in seawater

USGS Publications Warehouse

Gulbrandsen, R.A.; Roberson, C.E.; Neil, S.T.

1984-01-01

Carbonate fluorapatite has been synthesized in seawater in an experiment of nearly 10-years duration. The addition of phosphate to seawater whose fluoride concentration had been increased to 7.6 mg/l brought about an initial amorphous phosphate precipitate. After 20 months, a crystalline magnesium phosphate phase developed within the amorphous phosphate. Crystallization of apatite, which occurred during the last 3 years of the experiment, was accompanied by dissolution of the crystalline magnesium phosphate phase. The MgO content of the apatite (1.9 percent) is high in comparison to Tertiary and older apatite but similar to some young apatite; the CO2 content (3.6 percent) is medium, and the fluorine content (2.2 percent) is low but again similar to some young apatite. The hydroxyl ion (OH-) likely fills the need for additional fluorine-position atoms. The mole ratio of Ca plus substituent elements to P plus substituent elements (1.50) is low in comparison to the expected ratio of 1.67. The substitution of the hydronium ion (H3O+) for Ca may account for this difference. The synthesis of apatite in seawater demonstrates that the factor of time overcomes the well known inhibiting effect of magnesium upon the crystallization of apatite. It also implies that given an adequate supply of phosphate, apatite can form in most ocean environments and likely plays a major pan in the control of the phosphate content of seawater. ?? 1984.

Both Phosphorus Fertilizers and Indigenous Bacteria Enhance Arsenic Release into Groundwater in Arsenic-Contaminated Aquifers.

PubMed

Lin, Tzu-Yu; Wei, Chia-Cheng; Huang, Chi-Wei; Chang, Chun-Han; Hsu, Fu-Lan; Liao, Vivian Hsiu-Chuan

2016-03-23

Arsenic (As) is a human carcinogen, and arsenic contamination in groundwater is a worldwide public health concern. Arsenic-affected areas are found in many places but are reported mostly in agricultural farmlands, yet the interaction of fertilizers, microorganisms, and arsenic mobilization in arsenic-contaminated aquifers remains uncharacterized. This study investigates the effects of fertilizers and bacteria on the mobilization of arsenic in two arsenic-contaminated aquifers. We performed microcosm experiments using arsenic-contaminated sediments and amended with inorganic nitrogenous or phosphorus fertilizers for 1 and 4 months under aerobic and anaerobic conditions. The results show that microcosms amended with 100 mg/L phosphorus fertilizers (dipotassium phosphate), but not nitrogenous fertilizers (ammonium sulfate), significantly increase aqueous As(III) release in arsenic-contaminated sediments under anaerobic condition. We also show that concentrations of iron, manganese, potassium, sodium, calcium, and magnesium are increased in the aqueous phase and that the addition of dipotassium phosphate causes a further increase in aqueous iron, potassium, and sodium, suggesting that multiple metal elements may take part in the arsenic release process. Furthermore, microbial analysis indicates that the dominant microbial phylum is shifted from α-proteobacteria to β- and γ-proteobacteria when the As(III) is increased and phosphate is added in the aquifer. Our results provide evidence that both phosphorus fertilizers and microorganisms can mediate the release of arsenic to groundwater in arsenic-contaminated sediments under anaerobic condition. Our study suggests that agricultural activity such as the use of fertilizers and monitoring phosphate concentration in groundwater should be taken into consideration for the management of arsenic in groundwater.

Detection of innersphere interactions between magnesium hydrate and the phosphate backbone of the HDV ribozyme using Raman crystallography.

PubMed

Gong, Bo; Chen, Yuanyuan; Christian, Eric L; Chen, Jui-Hui; Chase, Elaine; Chadalavada, Durga M; Yajima, Rieko; Golden, Barbara L; Bevilacqua, Philip C; Carey, Paul R

2008-07-30

A Raman microscope and Raman difference spectroscopy are used to detect the vibrational signature of RNA-bound magnesium hydrate in crystals of hepatitis delta virus (HDV) ribozyme and to follow the effects of magnesium hydrate binding to the nonbridging phosphate oxygens in the phosphodiester backbone. There is a correlation between the Raman intensity of the innersphere magnesium hydrate signature peak, near 322 cm-1, and the intensity of the PO2- symmetric stretch, near 1100 cm-1, perturbed by magnesium binding, demonstrating direct observation of -PO2-...Mg2+(H2O)x innersphere complexes. The complexes may be pentahydrates (x = 5) and tetrahydrates (x = 4). The assignment of the Raman feature near 322 cm-1 to a magnesium hydrate species is confirmed by isotope shifts observed in D2O and H218O that are semiquantitatively reproduced by calculations. The standardized intensity changes in the 1100 cm-1 PO2- feature seen upon magnesium hydrate binding indicates that there are approximately 5 innersphere Mg2+...-O2P contacts per HDV molecule when the crystal is exposed to a solution containing 20 mM magnesium.

Color stable phosphors for LED lamps and methods for preparing them

DOEpatents

Murphy, James Edward; Setlur, Anant Achyut; Camardello, Samuel Joseph

2013-11-26

An LED lamp includes a light source configured to emit radiation with a peak intensity at a wavelength between about 250 nm and about 550 nm; and a phosphor composition configured to be radiationally coupled to the light source. The phosphor composition includes particles of a phosphor of formula I, said particles having a coating composition disposed on surfaces thereof; ((Sr.sub.1-zM.sub.z).sub.1-(x+w)A.sub.wCe.sub.x).sub.3(Al.sub.1-ySi.sub.y-)O.sub.4+y+3(x-w)F.sub.1-y-3(x-w) I wherein the coating composition comprises a material selected from aluminum oxide, magnesium oxide, calcium oxide, barium oxide, strontium oxide, zinc oxide, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, barium hydroxide, strontium hydroxide, zinc hydroxide, aluminum phosphate, magnesium phosphate, calcium phosphate, barium phosphate, strontium phosphate, and combinations thereof; and A is Li, NA, K, or Rb, or a combination thereof; M is Ca, Ba, Mg, Zn, or a combination thereof; and 0

The structure of human DNase I bound to magnesium and phosphate ions points to a catalytic mechanism common to members of the DNase I-like superfamily.

PubMed

Parsiegla, Goetz; Noguere, Christophe; Santell, Lydia; Lazarus, Robert A; Bourne, Yves

2012-12-21

Recombinant human DNase I (Pulmozyme, dornase alfa) is used for the treatment of cystic fibrosis where it improves lung function and reduces the number of exacerbations. The physiological mechanism of action is thought to involve the reduction of the viscoelasticity of cystic fibrosis sputum by hydrolyzing high concentrations of DNA into low-molecular mass fragments. Here we describe the 1.95 Å resolution crystal structure of recombinant human DNase I (rhDNase I) in complex with magnesium and phosphate ions, both bound in the active site. Complementary mutagenesis data of rhDNase I coupled to a comprehensive structural analysis of the DNase I-like superfamily argue for the key catalytic role of Asn7, which is invariant among mammalian DNase I enzymes and members of this superfamily, through stabilization of the magnesium ion coordination sphere. Overall, our combined structural and mutagenesis data suggest the occurrence of a magnesium-assisted pentavalent phosphate transition state in human DNase I during catalysis, where Asp168 may play a key role as a general catalytic base.

The formation of an organic coat and the release of corrosion microparticles from metallic magnesium implants.

PubMed

Badar, Muhammad; Lünsdorf, Heinrich; Evertz, Florian; Rahim, Muhammad Imran; Glasmacher, Birgit; Hauser, Hansjörg; Mueller, Peter P

2013-07-01

Magnesium alloys have been proposed as prospective degradable implant materials. To elucidate the complex interactions between the corroding implants and the tissue, magnesium implants were analyzed in a mouse model and the response was compared to that induced by Ti and by the resorbable polymer polyglactin, respectively. One month after implantation, distinct traces of corrosion were apparent but the magnesium implants were still intact, whereas resorbable polymeric wound suture implants were already fragmented. Analysis of magnesium implants 2weeks after implantation by energy-dispersive X-ray spectroscopy indicated that magnesium, oxygen, calcium and phosphate were present at the implant surface. One month after implantation, the element composition of the outermost layer of the implant was indicative of tissue without detectable levels of magnesium, indicating a protective barrier function of this organic layer. In agreement with this notion, gene expression patterns in the surrounding tissue were highly similar for all implant materials investigated. However, high-resolution imaging using energy-filtered transmission electron microscopy revealed magnesium-containing microparticles in the tissue in the proximity of the implant. The release of such corrosion particles may contribute to the accumulation of calcium phosphate in the nearby tissue and to bone conductive activities of magnesium implants. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Evaluation of Rapid-Setting Concretes for Airfield Spall Repair

DTIC Science & Technology

1991-04-01

repair concretes for Rapid Runway Repair (RRR). The three were a methyl methacrylate binder (Silikal RI7AF), a magnesium phosphate mortar mix (Set-45...reld Methyl methacrylate Rapid-setting 82 Blended cement Pavement materials 16. PRICE CODE Magnesium phosphate cement Rapid runway repair Spall repair 17...conditions, and for use during RRR training. Silikal is a methyl methacrylate , which forms a solid mass within minutes after its two components are mixed. It

Performance of phosphogypsum and calcium magnesium phosphate fertilizer for nitrogen conservation in pig manure composting.

PubMed

Li, Yun; Luo, Wenhai; Li, Guoxue; Wang, Kun; Gong, Xiaoyan

2018-02-01

This study investigated the performance of phosphogypsum and calcium magnesium phosphate fertilizer for nitrogen conservation during pig manure composting with cornstalk as the bulking agent. Results show that phosphogypsum increased nitrous oxide (N 2 O) emission, but significantly reduced ammonia (NH 3 ) emission and thus enhanced the mineral and total nitrogen (TN) contents in compost. Although N 2 O emission could be reduced by adding calcium magnesium phosphate fertilizer, NH 3 emission was considerably increased, resulting in an increase in TN loss during composting. By blending these two additives, both NH 3 and N 2 O emissions could be mitigated, achieving effective nitrogen conservation in composting. More importantly, with the addition of 20% TN of the mixed composting materials, these two additives could synergistically improve the compost maturity and quality. Copyright © 2017 Elsevier Ltd. All rights reserved.

STUDYING THE EFFECTS OF CALCIUM AND MAGNESIUM ON SIZE-DISTRIBUTED NITRATE AND AMMONIUM WITH EQUISOLV II. (R823186)

EPA Science Inventory

Abstract

A chemical equilibrium code was improved and used to show that calcium and magnesium have a large yet different effect on the aerosol size distribution in different regions of Los Angeles. In the code, a new technique of solving individual equilibrium equation...

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

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

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

Evidence for a hydroxide ion bridging two magnesium ions at the active site of the hammerhead ribozyme.

PubMed Central

Hermann, T; Auffinger, P; Scott, W G; Westhof, E

1997-01-01

In the presence of magnesium ions, cleavage by the hammerhead ribozyme RNA at a specific residue leads to 2'3'-cyclic phosphate and 5'-OH extremities. In the cleavage reaction an activated ribose 2'-hydroxyl group attacks its attached 3'-phosphate. Molecular dynamics simulations of the crystal structure of the hammerhead ribozyme, obtained after flash-freezing of crystals under conditions where the ribozyme is active, provide evidence that a mu-bridging OH-ion is located between two Mg2+ions close to the cleavable phosphate. Constrained simulations show further that a flip from the C3'- endo to the C2'- endo conformation of the ribose at the cleavable phosphate brings the 2'-hydroxyl in proximity to both the attacked phosphorous atom and the mu-bridging OH-ion. Thus, the simulations lead to a detailed new insight into the mechanism of hammerhead ribozyme cleavage where a mu-hydroxo bridged magnesium cluster, located on the deep groove side, provides an OH-ion that is able to activate the 2'-hydroxyl nucleophile after a minor and localized conformational change in the RNA. PMID:9254698

Development of chemically bonded phosphate ceramics for stabilizing low-level mixed wastes

NASA Astrophysics Data System (ADS)

Jeong, Seung-Young

1997-11-01

Novel chemically bonded phosphate ceramics have been developed by acid-base reactions between magnesium oxide and an acid phosphate at room temperature for stabilizing U.S. Department of Energy's low-level mixed waste streams that include hazardous chemicals and radioactive elements. Newberyite (MgHPOsb4.3Hsb2O)-rich magnesium phosphate ceramic was formed by an acid-base reaction between phosphoric acid and magnesium oxide. The reaction slurry, formed at room-temperature, sets rapidly and forms stable mineral phases of newberyite, lunebergite, and residual MgO. Rapid setting also generates heat due to exothermic acid-base reaction. The reaction was retarded by partially neutralizing the phosphoric acid solution by adding sodium or potassium hydroxide. This reduced the rate of reaction and heat generation and led to a practical way of producing novel magnesium potassium phosphate ceramic. This ceramic was formed by reacting stoichiometric amount of monopotassium dihydrogen phosphate crystals, MgO, and water, forming pure-phase of MgKPOsb4.6Hsb2O (MKP) with moderate exothermic reaction. Using this chemically bonded phosphate ceramic matrix, low-level mixed waste streams were stabilized, and superior waste forms in a monolithic structure were developed. The final waste forms showed low open porosity and permeability, and higher compression strength than the Land Disposal Requirements (LDRs). The novel MKP ceramic technology allowed us to develop operational size waste forms of 55 gal with good physical integrity. In this improved waste form, the hazardous contaminants such as RCRA heavy metals (Hg, Pb, Cd, Cr, Ni, etc) were chemically fixed by their conversion into insoluble phosphate forms and physically encapsulated by the phosphate ceramic. In addition, chemically bonded phosphate ceramics stabilized radioactive elements such U and Pu. This was demonstrated with a detailed stabilization study on cerium used as a surrogate (chemically equivalent but nonradioactive) of U and Pu as well as on actual U-contaminated waste water. In particular, the leaching level of mercury in the Toxicity Characteristic Leaching Procedure (TCLP) test was reduced from 5000 to 0.00085 ppm, and the leaching level of cerium in the long term leaching test (ANS 16.1 test) was below the detection limit. These results show that the chemically bonded phosphate ceramics process may be a simple, inexpensive, and efficient method for stabilizing low-level mixed waste streams.

Effects of a magnesium-free dialysate on magnesium metabolism during continuous ambulatory peritoneal dialysis.

PubMed

Shah, G M; Winer, R L; Cutler, R E; Arieff, A I; Goodman, W G; Lacher, J W; Schoenfeld, P Y; Coburn, J W; Horowitz, A M

1987-10-01

While the use of magnesium-containing compounds is usually contraindicated in dialysis patients, the risk of toxicity from hypermagnesemia can be reduced by lowering the magnesium concentration in dialysate. We examined the effects of a magnesium-free dialysate on both serum magnesium level and the peritoneal removal rate of magnesium over 12 weeks in 25 stable patients undergoing continuous ambulatory peritoneal dialysis (CAPD). After 2 weeks, the serum magnesium level decreased from 2.2 to 1.9 mg/dL (0.9 to 0.8 mmol/L) (P less than .02) and the peritoneal removal rate increased from 66 to 83 mg/d (2.8 to 3.5 mmol/d) (P less than .05), with both values remaining stable thereafter. There was a strong association between these parameters (r = -0.62, P less than .05), suggesting that the serum magnesium level decreased as a result of the initial increased peritoneal removal rate. For an additional 4-week period, a subgroup of nine patients received magnesium-containing, phosphate binding agents instead of those containing only aluminum. During this phase, serum inorganic phosphorus was well controlled. The serum magnesium level increased only from 1.8 to 2.5 mg/dL (0.7 to 1.0 mmol/L) (P less than .05), due in great part to the concomitant 41% rise in peritoneal magnesium removal from 91 to 128 mg/d (3.8 to 5.3 mmol/d) (P less than .05). No toxicity was noted during the entire 16-week study period, nor did serum calcium change. Thus, serum magnesium levels remained within an acceptable range as magnesium-containing phosphate binders were given through the use of magnesium-free peritoneal dialysate.(ABSTRACT TRUNCATED AT 250 WORDS)

40 CFR 721.5293 - Poly(oxy-1,2-ethanediyl), alpha-(9Z)-9-octadecenyl-.omega.-hydroxy-, phosphate, ammonium salt.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Poly(oxy-1,2-ethanediyl), alpha-(9Z)-9... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.5293 Poly(oxy-1,2-ethanediyl), alpha...), alpha-(9Z)-9-octadecenyl-.omega.-hydroxy-, phosphate, ammonium salt (PMN P-99-920; CAS No. 58857-49-1...

40 CFR 721.5293 - Poly(oxy-1,2-ethanediyl), alpha-(9Z)-9-octadecenyl-.omega.-hydroxy-, phosphate, ammonium salt.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Poly(oxy-1,2-ethanediyl), alpha-(9Z)-9... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.5293 Poly(oxy-1,2-ethanediyl), alpha...), alpha-(9Z)-9-octadecenyl-.omega.-hydroxy-, phosphate, ammonium salt (PMN P-99-920; CAS No. 58857-49-1...

40 CFR 721.5293 - Poly(oxy-1,2-ethanediyl), alpha-(9Z)-9-octadecenyl-.omega.-hydroxy-, phosphate, ammonium salt.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Poly(oxy-1,2-ethanediyl), alpha-(9Z)-9... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.5293 Poly(oxy-1,2-ethanediyl), alpha...), alpha-(9Z)-9-octadecenyl-.omega.-hydroxy-, phosphate, ammonium salt (PMN P-99-920; CAS No. 58857-49-1...

40 CFR 721.5293 - Poly(oxy-1,2-ethanediyl), alpha-(9Z)-9-octadecenyl-.omega.-hydroxy-, phosphate, ammonium salt.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Poly(oxy-1,2-ethanediyl), alpha-(9Z)-9... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.5293 Poly(oxy-1,2-ethanediyl), alpha...), alpha-(9Z)-9-octadecenyl-.omega.-hydroxy-, phosphate, ammonium salt (PMN P-99-920; CAS No. 58857-49-1...

Antimicrobial properties and dentin bonding strength of magnesium phosphate cements.

PubMed

Mestres, G; Abdolhosseini, M; Bowles, W; Huang, S-H; Aparicio, C; Gorr, S-U; Ginebra, M-P

2013-09-01

The main objective of this work was to assess the antimicrobial properties and the dentin-bonding strength of novel magnesium phosphate cements (MPC). Three formulations of MPC, consisting of magnesium oxide and a phosphate salt, NH4H2PO4, NaH2PO4 or a mixture of both, were evaluated. As a result of the setting reaction, MPC transformed into either struvite (MgNH4PO4·6H2O) when NH4H2PO4 was used or an amorphous magnesium sodium phosphate when NaH2PO4 was used. The MPC had appropriate setting times for hard tissue applications, high early compressive strengths and higher strength of bonding to dentin than commercial mineral trioxide aggregate cement. Bacteriological studies were performed with fresh and aged cements against three bacterial strains, Escherichia coli, Pseudomonas aeruginosa (planktonic and in biofilm) and Aggregatibacter actinomycetemcomitans. These bacteria have been associated with infected implants, as well as other frequent hard tissue related infections. Extracts of different compositions of MPC had bactericidal or bacteriostatic properties against the three bacterial strains tested. This was associated mainly with a synergistic effect between the high osmolarity and alkaline pH of the MPC. These intrinsic antimicrobial properties make MPC preferential candidates for applications in dentistry, such as root fillers, pulp capping agents and cavity liners. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Assessment of salivary calcium, phosphate, magnesium, pH, and flow rate in healthy subjects, periodontitis, and dental caries.

PubMed

Rajesh, K S; Zareena; Hegde, Shashikanth; Arun Kumar, M S

2015-01-01

This study was conducted to estimate and compare inorganic salivary calcium, phosphate, magnesium, salivary flow rate, and pH of unstimulated saliva and oral hygiene status of healthy subjects, subjects with periodontitis and dental caries, and to correlate salivary calcium level with number of intact teeth. The study population consisted of 48 systemically healthy subjects in the age group of 18-55 years, which was further divided into three groups: healthy, periodontitis, and dental caries. Oral hygiene index-simplified, probing pocket depth, clinical attachment level, the number of intact teeth, and active carious lesions were recorded. Estimation of inorganic salivary calcium, phosphate, and magnesium was performed spectrophotometrically using Vitros 5.1 FS. Statistical analysis was performed using the one-way analysis of variance test at 5% significance level. There was a statistically significant increase in inorganic salivary calcium, phosphate, pH, flow rate, and poor oral hygiene status in periodontitis group compared to dental caries and healthy group. Subjects with increased inorganic salivary calcium, phosphate, pH, flow rate, and poor oral hygiene are at a higher risk of developing periodontitis. Since there is increased remineralization potential, these subjects have more number of intact teeth compared to the dental caries group.

Assessment of salivary calcium, phosphate, magnesium, pH, and flow rate in healthy subjects, periodontitis, and dental caries

PubMed Central

Rajesh, K. S.; Zareena; Hegde, Shashikanth; Arun Kumar, M. S.

2015-01-01

Aim: This study was conducted to estimate and compare inorganic salivary calcium, phosphate, magnesium, salivary flow rate, and pH of unstimulated saliva and oral hygiene status of healthy subjects, subjects with periodontitis and dental caries, and to correlate salivary calcium level with number of intact teeth. Materials and Methods: The study population consisted of 48 systemically healthy subjects in the age group of 18-55 years, which was further divided into three groups: healthy, periodontitis, and dental caries. Oral hygiene index-simplified, probing pocket depth, clinical attachment level, the number of intact teeth, and active carious lesions were recorded. Estimation of inorganic salivary calcium, phosphate, and magnesium was performed spectrophotometrically using Vitros 5.1 FS. Statistical analysis was performed using the one-way analysis of variance test at 5% significance level. Results: There was a statistically significant increase in inorganic salivary calcium, phosphate, pH, flow rate, and poor oral hygiene status in periodontitis group compared to dental caries and healthy group. Conclusion: Subjects with increased inorganic salivary calcium, phosphate, pH, flow rate, and poor oral hygiene are at a higher risk of developing periodontitis. Since there is increased remineralization potential, these subjects have more number of intact teeth compared to the dental caries group. PMID:26681848

Growth characteristics of a new methylomonad.

PubMed Central

Chen, B J; Hirt, W; Lim, H C; Tsao, G T

1977-01-01

A methylomonad culture was isolated from pond water and examined as a potential source of single-cell protein. A medium containing magnesium sulfate, ammonium hydroxide, sodium phosphate, tap water, and methanol supported the growth of the isolate. Optimal growth conditions in batch cultures for the organism were: temperature, 30 to 33 degrees C; pH 7.1; and phosphate concentration, 0.015 M. The minimum doubling time obtained was 1.6 h. The specific growth rate in batch culture was dependent on the methanol concentration, reaching a maximum around 0.2% (wt/vol). Growth inhibition was apparent above 0.3% (wt/vol), and growth was completely inhibited above 4.6% (wt/vol) methanol. Although the inhibitory effect of formaldehyde on the specific growth rate was much greater than that of formate, the organism utilized formaldehyde, but not formate, as a sole carbon and energy source in batch cultures. The isolate was identified primarily by its inability to utilize any carbon source other than methanol and formaldehyde for growth. Although it is capable of rapid growth on methanol, the organism showed a very weak catalase activity. The amino acid content of the cells compared favorably with the reference levels for the essential amino acids specific by the Food and Agricultural Organization of the United Nations. PMID:15510

Study on the injectability of a novel glucose modified magnesium potassium phosphate chemically bonded ceramic.

PubMed

Tan, Yongshan; Dong, Jinmei; Yu, Hongfa; Li, Ying; Wen, Jing; Wu, Chengyou

2017-10-01

A novel magnesium potassium phosphate chemically bonded ceramic (MKPCBC) was prepared as a byproduct of boron-containing magnesium oxide (B-MgO) after extracting Li 2 CO 3 from salt lakes. In this work, the influence of glucose on the properties of MKPCBC, such as the setting time, compressive strength and hydration heat, was investigated. In addition, we studied the effect of the magnesium-phosphate ratio (M/P) and liquid-solid ratio (L/S) on the injectability of MKPCBC. The pH change in glucose modified MKPCBC paste was also investigated. The phase composition and microstructure were studied in detail by using X-ray diffraction (XRD) and scanning electron microscopy-energy dispersive spectrometry (SEM-EDS). The results show that the optimal content of glucose is 6wt%. The optimum proportions of M/P and L/S for MKPCBC are 1.5 and 0.25, respectively. The properties of the novel MPCBC can meet the requirements of biomaterials. In addition, the retardation mechanism of glucose on MKPCBC and the hydration mechanism of novel MKPCBC were studied in detail through the continuous monitoring of the phase composition and microstructure. Copyright © 2017. Published by Elsevier B.V.

Effect of magnesium ions on the structure of DNA thin films: an infrared spectroscopy study

PubMed Central

Serec, Kristina; Babić, Sanja Dolanski; Podgornik, Rudolf; Tomić, Silvia

2016-01-01

Utilizing Fourier transform infrared spectroscopy we have investigated the vibrational spectrum of thin dsDNA films in order to track the structural changes upon addition of magnesium ions. In the range of low magnesium concentration ([magnesium]/[phosphate] = [Mg]/[P] < 0.5), both the red shift and the intensity of asymmetric PO2 stretching band decrease, indicating an increase of magnesium-phosphate binding in the backbone region. Vibration characteristics of the A conformation of the dsDNA vanish, whereas those characterizing the B conformation become fully stabilized. In the crossover range with comparable Mg and intrinsic Na DNA ions ([Mg]/[P] ≈ 1) B conformation remains stable; vibrational spectra show moderate intensity changes and a prominent blue shift, indicating a reinforcement of the bonds and binding in both the phosphate and the base regions. The obtained results reflect the modified screening and local charge neutralization of the dsDNA backbone charge, thus consistently demonstrating that the added Mg ions interact with DNA via long-range electrostatic forces. At high Mg contents ([Mg]/[P] > 10), the vibrational spectra broaden and show a striking intensity rise, while the base stacking remains unaffected. We argue that at these extreme conditions, where a charge compensation by vicinal counterions reaches 92–94%, DNA may undergo a structural transition into a more compact form. PMID:27484473

Semi-dynamic leaching tests of nickel containing wastes stabilized/solidified with magnesium potassium phosphate cements.

PubMed

Torras, Josep; Buj, Irene; Rovira, Miquel; de Pablo, Joan

2011-02-28

Herein is presented a study on the long-term leaching behaviour of nickel containing wastes stabilized/solidified with magnesium potassium phosphate cements. Two different semi-dynamic leaching tests were carried out on monolithic materials: ANS 16.1 test with liquid-to-solid ratio (L/S) of 10 dm(3) kg(-1) and increasing renewal times, and ASTM C1308 test with liquid-to-solid ratio (L/S) of 100 dm(3) kg(-1) and constant renewal time of 1 day. ASTM C1308 provides a lower degree of saturation of the leachant with respect to the leached material. The effectiveness of magnesium potassium phosphate cements for the inertization of nickel was proved. XRD analyses showed the presence of bobierrite on the monolith's surface after the leaching test, which had not been detected prior to the leaching test. In addition, the calculated cumulative release of the main components of the stabilization matrix (Mg(2+), total P and K(+)) was represented versus time in logarithmic scale and it was determined if the leaching mechanism corresponds to diffusion. Potassium is released by diffusion, while total phosphorous and magnesium show dissolution. Magnesium release in ANS 16.1 is slowed down because of saturation of the leachant. Experimental results demonstrate the importance of L/S ratio and renewal times in semi-dynamic leaching tests. Copyright © 2010 Elsevier B.V. All rights reserved.

Occupational exposures in two industrial plants devoted to the production of ammonium phosphate fertilisers.

PubMed

Bolívar, J P; García-Tenorio, R; Mosqueda, F; Gázquez, M J; López-Coto, I; Adame, J A; Vaca, F

2013-03-01

In order to fill a gap in the open literature, occupational exposures and activity concentrations have been assessed in two NORM industrial plants, located in the south-west of Spain, devoted to the production of mono-ammonium phosphate (MAP) and di-ammonium phosphate (DAP) fertilisers. The annual effective doses received by the workers from these plants are clearly below 1 mSv yr(-1) and the contribution due to external radiation is similar to that due to inhalation. The contribution to the maximum effective doses due to inhalation of particulate matter has been estimated to be about 0.12 mSv yr(-1), while the (222)Rn concentrations inside the plants are of no concern. Consequently, no additional actions or radiological protection measures need to be taken to decrease the natural radiation received by the workers in these facilities.

Glyphosate sensitivity of 5-enol-pyruvylshikimate-3-phosphate synthase from Bacillus subtilis depends upon state of activation induced by monovalent cations.

PubMed

Fischer, R S; Rubin, J L; Gaines, C G; Jensen, R A

1987-07-01

The 5-enol-pyruvylshikimate-3-phosphate (EPSP) synthase from Bacillus subtilis was activated by monovalent cations, catalytic activity being negligible in the absence of monovalent cations. The order of cation effectiveness (NH4+ greater than K+ greater than Rb+ greater than Na+ = Cs+ = Li+) indicated that the extent of activation was directly related to the unhydrated cation radius. Ammonium salts, at physiological concentrations, were dramatically more effective than other cations. Activation by ammonium was instantaneous, was not influenced by the counter ion, and gave a hyperbolic saturation curve. Hill plots did not show detectable cooperativity in the binding of ammonium. Double-reciprocal plots indicated that ammonium increases the maximal velocity and decreases the apparent Michaelis constants of EPSP synthase with respect to both phosphoenol pyruvate (PEP) and shikimate 3-phosphate (S3P). A direct relationship between sensitivity to inhibition by glyphosate and the activation state of EPSP synthase was demonstrated. Hill plots indicated a single value for glyphosate binding throughout the range of ammonium activation. Double-reciprocal plots of substrate saturation data obtained with ammonium-activated enzyme in the presence of glyphosate showed glyphosate to behave as a competitive inhibitor with respect to PEP and as a mixed-type inhibitor relative to S3P. The increased glyphosate sensitivity of ammonium-activated EPSP synthase is attributed to a lowering of the inhibitor constant of glyphosate with respect to PEP. Erroneous underestimates of sensitivities of some bacterial EPSP synthases to inhibition by glyphosate may result from failure to recognize cation requirements of EPSP synthases.

Synthesis of novel magnesium ferrite (MgFe2O4)/biochar magnetic composites and its adsorption behavior for phosphate in aqueous solutions.

PubMed

Jung, Kyung-Won; Lee, Soonjae; Lee, Young Jae

2017-12-01

In this work, magnesium ferrite (MgFe 2 O 4 )/biochar magnetic composites (MFB-MCs) were prepared and utilized to remove phosphate from aqueous solutions. MFB-MCs were synthesized via co-precipitation of Fe and Mg ions onto a precursor, followed by pyrolysis. Characterization results confirmed that MgFe 2 O 4 nanoparticles with a cubic spinel structure were successfully embedded in the biochar matrix, and this offered magnetic separability with superparamagnetic behavior and enabled higher phosphate adsorption performance than that of pristine biochar and sole MgFe 2 O 4 nanoparticles. Batch experiments indicated that phosphate adsorption on the MFB-MCs is highly dependent on the pH, initial phosphate concentration, and temperature, while it was less affected by ionic strength. Analysis of activation and thermodynamic parameters as well as the isosteric heat of adsorption demonstrated that the phosphate adsorption is an endothermic and physisorption process. Lastly, highly efficient recyclability of the MFB-MCs suggested that they are a promising adsorbent for phosphate removal from wastewater. Copyright © 2017 Elsevier Ltd. All rights reserved.

Energetics of phosphate binding to ammonium and guanidinium containing metallo-receptors in water.

PubMed

Tobey, Suzanne L; Anslyn, Eric V

2003-12-03

The design and synthesis of receptors containing a Cu(II) binding site with appended ammonium groups (1) and guanidinium groups (2), along with thermodynamics analyses of anion binding, are reported. Both receptors 1 and 2 show high affinities (10(4) M(-1)) and selectivities for phosphate over other anions in 98:2 water:methanol at biological pH. The binding of the host-guest pairs is proposed to proceed through ion-pairing interactions between the charged functional groups on both the host and the guest. The affinities and selectivities for oxyanions were determined using UV/vis titration techniques. Additionally, thermodynamic investigations indicate that the 1:phosphate complex is primarily entropy driven, while the 2:phosphate complex displays both favorable enthalpy and entropy changes. The thermodynamic data for binding provide a picture of the roles of the host, guest, counterions, and solvent. The difference in the entropy and enthalpy driving forces for the ammonium and guanidinium containing hosts are postulated to derive primarily from differences in the solvation shell of these two groups.

Calcium and nitrogen balance, experiment M007

NASA Technical Reports Server (NTRS)

Whedon, G. D.; Lutwak, L.; Neuman, W. F.; Lachance, P. A.

1971-01-01

The collection of data on the response of the skeletal and muscular systems to 14-day space flights was evaluated for loss of calcium, nitrogen, and other metabolically related elements. Considerable interindividual variability was demonstrated in all experimental factors that were measured. Calcium balance became less positive and urinary phosphate excretion increased substantially in flight despite a reduction in phosphate intake. Patterns of excretion of magnesium, sodium, potassium, and chloride were different for each subject, and, in part, could be correlated with changes in adrenocortical steroid production. The principal hormonal change was a striking decrease during flight in the urinary excretion of 17-hydroxycortocosteroids. Dermal losses of calcium, magnesium, sulfate, and phosphate were insignificant during all three phases.

Strong and tough magnesium wire reinforced phosphate cement composites for load-bearing bone replacement.

PubMed

Krüger, Reinhard; Seitz, Jan-Marten; Ewald, Andrea; Bach, Friedrich-Wilhelm; Groll, Jürgen

2013-04-01

Calcium phosphate cements are brittle biomaterials of low bending strength. One promising approach to improve their mechanical properties is reinforcement with fibers. State of the art degradable reinforced composites contain fibers made of polymers, resorbable glass or whiskers of calcium minerals. We introduce a new class of composite that is reinforced with degradable magnesium alloy wires. Bending strength and ductility of the composites increased with aspect ratio and volume content of the reinforcements up to a maximal bending strength of 139±41MPa. Hybrid reinforcement with metal and polymer fibers (PLA) further improved the qualitative fracture behavior and gave indication of enhanced strength and ductility. Immersion tests of composites in SBF for seven weeks showed high corrosion stability of ZEK100 wires and slow degradation of the magnesium calcium phosphate cement by struvite dissolution. Finally, in vitro tests with the osteoblast-like cell line MG63 demonstrate cytocompatibility of the composite materials. Copyright © 2013 Elsevier Ltd. All rights reserved.

Magnesium Carbonate‐Containing Phosphate Binder Prevents Connective Tissue Mineralization in Abcc6 −/− Mice–Potential for Treatment of Pseudoxanthoma Elasticum

PubMed Central

Li, Qiaoli; LaRusso, Jennifer; Grand‐Pierre, Alix E.; Uitto, Jouni

2009-01-01

Abstract Pseudoxanthoma elasticum (PXE) is a heritable disorder characterized by ectopic mineralization of connective tissues primarily in the skin, eyes, and the cardiovascular system. PXE is caused by mutations in the ABCC6 gene. While PXE is associated with considerable morbidity and mortality, there is currently no effective or specific treatment. In this study, we tested oral phosphate binders for treatment of a mouse model of PXE which we have developed by targeted ablation of the corresponding mouse gene (Abcc6 −/−). This “knock‐out” (KO) mouse model recapitulates features of PXE and demonstrates mineralization of a number of tissues, including the connective tissue capsule surrounding vibrissae in the muzzle skin which serves as an early biomarker of the mineralization process. Treatment of these mice with a magnesium carbonate‐enriched diet (magnesium concentration being 5‐fold higher than in the control diet) completely prevented mineralization of the vibrissae up to 6 months of age, as demonstrated by computerized morphometric analysis of histopathology as well as by calcium and phosphate chemical assays. The magnesium carbonate‐enriched diet also prevented the progression of mineralization when the mice were placed on that experimental diet at 3 months of age and followed up to 6 months of age. Treatment with magnesium carbonate was associated with a slight increase in the serum concentration of magnesium, with no effect on serum calcium and phosphorus levels. In contrast, concentration of calcium in the urine was increased over 10‐fold while the concentration of phosphorus was markedly decreased, being essentially undetectable after long‐term (>4 month) treatment. No significant changes were noted in the serum parathyroid hormone levels. Computerized axial tomography scan of bones in mice placed on magnesium carbonate‐enriched diet showed no differences in the bone density compared to mice on the control diet, and chemical assays showed a small increase in the calcium and phosphate content of the femurs by chemical assay, in comparison to mice on control diet. Similar experiments with another experimental diet supplemented with lanthanum carbonate did not interfere with the mineralization process in Abcc6 −/− mice. These results suggest that magnesium carbonate may offer a potential treatment modality for PXE, a currently intractable disease, as well as for other conditions characterized by ectopic mineralization of connective tissues. PMID:20443931

Magnesium carbonate-containing phosphate binder prevents connective tissue mineralization in Abcc6(-/-) mice-potential for treatment of pseudoxanthoma elasticum.

PubMed

Li, Qiaoli; Larusso, Jennifer; Grand-Pierre, Alix E; Uitto, Jouni

2009-12-01

Pseudoxanthoma elasticum (PXE) is a heritable disorder characterized by ectopic mineralization of connective tissues primarily in the skin, eyes, and the cardiovascular system. PXE is caused by mutations in the ABCC6 gene. While PXE is associated with considerable morbidity and mortality, there is currently no effective or specific treatment. In this study, we tested oral phosphate binders for treatment of a mouse model of PXE which we have developed by targeted ablation of the corresponding mouse gene (Abcc6(-/-)). This "knock-out" (KO) mouse model recapitulates features of PXE and demonstrates mineralization of a number of tissues, including the connective tissue capsule surrounding vibrissae in the muzzle skin which serves as an early biomarker of the mineralization process. Treatment of these mice with a magnesium carbonate-enriched diet (magnesium concentration being 5-fold higher than in the control diet) completely prevented mineralization of the vibrissae up to 6 months of age, as demonstrated by computerized morphometric analysis of histopathology as well as by calcium and phosphate chemical assays. The magnesium carbonate-enriched diet also prevented the progression of mineralization when the mice were placed on that experimental diet at 3 months of age and followed up to 6 months of age. Treatment with magnesium carbonate was associated with a slight increase in the serum concentration of magnesium, with no effect on serum calcium and phosphorus levels. In contrast, concentration of calcium in the urine was increased over 10-fold while the concentration of phosphorus was markedly decreased, being essentially undetectable after long-term (> 4 month) treatment. No significant changes were noted in the serum parathyroid hormone levels. Computerized axial tomography scan of bones in mice placed on magnesium carbonate-enriched diet showed no differences in the bone density compared to mice on the control diet, and chemical assays showed a small increase in the calcium and phosphate content of the femurs by chemical assay, in comparison to mice on control diet. Similar experiments with another experimental diet supplemented with lanthanum carbonate did not interfere with the mineralization process in Abcc6(-/-) mice. These results suggest that magnesium carbonate may offer a potential treatment modality for PXE, a currently intractable disease, as well as for other conditions characterized by ectopic mineralization of connective tissues.

Mechanical, degradation and cytocompatibility properties of magnesium coated phosphate glass fibre reinforced polycaprolactone composites.

PubMed

Liu, Xiaoling; Hasan, Muhammad S; Grant, David M; Harper, Lee T; Parsons, Andrew J; Palmer, Graham; Rudd, Chris D; Ahmed, Ifty

2014-11-01

Retention of mechanical properties of phosphate glass fibre reinforced degradable polyesters such as polycaprolactone and polylactic acid in aqueous media has been shown to be strongly influenced by the integrity of the fibre/polymer interface. A previous study utilising 'single fibre' fragmentation tests found that coating with magnesium improved the fibre and matrix interfacial shear strength. Therefore, the aim of this study was to investigate the effects of a magnesium coating on the manufacture and characterisation of a random chopped fibre reinforced polycaprolactone composite. Short chopped strand non-woven phosphate glass fibre mats were sputter coated with degradable magnesium to manufacture phosphate glass fibre/polycaprolactone composites. The degradation behaviour (water uptake, mass loss and pH change of the media) of these polycaprolactone composites as well as of pure polycaprolactone was investigated in phosphate buffered saline. The Mg coated fibre reinforced composites revealed less water uptake and mass loss during degradation compared to the non-coated composites. The cations released were also explored and a lower ion release profile for all three cations investigated (namely Na(+), Mg(2+) and Ca(2+)) was seen for the Mg coated composite samples. An increase of 17% in tensile strength and 47% in tensile modulus was obtained for the Mg coated composite samples. Both flexural and tensile properties were investigated and a higher retention of mechanical properties was obtained for the Mg coated fibre reinforced composite samples up to 10 days immersion in PBS. Cytocompatibility study showed both composite samples (coated and non-coated) had good cytocompatibility with human osteosarcoma cell line. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Harvesting Chlorella vulgaris by natural increase in pH: effect of medium composition.

PubMed

Nguyen, Thi Dong Phuong; Frappart, Matthieu; Jaouen, Pascal; Pruvost, Jérémy; Bourseau, Patrick

2014-01-01

The freshwater microalga Chlorella vulgaris was harvested by autoflocculation resulting from the precipitation of magnesium or calcium compounds induced by a slow increase in pH in the absence of CO2 input. Autoflocculation was tested in two culture media with, respectively, ammonium (NH4+) and nitrate (NO3-) ions as nitrogen source. The culture pH increased because of photosynthesis and CO2 stripping. pH rose to 11 after 8 h in the NO3- medium, but did not exceed 9 in the NH4+ medium. No flocculation took place in any of the media. Autoflocculation tests were repeated in the NO(3-)-based culture medium by progressively increasing the concentrations of Ca2+ and Mg2+ until inorganic compounds precipitated and flocculated microalgae. The minimal concentrations for flocculation were found to be 120 mg Ca2 L(-1) and 1000 mg Mg2+ L(-1). These values were, respectively, 3.5 times and 20 times higher than those allowing flocculation by NaOH addition. Energy-dispersive X-ray spectroscopy, zeta potential measurement, and ionic chromatography suggest that the mechanisms involved are different. The rate of cell removal was close to 90% in both cases, but cells were more concentrated in the aggregates obtained by magnesium compound precipitation, with an estimated concentration close to 33 g (dry matter) L(-1), against 19 g L(-1) for calcium phosphates.

75 FR 64585 - Bulk Solid Hazardous Materials: Harmonization With the International Maritime Solid Bulk Cargoes...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-19

... Purpose. 148.205 Ammonium nitrate and ammonium nitrate fertilizers. 148.220 Ammonium nitrate-phosphate fertilizers. 148.225 Calcined pyrites (pyritic ash, fly ash). 148.227 Calcium nitrate fertilizers. 148.230... tankage fertilizer. 148.325 Wood chips; wood pellets; wood pulp pellets. 148.330 Zinc ashes; zinc dross...

Transurethral lithotripsy with holmium-YAG laser of a large exogenous prostatic calculus.

PubMed

Hasegawa, Masanori; Ohara, Rei; Kanao, Kent; Nakajima, Yosuke

2011-04-01

Prostatic calculi are classified into two types, endogenous and exogenous calculi, based on their origin. Endogenous calculi are commonly observed in elderly men; however, exogenous prostatic calculi are extremely rare. We report here the case of a 51-year-old man who suffered incontinence and pollakiuria with a giant exogenous prostatic calculus almost completely replacing the prostatic tissue. X-rays and computed tomography demonstrated a large calculus of 65 × 58 mm in the small pelvic cavity. The patient underwent a transurethral lithotripsy with a holmium-YAG laser and a total of 85 g of disintegrated stones was retrieved and chemical stone analysis revealed the presence of magnesium ammonium phosphate. The incontinence improved and the voiding volume increased dramatically, and no stone recurrence in the prostatic fossa occurred at the 2 years follow-up. The etiology of this stone formation seemed to be based on some exogenous pathways combined with urinary stasis and chronic urinary infection due to compression fracture of the lumbar vertebra.

Dielectric studies on struvite urinary crystals, a gateway to the new treatment modality for urolithiasis

NASA Astrophysics Data System (ADS)

Rajan, Reshma; Raj, N. Arunai Nambi; Madeswaran, S.; Babu, D. Rajan

2015-09-01

Struvite or magnesium ammonium phosphate hexahydrate (MAPH) are biological crystals, found in the kidney, which are formed due to the infection caused by urea splitting bacteria in the urinary tract. The struvite crystals observe different morphologies and were developed using single diffusion gel growth technique. The crystalline nature and its composition were studied from different characterization techniques like X-ray Diffraction (XRD) and FTIR. The dielectric behavior of the developed crystal was studied by varying temperature and at different frequencies. The parameters like dielectric constant, dielectric loss, ac conductivity, ac resistivity, impedance and admittance of the struvite crystals were calculated. The studies proved that the dielectric loss or dissipation heat is high in lower frequencies at normal body temperature, which develops a plasma state in the stones and in turn leads to the disintegration of urinary stones. The dielectric nature of the stones leads to the dielectric therapy, which will be a gateway for future treatment modality for urolithiasis.

Renal geology (quantitative renal stone analysis) by 'Fourier transform infrared spectroscopy'.

PubMed

Singh, Iqbal

2008-01-01

To prospectively determine the precise stone composition (quantitative analysis) by using infrared spectroscopy in patients with urinary stone disease presenting to our clinic. To determine an ideal method for stone analysis suitable for use in a clinical setting. After routine and a detailed metabolic workup of all patients of urolithiasis, stone samples of 50 patients of urolithiasis satisfying the entry criteria were subjected to the Fourier transform infrared spectroscopic analysis after adequate sample homogenization at a single testing center. Calcium oxalate monohydrate and dihydrate stone mixture was most commonly encountered in 35 (71%) followed by calcium phosphate, carbonate apatite, magnesium ammonium hexahydrate and xanthine stones. Fourier transform infrared spectroscopy allows an accurate, reliable quantitative method of stone analysis. It also helps in maintaining a computerized large reference library. Knowledge of precise stone composition may allow the institution of appropriate prophylactic therapy despite the absence of any detectable metabolic abnormalities. This may prevent and or delay stone recurrence.

Data from synoptic water-quality studies on the Colorado River in the Grand Canyon, Arizona, November 1990 and June 1991

USGS Publications Warehouse

Taylor, Howard E.; Peart, D.B.; Antweiler, Ronald C.; Brinton, T.I.; Campbell, W.L.; Barbarino, J.R.; Roth, D.A.; Hart, R.J.; Averett, R.C.

1996-01-01

Two water-quality synoptic studies were made on the Colorado River in the Grand Canyon, Arizona. Field measurements and the collection of water samples for laboratory analysis were made at 10 mainstem and 6 tributary sites every 6 hours for a 48-hour period on November 5-6, 1990, and again on June 18-20, 1991. Field measurements included discharge, alkalinity, water temperature, light penetration, pH, specific conductance, and dissolved oxygen. Water samples were collected for the laboratory analysis of major and minor ions (calcium, magnesium, sodium, potassium, strontium, chloride, sulfate, silica as SiO2), trace elements (aluminum, arsenic, boron, barium, beryllium, cadmium, cobalt, chromium, copper, iron, lead, lithium, manganese, molybdenum, nickel, selenium, thallium, uranium, vanadium and zinc), and nutrients (phosphate, nitrate, ammonium, nitrite, total dissolved nitrogen, total dissolved phosphorus and dissolved organic carbon). Biological measurements included drift (benthic invertebrates and detrital material), and benthic invertebrates from the river bottom.

The ultimate mineral processing challenge: Recovery of rare earths, phosphorus and uranium from Florida phosphatic clay

DOE PAGES

Zhang, Patrick; Liang, Haijun; Jin, Zhen; ...

2017-11-01

We report phosphate beneficiation in Florida generates more than one tonne of phosphatic clay, or slime, per tonne of phosphate rock produced. Since the start of the practice of large-scale washing and desliming for phosphate beneficiation, more than 2 Gt of slime has accumulated, containing approximately 600 Mt of phosphate rock, 600 kt of rare earth elements (REEs) and 80 million kilograms of uranium. The recovery of these valuable elements from the phosphatic clay is one of the most challenging endeavors in mineral processing, because the clay is extremely dilute, with an average solids concentration of 3 percent, and finemore » in size, with more than 50 percent having particle size smaller than 2 μm, and it contains nearly 50 percent clay minerals as well as large amounts of magnesium, iron and aluminum. With industry support and under funding from the Critical Materials Institute, the Florida Industrial and Phosphate Research Institute in conjunction with the Oak Ridge National Laboratory undertook the task to recover phosphorus, rare earths and uranium from Florida phosphatic clay. This paper presents the results from the preliminary testing of two approaches. The first approach involves three-stage cycloning using cyclones with diameters of 12.4 cm (5 in.), 5.08 cm (2 in.) and 2.54 cm (1 in.), respectively, to remove clay minerals followed by flotation and leaching. The second approach is a two-step leaching process. In the first step, selective leaching was conducted to remove magnesium, thus allowing the production of phosphoric acid suitable for the manufacture of diammonium phosphate (DAP) in the second leaching step. The results showed that multistage cycloning with small cyclones is necessary to remove clay minerals. Finally, selective leaching at about pH 3.2 using sulfuric acid was found to be effective for removing more than 80 percent of magnesium from the feed with minimal loss of phosphorus.« less

The ultimate mineral processing challenge: Recovery of rare earths, phosphorus and uranium from Florida phosphatic clay

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Patrick; Liang, Haijun; Jin, Zhen

We report phosphate beneficiation in Florida generates more than one tonne of phosphatic clay, or slime, per tonne of phosphate rock produced. Since the start of the practice of large-scale washing and desliming for phosphate beneficiation, more than 2 Gt of slime has accumulated, containing approximately 600 Mt of phosphate rock, 600 kt of rare earth elements (REEs) and 80 million kilograms of uranium. The recovery of these valuable elements from the phosphatic clay is one of the most challenging endeavors in mineral processing, because the clay is extremely dilute, with an average solids concentration of 3 percent, and finemore » in size, with more than 50 percent having particle size smaller than 2 μm, and it contains nearly 50 percent clay minerals as well as large amounts of magnesium, iron and aluminum. With industry support and under funding from the Critical Materials Institute, the Florida Industrial and Phosphate Research Institute in conjunction with the Oak Ridge National Laboratory undertook the task to recover phosphorus, rare earths and uranium from Florida phosphatic clay. This paper presents the results from the preliminary testing of two approaches. The first approach involves three-stage cycloning using cyclones with diameters of 12.4 cm (5 in.), 5.08 cm (2 in.) and 2.54 cm (1 in.), respectively, to remove clay minerals followed by flotation and leaching. The second approach is a two-step leaching process. In the first step, selective leaching was conducted to remove magnesium, thus allowing the production of phosphoric acid suitable for the manufacture of diammonium phosphate (DAP) in the second leaching step. The results showed that multistage cycloning with small cyclones is necessary to remove clay minerals. Finally, selective leaching at about pH 3.2 using sulfuric acid was found to be effective for removing more than 80 percent of magnesium from the feed with minimal loss of phosphorus.« less

Diffusion, Viscosity and Crystal Growth in Microgravity

NASA Technical Reports Server (NTRS)

Myerson, Allan S.

1996-01-01

The diffusivity of TriGlycine Sulfate (TGS), Potassium Dihydrogen Phosphate (KDP), Ammonium Dihydrogen Phosphate (ADF) and other compounds of interest to microgravity crystal growth, in supersaturated solutions as a function of solution concentration, 'age' and 'history was studied experimentally. The factors that affect the growth of crystals from water solutions in microgravity have been examined. Three non-linear optical materials have been studied, potassium dihydrogen phosphate (KDP), ammonium dihydrogen phosphate (ADP) and triglycine sulfate (TGC). The diffusion coefficient and viscosity of supersaturated water solutions were measured. Also theoretical model of diffusivity and viscosity in a metastable state, model of crystal growth from solution including non-linear time dependent diffusivity and viscosity effect and computer simulation of the crystal growth process which allows simulation of the microgravity crystal growth were developed.

Ammonium iron(III) phosphate(V) fluoride, (NH4)0.5[(NH4)0.375K0.125]FePO4F, with ammonium partially substituted by potassium

PubMed Central

Wang, Lei; Zhou, Yan; Huang, Ya-Xi; Mi, Jin-Xiao

2009-01-01

The title compound, ammonium potassium iron(III) phosphate fluoride, (NH4)0.875K0.125FePO4F, is built from zigzag chains ∞ 1{[FeO4F2]7−}, with Fe3+ in a distorted octahedral coordination, extending along both the [011] and [01] directions. These chains are made up of alternating trans-[FeO4F2] and cis-[FeO4F2] octa­hedra via shared F-atom corners, and are linked by PO4 tetra­hedra, resulting in an open-framework structure with channels along the [010] and [100] directions. There are two crystallographically independent ammonium sites: one in the [010] channels and the other, partially substituted by K+ ions, in the [100] channels. The ammonium in the [010] channels is fixed to the framework via eight hydrogen bonds (six N—H⋯O and two N—H⋯F). PMID:21581466

21 CFR 163.112 - Breakfast cocoa.

Code of Federal Regulations, 2011 CFR

2011-04-01

... ingredients. Ammonium, potassium, or sodium bicarbonate, carbonate, or hydroxide, or magnesium carbonate or oxide, used as such, or in aqueous solution; (2) Neutralizing agents. Phosphoric acid, citric acid and L...

The mineral phase in the cuticles of two species of Crustacea consists of magnesium calcite, amorphous calcium carbonate, and amorphous calcium phosphate.

PubMed

Becker, Alexander; Ziegler, Andreas; Epple, Matthias

2005-05-21

The cuticules (shells) of the woodlice Porcellio scaber and Armadillidium vulgare were analysed with respect to their content of inorganic material. It was found that the cuticles consist of crystalline magnesium calcite, amorphous calcium carbonate (ACC), and amorphous calcium phosphate (ACP), besides small amounts of water and an organic matrix. It is concluded that the cuticle, which constitutes a mineralized protective organ, is chemically adapted to the biological requirements by this combination of different materials.

EPR and optical studies of Cu2+ ions doped in magnesium potassium phosphate hexahydrate single crystals

NASA Astrophysics Data System (ADS)

Kripal, Ram; Shukla, Santwana

2011-03-01

An electron paramagnetic resonance (EPR) study of Cu2+-doped magnesium potassium phosphate is performed at liquid nitrogen temperature (LNT; 77 K). Two magnetically non-equivalent sites for Cu2+ are observed. The spin Hamiltonian parameters are determined with the fitting of spectra to a rhombic symmetry crystalline field. The ground state wavefunction is also determined. The g-anisotropy is evaluated and compared with the experimental value. With the help of an optical study, the nature of the bonding in the complex is discussed.

Influence of shot peening on corrosion properties of biocompatible magnesium alloy AZ31 coated by dicalcium phosphate dihydrate (DCPD).

PubMed

Mhaede, Mansour; Pastorek, Filip; Hadzima, Branislav

2014-06-01

Magnesium alloys are promising materials for biomedical applications because of many outstanding properties like biodegradation, bioactivity and their specific density and Young's modulus are closer to bone than the commonly used metallic implant materials. Unfortunately their fatigue properties and low corrosion resistance negatively influenced their application possibilities in the field of biomedicine. These problems could be diminished through appropriate surface treatments. This study evaluates the influence of a surface pre-treatment by shot peening and shot peening+coating on the corrosion properties of magnesium alloy AZ31. The dicalcium phosphate dihydrate coating (DCPD) was electrochemically deposited in a solution containing 0.1M Ca(NO3)2, 0.06M NH4H2PO4 and 10mL/L of H2O2. The effect of shot peening on the surface properties of magnesium alloy was evaluated by microhardness and surface roughness measurements. The influence of the shot peening and dicalcium phosphate dihydrate layer on the electrochemical characteristics of AZ31 magnesium alloy was evaluated by potentiodynamic measurements and electrochemical impedance spectroscopy in 0.9% NaCl solution at a temperature of 22±1°C. The obtained results were analyzed by the Tafel-extrapolation method and equivalent circuit method. The results showed that the application of shot peening process followed by DCPD coating improves the properties of the AZ31 surface from corrosion and mechanical point of view. Copyright © 2014 Elsevier B.V. All rights reserved.

The flame photometric determination of calcium in phosphate, carbonate, and silicate rocks

USGS Publications Warehouse

Kramer, H.

1957-01-01

A flame photometric method of determining calcium in phosphate, carbonate, and silicate locks has been developed Aluminum and phosphate interference was overcome by the addition of a large excess of magnesium. The method is rapid and suitable for routine analysis Results obtained are within ?? 2% of the calcium oxide content. ?? 1957.

Strength reliability and in vitro degradation of three-dimensional powder printed strontium-substituted magnesium phosphate scaffolds.

PubMed

Meininger, Susanne; Mandal, Sourav; Kumar, Alok; Groll, Jürgen; Basu, Bikramjit; Gbureck, Uwe

2016-02-01

Strontium ions (Sr(2+)) are known to prevent osteoporosis and also encourage bone formation. Such twin requirements have motivated researchers to develop Sr-substituted biomaterials for orthopaedic applications. The present study demonstrates a new concept of developing Sr-substituted Mg3(PO4)2 - based biodegradable scaffolds. In particular, this work reports the fabrication, mechanical properties with an emphasis on strength reliability as well as in vitro degradation of highly biodegradable strontium-incorporated magnesium phosphate cements. These implantable scaffolds were fabricated using three-dimensional powder printing, followed by high temperature sintering and/or chemical conversion, a technique adaptable to develop patient-specific implants. A moderate combination of strength properties of 36.7MPa (compression), 24.2MPa (bending) and 10.7MPa (tension) were measured. A reasonably modest Weibull modulus of up to 8.8 was recorded after uniaxial compression or diametral tensile tests on 3D printed scaffolds. A comparison among scaffolds with varying compositions or among sintered or chemically hardened scaffolds reveals that the strength reliability is not compromised in Sr-substituted scaffolds compared to baseline Mg3(PO4)2. The micro-computed tomography analysis reveals the presence of highly interconnected porous architecture in three-dimension with lognormal pore size distribution having median in the range of 17.74-26.29μm for the investigated scaffolds. The results of extensive in vitro ion release study revealed passive degradation with a reduced Mg(2+) release and slow but sustained release of Sr(2+) from strontium-substituted magnesium phosphate scaffolds. Taken together, the present study unequivocally illustrates that the newly designed Sr-substituted magnesium phosphate scaffolds with good strength reliability could be used for biomedical applications requiring consistent Sr(2+)- release, while the scaffold degrades in physiological medium. The study investigates the additive manufacturing of scaffolds based on different strontium-substituted magnesium phosphate bone cements by means of three-dimensional powder printing technique (3DPP). Magnesium phosphates were chosen due to their higher biodegradability compared to calcium phosphates, which is due to both a higher solubility as well as the absence of phase changes (to low soluble hydroxyapatite) in vivo. Since strontium ions are known to promote bone formation by stimulating osteoblast growth, we aimed to establish such a highly degradable magnesium phosphate ceramic with an enhanced bioactivity for new bone ingrowth. After post-processing, mechanical strengths of up to 36.7MPa (compression), 24.2MPa (bending) and 10.7MPa (tension) could be achieved. Simultaneously, the failure reliability of those bioceramic implant materials, measured by Weibull modulus calculations, were in the range of 4.3-8.8. Passive dissolution studies in vitro proved an ion release of Mg(2+) and PO4(3-) as well as Sr(2+), which is fundamental for in vivo degradation and a bone growth promoting effect. In our opinion, this work broadens the range of bioceramic bone replacement materials suitable for additive manufacturing processing. The high biodegradability of MPC ceramics together with the anticipated promoting effect on osseointegration opens up the way for a patient-specific treatment with the prospect of a fast and complete healing of bone fractures. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

A critical evaluation and a search for the ideal colonoscopic preparation.

PubMed

Arora, Manish; Senadhi, Viplove; Arora, Deepika; Weinstock, Joyce; Dubin, Ethan; Okolo, Patrick I; Dutta, Sudhir K

2013-04-01

The aim of this study was to evaluate the efficacy of various bowel preparations in accomplishing colonic cleansing for optimal mucosal visualization during colonoscopy. The study included a cohort of 980 patients who underwent colonoscopy at our endoscopy center within the last 3 years. All of the study patients were subdivided into four groups. Each group included 245 patients, all receiving a different type of bowel preparation. The bowel preparations used in this study included: magnesium citrate (Group I), a combination of oral sodium phosphate (fleets) and powder PEG-3350 (Group II), powder polyethylene glycol-3350 (PEG-3350 powder for Group III), and oral sodium phosphate (fleets for Group IV). A Colon Prep Score (CPS) was devised to compare the quality of the different bowel preparations used. The colonoscopy results from all of these patients were tabulated and analyzed statistically and expressed as mean ± 1 standard deviation. Statistical analysis was performed using a one way ANOVA with Holm-Sidak method for intergroup analysis. Group I patients received magnesium citrate and had a mean CPS ± 1 SD of 3.11 ± 0.91. Group II patients (fleets and powder PEG-3350 combination) achieved a CPS of 3.37 ± 1.16. The patients in Group III (powder PEG-3350) actually showed the highest mean CPS of 3.44 ± 1.12. Group IV patients who used oral sodium phosphate alone reached a mean CPS of 3.23 ± 1.01. Group III patients (powder PEG-3350 only) demonstrated a statistically higher CPS (P<0.0006) in colon cleansing as compared to Group I patients (magnesium citrate). Similarly, Group II patients (oral sodium phosphate and powder PEG-3350 combination) also showed improved colon cleansing statistically (P<0.006) as compared to Group I patients (magnesium citrate). Overall, all four colon preparations achieved an average CPS greater than 3.0 indicating clinically adequate colonic cleansing. However, powder PEG-3350 alone and in combination with oral sodium phosphate was observed to be statistically superior to magnesium citrate, when used for colon preparation for colonoscopy. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

RGDC Peptide-Induced Biomimetic Calcium Phosphate Coating Formed on AZ31 Magnesium Alloy

PubMed Central

Cao, Lin; Wang, Lina; Fan, Lingying; Xiao, Wenjun; Lin, Bingpeng; Xu, Yimeng; Liang, Jun; Cao, Baocheng

2017-01-01

Magnesium alloys as biodegradable metal implants have received a lot of interest in biomedical applications. However, magnesium alloys have extremely high corrosion rates a in physiological environment, which have limited their application in the orthopedic field. In this study, calcium phosphate compounds (Ca–P) coating was prepared by arginine–glycine–aspartic acid–cysteine (RGDC) peptide-induced mineralization in 1.5 simulated body fluid (SBF) to improve the corrosion resistance and biocompatibility of the AZ31 magnesium alloys. The adhesion of Ca–P coating to the AZ31 substrates was evaluated by a scratch test. Corrosion resistance and cytocompatibility of the Ca–P coating were investigated. The results showed that the RGDC could effectively promote the nucleation and crystallization of the Ca–P coating and the Ca–P coating had poor adhesion to the AZ31 substrates. The corrosion resistance and biocompatibility of the biomimetic Ca–P coating Mg alloys were greatly improved compared with that of the uncoated sample. PMID:28772717

[Single cell gel electrophoresis of a magnesium alloy coated with beta-tricalcium phosphate].

PubMed

Hao, Yu-quan; Tan, Li-li; Yan, Ting-ting; Yan, Xiu-lin; Yang, Ke; Ai, Hong-jun

2009-10-01

To evaluate the genotoxicity of a magnesium alloy coated with beta-tricalcium phosphate (beta-TCP). Four groups were designed. In the first group, AZ31B magnesium alloy surface was coated with beta-TCP using chemical bath deposition, and in the second group magnesium alloy was tested. The other two groups were negative control (pure titanium) and positive control groups (0.5 mg/L bleomycin). Single cell gel electrophoresis was adopted to investigate genotoxicity of the alloy samples in different groups, and 60 cells from each group were analysed. Tail moment and tail DNA percentage were used as reliable indicators to show DNA damage in lymphocytes induced by every testing sample. Student-Newman-Keuls (SNK) test was used to compare results from 4 groups. There were no significant differences in tail moment and tail DNA percentage between magnesium alloy group [(0.52 +/- 0.12), (6.82 +/- 1.81)%] and magnesium alloy coated with beta-TCP group [(0.51 +/- 0.12), (6.89 +/- 1.93)%, P > 0.05]. Tail moment and tail DNA percentage in negative group were (0.47 +/- 0.14) and (6.29 +/- 1.64)%, and tail moment and tail DNA percentage in positive group were (5.17 +/- 1.23) and (22.09 +/- 4.51)%. No significant increase was found in DNA damage in lymphocytes induced by magnesium alloy coated with beta-TCP.

Effect of raw material ratios on the compressive strength of magnesium potassium phosphate chemically bonded ceramics.

PubMed

Wang, Ai-juan; Yuan, Zhi-long; Zhang, Jiao; Liu, Lin-tao; Li, Jun-ming; Liu, Zheng

2013-12-01

The compressive strength of magnesium potassium phosphate chemically bonded ceramics is important in biomedical field. In this work, the compressive strength of magnesium potassium phosphate chemically bonded ceramics was investigated with different liquid-to-solid and MgO-to-KH2PO4 ratios. X-ray diffractometer was applied to characterize its phase composition. The microstructure was imaged using a scanning electron microscope. The results showed that the compressive strength of the chemically bonded ceramics increased with the decrease of liquid-to-solid ratio due to the change of the packing density and the crystallinity of hydrated product. However, with the increase of MgO-to-KH2PO4 weight ratio, its compressive strength increased firstly and then decreased. The low compressive strength in lower MgO-to-KH2PO4 ratio might be explained by the existence of the weak phase KH2PO4. However, the low value of compressive strength with the higher MgO-to-KH2PO4 ratio might be caused by lack of the joined phase in the hydrated product. Besides, it has been found that the microstructures were different in these two cases by the scanning electron microscope. Colloidal structure appeared for the samples with lower liquid-to-solid and higher MgO-to-KH2PO4 ratios possibly because of the existence of amorphous hydrated products. The optimization of both liquid-to-solid and MgO-to-KH2PO4 ratios was important to improve the compressive strength of magnesium potassium phosphate chemically bonded ceramics. © 2013.

Effect of various electrolytes upon cardiac and skeletal musculature

PubMed Central

Selye, H.; Bajusz, E.

1959-01-01

In rats kept on a low-potassium diet that contains only maintenance levels of magnesium, cardiac necroses and muscular cramps were readily induced by the oral administration of sodium perchlorate or disodium hydrogen phosphate. The precipitation of these cardiac and skeletal muscle changes by sodium chlorate was prevented by the prophylactic administration of either potassium or magnesium chlorides. The protective effect of these chlorides against the cardiotoxic and convulsive effects of disodium hydrogen phosphate has already been demonstrated by our earlier experiments. Sodium sulphate produced cardiac necroses in rats maintained on the same diet, and both potassium and magnesium chlorides had a prophylactic action. Unlike sodium perchlorate, however, sodium sulphate produced no muscular cramps under these conditions. Equimolecular amounts of sodium given in the form of sodium chloride (instead of sodium perchlorate, sodium sulphate, or disodium hydrogen phosphate) did not cause cardiac necroses or muscular cramps in rats maintained on the potassium-deficient diet. As the same three sodium salts, namely the perchlorate, the sulphate, and the hydrogen phosphate, produced cardiac necroses in rats sensitized by either a potassium-deficient diet or by certain corticoids, it seems that the anion must play a decisive rôle, since equivalent amounts of NaCl are ineffective. PMID:13651583

Inert Reassessment Document for Alkyl (C8-C24)

EPA Pesticide Factsheets

Inert Ingredient Tolerance Reassessments: Two Exemptions from theRequirement of a Tolerance for Alkyl (C8-C24) Benzenesulfonic Acid and its Ammonium, Calcium, Magnesium, Potassium, Sodium, and Zinc Salts

DNA-encapsulated magnesium phosphate nanoparticles elicit both humoral and cellular immune responses in mice

PubMed Central

Bhakta, Gajadhar; Nurcombe, Victor; Maitra, Amarnath; Shrivastava, Anju

2014-01-01

The efficacy of pEGFP (plasmid expressing enhanced green fluorescent protein)-encapsulated PEGylated (meaning polyethylene glycol coated) magnesium phosphate nanoparticles (referred to as MgPi-pEGFP nanoparticles) for the induction of immune responses was investigated in a mouse model. MgPi-pEGFP nanoparticles induced enhanced serum antibody and antigen-specific T-lymphocyte responses, as well as increased IFN-? and IL-12 levels compared to naked pEGFP when administered via intravenous, intraperitoneal or intramuscular routes. A significant macrophage response, both in size and activity, was also observed when mice were immunized with the nanoparticle formulation. The response was highly specific for the antigen, as the increase in interaction between macrophages and lymphocytes as well as lymphocyte proliferation took place only when they were re-stimulated with recombinant green fluorescence protein (rGFP). Thus the nanoparticle formulation elicited both humoral as well as cellular responses. Cytokine profiling revealed the induction of Th-1 type responses. The results suggest DNA-encapsulated magnesium phosphate (MgPi) nanoparticles may constitute a safer, more stable and cost-efficient DNA vaccine formulation. PMID:24936399

Mg- and Zn-modified calcium phosphates prepared by biomimetic precipitation and subsequent treatment at high temperature.

PubMed

Rabadjieva, D; Tepavitcharova, S; Gergulova, R; Sezanova, K; Titorenkova, R; Petrov, O; Dyulgerova, E

2011-10-01

Powders of magnesium-modified as well as zinc-modified calcium phosphates (Me-β-TCP and HA) with a (Ca(2+)+Mg(2+)+Zn(2+)+Na(+)+K(+))/P ratio of 1.3-1.4 and various Me(2+)/(Me(2+)+Ca(2+)) ratios (from 0.005 to 0.16) were prepared in biomimetic electrolyte systems at pH 8, mother liquid maturation and further syntering at 600-1000°C. Some differences in zinc and magnesium modifications have been prognosed on the basis of thermodynamic modeling of the studied systems and explained by the Mg(2+) and Zn(2+) ion chemical behaviour. The temperature as well as the degree of Zn(2+) and Mg(2+) ions substitutions were found to stabilize the β-TCP structure and this effect was more prononced for zinc. Thus, zinc-modified β-TCP powders consisting of idiomorphic crystals were obtained through sintering of Zn(2+) ion substituted calcium phosphates precursors at 800-1000°C. The Mg(2+) ion substitution leads to obtaining magnesium-modified β-TCP with spherical grains.

Magnesium coated bioresorbable phosphate glass fibres: investigation of the interface between fibre and polyester matrices.

PubMed

Liu, Xiaoling; Grant, David M; Parsons, Andrew J; Harper, Lee T; Rudd, Chris D; Ahmed, Ifty

2013-01-01

Bioresorbable phosphate glass fibre reinforced polyester composites have been investigated as replacement for some traditional metallic orthopaedic implants, such as bone fracture fixation plates. However, composites tested revealed loss of the interfacial integrity after immersion within aqueous media which resulted in rapid loss of mechanical properties. Physical modification of fibres to change fibre surface morphology has been shown to be an effective method to improve fibre and matrix adhesion in composites. In this study, biodegradable magnesium which would gradually degrade to Mg(2+) in the human body was deposited via magnetron sputtering onto bioresorbable phosphate glass fibres to obtain roughened fibre surfaces. Fibre surface morphology after coating was observed using scanning electron microscope (SEM). The roughness profile and crystalline texture of the coatings were determined via atomic force microscope (AFM) and X-ray diffraction (XRD) analysis, respectively. The roughness of the coatings was seen to increase from 40 ± 1 nm to 80 ± 1 nm. The mechanical properties (tensile strength and modulus) of fibre with coatings decreased with increased magnesium coating thickness.

Magnesium Coated Bioresorbable Phosphate Glass Fibres: Investigation of the Interface between Fibre and Polyester Matrices

PubMed Central

Liu, Xiaoling; Grant, David M.; Parsons, Andrew J.; Harper, Lee T.; Rudd, Chris D.; Ahmed, Ifty

2013-01-01

Bioresorbable phosphate glass fibre reinforced polyester composites have been investigated as replacement for some traditional metallic orthopaedic implants, such as bone fracture fixation plates. However, composites tested revealed loss of the interfacial integrity after immersion within aqueous media which resulted in rapid loss of mechanical properties. Physical modification of fibres to change fibre surface morphology has been shown to be an effective method to improve fibre and matrix adhesion in composites. In this study, biodegradable magnesium which would gradually degrade to Mg2+ in the human body was deposited via magnetron sputtering onto bioresorbable phosphate glass fibres to obtain roughened fibre surfaces. Fibre surface morphology after coating was observed using scanning electron microscope (SEM). The roughness profile and crystalline texture of the coatings were determined via atomic force microscope (AFM) and X-ray diffraction (XRD) analysis, respectively. The roughness of the coatings was seen to increase from 40 ± 1 nm to 80 ± 1 nm. The mechanical properties (tensile strength and modulus) of fibre with coatings decreased with increased magnesium coating thickness. PMID:24066297

Efficient methods for enol phosphate synthesis using carbon-centred magnesium bases.

PubMed

Kerr, William J; Lindsay, David M; Patel, Vipulkumar K; Rajamanickam, Muralikrishnan

2015-10-28

Efficient conversion of ketones into kinetic enol phosphates under mild and accessible conditions has been realised using the developed methods with di-tert-butylmagnesium and bismesitylmagnesium. Optimisation of the quench protocol resulted in high yields of enol phosphates from a range of cyclohexanones and aryl methyl ketones, with tolerance of a range of additional functional units.

Composition of urinary calculi in infants: a report from an endemic country.

PubMed

Zafar, Mirza Naqi; Ayub, Salma; Tanwri, Hafsa; Naqvi, Syed Ali Anwar; Rizvi, Syed Adibul Hasan

2017-11-03

Pediatric urolithiasis remains endemic in low-resource countries where infants constitute 17-40% of all children with urolithiasis. This study reports socio-economic factors, medical history and chemical composition of urinary stones in 976 infants of up to 2 years of age. Between 1992 and 2016, 976 infants presented to our institute with 1038 stones. Chemical composition of stones was analyzed by Fourier transformation infrared spectroscopy (FTIR). The mean age of infants was 19.5 ± 5.74 months with a M:F ratio of 5.5:1. Half (50%) of the infants were rural dwellers, 90% belonged to low socio-economic class and 70% were malnourished. A history of chronic diarrhoea was reported in 13% and urinary tract infections in 5%. The anatomic location was bladder in 487 (46.9%), kidney in 246 (23.6%), ureter in 142 (13.6%), urethra in 2 (0.2%) and 161 (15.5%) were passed spontaneously. Overall frequency of compounds in stones showed ammonium acid urate (AAU) in 772 (74.37%), calcium oxalate (CaOx) in 410 (39.5%). Uric acid (UA) in 119 (11.46%), calcium phosphate apatite (CaP) in 96 (9.25%), magnesium ammonium phosphate (Struvite) in 45 (4.34%), cystine in 12 (1.16%) and xanthine in 40 (3.85%). Frequency of compounds was similar in genders. Infants of age 0-6 months had higher frequency of UA (28%), CaOx (50%) and low AAU (61%) as compared to 11, 39 and 75%, respectively, in 7-24 months (p < 0.049) (p < 0.002) (p < 0.001). Nucleus of stones showed pure AAU in 63 and 43% on the surface due to addition of CaOx, struvite and CaP. Our study has shown that AAU is a major component of stones in infants where the main risk factors are poverty, malnutrition, diarrheal diseases and dehydration.

Identification of mineral compositions in some renal calculi by FT Raman and IR spectral analysis

NASA Astrophysics Data System (ADS)

Tonannavar, J.; Deshpande, Gouri; Yenagi, Jayashree; Patil, Siddanagouda B.; Patil, Nikhil A.; Mulimani, B. G.

2016-02-01

We present in this paper accurate and reliable Raman and IR spectral identification of mineral constituents in nine samples of renal calculi (kidney stones) removed from patients suffering from nephrolithiasis. The identified mineral components include Calcium Oxalate Monohydrate (COM, whewellite), Calcium Oxalate Dihydrate (COD, weddellite), Magnesium Ammonium Phosphate Hexahydrate (MAPH, struvite), Calcium Hydrogen Phosphate Dihydrate (CHPD, brushite), Pentacalcium Hydroxy Triphosphate (PCHT, hydroxyapatite) and Uric Acid (UA). The identification is based on a satisfactory assignment of all the observed IR and Raman bands (3500-400 cm- 1) to chemical functional groups of mineral components in the samples, aided by spectral analysis of pure materials of COM, MAPH, CHPD and UA. It is found that the eight samples are composed of COM as the common component, the other mineral species as common components are: MAPH in five samples, PCHT in three samples, COD in three samples, UA in three samples and CHPD in two samples. One sample is wholly composed of UA as a single component; this inference is supported by the good agreement between ab initio density functional theoretical spectra and experimental spectral measurements of both sample and pure material. A combined application of Raman and IR techniques has shown that, where the IR is ambiguous, the Raman analysis can differentiate COD from COM and PCHT from MAPH.

Identification of mineral compositions in some renal calculi by FT Raman and IR spectral analysis.

PubMed

Tonannavar, J; Deshpande, Gouri; Yenagi, Jayashree; Patil, Siddanagouda B; Patil, Nikhil A; Mulimani, B G

2016-02-05

We present in this paper accurate and reliable Raman and IR spectral identification of mineral constituents in nine samples of renal calculi (kidney stones) removed from patients suffering from nephrolithiasis. The identified mineral components include Calcium Oxalate Monohydrate (COM, whewellite), Calcium Oxalate Dihydrate (COD, weddellite), Magnesium Ammonium Phosphate Hexahydrate (MAPH, struvite), Calcium Hydrogen Phosphate Dihydrate (CHPD, brushite), Pentacalcium Hydroxy Triphosphate (PCHT, hydroxyapatite) and Uric Acid (UA). The identification is based on a satisfactory assignment of all the observed IR and Raman bands (3500-400c m(-1)) to chemical functional groups of mineral components in the samples, aided by spectral analysis of pure materials of COM, MAPH, CHPD and UA. It is found that the eight samples are composed of COM as the common component, the other mineral species as common components are: MAPH in five samples, PCHT in three samples, COD in three samples, UA in three samples and CHPD in two samples. One sample is wholly composed of UA as a single component; this inference is supported by the good agreement between ab initio density functional theoretical spectra and experimental spectral measurements of both sample and pure material. A combined application of Raman and IR techniques has shown that, where the IR is ambiguous, the Raman analysis can differentiate COD from COM and PCHT from MAPH. Copyright © 2015 Elsevier B.V. All rights reserved.

Dynamical Jahn Teller distortion in single crystals of Cu(II) doped magnesium potassium phosphate hexahydrate: a variable temperature EPR study

NASA Astrophysics Data System (ADS)

PrabhuKantan, A.; Velavan, K.; Venkatesan, R.; Sambasiva Rao, P.

2003-05-01

Single crystal electron paramagnetic resonance (EPR) studies on Cu(II)-doped magnesium potassium phosphate hexahydrate have been carried out at room temperature. The temperature dependence of g and A values has been obtained for the polycrystalline sample and the ground state is unambiguously identified. These results indicate the existence of a dynamic Jahn-Teller distortion for Cu(II) ion. The g and A tensor direction cosines are evaluated and compared with Mg-O directions, which confirms that Cu(II) enters substitutionally in the lattice.

Chemically bonded phospho-silicate ceramics

DOEpatents

Wagh, Arun S.; Jeong, Seung Y.; Lohan, Dirk; Elizabeth, Anne

2003-01-01

A chemically bonded phospho-silicate ceramic formed by chemically reacting a monovalent alkali metal phosphate (or ammonium hydrogen phosphate) and a sparsely soluble oxide, with a sparsely soluble silicate in an aqueous solution. The monovalent alkali metal phosphate (or ammonium hydrogen phosphate) and sparsely soluble oxide are both in powder form and combined in a stochiometric molar ratio range of (0.5-1.5):1 to form a binder powder. Similarly, the sparsely soluble silicate is also in powder form and mixed with the binder powder to form a mixture. Water is added to the mixture to form a slurry. The water comprises 50% by weight of the powder mixture in said slurry. The slurry is allowed to harden. The resulting chemically bonded phospho-silicate ceramic exhibits high flexural strength, high compression strength, low porosity and permeability to water, has a definable and bio-compatible chemical composition, and is readily and easily colored to almost any desired shade or hue.

Effectivity of fluoride treatment on hydrogen and corrosion product generation in temporal implants for different magnesium alloys.

PubMed

Trinidad, Javier; Arruebarrena, Gurutze; Marco, Iñigo; Hurtado, Iñaki; Sáenz de Argandoña, Eneko

2013-12-01

The increasing interest on magnesium alloys relies on their biocompatibility, bioabsorbility and especially on their mechanical properties. Due to these characteristics, magnesium alloys are becoming a promising solution to be used, as temporary implants. However, magnesium alloys must overcome their poor corrosion resistance. This article analyses the corrosion behaviour in phosphate-buffered saline solution of three commercial magnesium alloys (AZ31B, WE43 and ZM21) as well as the influence of fluoride treatment on their corrosion behaviour. It is shown that the corrosion rate of all the alloys is decreased by fluoride treatment. However, fluoride treatment affects each alloy differently.

Augmenting Laboratory Rearing of Stable Fly (Diptera: Muscidae) Larvae With Ammoniacal Salts

PubMed Central

Friesen, Kristina; Berkebile, Dennis R.; Zhu, Jerry J.

2017-01-01

Stable flies are blood feeding parasites and serious pests of livestock. The immature stages develop in decaying materials which frequently have high ammonium content. We added various ammonium salts to our laboratory stable fly rearing medium and measured their effect on size and survival as well as the physical properties of the used media. The addition of ammonium hydroxide, ammonium phosphate and ammonium sulfate reduced larval survival. These compounds decreased pH and increased ammonium content of the used media. Ammonium bicarbonate had no effect on pH and marginally increased ammonium while increasing survival twofold. The optimal level of ammonium bicarbonate was 50 g (0.63 mol) per pan. Larval survival decreased when pH was outside the range of 8.5 to 9.0. PMID:28130462

Effect of the synthesis conditions on the electrochemical properties of LiFePO{sub 4} obtained from NH{sub 4}FePO{sub 4}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prosini, Pier Paolo, E-mail: pierpaolo.prosini@enea.it; Gislon, Paola; Cento, Cinzia

Graphical abstract: - Highlights: • Four different samples of FAP were synthesized by precipitation techniques. • The samples were used as precursors to synthesize electrochemical active LiFePO{sub 4}. • Their morphology, composition, structure and electrochemical performance were studied. • The LiFePO{sub 4} electrochemical performance resulted affected by the preparation method - Abstract: In this paper the morphological, structural and electrochemical properties of crystalline lithium iron phosphate (LiFePO{sub 4}) obtained from ferrous ammonium phosphate (FAP) have been studied. The FAP was obtained following four different processes, namely: (1) homogeneous phase precipitation, (2) heterogeneous phase precipitation from stoichiometric sodium phosphate, (3) heterogeneousmore » phase precipitation from stoichiometric ammonium phosphate, and (4) heterogeneous phase precipitation from over stoichiometric ammonium phosphate. Lithium iron phosphate was prepared by solid state reaction of FAP with lithium hydroxide. In order to evaluate the effect of reaction time and synthesis temperature the LiFePO{sub 4} was prepared varying the heating temperatures (550, 600 and 700 °C) and the reaction times (1 or 2 h). The morphology of the materials was evaluated by scanning electron microscopy while the chemical composition was determined by electron energy loss spectroscopy. X-ray diffraction was used to evaluate phase composition, crystal structure and crystallite size. The so obtained LiFePO{sub 4}'s were fully electrochemical characterized and a correlation was found between the crystal size and the electrochemical performance.« less

Effect of tetracalcium phosphate/monetite toothpaste on dentin remineralization and tubule occlusion in vitro.

PubMed

Medvecky, L; Stulajterova, R; Giretova, M; Mincik, J; Vojtko, M; Balko, J; Briancin, J

2018-03-01

To investigate the tubule occlusion and remineralization potential of a novel toothpaste with active tetracalcium phosphate/monetite mixtures under de/remineralization cycling. Dentin de/remineralization cycling protocol consisted of demineralization in 1% citric acid at pH 4.6 with following remineralization with toothpastes and soaking in artificial saliva. Effectiveness of toothpastes to promote remineralization was evaluated by measurement of microhardness recovery, analysis of surface roughness, thickness of coating and scanning electron microscopy. The novel tetracalcium phosphate/monetite dentifrice had comparable remineralization potential as commercial calcium silicate/phosphate (SENSODYNE ® ) and magnesium aluminum silicate (Colgate ® ) toothpastes and significantly higher than control saliva (p<0.02). Surface roughness was significantly lower after treatment with prepared and SENSODYNE ® dentifirice (p<0.05). The coatings on dentin surfaces was significantly thicker after applying toothpastes as compared to negative control (p<0.001). The new fluoride toothpaste formulation with bioactive tetracalcium phosphate/monetite calcium phosphate mixture effectively occluded dentin tubules and showed good dentin remineralization potential under de/remineralization cycling. It could replace professional powder preparation based on this mixture. It was demonstrated that prepared dentifrice had comparable properties with commercial fluoride calcium silicate/phosphate or magnesium aluminum silicate dentifrices. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Contamination of lithium heparin blood by K2-ethylenediaminetetraacetic acid (EDTA): an experimental evaluation.

PubMed

Lima-Oliveira, Gabriel; Salvagno, Gian Luca; Danese, Elisa; Brocco, Giorgio; Guidi, Gian Cesare; Lippi, Giuseppe

2014-01-01

The contamination of serum or lithium heparin blood with ethylenediaminetetraacetic acid (EDTA) salts may affect accuracy of some critical analytes and jeopardize patient safety. The aim of this study was to evaluate the effect of lithium heparin sample contamination with different amounts of K2EDTA. Fifteen volunteers were enrolled among the laboratory staff. Two lithium heparin tubes and one K2EDTA tube were collected from each subject. The lithium-heparin tubes of each subject were pooled and divided in 5 aliquots. The whole blood of K2EDTA tube was then added in scalar amount to autologous heparinised aliquots, to obtained different degrees of K2EDTA blood volume contamination (0%; 5%; 13%; 29%; 43%). The following clinical chemistry parameters were then measured in centrifuged aliquots: alanine aminotranspherase (ALT), bilirubin (total), calcium, chloride, creatinine, iron, lactate dehydrogenase (LD), lipase, magnesium, phosphate, potassium, sodium. A significant variation starting from 5% K2EDTA contamination was observed for calcium, chloride, iron, LD, magnesium (all decreased) and potassium (increased). The variation of phosphate and sodium (both increased) was significant after 13% and 29% K2EDTA contamination, respectively. The values of ALT, bilirubin, creatinine and lipase remained unchanged up to 43% K2EDTA contamination. When variations were compared with desirable quality specifications, the bias was significant for calcium, chloride, LD, magnesium and potassium (from 5% K2EDTA contamination), sodium, phosphate and iron (from 29% K2EDTA contamination). The concentration of calcium, magnesium, potassium, chloride and LD appears to be dramatically biased by even modest K2EDTA contamination (i.e., 5%). The values of iron, phosphate, and sodium are still reliable up to 29% K2EDTA contamination, whereas ALT, bilirubin, creatinine and lipase appear overall less vulnerable towards K2EDTA contamination.

Magnesium modification of a calcium phosphate cement alters bone marrow stromal cell behavior via an integrin-mediated mechanism.

PubMed

Zhang, Jing; Ma, Xiaoyu; Lin, Dan; Shi, Hengsong; Yuan, Yuan; Tang, Wei; Zhou, Huanjun; Guo, Han; Qian, Jiangchao; Liu, Changsheng

2015-06-01

The chemical composition, structure and surface characteristics of biomaterials/scaffold can affect the adsorption of proteins, and this in turn influences the subsequent cellular response and tissue regeneration. With magnesium/calcium phosphate cements (MCPC) as model, the effects of magnesium (Mg) on the initial adhesion and osteogenic differentiation of bone marrow stromal cells (BMSCs) as well as the underlying mechanism were investigated. A series of MCPCs with different magnesium phosphate cement (MPC) content (0∼20%) in calcium phosphate cement (CPC) were synthesized. MCPCs with moderate proportion of MPC (5% and 10%, referred to as 5MCPC and 10MCPC) were found to effectively modulate the orientation of the adsorbed fibronectin (Fn) to exhibit enhanced receptor binding affinity, and to up-regulate integrin α5β1 expression of BMSCs, especially for 5MCPC. As a result, the attachment, morphology, focal adhesion formation, actin filaments assembly and osteogenic differentiation of BMSCs on 5MCPC were strongly enhanced. Further in vivo experiments confirmed that 5MCPC induced promoted osteogenesis in comparison to ot her CPC/MCPCs. Our results also suggested that the Mg on the underlying substrates but not the dissolved Mg ions was the main contributor to the above positive effects. Based on these results, it can be inferred that the specific interaction of Fn and integrin α5β1 had predominant effect on the MCPC-induced enhanced cellular response of BMSCs. These results provide a new strategy to regulate BMSCs adhesion and osteogenic differentiation by adjusting the Mg/Ca content and distribution in CPC, guiding the development of osteoinductive scaffolds for bone tissue regeneration. Copyright © 2015 Elsevier Ltd. All rights reserved.

Magnesium phosphate cements for endodontic applications with improved long-term sealing ability.

PubMed

Mestres, G; Aguilera, F S; Manzanares, N; Sauro, S; Osorio, R; Toledano, M; Ginebra, M P

2014-02-01

To characterize three radiopaque Magnesium Phosphate Cements (MPCs) developed for endodontic purposes. Three experimental MPCs containing Bi2 O3 were formulated. The experimental cements, which consisted of mixtures of magnesium oxide with different phosphate salts, were characterized for setting time, injectability, porosity, compressive strength and phase composition. The long-term sealing ability of the experimental MPCs applied in single-rooted teeth as root canal filling material or as sealer in combination with gutta-percha was also assessed using a highly sensitive fluid filtration system. A mineral trioxide aggregate (MTA) cement was used as control. Statistical analysis was performed with two- or three-way analysis of variance (anova) and Tukey's test was used for comparisons. The addition of 10 wt% Bi2 O3 within the composition of the MPCs provided an adequate radiopacity for endodontic applications according to ISO 6876 standard. The reaction products resulting from the MPCs were either struvite (MgNH4 PO4 ·6H2 O) or an amorphous sodium magnesium phosphate. The porosity of the three MPCs ranged between 4% and 11%. The initial setting time of the experimental cements was between 6 and 9 min, attaining high early compressive strength values (17-34 MPa within 2 h). All MPC formulations achieved greater sealing ability than MTA (P < 0.05) after 3 months, which was maintained after 6 months for two of the experimental cements (P < 0.05). These MPCs had adequate handling and mechanical properties and low degradation rates. Furthermore, a stable sealing ability was demonstrated up to 6 months when using the cement both as root filling material and as sealer in conjunction with gutta-percha. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Agricultural chemicals: life changer for mosquito vectors in agricultural landscapes?

PubMed

Kibuthu, Tabitha W; Njenga, Sammy M; Mbugua, Amos K; Muturi, Ephantus J

2016-09-13

Although many mosquito species develop within agricultural landscapes where they are potentially exposed to agricultural chemicals (fertilizers and pesticides), the effects of these chemicals on mosquito biology remain poorly understood. This study investigated the effects of sublethal concentrations of four agricultural chemicals on the life history traits of Anopheles arabiensis and Culex quinquefasciatus mosquitoes. Field and laboratory experiments were conducted to examine how sublethal concentrations of four agricultural chemicals: an insecticide (cypermethrin), a herbicide (glyphosate), and two nitrogenous fertilizers (ammonium sulfate and diammonium phosphate) alter oviposition site selection, emergence rates, development time, adult body size, and longevity of An. arabiensis and Cx. quinquefasciatus. Both mosquito species had preference to oviposit in fertilizer treatments relative to pesticide treatments. Emergence rates for An. arabiensis were significantly higher in the control and ammonium sulfate treatments compared to cypermethrin treatment, while emergence rates for Cx. quinquefasciatus were significantly higher in the diammonium phosphate treatment compared to glyphosate and cypermethrin treatments. For both mosquito species, individuals from the ammonium sulfate and diammonium phosphate treatments took significantly longer time to develop compared to those from cypermethrin and glyphosate treatments. Although not always significant, males and females of both mosquito species tended to be smaller in the ammonium sulfate and diammonium phosphate treatments compared to cypermethrin and glyphosate treatments. There was no significant effect of the agrochemical treatments on the longevity of either mosquito species. These results demonstrate that the widespread use of agricultural chemicals to enhance crop production can have unexpected effects on the spatial distribution and abundance of mosquito vectors of malaria and lymphatic filariasis.

Significant decrease of broth viscosity and glucose consumption in erythromycin fermentation by dynamic regulation of ammonium sulfate and phosphate.

PubMed

Chen, Yong; Wang, Zejian; Chu, Ju; Zhuang, Yingping; Zhang, Siliang; Yu, Xiaoguang

2013-04-01

In this study, the effects of nitrogen sources on broth viscosity and glucose consumption in erythromycin fermentation were investigated. By controlling ammonium sulfate concentration, broth viscosity and glucose consumption were decreased by 18.2% and 61.6%, respectively, whereas erythromycin biosynthesis was little affected. Furthermore, erythromycin A production was increased by 8.7% still with characteristics of low broth viscosity and glucose consumption through the rational regulations of phosphate salt, soybean meal and ammonium sulfate. It was found that ammonium sulfate could effectively control proteinase activity, which was correlated with the utilization of soybean meal as well as cell growth. The pollets formation contributed much to the decrease of broth viscosity. The accumulation of extracellular propionate and succinate under the new regulation strategy indicated that higher propanol consumption might increase the concentration of methylmalonyl-CoA and propionyl-CoA and thus could increase the flux leading to erythromycin A. Copyright © 2013 Elsevier Ltd. All rights reserved.

Synthesis and Characterization of Ca, Mg, La- PMMA Polymer Composites for Phosphate Removal

EPA Science Inventory

In this study calcium, magnesium and lanthanum- PMMA polymer composites were synthesized, characterized and investigated for phosphate removal from wastewater using rapid small scale column tests. Theoretical and experimental capacity of the media was determined and unused and sp...

Mg-Enriched Engineered Carbon from Lithium-Ion Battery Anode for Phosphate Removal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Yan; Guo, Xingming; Yao, Ying

2016-02-10

Three Mg-enriched engineered carbons (mesocarbon microbeads, MCMB) were produced from lithium-ion battery anode using concentrated nitric acid oxidization and magnesium nitrate pretreatment. The obtained 15%Mg-MCMB, 30%Mg-MCMB, and 40%Mg-MCMB have magnesium level of 10.19, 19.13, and 19.96%, respectively. FTIR spectrum shows the functional groups present on the oxidized MCMB including OH, C=O, C–H, and C–O. XRD, SEM-EDX, and XPS analyses show that nanoscale Mg(OH) 2 and MgO particles were presented on the surface of the Mg-MCMB samples, which could serve as the main adsorption mechanism as to precipitate phosphate from aqueous solutions. The sorption experiments indicate that Mg modification dramatically promotesmore » MCMB’s phosphate removal ability and phosphate removal rates reach as high as 95%. Thus, modification of the spent LIBs anode could provide a novel direction of preparing wastewater adsorbent and develop an innovative way to achieve sustainable development.« less

Sequential injection system with multi-parameter analysis capability for water quality measurement.

PubMed

Kaewwonglom, Natcha; Jakmunee, Jaroon

2015-11-01

A simple sequential injection (SI) system with capability to determine multi-parameter has been developed for the determination of iron, manganese, phosphate and ammonium. A simple and compact colorimeter was fabricated in the laboratory to be employed as a detector. The system was optimized for suitable conditions for determining each parameter by changing software program and without reconfiguration of the hardware. Under the optimum conditions, the methods showed linear ranges of 0.2-10 mg L(-1) for iron and manganese determinations, and 0.3-5.0 mg L(-1) for phosphate and ammonium determinations, with correlation coefficients of 0.9998, 0.9973, 0.9987 and 0.9983, respectively. The system provided detection limits of 0.01, 0.14, 0.004 and 0.02 mg L(-1) for iron, manganese, phosphate and ammonium, respectively. The proposed system has good precision, low chemical consumption and high throughput. It was applied for monitoring water quality of Ping river in Chiang Mai, Thailand. Recoveries of the analysis were obtained in the range of 82-119%. Copyright © 2015 Elsevier B.V. All rights reserved.

Development of magnesium calcium phosphate biocement for bone regeneration.

PubMed

Jia, Junfeng; Zhou, Huanjun; Wei, Jie; Jiang, Xin; Hua, Hong; Chen, Fangping; Wei, Shicheng; Shin, Jung-Woog; Liu, Changsheng

2010-08-06

Magnesium calcium phosphate biocement (MCPB) with rapid-setting characteristics was fabricated by using the mixed powders of magnesium oxide (MgO) and calcium dihydrogen phosphate (Ca(H(2)PO(4))(2).H(2)O). The results revealed that the MCPB hardened after mixing the powders with water for about 7 min, and the compressive strength reached 43 MPa after setting for 1 h, indicating that the MCPB had a short setting time and high initial mechanical strength. After the acid-base reaction of MCPB containing MgO and Ca(H(2)PO(4))(2).H(2)O in a molar ratio of 2 : 1, the final hydrated products were Mg(3)(PO(4))(2) and Ca(3)(PO(4))(2). The MCPB was degradable in Tris-HCl solution and the degradation ratio was obviously higher than calcium phosphate biocement (CPB) because of its fast dissolution. The attachment and proliferation of the MG(63) cells on the MCPB were significantly enhanced in comparison with CPB, and the alkaline phosphatase activity of MG(63) cells on the MCPB was significantly higher than on the CPB at 7 and 14 days. The MG(63) cells with normal phenotype spread well on the MCPB surfaces, and were attached in close proximity to the substrate, as seen by scanning electron microscopy (SEM). The results demonstrated that the MCPB had a good ability to support cell attachment, proliferation and differentiation, and exhibited good cytocompatibility.

Simultaneous recovery of phosphorus and potassium as magnesium potassium phosphate from synthetic sewage sludge effluent.

PubMed

Nakao, Satoshi; Nishio, Takayuki; Kanjo, Yoshinori

2017-10-01

Bench-scale experiments were performed to investigate simultaneous recovery of phosphorus and potassium from synthetic sewage sludge effluent as crystals of magnesium potassium phosphate (MPP or struvite-(K), MgKPO 4 ·6H 2 O). The optimal pH of MPP formation was 11.5. A phosphorus level of at least 3 mM and K:P molar ratio over 3 were necessary to form MPP, which showed higher content rate of phosphorus and potassium in precipitate. MPP crystallization was confirmed by analysing the precipitates using a scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDX) apparatus and an X-ray Diffractometer (XRD). Inhibition of MPP crystallization by iron and aluminium was confirmed by precipitation experiments and SEM-EDX analysis. Potassium ratio against magnesium in precipitate decreased for iron concentrations greater than over 0.2 mM and aluminium concentrations over 0.05 mM.

Changes in soil toxicity by phosphate-aided soil washing: effect of soil characteristics, chemical forms of arsenic, and cations in washing solutions.

PubMed

Jho, Eun Hea; Im, Jinwoo; Yang, Kyung; Kim, Young-Jin; Nam, Kyoungphile

2015-01-01

This study was set to investigate the changes in the toxicity of arsenic (As)-contaminated soils after washing with phosphate solutions. The soil samples collected from two locations (A: rice paddy and B: forest land) of a former smelter site were contaminated with a similar level of As. Soil washing (0.5 M phosphate solution for 2 h) removed 24.5% As, on average, in soil from both locations. Regardless of soil washing, Location A soil toxicities, determined using Microtox, were greater than that of Location B and this could be largely attributed to different soil particle size distribution. With soils from both locations, the changes in As chemical forms resulted in either similar or greater toxicities after washing. This emphasizes the importance of considering ecotoxicological aspects, which are likely to differ depending on soil particle size distribution and changes in As chemical forms, in addition to the total concentration based remedial goals, in producing ecotoxicologically-sound soils for reuse. In addition, calcium phosphate used as the washing solution seemed to contribute more on the toxic effects of the washed soils than potassium phosphate and ammonium phosphate. Therefore, it would be more appropriate to use potassium or ammonium phosphate than calcium phosphate for phosphate-aided soil washing of the As-contaminated soils. Copyright © 2014 Elsevier Ltd. All rights reserved.

Influence of magnesia-to-phosphate molar ratio on microstructures, mechanical properties and thermal conductivity of magnesium potassium phosphate cement paste with large water-to-solid ratio

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Biwan, E-mail: xubiwan@gmail.com; Ma, Hongyan, E-mail: mhy1103@gmail.com; Li, Zongjin

2015-02-15

This paper describes the influence of the magnesia-to-phosphate (M/P) molar ratios ranging from 4 to 12, on the properties and microstructures of magnesium potassium phosphate cement (MKPC) pastes with a large water-to-solid ratio (w/s) of 0.50. The setting behavior, compressive strength, tensile bonding strength and thermal conductivity of the MKPC pastes, were investigated. The results show that an increase in the M/P ratio can slow down the setting reaction, and clearly degrade the mechanical strengths, but clearly improve the thermal conductivity of MKPC pastes. Furthermore, micro-characterizations including X-ray diffraction, scanning electron microscopy and thermogravimetric analysis, on the MKPC pastes revealmore » that a lower M/P ratio can facilitate better crystallization of the resultant magnesium potassium phosphate hexahydrate (MKP) and a denser microstructure. Moreover, strong linear correlations are found between the mechanical strengths and the MKP-to-space ratio, and between thermal conductivity and the volume ratio of the unreacted magnesia to the MKP. - Highlights: • Increase of M/P molar ratio causes clear mechanical degradations on MKPC pastes. • Thermal conductivity of MKPC pastes is improved with increase of M/P molar ratio. • Lower M/P ratio leads to better MKP crystallization and denser microstructure. • Strengths of MKPC pastes are linearly correlated to the MKP-to-space ratios. • Thermal conductivity is affected by the volume ratio of unreacted magnesia to MKP.« less

Improving Water Use Efficiency of Lettuce (Lactuca sativa L.) Using Phosphorous Fertilizers.

PubMed

Alkhader, Asad M F; Abu Rayyan, Azmi M

2013-01-01

A greenhouse pot experiment was conducted to evaluate the effect of phosphorous (P) fertilizers application to an alkaline calcareous soil on the water use efficiency (WUE) of lettuce cultivar "robinson" of iceberg type. Head fresh and dry weights, total water applied and WUE were affected significantly by the P fertilizer type and rate. P fertilizers addition induced a significant enhancement in the WUE and fresh and dry weights of the crop. A local phosphate rock (PR) applied directly was found to be inferior to the other types of P fertilizers (Mono ammonium phosphate (MAP), Single superphosphate (SSP), and Di ammonium phosphate ((DAP)). MAP fertilizer at 375 and 500 kg P2O5/ha application rates recorded the highest significant values of head fresh weight and WUE, respectively.

A Calcium Enterolith in a Patient with Crohn's Disease and Its In Vitro Dissolubility in Citric Acid

PubMed Central

Urata, Haruo; Ohmori, Masayasu; Kondo, Yoshitaka; Kawahara, Yoshiro; Okada, Hiroyuki

2017-01-01

The microstructure and dissolubility of a calcified enterolith and enterolith pieces removed from a 26-year-old Japanese woman with Crohn's disease were analyzed using scanning electron microscopy and energy dispersive X-ray spectroscopy. The enterolith showed a multilayered structure with fatty acid calcium and magnesium phosphate. The amount of calcium, magnesium, and phosphate decreased after they were immersed in a citric acid solution, suggesting a potential contribution of acidic aqueous solution to elute inorganic substances contained in calcified enteroliths. This is the first study to investigate the in vitro dissolubility of calcified enteroliths induced by citric acid solution. PMID:29082049

Enhancement of struvite pellets crystallization in a full-scale plant using an industrial grade magnesium product.

PubMed

Crutchik, D; Morales, N; Vázquez-Padín, J R; Garrido, J M

2017-02-01

A full-scale struvite crystallization system was operated for the treatment of the centrate obtained from the sludge anaerobic digester in a municipal wastewater treatment plant. Additionally, the feasibility of an industrial grade Mg(OH) 2 as a cheap magnesium and alkali source was also investigated. The struvite crystallization plant was operated for two different periods: period I, in which an influent with low phosphate concentration (34.0 mg P·L -1 ) was fed to the crystallization plant; and period II, in which an influent with higher phosphate concentration (68.0 mg P·L -1 ) was used. A high efficiency of phosphorus recovery by struvite crystallization was obtained, even when the effluent treated had a high level of alkalinity. Phosphorus recovery percentage was around 77%, with a phosphate concentration in the effluent between 10.0 and 30.0 mg P·L -1 . The experiments gained struvite pellets of 0.5-5.0 mm size. Moreover, the consumption of Mg(OH) 2 was estimated at 1.5 mol Mg added·mol P recovered -1 . Thus, industrial grade Mg(OH) 2 can be an economical alternative as magnesium and alkali sources for struvite crystallization at industrial scale.

Topography, wetting, and corrosion responses of electrodeposited hydroxyapatite and fluoridated hydroxyapatite on magnesium.

PubMed

Assadian, Mahtab; Jafari, Hassan; Ghaffari Shahri, Seyed Morteza; Idris, Mohd Hasbullah; Almasi, Davood

2016-08-12

In this study, different types of calcium-phosphate phases were coated on NaOH pre-treated pure magnesium. The coating was applied by electrodeposition method in order to provide higher corrosion resistance and improve biocompatibility for magnesium. Thickness, surface morphology and topography of the coatings were analyzed using optical, scanning electron and atomic-force microscopies, respectively. Composition and chemical bonding, crystalline structures and wettability of the coatings were characterized using energy-dispersive and attenuated total reflectance-Fourier transform infrared spectroscopies, grazing incidence X-ray diffraction and contact angle measurement, respectively. Degradation behavior of the coated specimens was also investigated by potentiodynamic polarization and immersion tests. The experiments proved the presence of a porous coating dominated by dicalcium-phosphate dehydrate on the specimens. It was also verified that the developed hydroxyapatite was crystallized by alkali post-treatment. Addition of supplemental fluoride to the coating electrolyte resulted in stable and highly crystallized structures of fluoridated hydroxyapatite. The coatings were found effective to improve biocompatibility combined with corrosion resistance of the specimens. Noticeably, the fluoride supplemented layer was efficient in lowering corrosion rate and increasing surface roughness of the specimens compared to hydroxyapatite and dicalcium-phosphate dehydrates layers.

Evaluation of amorphous magnesium phosphate (AMP) based non-exothermic orthopedic cements.

PubMed

Babaie, Elham; Lin, Boren; Goel, Vijay K; Bhaduri, Sarit B

2016-10-07

This paper reports for the first time the development of a biodegradable, non-exothermic, self-setting orthopedic cement composition based on amorphous magnesium phosphate (AMP). The occurrence of undesirable exothermic reactions was avoided through using AMP as the solid precursor. The phenomenon of self-setting with optimum rheology is achieved by incorporating a water soluble biocompatible/biodegradable polymer, polyvinyl alcohol (PVA). Additionally, PVA enables a controlled growth of the final phase via a biomimetic process. The AMP powder was synthesized using a precipitation method. The powder, when in contact with the aqueous PVA solution, forms a putty resulting in a nanocrystalline magnesium phosphate phase of cattiite. The as-prepared cement compositions were evaluated for setting times, exothermicity, compressive strength, biodegradation, and microstructural features before and after soaking in SBF, and in vitro cytocompatibility. Since cattiite is relatively unexplored in the literature, a first time evaluation reveals that it is cytocompatible, just like the other phases in the MgO-P 2 O 5 (Mg-P) system. The cement composition prepared with 15% PVA in an aqueous medium achieved clinically relevant setting times, mechanical properties, and biodegradation. Simulated body fluid (SBF) soaking resulted in coating of bobierrite onto the cement particle surfaces.

Bone regeneration capacity of magnesium phosphate cements in a large animal model.

PubMed

Kanter, Britta; Vikman, Anna; Brückner, Theresa; Schamel, Martha; Gbureck, Uwe; Ignatius, Anita

2018-03-15

Magnesium phosphate minerals have captured increasing attention during the past years as suitable alternatives for calcium phosphate bone replacement materials. Here, we investigated the degradation and bone regeneration capacity of experimental struvite (MgNH 4 PO 4 ·6H 2 O) forming magnesium phosphate cements in two different orthotopic ovine implantation models. Cements formed at powder to liquid ratios (PLR) of 2.0 and 3.0 g ml -1 were implanted into trabecular bone using a non-load-bearing femoral drill-hole model and a load-bearing tibial defect model. After 4, 7 and 10 months the implants were retrieved and cement degradation and new bone formation was analyzed by micro-computed tomography (µCT) and histomorphometry. The results showed cement degradation in concert with new bone formation at both defect locations. Both cements were almost completely degraded after 10 months. The struvite cement formed with a PLR of 2.0 g ml -1 exhibited a slightly accelerated degradation kinetics compared to the cement with a PLR of 3.0 g ml -1 . Tartrat-resistant acid phosphatase (TRAP) staining indicated osteoclastic resorption at the cement surface. Energy dispersive X-ray analysis (EDX) revealed that small residual cement particles were mostly accumulated in the bone marrow in between newly formed bone trabeculae. Mechanical loading did not significantly increase bone formation associated with cement degradation. Concluding, struvite-forming cements might be promising bone replacement materials due to their good degradation which is coupled with new bone formation. Recently, the interest in magnesium phosphate cements (MPC) for bone substitution increased, as they exhibit high initial strength, comparably elevated degradation potential and the release of valuable magnesium ions. However, only few in vivo studies, mostly including non-load-bearing defects in small animals, have been performed to analyze the degradation and regeneration capability of MPC derived compounds. The present study examined the in vivo behavior of magnesiumammoniumphosphate hexahydrate (struvite) implants with different porosity in both mechanically loaded and non-loaded defects of merino sheep. For the first time, the effect of mechanical stimuli on the biological outcome of this clinically relevant replacement material is shown and directly compared to the conventional unloaded defect situation in a large animal model. Copyright © 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Crystallization of Chicken Egg White Lysozyme from Sulfate Salts

NASA Technical Reports Server (NTRS)

Forsythe, Elizabeth; Pusey, Marc

1998-01-01

It has been "known" that chicken egg white lysozyme does not crystallize from sulfate, particularly ammonium sulfate, salts, but instead gives amorphous precipitates. This has been the basis of several studies using lysozyme comparing macromolecule crystal nucleation and amorphous precipitation. Recently Ries-Kautt et al (Acta Cryst D50, (1994) 366) have shown that purified isoionic CEWL could be crystallized from low concentrations of sulfate at basic pH, and we subsequently showed that in fact CEWL could be purified in both the tetragonal and orthorhombic forms using ammonium sulfate over the pH range 4.0 to 7.8 (Acta Cryst D53, (1997) 795). We have now extended these observations to include a range of common sulfate salts, specifically sodium, potassium, rubidium, magnesium, and manganese sulfates. In all cases but the manganese sulfates both the familiar tetragonal and orthorhombic forms were obtained, with unit cell dimensions close to those known for the "classic" sodium chloride crystallized forms. Manganese sulfate has only yielded orthorhombic crystals to date. All crystallizations were carried out using low (typically less than or equal to 6 M) salt and high (greater than approximately 90 mg/ml) protein concentrations. As with ammonium sulfate, the tetragonal - orthorhombic phase shift appears to be a function of both the temperature and the protein concentration, with higher temperatures and concentrations favoring the orthorhombic and lower the tetragonal form. The phase change range is somewhat reduced for the sulfate salts, depending upon conditions being typically between approximately 15 - 20 C. Both the magnesium and manganese sulfates gave crystals at salt concentrations over 0.6 M as well, with magnesium sulfate giving a very slowly nucleating and growing hexagonal form. A triclinic crystal form, characterized by aggressively small crystals (typically 0.1 mm in size) has been occasionally obtained from ammonium sulfate. Finally, preliminary spot solubility determinations have suggested that in some cases the solubility increases with increasing salt concentrations.

Media calcification, low erythrocyte magnesium, altered plasma magnesium, and calcium homeostasis following grafting of the thoracic aorta to the infrarenal aorta in the rat--differential preventive effects of long-term oral magnesium supplementation alone and in combination with alkali.

PubMed

Schwille, P O; Schmiedl, A; Schwille, R; Brunner, P; Kissler, H; Cesnjevar, R; Gepp, H

2003-03-01

Calcifications in arterial media are clinically well documented, but the role played by magnesium in pathophysiology and therapy is uncertain. To clarify this, an animal model in which the juxtacardial aorta was grafted to the infrarenal aorta, and the subsequent calcifications in the media of the graft and their response to oral supplementation with three magnesium-containing and alkalinizing preparations was investigated. Groups of highly inbred rats were formed as follows: sham-operation (Sham, n = 12), aorta transplantation (ATx, n = 12), ATx + magnesium citrate (MgC, n = 12), ATx + MgC + potassium citrate (MgCPC, n = 12), ATx + MgC + MgCPC (MgCPCSB, n = 12). At 84 (+/-2) days after ATx with or without treatment the following observations were made: (1) weight gain and general status were normal; (2) ATx rats developed massive media calcification, mineral accumulation in the graft, decreased erythrocyte magnesium and plasma parathyroid hormone, and increased plasma ionized magnesium and calcium, and uric acid; (3) Mg-treated rats developed variable degrees of metabolic alkalosis, but only MgCPCSB supplementation prevented calcifications. Additional findings after ATx alone were: imbalance in endothelin and nitric oxide production, the mineral deposited in media was poorly crystallized calcium phosphate, calcium exchange between plasma and graft, and bone resorption were unchanged. The superior anti-calcification effect of MgCPCSB was characterized by complete restoration of normal extracellular mineral homeostasis and uric acid, but sub-optimal normalization of erythrocyte magnesium. It was concluded that in the rat: (1) ATx causes loss of cellular magnesium, excess of extracellular magnesium and calcium in the presence of apparently unchanged bone resorption, and increased uricemia; (2) ATx facilitates enhanced influx of calcium into vascular tissue, leading to calcium phosphate deposition in the media; (3) ATx-induced calcification is prevented by dietary supplementation with a combination of magnesium, alkali citrate and bases. Although the described circulatory model of media calcification in the rat requires further investigation, the data allow ascribing a fundamental role to magnesium and acid-base metabolism.

[In vitro study with techniques of imaging of the composition of urinary calculi].

PubMed

Tellez Martínez-Fornés, M; Burgos Revilla, F J; Sáez Garrido, J C; Soria Descalzo, J; Barbero González, J; Sánchez Corral, J; Minaya Minaya, A; Vallejo Herrador, J

1997-02-01

Pre-treatment knowledge of the lithiasic composition can be useful to design the most appropriate therapeutic scheme for each kind of stone. The relationship between the stone's densitometry information provided by the different imaging techniques, conventional radiology (RX), computerized axial tomography (CAT) and dual energy radiographic densitometry (DO) is analyzed, as well as the elemental composition determined by the microanalysis of fragments obtained post-lithotrity using a scanning electronic microscope (SEM) associated to X-ray dispersion energy (XDE). 60 stones, 12 for each pure composition selected (calcium oxalate mono and dihydro, phosphocarbonate, magnesium ammonium phosphate and uric acid), were studied with XR, CAT and DO and were later subjected to lithofragmentation in vitro. Fragments analysis was carried out post-lithotrity with SEM associated to XDE. The X-ray does not allow to establish the composition of some calculi. CAT quantifies the mineral contents of the oxalocalcic and infective calculi and differentiates the uric acid from the other compositions because the mean density values are under 500 Hounsfield Units. DO evaluates the lithiasic content in phosphocarbonate salts which are structurally similar to bone hydroxyapatite.

Elevated Dietary Magnesium Prevents Connective Tissue Mineralization in a Mouse Model of Pseudoxanthoma Elasticum (Abcc6−/−)

PubMed Central

LaRusso, Jennifer; Li, Qiaoli; Jiang, Qiujie; Uitto, Jouni

2010-01-01

Pseudoxanthoma elasticum (PXE) is an autosomal recessive multi-system disorder characterized by ectopic connective tissue mineralization, with clinical manifestations primarily in the skin, eyes and the cardiovascular system. There is considerable, both intra-and inter-familial variability in the spectrum of phenotypic presentation. Previous studies have suggested that mineral content of the diet may modify the severity of the clinical phenotype in PXE. In this study, we utilized a targeted mutant mouse (Abcc6−/−) as a model system for PXE. We examined the effects of changes in dietary phosphate and magnesium on the mineralization process using calcification of the connective tissue capsule surrounding the vibrissae as an early phenotypic biomarker. Mice placed on custom-designed diets either high or low in phosphate did not show changes in mineralization, which was similar to that noted in Abcc6−/− mice on control diet. However, mice placed on diet enriched in magnesium (5-fold) showed no evidence of connective tissue mineralization in this mouse model of PXE. The inhibitory capacity of magnesium was confirmed in a cell-based mineralization assay system in vitro. Collectively, our observations suggest that assessment of dietary magnesium in patients with PXE may be warranted. PMID:19122649

Overexpression, crystallization and preliminary X-ray crystallographic analysis of erythronate-4-phosphate dehydrogenase from Pseudomonas aeruginosa.

PubMed

Ha, Jun Yong; Lee, Ji Hyun; Kim, Kyoung Hoon; Kim, Do Jin; Lee, Hyung Ho; Kim, Hye-Kyung; Yoon, Hye-Jin; Suh, Se Won

2006-02-01

The enzyme erythronate-4-phosphate dehydrogenase catalyses the conversion of erythronate-4-phosphate to 3-hydroxy-4-phospho-hydroxy-alpha-ketobutyrate. It belongs to the D-isomer-specific 2-hydroxyacid dehydrogenase family. It is essential for de novo biosynthesis of vitamin B6 (pyridoxine). Erythronate-4-phosphate dehydrogenase from Pseudomonas aeruginosa, a homodimeric enzyme consisting of two identical 380-residue subunits, has been overexpressed in Escherichia coli with a C-terminal purification tag and crystallized at 297 K using 0.7 M ammonium dihydrogen phosphate, 0.4 M ammonium tartrate, 0.1 M sodium citrate pH 5.6 and 10 mM cupric chloride. X-ray diffraction data were collected to 2.20 A from a crystal grown in the presence of NADH. The crystals belong to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 84.77, b = 101.28, c = 142.58 A. A dimeric molecule is present in the asymmetric unit, giving a crystal volume per protein weight (VM) of 3.64 A3 Da(-1) and a solvent content of 66%.

Engineered carbon (biochar) prepared by direct pyrolysis of Mg-accumulated tomato tissues: Characterization and phosphate removal potential

USDA-ARS?s Scientific Manuscript database

An innovative synthesis was developed to produce engineered biochar from magnesium (Mg) enriched tomato tissues through slow pyrolysis in a N2 environment. The resulting Mg-biochar composites showed excellent sorption ability to phosphate in aqueous solutions. The engineered biochar contained nanosc...

Selective separation of phosphate and fluoride from semiconductor wastewater.

PubMed

Warmadewanthi, B; Liu, J C

2009-01-01

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

Effects of phosphates on microstructure and bioactivity of micro-arc oxidized calcium phosphate coatings on Mg-Zn-Zr magnesium alloy.

PubMed

Pan, Y K; Chen, C Z; Wang, D G; Zhao, T G

2013-09-01

Calcium phosphate (CaP) coatings were prepared on Mg-Zn-Zr magnesium alloy by micro-arc oxidation (MAO) in electrolyte containing calcium acetate monohydrate (CH3COO)2Ca·H2O) and different phosphates (i.e. disodium hydrogen phosphate dodecahydrate (Na2HPO4·12H2O), sodium phosphate (Na3PO4·H2O) and sodium hexametaphosphate((NaPO3)6)). Scanning electron microscope (SEM), energy-dispersive X-ray spectrometry (EDS) and X-ray diffractometer (XRD) were employed to characterize the microstructure, elemental distribution and phase composition of the CaP coatings. Simulated body fluid (SBF) immersion test was used to evaluate the coating bioactivity and degradability. Systemic toxicity test was used to evaluate the coating biocompatibility. Fluoride ion selective electrode (ISE) was used to measure F(-) ions concentration during 30 days SBF immersion. The CaP coatings effectively reduced the corrosion rate and the surfaces of CaP coatings were covered by a new layer formed of numerous needle-like and scale-like apatites. The formation of these calcium phosphate apatites indicates that the coatings have excellent bioactivity. The coatings formed in (NaPO3)6-containging electrolyte exhibit thicker thickness, higher adhesive strength, slower degradation rate, better apatite-inducing ability and biocompatibility. Copyright © 2013 Elsevier B.V. All rights reserved.

Method and product for phosphosilicate slurry for use in dentistry and related bone cements

DOEpatents

Wagh, Arun S.; Primus, Carolyn

2006-08-01

The present invention is directed to magnesium phosphate ceramics and their methods of manufacture. The composition of the invention is produced by combining a mixture of a substantially dry powder component with a liquid component. The substantially dry powder component comprises a sparsely soluble oxide powder, an alkali metal phosphate powder, a sparsely soluble silicate powder, with the balance of the substantially dry powder component comprising at least one powder selected from the group consisting of bioactive powders, biocompatible powders, fluorescent powders, fluoride releasing powders, and radiopaque powders. The liquid component comprises a pH modifying agent, a monovalent alkali metal phosphate in aqueous solution, the balance of the liquid component being water. The use of calcined magnesium oxide as the oxide powder and hydroxylapatite as the bioactive powder produces a self-setting ceramic that is particularly suited for use in dental and orthopedic applications.

Preparation of flexible bone tissue scaffold utilizing sea urchin test and collagen.

PubMed

Manchinasetty, Naga Vijaya Lakshmi; Oshima, Sho; Kikuchi, Masanori

2017-10-13

Gonads of sea urchin are consumed in Japan and some countries as food and most parts including its tests are discarded as marine wastes. Therefore, utilization of them as functional materials would reduce the waste as well as encourage Japanese fishery. In this study, magnesium containing calcite granules collected from sea urchin tests were hydrothermally phosphatized and the obtained granules were identified as approximately 82% in mass of magnesium containing β-tricalcium phosphate and 18% in mass of nonstoichiometric hydroxyapatite, i.e., a biphasic calcium phosphate, maintaining the original porous network. Shape-controlled scaffolds were fabricated with the obtained biphasic calcium phosphate granules and collagen. The scaffolds showed good open porosity (83.84%) and adequate mechanical properties for handling during cell culture and subsequent operations. The MG-63 cells showed higher proliferation and osteogenic differentiation in comparison to a control material, the collagen sponge with the same size. Furthermore, cell viability assay proved that the scaffolds were not cytotoxic. These results suggest that scaffold prepared using sea urchin test derived calcium phosphate and collagen could be a potential candidate of bone void fillers for non-load bearing defects in bone reconstruction as well as scaffolds for bone tissue engineering.

Evaluation of calcium acetate/magnesium carbonate as a phosphate binder compared with sevelamer hydrochloride in haemodialysis patients: a controlled randomized study (CALMAG study) assessing efficacy and tolerability.

PubMed

de Francisco, Angel L M; Leidig, Michael; Covic, Adrian C; Ketteler, Markus; Benedyk-Lorens, Ewa; Mircescu, Gabriel M; Scholz, Caecilia; Ponce, Pedro; Passlick-Deetjen, Jutta

2010-11-01

Phosphate binders are required to control serum phosphorus in dialysis patients. A phosphate binder combining calcium and magnesium offers an interesting therapeutic option. This controlled randomized, investigator-masked, multicentre trial investigated the effect of calcium acetate/magnesium carbonate (CaMg) on serum phosphorus levels compared with sevelamer hydrochloride (HCl). The study aim was to show non-inferiority of CaMg in lowering serum phosphorus levels into Kidney Disease Outcome Quality Initiative (K/DOQI) target level range after 24 weeks. Three hundred and twenty-six patients from five European countries were included. After a phosphate binder washout period, 255 patients were randomized in a 1:1 fashion. Two hundred and four patients completed the study per protocol (CaMg, N = 105; dropouts N = 18; sevelamer-HCl, N = 99; dropouts N = 34). Patient baseline characteristics were similar in both groups. Serum phosphorus levels had decreased significantly with both drugs at week 25, and the study hypothesis of CaMg not being inferior to sevelamer-HCl was confirmed. The area under the curve for serum phosphorus (P = 0.0042) and the number of visits above K/DOQI (≤1.78 mmol/L, P = 0.0198) and Kidney disease: Improving global outcomes (KDIGO) targets (≤1.45 mmol/L, P = 0.0067) were significantly lower with CaMg. Ionized serum calcium did not differ between groups; total serum calcium increased in the CaMg group (treatment difference 0.0477 mmol/L; P = 0.0032) but was not associated with a higher risk of hypercalcaemia. An asymptomatic increase in serum magnesium occurred in CaMg-treated patients (treatment difference 0.2597 mmol/L, P < 0.0001). There was no difference in the number of patients with adverse events. CaMg was non-inferior to the comparator at controlling serum phosphorus levels at Week 25. There was no change in ionized calcium; there was minimal increase in total serum calcium and a small increase in serum magnesium. It had a good tolerability profile and thus may represent an effective treatment of hyperphosphataemia.

ADSORPTION CHARACTERISTICS OF PERCHLORATE IN SOILS

EPA Science Inventory

Perchlorate(CI04) is an oxyanion that originates as a contaminant in ground and surface waters from the dissolution of ammonium, potassium, magnesium or sodium salts. Perchlorate is mainly used in solid rocket fuels, explosives, and military batteries. Because of its potential ha...

Solid State Research, 1973:2.

DTIC Science & Technology

MERCURY COMPOUNDS, CADMIUM COMPOUNDS, TELLURIDES, NEODYMIUM COMPOUNDS, PHOSPHATES , ELECTRON TRANSITIONS, INFRARED OPTICAL MATERIALS, CRYSTAL GROWTH, MAGNESIUM OXIDES, PHOSPHORESCENT MATERIALS, SEMICONDUCTOR DIODES, MICROELECTRONICS

A regenerable potassium and phosphate sorbent system to enhance dialysis efficacy and device portability: an in vitro study.

PubMed

Wester, Maarten; Simonis, Frank; Gerritsen, Karin G; Boer, Walther H; Wodzig, Will K; Kooman, Jeroen P; Joles, Jaap A

2013-09-01

Continuous dialysis could provide benefit by constant removal of potassium and phosphate. This study investigates the suitability of specific potassium and phosphate sorbents for incorporation in an extracorporeal device by capacity and regenerability testing. Capacity testing was performed in uraemic plasma. Regenerability was tested for potassium sorbents, with adsorption based on cationic exchange for sodium, with 0.1 M and 1.0 M NaCl. To regenerate phosphate sorbents, with adsorption based on anionic exchange, 0.1 M and 1.0 M NaHCO3 and NaOH were used. Subsequently, sodium polystyrene divinylbenzene sulphonate (RES-A) and iron oxide hydroxide (FeOOH) beads were incorporated in a cartridge for testing in bovine blood using a recirculating blood circuit and a dialysis circuit separated by a high-flux dialyzer (dynamic setup). Preloading was tested to assess whether this could limit calcium and magnesium adsorption. In the batch-binding assays, zirconium phosphate most potently adsorbed potassium (0.44 ± 0.05 mmol/g) and RES-A was the best regenerable potassium sorbent (92.9 ± 5.7% with 0.1 M NaCl). Zirconium oxide hydroxide (ZIR-hydr) most potently adsorbed phosphate (0.23 ± 0.05 mmol/g) and the polymeric amine sevelamer carbonate was the best regenerable sorbent (85.7 ± 5.2% with 0.1 M NaHCO3). In the dynamic setup, a potassium adsorption of 10.72 ± 2.06 mmol in 3 h was achieved using 111 g of RES-A and a phosphate adsorption of 4.73 ± 0.53 mmol in 3 h using 55 g of FeOOH. Calcium and magnesium preloading was shown to reduce the net adsorption in 3 h from 3.57 ± 0.91 to -0.29 ± 1.85 and 1.02 ± 0.05 to -0.31 ± 0.18 mmol, respectively. RES-A and FeOOH are suitable, regenerizable sorbents for potassium and phosphate removal in dialysate regeneration. Use of zirconium carbonate and ZIR-hydr may further increase phosphate adsorption, but may compromise sorbent regenerability. Use of polymeric amines for phosphate adsorption may enhance sorbent regenerability. Calcium and magnesium preloading considerably reduced net adsorption of these ions.

Tertiary and Quaternary Ammonium-Phosphate Ionic Liquids as Lubricant Additives

DOE PAGES

Barnhill, William C.; Luo, Huimin; Meyer, III, Harry M; ...

2016-06-23

In this work we investigated the feasibility of five quaternary (aprotic) and four tertiary (protic) ammonium ionic liquids (ILs) with an identical organophosphate anion as lubricant antiwear additives. Viscosity, oil solubility, thermal stability, and corrosivity of the candidate ILs were characterized and correlated to the molecular structure. The protic group exhibits higher oil solubility than the aprotic group, and longer alkyl chains seem to provide better oil solubility and higher thermal stability. Selected ILs were applied as oil additives in steel-cast iron tribological tests and demonstrated promising anti-scuffing and anti-wear functionality. The thickness, nanostructure, coverage and composition of the tribofilmmore » formed by the besting performing IL were revealed by surface characterization for mechanistic understanding of the tribochemical interactions between the IL and metal surface. Results provide fundamental insights of the correlations among the molecular structure, physiochemical properties and lubricating performance for ammonium-phosphate ILs.« less

Tertiary and Quaternary Ammonium-Phosphate Ionic Liquids as Lubricant Additives

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barnhill, William C.; Luo, Huimin; Meyer, III, Harry M

In this work we investigated the feasibility of five quaternary (aprotic) and four tertiary (protic) ammonium ionic liquids (ILs) with an identical organophosphate anion as lubricant antiwear additives. Viscosity, oil solubility, thermal stability, and corrosivity of the candidate ILs were characterized and correlated to the molecular structure. The protic group exhibits higher oil solubility than the aprotic group, and longer alkyl chains seem to provide better oil solubility and higher thermal stability. Selected ILs were applied as oil additives in steel-cast iron tribological tests and demonstrated promising anti-scuffing and anti-wear functionality. The thickness, nanostructure, coverage and composition of the tribofilmmore » formed by the besting performing IL were revealed by surface characterization for mechanistic understanding of the tribochemical interactions between the IL and metal surface. Results provide fundamental insights of the correlations among the molecular structure, physiochemical properties and lubricating performance for ammonium-phosphate ILs.« less

Synthesis of Struvite using a Vertical Canted Reactor with Continuous Laminar Flow Process

NASA Astrophysics Data System (ADS)

Sutiyono, S.; Edahwati, L.; Muryanto, S.; Jamari, J.; Bayuseno, A. P.

2018-01-01

Struvite is a white crystalline that is chemically known as magnesium ammonium phosphorus hexahydrate (MgNH4PO4·6H2O). It can easily dissolve in acidic conditions and slightly soluble in neutral and alkaline conditions. In industry, struvite forms as a scale deposit on a pipe with hot flow fluid. However, struvite can be used as fertilizer because of its phosphate content. A vertical canted reactor is a promising technology for recovering phosphate levels in wastewater through struvite crystallization. The study was carried out with the vertical canted reactor by mixing an equimolar stock solution of MgCl2, NH4OH, and H3PO4 in 1: 1: 1 ratio. The crystallization process worked with the flow rate of three stock solution entering the reactor in the range of 16-38 ml/min, the temperature in the reactor is worked on 20°, 30°, and 40°C, while the incoming air rate is kept constant at 0.25 liters/min. Moreover, pH was maintained at a constant value of 9. The struvite crystallization process run until the steady state was reached. Then, the result of crystal precipitates was filtered and dried at standard temperature room for 48 hours. After that, struvite crystals were stored for the subsequent analysis by Scanning Electron Microscope (SEM) and XRD (X-Ray Diffraction) method. The use of canted reactor provided the high pure struvite with a prismatic crystal morphology.

Solid-state reaction kinetics of neodymium doped magnesium hydrogen phosphate system

NASA Astrophysics Data System (ADS)

Gupta, Rashmi; Slathia, Goldy; Bamzai, K. K.

2018-05-01

Neodymium doped magnesium hydrogen phosphate (NdMHP) crystals were grown by using gel encapsulation technique. Structural characterization of the grown crystals has been carried out by single crystal X-ray diffraction (XRD) and it revealed that NdMHP crystals crystallize in orthorhombic crystal system with space group Pbca. Kinetics of the decomposition of the grown crystals has been studied by non-isothermal analysis. The estimation of decomposition temperatures and weight loss has been made from the thermogravimetric/differential thermo analytical (TG/DTA) in conjuncture with DSC studies. The various steps involved in the thermal decomposition of the material have been analysed using Horowitz-Metzger, Coats-Redfern and Piloyan-Novikova equations for evaluating various kinetic parameters.

Formulating Precursors for Coating Metals and Ceramics

NASA Technical Reports Server (NTRS)

Morales, Wilfredo; Gatica, Jorge E.; Reye, John T.

2005-01-01

A protocol has been devised for formulating low-vapor-pressure precursors for protective and conversion coatings on metallic and ceramic substrates. The ingredients of a precursor to which the protocol applies include additives with phosphate esters, or aryl phosphate esters in solution. Additives can include iron, chromium, and/or other transition metals. Alternative or additional additives can include magnesium compounds to facilitate growth of films on substrates that do not contain magnesium. Formulation of a precursor begins with mixing of the ingredients into a high-vapor-pressure solvent to form a homogeneous solution. Then the solvent is extracted from the solution by evaporation - aided, if necessary, by vacuum and/or slight heating. The solvent is deemed to be completely extracted when the viscosity of the remaining solution closely resembles the viscosity of the phosphate ester or aryl phosphate ester. In addition, satisfactory removal of the solvent can be verified by means of a differential scanning calorimetry essay: the absence of endothermic processes for temperatures below 150 C would indicate that the residual solvent has been eliminated from the solution beyond a detectable dilution level.

Effect of Chemistry on Osteogenesis and Angiogenesis Towards Bone Tissue Engineering Using 3D Printed Scaffolds.

PubMed

Bose, Susmita; Tarafder, Solaiman; Bandyopadhyay, Amit

2017-01-01

The functionality or survival of tissue engineering constructs depends on the adequate vascularization through oxygen transport and metabolic waste removal at the core. This study reports the presence of magnesium and silicon in direct three dimensional printed (3DP) tricalcium phosphate (TCP) scaffolds promotes in vivo osteogenesis and angiogenesis when tested in rat distal femoral defect model. Scaffolds with three different interconnected macro pore sizes were fabricated using direct three dimensional printing. In vitro ion release in phosphate buffer for 30 days showed sustained Mg 2+  and Si 4+  release from these scaffolds. Histolomorphology and histomorphometric analysis from the histology tissue sections revealed a significantly higher bone formation, between 14 and 20% for 4-16 weeks, and blood vessel formation, between 3 and 6% for 4-12 weeks, due to the presence of magnesium and silicon in TCP scaffolds compared to bare TCP scaffolds. The presence of magnesium in these 3DP TCP scaffolds also caused delayed TRAP activity. These results show that magnesium and silicon incorporated 3DP TCP scaffolds with multiscale porosity have huge potential for bone tissue repair and regeneration.

Effect of chemistry on osteogenesis and angiogenesis towards bone tissue engineering using 3D printed scaffolds

PubMed Central

Bose, Susmita; Tarafder, Solaiman; Bandyopadhyay, Amit

2016-01-01

The functionality or survival of tissue engineering constructs depends on the adequate vascularization through oxygen transport and metabolic waste removal at the core. This study reports the presence of magnesium and silicon in 3D printed tricalcium phosphate (TCP) scaffolds promotes in vivo osteogenesis and angiogenesis when tested in rat distal femoral defect model. Scaffolds with three different interconnected macro pore sizes were fabricated using direct three dimensional printing (3DP). In vitro release in phosphate buffer for 30 days showed sustained Mg2+ and Si4+ release from these scaffolds. Histolomorphology and histomorphometric analysis from the histology tissue sections revealed a significantly higher bone, between 14 and 20 % for 4 to 16 weeks, and blood vessel, between 3 and 6% for 4 to 12 weeks, formation due to the presence of magnesium and silicon in TCP scaffolds compared to bare TCP scaffolds. The presence of magnesium in these 3DP TCP scaffolds also caused delayed TRAP activity. These results show that magnesium and silicon incorporated 3DP TCP scaffolds with multiscale porosity have huge potential for bone tissue repair and regeneration. PMID:27287311

Effects of fresh and aged biochars from pyrolysis and hydrothermal carbonization on nutrient sorption in agricultural soils

NASA Astrophysics Data System (ADS)

Gronwald, M.; Don, A.; Tiemeyer, B.; Helfrich, M.

2015-01-01

Leaching of nutrients from agricultural soils causes major environmental problems that may be reduced with biochar amendments to the soils. Biochars are characterised by a high adsorption capacity, i.e., they may retain nutrients such nitrate and ammonium. However, biochar properties strongly depend on feedstock and the production process. We investigated the nutrient retention capacity of biochars derived from pyrolysis (pyrochar) as well as from hydrothermal carbonization (hydrochar; produced at 200 and 250 °C) from three different feedstocks (digestates, Miscanthus, woodchips) mixed into different soil substrates (sandy loam and silty loam). Moreover, we investigated the influence of biochar degradation on its nutrient retention capacity using a seven-month in-situ field incubation of pyrochar and hydrochar. Pyrochars showed the highest ability to retain nitrate, ammonium and phosphate, with pyrochar from woodchips being particularly efficient in nitrate adsorption. Ammonium adsorption of pyrochars was controlled by the soil type of the soil-biochar mixture. We found some ammonium retention on sandy soils, but no pyrochar effect or even ammonium leaching from the loamy soil. The phosphate retention capacity of pyrochars strongly depended on the pyrochar feedstock with large phosphate leaching from digestate-derived pyrochar and some adsorption capacity from woodchip-derived pyrochar. Application of hydrochars to agricultural soils caused small, and often not significant, effects on nutrient retention. In contrast, some hydrochars did increase the leaching of nutrients compared to the non-amended control soil. We found a surprisingly rapid loss of the biochars' adsorption capacity after field application of the biochars. For all sites and for hydrochar and pyrochar, the adsorption capacity was reduced by 60-80% to less or no nitrate and ammonium adsorption. Thus, our results cast doubt on the efficiency of biochar applications to temperate zone soils to minimize nutrient losses via leaching.

Effects of fresh and aged chars from pyrolysis and hydrothermal carbonization on nutrient sorption in agricultural soils

NASA Astrophysics Data System (ADS)

Gronwald, M.; Don, A.; Tiemeyer, B.; Helfrich, M.

2015-06-01

Leaching of nutrients from agricultural soils causes major environmental problems that may be reduced with amendments of chars derived from pyrolysis (pyrochars) or hydrothermal carbonization (hydrochars). Chars are characterized by a high adsorption capacity - i.e. they may retain nutrients such as nitrate and ammonium. However, the physicochemical properties of the chars and hence their sorption capacity likely depend on feedstock and the production process. We investigated the nutrient retention capacity of pyrochars and hydrochars from three different feedstocks (digestates, Miscanthus, woodchips) mixed into different soil substrates (sandy loam and silty loam). Moreover, we investigated the influence of char degradation on its nutrient retention capacity using a 7-month in situ field incubation of pyrochar and hydrochar mixed into soils at three different field sites. Pyrochars showed the highest ability to retain nitrate, ammonium and phosphate, with pyrochar from woodchips being particularly efficient in nitrate adsorption. Ammonium adsorption of pyrochars was controlled by the soil type of the soil-char mixture. We found some ammonium retention on sandy soils, but no pyrochar effect or even ammonium leaching from the loamy soil. The phosphate retention capacity of pyrochars strongly depended on the pyrochar feedstock with large phosphate leaching from digestate-derived pyrochar and some adsorption capacity from woodchip-derived pyrochar. Application of hydrochars to agricultural soils caused small, and often not significant, effects on nutrient retention. In contrast, some hydrochars did increase the leaching of nutrients compared to the non-amended control soil. We found a surprisingly rapid loss of the chars' adsorption capacity after field application of the chars. For all sites and for hydrochar and pyrochar, the adsorption capacity was reduced by 60-80 % to less or no nitrate and ammonium adsorption. Thus, our results cast doubt on the efficiency of char applications to temperate zone soils to minimize nutrient losses via leaching.

Electricity production coupled to ammonium in a microbial fuel cell.

PubMed

He, Zhen; Kan, Jinjun; Wang, Yanbing; Huang, Yuelong; Mansfeld, Florian; Nealson, Kenneth H

2009-05-01

The production of electricity from ammonium was examined using a rotating-cathode microbial fuel cell (MFC). The addition of ammonium chloride, ammonium sulfate, or ammonium phosphate (monobasic) resulted in electricity generation, while adding sodium chloride, nitrate, or nitrite did not cause any increase in current production. The peak current increased with increasing amount of ammonium addition up to 62.3 mM of ammonium chloride, suggesting that ammonium was involved in electricity generation either directly as the anodic fuel or indirectly as substrates for nitrifiers to produce organic compounds for heterotrophs. Adding nitrate or nitrite with ammonium increased current production compared to solely ammonium addition. Using 16S rRNA-linked molecular analyses, we found ammonium-oxidizing bacteria and denitrifying bacteria on both the anode and cathode electrodes, whereas no anammox bacteria were detected. The dominant ammonium-oxidizing bacteria were closely related to Nitrosomonas europaea. The present MFC achieved an ammonium removal efficiency of 49.2 +/- 5.9 or 69.7 +/- 3.6%, depending on hydraulic retention time, but exhibited a very low Coulombic efficiency.

Magnesium based degradable biomaterials: A review

NASA Astrophysics Data System (ADS)

Gu, Xue-Nan; Li, Shuang-Shuang; Li, Xiao-Ming; Fan, Yu-Bo

2014-09-01

Magnesium has been suggested as a revolutionary biodegradable metal for biomedical applications. The corrosion of magnesium, however, is too rapid to match the rates of tissue healing and, additionally, exhibits the localized corrosion mechanism. Thus it is necessary to control the corrosion behaviors of magnesium for their practical use. This paper comprehensively reviews the research progress on the development of representative magnesium based alloys, including Mg-Ca, Mg-Sr, Mg-Zn and Mg-REE alloy systems as well as the bulk metallic glass. The influence of alloying element on their microstructures, mechanical properties and corrosion behaviors is summarized. The mechanical and corrosion properties of wrought magnesium alloys are also discussed in comparison with those of cast alloys. Furthermore, this review also covers research carried out in the field of the degradable coatings on magnesium alloys for biomedical applications. Calcium phosphate and biodegradable polymer coatings are discussed based on different preparation techniques used. We also compare the effect of different coatings on the corrosion behaviors of magnesium alloys substrate.

The Role of Magnesium for Geometry and Charge in GTP Hydrolysis, Revealed by Quantum Mechanics/Molecular Mechanics Simulations

PubMed Central

Rudack, Till; Xia, Fei; Schlitter, Jürgen; Kötting, Carsten; Gerwert, Klaus

2012-01-01

The coordination of the magnesium ion in proteins by triphosphates plays an important role in catalytic hydrolysis of GTP or ATP, either in signal transduction or energy conversion. For example, in Ras the magnesium ion contributes to the catalysis of GTP hydrolysis. The cleavage of GTP to GDP and Pi in Ras switches off cellular signaling. We analyzed GTP hydrolysis in water, Ras, and Ras·Ras-GTPase-activating protein using quantum mechanics/molecular mechanics simulations. By comparison of the theoretical IR-difference spectra for magnesium ion coordinated triphosphate to experimental ones, the simulations are validated. We elucidated thereby how the magnesium ion contributes to catalysis. It provides a temporary storage for the electrons taken from the triphosphate and it returns them after bond cleavage and Pi release back to the diphosphate. Furthermore, the Ras·Mg2+ complex forces the triphosphate into a stretched conformation in which the β- and γ-phosphates are coordinated in a bidentate manner. In this conformation, the triphosphate elongates the bond, which has to be cleaved during hydrolysis. Furthermore, the γ-phosphate adopts a more planar structure, driving the conformation of the molecule closer to the hydrolysis transition state. GTPase-activating protein enhances these changes in GTP conformation and charge distribution via the intruding arginine finger. PMID:22853907

Contamination of lithium heparin blood by K2-ethylenediaminetetraacetic acid (EDTA): an experimental evaluation

PubMed Central

Lima-Oliveira, Gabriel; Salvagno, Gian Luca; Danese, Elisa; Brocco, Giorgio; Guidi, Gian Cesare; Lippi, Giuseppe

2014-01-01

Introduction: The contamination of serum or lithium heparin blood with ethylenediaminetetraacetic acid (EDTA) salts may affect accuracy of some critical analytes and jeopardize patient safety. The aim of this study was to evaluate the effect of lithium heparin sample contamination with different amounts of K2EDTA. Materials and methods: Fifteen volunteers were enrolled among the laboratory staff. Two lithium heparin tubes and one K2EDTA tube were collected from each subject. The lithium-heparin tubes of each subject were pooled and divided in 5 aliquots. The whole blood of K2EDTA tube was then added in scalar amount to autologous heparinised aliquots, to obtained different degrees of K2EDTA blood volume contamination (0%; 5%; 13%; 29%; 43%). The following clinical chemistry parameters were then measured in centrifuged aliquots: alanine aminotranspherase (ALT), bilirubin (total), calcium, chloride, creatinine, iron, lactate dehydrogenase (LD), lipase, magnesium, phosphate, potassium, sodium. Results: A significant variation starting from 5% K2EDTA contamination was observed for calcium, chloride, iron, LD, magnesium (all decreased) and potassium (increased). The variation of phosphate and sodium (both increased) was significant after 13% and 29% K2EDTA contamination, respectively. The values of ALT, bilirubin, creatinine and lipase remained unchanged up to 43% K2EDTA contamination. When variations were compared with desirable quality specifications, the bias was significant for calcium, chloride, LD, magnesium and potassium (from 5% K2EDTA contamination), sodium, phosphate and iron (from 29% K2EDTA contamination). Conclusions: The concentration of calcium, magnesium, potassium, chloride and LD appears to be dramatically biased by even modest K2EDTA contamination (i.e., 5%). The values of iron, phosphate, and sodium are still reliable up to 29% K2EDTA contamination, whereas ALT, bilirubin, creatinine and lipase appear overall less vulnerable towards K2EDTA contamination. PMID:25351354

Prevalence of Risk Factors for the Refeeding Syndrome in Older Hospitalized Patients.

PubMed

Pourhassan, M; Cuvelier, I; Gehrke, I; Marburger, C; Modreker, M K; Volkert, D; Willschrei, H P; Wirth, R

2018-01-01

The incidence of refeeding syndrome (RFS) in older patients is not well-known. The aim of the study was to determine the prevalence of known risk factors for RFS in older individuals during hospitalization at geriatric hospital departments. 342 consecutive older participants (222 females) who admitted at acute geriatric hospital wards were included in a cross-sectional study. We applied the National Institute for Health and Clinical Excellence (NICE) criteria for determining patients at risk of RFS. In addition, Mini Nutritional Assessment Short Form (MNA®-SF) was used to identify patients at risk of malnutrition. Weight and height were assessed. The degree of weight loss was obtained by interview. Serum phosphate, magnesium, potassium, sodium, calcium, creatinine and urea were analyzed according to standard procedures. Of 342 older participants included in the study (mean age 83.1 ± 6.8, BMI range of 14.7-43.6 kg/m2), 239 (69.9%) were considered to be at risk of RFS, in which 43.5% and 11.7% were at risk of malnutrition and malnourished, respectively, according to MNA-SF. Patients in the risk group had significantly higher weight loss, lower phosphate and magnesium levels. In a multivariate logistic regression analysis, low levels of phosphate and magnesium followed by weight loss were the major risk factors for fulfilling the NICE criteria. The incidence of risk factors for RFS was relatively high in older individuals acutely admitted in geriatric hospital units, suggesting that, RFS maybe more frequent among older persons than we are aware of. Patients with low serum levels of phosphate and magnesium and higher weight loss are at increased risk of RFS. The clinical characteristics of the older participants at risk of RFS indicate that these patients had a relatively poor nutritional status which can help us better understand the potential scale of RFS on admission or during the hospital stay.

Efficacy of Trichloro-Acetic Acid Peel Alone Versus Combined Topical Magnesium Ascorbyl Phosphate for Epidermal Melasma.

PubMed

Murtaza, Fatima; Bangash, Abdur Rahim; Khushdil, Arshad; Noor, Sahibzada Mahmood

2016-07-01

To compare the efficacy in terms of reduction in melasma area and severity index (MASI) score by more than 10 of a combination of 20% trichloro-acetic acid peel plus 5% topical magnesium ascorbyl phosphate versus 20% trichloroacetic acid peel alone in the treatment of epidermal melasma. Randomized controlled trial. Department of Dermatology, Lady Reading Hospital (LRH), Peshawar, from May 2012 to May 2013. Patients aged 18 - 65 years, with Fitzpatrick skin type III-V were divided into two equal groups having 74 patients each. Detailed history was taken and Wood's lamp examination done to rule out mixed and dermal melasma. Melasma area and severity index (MASI) score was calculated for every patient. Priming was done for all patients with tretinoin cream applied once daily at night for 2 weeks, and to use a broad spectrum sun block cream before sun exposure. Patients in group Awere subjected to combined treatment, i.e. trichloro-acetic acid peel 20% (weekly) plus magnesium ascorbyl phosphate cream (applied once daily), while patients in group B were subjected to trichloro-acetic acid peel 20% (weekly) alone. Treatment was continued for 6 weeks. After completion of treatment, MASI score was recalculated. Proportion of patients with significant MASI score reduction was compared using chi-square test with significance at p < 0.05. Male and female patients were 11 (14.9%) and 63 (85.1%), respectively in group A, whereas 13 (17.6%) and 61 (82.4%) in group B. The mean age in group Awas 30.28 ±8.08 years, and 29.36 ±6.84 years in group B. Significant MASI score reduction in group Awas seen in 60 (81.1%) patients and in group B 49 (66.2%, p= 0.040). Combination of trichloro-acetic acid peel and topical magnesium ascorbyl phosphate cream was significantly more effective than trichloro-acetic acid peel alone in treatment of melasma.

Discovery of the ammonium substrate site on glutamine synthetase, a third cation binding site.

PubMed Central

Liaw, S. H.; Kuo, I.; Eisenberg, D.

1995-01-01

Glutamine synthetase (GS) catalyzes the ATP-dependent condensation of ammonia and glutamate to yield glutamine, ADP, and inorganic phosphate in the presence of divalent cations. Bacterial GS is an enzyme of 12 identical subunits, arranged in two rings of 6, with the active site between each pair of subunits in a ring. In earlier work, we have reported the locations within the funnel-shaped active site of the substrates glutamate and ATP and of the two divalent cations, but the site for ammonia (or ammonium) has remained elusive. Here we report the discovery by X-ray crystallography of a binding site on GS for monovalent cations, Tl+ and Cs+, which is probably the binding site for the substrate ammonium ion. Fourier difference maps show the following. (1) Tl+ and Cs+ bind at essentially the same site, with ligands being Glu 212, Tyr 179, Asp 50', Ser 53' of the adjacent subunit, and the substrate glutamate. From its position adjacent to the substrate glutamate and the cofactor ADP, we propose that this monovalent cation site is the substrate ammonium ion binding site. This proposal is supported by enzyme kinetics. Our kinetic measurements show that Tl+, Cs+, and NH4+ are competitive inhibitors to NH2OH in the gamma-glutamyl transfer reaction. (2) GS is a trimetallic enzyme containing two divalent cation sites (n1, n2) and one monovalent cation site per subunit. These three closely spaced ions are all at the active site: the distance between n1 and n2 is 6 A, between n1 and Tl+ is 4 A, and between n2 and Tl+ is 7 A. Glu 212 and the substrate glutamate are bridging ligands for the n1 ion and Tl+. (3) The presence of a monovalent cation in this site may enhance the structural stability of GS, because of its effect of balancing the negative charges of the substrate glutamate and its ligands and because of strengthening the "side-to-side" intersubunit interaction through the cation-protein bonding. (4) The presence of the cofactor ADP increases the Tl+ binding to GS because ADP binding induces movement of Asp 50' toward this monovalent cation site, essentially forming the site. This observation supports a two-step mechanism with ordered substrate binding: ATP first binds to GS, then Glu binds and attacks ATP to form gamma-glutamyl phosphate and ADP, which complete the ammonium binding site. The third substrate, an ammonium ion, then binds to GS, and then loses a proton to form the more active species ammonia, which attacks the gamma-glutamyl phosphate to yield Gln. (5) Because the products (Glu or Gln) of the reactions catalyzed by GS are determined by the molecule (water or ammonium) attacking the intermediate gamma-glutamyl phosphate, this negatively charged ammonium binding pocket has been designed naturally for high affinity of ammonium to GS, permitting glutamine synthesis to proceed in aqueous solution. PMID:8563633

Overexpression, crystallization and preliminary X-­ray crystallographic analysis of erythronate-4-phosphate dehydrogenase from Pseudomonas aeruginosa

PubMed Central

Ha, Jun Yong; Lee, Ji Hyun; Kim, Kyoung Hoon; Kim, Do Jin; Lee, Hyung Ho; Kim, Hye-Kyung; Yoon, Hye-Jin; Suh, Se Won

2006-01-01

The enzyme erythronate-4-phosphate dehydrogenase catalyses the conversion of erythronate-4-phosphate to 3-hydroxy-4-phospho-hydroxy-α-ketobutyrate. It belongs to the d-isomer-specific 2-hydroxyacid dehydrogenase family. It is essential for de novo biosynthesis of vitamin B6 (pyridoxine). Erythronate-4-­phosphate dehydrogenase from Pseudomonas aeruginosa, a homodimeric enzyme consisting of two identical 380-residue subunits, has been overexpressed in Escherichia coli with a C-terminal purification tag and crystallized at 297 K using 0.7 M ammonium dihydrogen phosphate, 0.4 M ammonium tartrate, 0.1 M sodium citrate pH 5.6 and 10 mM cupric chloride. X-ray diffraction data were collected to 2.20 Å from a crystal grown in the presence of NADH. The crystals belong to the orthorhombic space group P212121, with unit-cell parameters a = 84.77, b = 101.28, c = 142.58 Å. A dimeric molecule is present in the asymmetric unit, giving a crystal volume per protein weight (V M) of 3.64 Å3 Da−1 and a solvent content of 66%. PMID:16511285

Preparation of immunoglobulin Y from egg yolk using ammonium sulfate precipitation and ion exchange chromatography.

PubMed

Ko, K Y; Ahn, D U

2007-02-01

The objective of this study was to develop an economical, simple, and large-scale separation method for IgY from egg yolk. Egg yolk diluted with 9 volumes of cold water was centrifuged after adjusting the pH to 5.0. The supernatant was added with 0.01% charcoal or 0.01% carrageenan and centrifuged at 2,800 x g for 30 min. The supernatant was filtered through a Whatman no. 1 filter paper and then the filtrate was concentrated to 20% original volume using ultrafiltration. The concentrated solution was further purified using either cation exchange chromatography or ammonium sulfate precipitation. For the cation exchange chromatography method, the concentrated sample was loaded onto a column equilibrated with 20 mM citrate-phosphate buffer at pH 4.8 and eluted with 200 mM citrate-phosphate buffer at pH 6.4. For the ammonium sulfate precipitation method, the concentrated sample was twice precipitated with 40% ammonium sulfate solution at pH 9.0. The yield and purity of IgY were determined by ELISA and electrophoresis. The yield of IgY from the cation exchange chromatography method was 30 to 40%, whereas that of the ammonium sulfate precipitation was 70 to 80%. The purity of IgY from the ammonium sulfate method was higher than that of the cation exchange chromatography. The cation exchange chromatography could handle only a small amount of samples, whereas the ammonium sulfate precipitation could handle a large volume of samples. This suggests that ammonium sulfate precipitation was a more efficient and useful purification method than cation exchange chromatography for the large-scale preparation of IgY from egg yolk.

Size distribution of ions in atmospheric aerosols

NASA Astrophysics Data System (ADS)

Krivácsy, Z.; Molnár, Á.

The aim of this paper is to present data about the concentration and size distribution of ions in atmospheric aerosol under slightly polluted urban conditions in Hungary. Concentration of inorganic cations (ammonium, sodium, potassium, calcium, magnesium), inorganic anions (sulfate, nitrate, chloride, carbonate) and organic acids (oxalic, malonic, succinic, formic and acetic acid) for 8 particle size range between 0.0625 and 16 μm were determined. As was the case for ammonium, sulfate and nitrate, the organic acids were mostly found in the fine particle size range. Potassium and chloride were rather uniformly distributed between fine and coarse particles. Sodium, calcium, magnesium and carbonate were practically observed in the coarse mode. The results obtained for the summer and the winter half-year were also compared. The mass concentrations were recalculated in equivalents, and the ion balance was found to be reasonable in most cases. Measurement of the pH of the aerosol extracts indicates that the aerosol is acidic in the fine mode, but alkaline in the coarse particle size range.

Citrate Inhibition-Resistant Form of 6-Phosphofructo-1-Kinase from Aspergillus niger

PubMed Central

Mlakar, Tina; Legiša, Matic

2006-01-01

Two forms of Aspergillus niger 6-phosphofructo-1-kinase (PFK1) have been described recently, the 85-kDa native enzyme and 49-kDa shorter fragment that is formed from the former by posttranslational modification. So far, kinetic characteristics have never been determined on the enzyme purified to near homogeneity. For the first time, kinetic parameters were determined for individual enzymes with respect to citrate inhibition. The native 85-kDa enzyme was found to be moderately inhibited by citrate, with the Ki value determined to be 1.5 mM, in the system with 5 mM Mg2+ ions, while increasing magnesium concentrations relieved the negative effect of citrate. An identical inhibition coefficient was determined also in the presence of ammonium ions, although ammonium acted as a strong activator of enzyme activity. On the other hand, the shorter fragment of PFK1 proved to be completely resistant to inhibition by citrate. Allosteric citrate binding sites were most probably lost after the truncation of the C-terminal part of the native protein, in which region some binding sites for inhibitor are known to be located. At near physiological conditions, characterized by low fructose-6-phosphate concentrations, a much higher efficiency of the shorter fragment was observed during an in vitro experiment. Since the enzyme became more susceptible to the positive control by specific ligands, while the negative control was lost after posttranslational modification, the shorter PFK1 fragment seems to be the enzyme most responsible for generating undisturbed metabolic flow through glycolysis in A. niger cells. PMID:16820438

citrate inhibition-resistant form of 6-phosphofructo-1-kinase from Aspergillus niger.

PubMed

Mlakar, Tina; Legisa, Matic

2006-07-01

Two forms of Aspergillus niger 6-phosphofructo-1-kinase (PFK1) have been described recently, the 85-kDa native enzyme and 49-kDa shorter fragment that is formed from the former by posttranslational modification. So far, kinetic characteristics have never been determined on the enzyme purified to near homogeneity. For the first time, kinetic parameters were determined for individual enzymes with respect to citrate inhibition. The native 85-kDa enzyme was found to be moderately inhibited by citrate, with the Ki value determined to be 1.5 mM, in the system with 5 mM Mg2+ ions, while increasing magnesium concentrations relieved the negative effect of citrate. An identical inhibition coefficient was determined also in the presence of ammonium ions, although ammonium acted as a strong activator of enzyme activity. On the other hand, the shorter fragment of PFK1 proved to be completely resistant to inhibition by citrate. Allosteric citrate binding sites were most probably lost after the truncation of the C-terminal part of the native protein, in which region some binding sites for inhibitor are known to be located. At near physiological conditions, characterized by low fructose-6-phosphate concentrations, a much higher efficiency of the shorter fragment was observed during an in vitro experiment. Since the enzyme became more susceptible to the positive control by specific ligands, while the negative control was lost after posttranslational modification, the shorter PFK1 fragment seems to be the enzyme most responsible for generating undisturbed metabolic flow through glycolysis in A. niger cells.

Effect of microstructure on the zinc phosphate conversion coatings on magnesium alloy AZ91

NASA Astrophysics Data System (ADS)

Van Phuong, Nguyen; Moon, Sungmo; Chang, Doyon; Lee, Kyu Hwan

2013-01-01

The effect of the microstructure, particularly of β-Mg17Al12 phase, on the formation and growth of zinc phosphate conversion coatings on magnesium alloy AZ91 (AZ91) was studied. The zinc phosphate coatings were formed on AZ91 with different microstructures produced by heat treatment. The effect of the microstructure on the zinc phosphate coatings were examined using optical microscope (OM), X-ray diffraction (XRD), coatings weight and etching weight balances, scanning electron microscopy (SEM) and salt immersion test. Results showed that as-cast AZ91 contained a high volume fraction of the β-Mg17Al12 phase and it was dissolved into α-Mg phase during heat treatment at 400 °C. The β-phase became center for hydrogen evolution during phosphating reaction (cathodic sites). The decreased volume fraction of the β-phase caused decreasing both coatings weight and etching weight of the phosphating process. However, it increased the crystal size of the coatings and improved corrosion resistance of AZ91 by immersing in 0.5 M NaCl solution. Results also showed that the structure of the zinc phosphate conversion on AZ91 consisted of two layers: an outer crystal Zn3(PO4)2·4H2O (hopeite) and an inner which was mainly composed of MgZn2(PO4)2 and Mg3(PO4)2. A mechanism for the formation of two layers of the coatings was also proposed in this study.

Augmenting Laboratory Rearing of Stable Fly (Diptera: Muscidae) Larvae With Ammoniacal Salts.

PubMed

Friesen, Kristina; Berkebile, Dennis R; Zhu, Jerry J; Taylor, David B

2017-01-01

Stable flies are blood feeding parasites and serious pests of livestock. The immature stages develop in decaying materials which frequently have high ammonium content. We added various ammonium salts to our laboratory stable fly rearing medium and measured their effect on size and survival as well as the physical properties of the used media. The addition of ammonium hydroxide, ammonium phosphate and ammonium sulfate reduced larval survival. These compounds decreased pH and increased ammonium content of the used media. Ammonium bicarbonate had no effect on pH and marginally increased ammonium while increasing survival twofold. The optimal level of ammonium bicarbonate was 50 g (0.63 mol) per pan. Larval survival decreased when pH was outside the range of 8.5 to 9.0. Published by Oxford University Press on behalf of the Entomological Society of America 2017. This work is written by US Government employees and is in the public domain in the US.

Wastes and by-products - alternatives for agricultural use

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boles, J.L.; Craft, D.J.; Parker, B.R.

1994-10-01

Top address a growing national problem with generation of wastes and by-products, TVA has been involved for several years with developing and commercializing environmentally responsible practices for eliminating, minimizing, or utilizing various wastes/by-products. In many cases, reducing waste generation is impractical, but the wastes/by-products can be converted into other environmentally sound products. In some instances, conversion of safe, value-added agricultural products in the best or only practical alternative. TVA is currently involved with a diversity of projects converting wastes/by-products into safe, economical, and agriculturally beneficial products. Environmental improvement projects have involved poultry litter, cellulosic wastes, used battery acid, ammonium sulfatemore » fines, lead smelting effluents, deep-welled sulfuric acid/ammonium bisulfate solutions, wood ash, waste magnesium ammonium sulfate slurry from recording tape production, and ammunition plant waste sodium nitrate/ammonium nitrate streams.« less

Genetics Home Reference: autosomal dominant hypocalcemia

MedlinePlus

... imbalance of other molecules in the blood as well, including too much phosphate (hyperphosphatemia) or too little magnesium (hypomagnesemia). Some people with autosomal dominant hypocalcemia also ...

Synthesis and Characterization of a Phosphate Prodrug of Isoliquiritigenin.

PubMed

Boyapelly, Kumaraswamy; Bonin, Marc-André; Traboulsi, Hussein; Cloutier, Alexandre; Phaneuf, Samuel C; Fortin, Daniel; Cantin, André M; Richter, Martin V; Marsault, Eric

2017-04-28

Isoliquiritigenin (1) possesses a variety of biological activities in vitro. However, its poor aqueous solubility limits its use for subsequent in vivo experimentation. In order to enable the use of 1 for in vivo studies without the use of toxic carriers or cosolvents, a phosphate prodrug strategy was implemented relying on the availability of phenol groups in the molecule. In this study, a phosphate group was added to position C-4 of 1, leading to the more water-soluble prodrug 2 and its ammonium salt 3, which possesses increased stability compared to 2. Herein are reported the synthesis, characterization, solubility, and stability of phosphate prodrug 3 in biological medium in comparison to 1, as well as new results on its anti-inflammatory properties in vivo. As designed, the solubility of prodrug 3 was superior to that of the parent natural product 1 (9.6 mg/mL as opposed to 3.9 μg/mL). Prodrug 3 as an ammonium salt was also found to possess excellent stability as a solid and in aqueous solution, as opposed to its phosphoric acid precursor 2.

Impact of thiocyanate salts on zein properties

USDA-ARS?s Scientific Manuscript database

A new class of zein plasticizer was investigated, thiocyanate salts. Ammonium (ATC), potassium (KTC), guanidine (GTC) and magnesium thiocyanate (MTC) salts were added to solutions of zein in 90% ethanol/10% water with various amounts of tri(ethylene glycol) (TEG), cast as films and then tested to de...

Effect of heavy metals and water content on the strength of magnesium phosphate cements.

PubMed

Buj, Irene; Torras, Josep; Casellas, Daniel; Rovira, Miquel; de Pablo, Joan

2009-10-15

In this paper the mechanical properties of magnesium potassium phosphate cements used for the Stabilization/Solidification (S/S) of galvanic wastes were investigated. Surrogate wastes (metal nitrate dissolutions) were employed containing Cd, Cr(III), Cu, Ni, Pb or Zn at a concentration of 25 g dm(-3) and different water-to-solid (W/S) ratios (0.3, 0.4, 0.5 and 0.6 dm(3)kg(-1)) have been employed. Cements were prepared by mixing hard burned magnesia of about 70% purity with potassium dihydrogen phosphate. Compressive strength and tensile strength of specimens were determined. In addition the volume of permeable voids was measured. It was found that when comparing pastes that the volume of permeable voids increases and mechanical strength decreases with the increase of water-to-solid ratio (W/S). Nevertheless pastes with the same material proportions containing different metals show different mechanical strength values. The hydration products were analyzed by XRD. With the increase of water content not previously reported hydration compound was detected: bobierrite.

Use of Ferrihydrite-Coated Pozzolana and Biogenic Green Rust to Purify Waste Water Containing Phosphate and Nitrate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ruby, Christian; Naille, Sébastien; Ona-Nguema, Georges

The activated sludge treatments combined to the addition of ferric chloride is commonly used to eliminate nitrate and phosphate from waste water in urban area. These processes that need costly infrastructures are not suitable for rural areas and passive treatments (lagoons, reed bed filters…) are more frequently performed. Reed bed filters are efficient for removing organic matter but are not suitable for treating phosphate and nitrate as well. Passive water treatments using various materials (hydroxyapatite, slag…) were already performed, but those allowing the elimination of both nitrate and phosphate are not actually available. The goal of this work is tomore » identify the most suitable iron based materials for such treatments and to determine their optimal use conditions, in particular in hydrodynamic mode. The reactivity of the iron based minerals was measured either by using free particles in suspension or by depositing these particles on a solid substrate. Pouzzolana that is characterized by a porous sponge-like structure suits for settling a high amount of iron oxides. The experimental conditions enabling to avoid any ammonium formation when green rust encounters nitrate were determined within the framework of a full factorial design. The process is divided into two steps that will be performed inside two separated reactors. Indeed, the presence of phosphate inhibits the reduction of nitrate by green rust and the dephosphatation process must precede the denitrification process. In order to remove phosphate, ferrihydrite coated pouzzolana is the best materials. The kinetics of reaction of green rust with nitrate is relatively slow and often leads to the formation of ammonium. The recommendation of the identified process is to favor the accumulation of nitrite in a first step, these species reacting much more quickly with green rust and do not transform into ammonium.« less

Fire performance and decay resistance of solid wood and plywood treated with quaternary ammonia compounds and common fire retardants

Treesearch

Evren Terzi; S. Nami Kartal; Robert White; Katsumi Shinoda; Yuji Imamura

2010-01-01

In this study, the fire performance and decay resistance of solid wood and plywood treated with quaternary ammonia compounds (didecyl dimethyl ammonium chloride (DDAC) and didecyl dimethyl ammonium tetrafluoroborate (DBF)) were compared with the performance of untreated control specimens and specimens treated with common fire retardants ((monoammonium phosphate (MAP),...

Predicting arsenic bioavailability to hyperaccumulator Pteris vittata in arsenic-contaminated soils.

PubMed

Gonzaga, Maria Isidória Silva; Ma, Lena Q; Pacheco, Edson Patto; dos Santos, Wallace Melo

2012-12-01

Using chemical extraction to evaluate plant arsenic availability in contaminated soils is important to estimate the time frame for site cleanup during phytoremediation. It is also of great value to assess As mobility in soil and its risk in environmental contamination. In this study, four conventional chemical extraction methods (water, ammonium sulfate, ammonium phosphate, and Mehlich III) and a new root-exudate based method were used to evaluate As extractability and to correlate it with As accumulation in P. vittata growing in five As-contaminated soils under greenhouse condition. The relationship between different soil properties, and As extractability and plant As accumulation was also investigated. Arsenic extractability was 4.6%, 7.0%, 18%, 21%, and 46% for water, ammonium sulfate, organic acids, ammonium phosphate, and Mehlich III, respectively. Root exudate (organic acids) solution was suitable for assessing As bioavailability (81%) in the soils while Mehlich III (31%) overestimated the amount of As taken up by plants. Soil organic matter, P and Mg concentrations were positively correlated to plant As accumulation whereas Ca concentration was negatively correlated. Further investigation is needed on the effect of Ca and Mg on As uptake by P. vittata. Moreover, additional As contaminated soils with different properties should be tested.

Dissolved inorganic nitrogen composition, transformation, retention, and transport in naturally phosphate-rich and phosphate-poor tropical streams

USGS Publications Warehouse

Triska, F.J.; Pringle, C.M.; Zellweger, G.W.; Duff, J.H.; Avanzino, R.J.

1993-01-01

In Costa Rica, the Salto River is enriched by geothermal-based soluble reactive phosphorus (SRP), which raises the concentration up to 200 ??g/L whereas Pantano Creek, an unimpacted tributary, has an SRP concentration <10 ??g/L. Ammonium concentration in springs adjacent to the Salto and Pantano was typically greater than channel water (13 of 22 locations) whereas nitrate concentration was less (20 of 22 locations). Ground waters were typically high in ammonium relative to nitrate whereas channel waters were high in nitrate relative to ammonium. Sediment slurry studies indicated nitrification potential in two sediment types, firm clay (3.34 ??g N.cm-3.d-1) and uncompacted organic-rich sediment (1.76 ??g N.cm-3.d-1). Ammonium and nitrate amendments to each stream separately resulted in nitrate concentrations in excess of that expected after correlation for dilution using a conservative tracer. SRP concentration was not affected by DIN amendment to either stream. SRP concentration in the Pantano appeared to be regulated by abiotic sediment exchange reactions. DIN composition and concentration were regulated by a combination of biotic and abiotic processes. -from Authors

Biochar can be used to capture essential nutrients from dairy wastewater and improve soil physico-chemical properties

NASA Astrophysics Data System (ADS)

Ghezzehei, T. A.; Sarkhot, D. V.; Berhe, A. A.

2014-09-01

Recently, the potential for biochar use to recapture excess nutrients from dairy wastewater has been a focus of a growing number of studies. It is suggested that biochar produced from locally available excess biomass can be important in reducing release of excess nutrient elements from agricultural runoff, improving soil productivity, and long-term carbon (C) sequestration. Here we present a review of a new approach that is showing promise for the use of biochar for nutrient capture. Using batch sorption experiments, it has been shown that biochar can adsorb up to 20-43% of ammonium and 19-65% of the phosphate in flushed dairy manure in 24 h. These results suggest a potential of biochar for recovering essential nutrients from dairy wastewater and improving soil fertility if the enriched biochar is returned to soil. Based on the sorption capacity of 2.86 and 0.23 mg ammonium and phosphate, respectively, per gram of biochar and 10-50% utilization of available excess biomass, in the state of California (US) alone, 11 440 to 57 200 tonnes of ammonium-N and 920-4600 tonnes of phosphate can be captured from dairy waste each year while at the same time disposing up to 8-40 million tons of excess biomass.

Biochar can be used to recapture essential nutrients from dairy wastewater and improve soil quality

NASA Astrophysics Data System (ADS)

Ghezzehei, T. A.; Sarkhot, D. V.; Berhe, A. A.

2014-04-01

Recently, the potential for biochar use to recapture excess nutrients from dairy wastewater has been a focus of a growing number of studies. It is suggested that biochar produced from locally available waste biomass can be important in reducing release of excess nutrient elements from agricultural runoff, improving soil productivity, and long-term carbon (C) sequestration. Here we present a review of a new approach that is showing promise for the use of biochar for nutrient capture. Using batch sorption experiments, it has been shown that biochar can adsorb up to 20 to 43% of ammonium and 19-65% of the phosphate in flushed dairy manure in 24 h. These results suggest a potential of biochar for recovering essential nutrients from dairy wastewater and improving soil fertility if the enriched biochar is returned to soil. Based on the sorption capacity of 2.86 and 0.23 mg ammonium and phosphate, respectively, per gram of biochar and 10-50% utilization of available excess biomass, in the state of California (US) alone, 11 440 to 57 200 t of ammonium-N and 920-4600 t of phosphate can be captured from dairy waste each year while at the same time disposing up to 8-40 million tons of waste biomass.

Nitrogen and phosphorus uptake rates of different species from a coral reef community after a nutrient pulse

PubMed Central

den Haan, Joost; Huisman, Jef; Brocke, Hannah J.; Goehlich, Henry; Latijnhouwers, Kelly R. W.; van Heeringen, Seth; Honcoop, Saskia A. S.; Bleyenberg, Tanja E.; Schouten, Stefan; Cerli, Chiara; Hoitinga, Leo; Vermeij, Mark J. A.; Visser, Petra M.

2016-01-01

Terrestrial runoff after heavy rainfall can increase nutrient concentrations in waters overlying coral reefs that otherwise experience low nutrient levels. Field measurements during a runoff event showed a sharp increase in nitrate (75-fold), phosphate (31-fold) and ammonium concentrations (3-fold) in waters overlying a fringing reef at the island of Curaçao (Southern Caribbean). To understand how benthic reef organisms make use of such nutrient pulses, we determined ammonium, nitrate and phosphate uptake rates for one abundant coral species, turf algae, six macroalgal and two benthic cyanobacterial species in a series of laboratory experiments. Nutrient uptake rates differed among benthic functional groups. The filamentous macroalga Cladophora spp., turf algae and the benthic cyanobacterium Lyngbya majuscula had the highest uptake rates per unit biomass, whereas the coral Madracis mirabilis had the lowest. Combining nutrient uptake rates with the standing biomass of each functional group on the reef, we estimated that the ammonium and phosphate delivered during runoff events is mostly taken up by turf algae and the two macroalgae Lobophora variegata and Dictyota pulchella. Our results support the often proposed, but rarely tested, assumption that turf algae and opportunistic macroalgae primarily benefit from episodic inputs of nutrients to coral reefs. PMID:27353576

Nitrogen and phosphorus uptake rates of different species from a coral reef community after a nutrient pulse

NASA Astrophysics Data System (ADS)

den Haan, Joost; Huisman, Jef; Brocke, Hannah J.; Goehlich, Henry; Latijnhouwers, Kelly R. W.; van Heeringen, Seth; Honcoop, Saskia A. S.; Bleyenberg, Tanja E.; Schouten, Stefan; Cerli, Chiara; Hoitinga, Leo; Vermeij, Mark J. A.; Visser, Petra M.

2016-06-01

Terrestrial runoff after heavy rainfall can increase nutrient concentrations in waters overlying coral reefs that otherwise experience low nutrient levels. Field measurements during a runoff event showed a sharp increase in nitrate (75-fold), phosphate (31-fold) and ammonium concentrations (3-fold) in waters overlying a fringing reef at the island of Curaçao (Southern Caribbean). To understand how benthic reef organisms make use of such nutrient pulses, we determined ammonium, nitrate and phosphate uptake rates for one abundant coral species, turf algae, six macroalgal and two benthic cyanobacterial species in a series of laboratory experiments. Nutrient uptake rates differed among benthic functional groups. The filamentous macroalga Cladophora spp., turf algae and the benthic cyanobacterium Lyngbya majuscula had the highest uptake rates per unit biomass, whereas the coral Madracis mirabilis had the lowest. Combining nutrient uptake rates with the standing biomass of each functional group on the reef, we estimated that the ammonium and phosphate delivered during runoff events is mostly taken up by turf algae and the two macroalgae Lobophora variegata and Dictyota pulchella. Our results support the often proposed, but rarely tested, assumption that turf algae and opportunistic macroalgae primarily benefit from episodic inputs of nutrients to coral reefs.

Nitrogen and phosphorus uptake rates of different species from a coral reef community after a nutrient pulse.

PubMed

den Haan, Joost; Huisman, Jef; Brocke, Hannah J; Goehlich, Henry; Latijnhouwers, Kelly R W; van Heeringen, Seth; Honcoop, Saskia A S; Bleyenberg, Tanja E; Schouten, Stefan; Cerli, Chiara; Hoitinga, Leo; Vermeij, Mark J A; Visser, Petra M

2016-06-29

Terrestrial runoff after heavy rainfall can increase nutrient concentrations in waters overlying coral reefs that otherwise experience low nutrient levels. Field measurements during a runoff event showed a sharp increase in nitrate (75-fold), phosphate (31-fold) and ammonium concentrations (3-fold) in waters overlying a fringing reef at the island of Curaçao (Southern Caribbean). To understand how benthic reef organisms make use of such nutrient pulses, we determined ammonium, nitrate and phosphate uptake rates for one abundant coral species, turf algae, six macroalgal and two benthic cyanobacterial species in a series of laboratory experiments. Nutrient uptake rates differed among benthic functional groups. The filamentous macroalga Cladophora spp., turf algae and the benthic cyanobacterium Lyngbya majuscula had the highest uptake rates per unit biomass, whereas the coral Madracis mirabilis had the lowest. Combining nutrient uptake rates with the standing biomass of each functional group on the reef, we estimated that the ammonium and phosphate delivered during runoff events is mostly taken up by turf algae and the two macroalgae Lobophora variegata and Dictyota pulchella. Our results support the often proposed, but rarely tested, assumption that turf algae and opportunistic macroalgae primarily benefit from episodic inputs of nutrients to coral reefs.

Microdetermination of calcium and magnesium in biological materials

PubMed Central

Bowden, C. H.; Patston, Valerie J.

1963-01-01

The use of the dye calcon (1-(2 hydroxy-1-naphthylazo)-2-naphthol-4 sulphonic acid) for the estimation of calcium using E.D.T.A. and a commercial photoelectric titrimeter is described. The interfering effects of magnesium and phosphate have been overcome. The method has been extended to estimations on biological materials. Results on 55 sera show that the E.D.T.A./calcon method gave slightly lower results (—0·15 mg./100 ml. ± 0·029) than the oxalate precipitation method. Magnesium may also be estimated by incorporating the use of Eriochrome black T. PMID:14014590

Potentiostatic pulse-deposition of calcium phosphate on magnesium alloy for temporary implant applications--an in vitro corrosion study.

PubMed

Kannan, M Bobby; Wallipa, O

2013-03-01

In this study, a magnesium alloy (AZ91) was coated with calcium phosphate using potentiostatic pulse-potential and constant-potential methods and the in vitro corrosion behaviour of the coated samples was compared with the bare metal. In vitro corrosion studies were carried out using electrochemical impedance spectroscopy and potentiodynamic polarization in simulated body fluid (SBF) at 37 °C. Calcium phosphate coatings enhanced the corrosion resistance of the alloy, however, the pulse-potential coating performed better than the constant-potential coating. The pulse-potential coating exhibited ~3 times higher polarization resistance than that of the constant-potential coating. The corrosion current density obtained from the potentiodynamic polarization curves was significantly less (~60%) for the pulse-deposition coating as compared to the constant-potential coating. Post-corrosion analysis revealed only slight corrosion on the pulse-potential coating, whereas the constant-potential coating exhibited a large number of corrosion particles attached to the coating. The better in vitro corrosion performance of the pulse-potential coating can be attributed to the closely packed calcium phosphate particles. Copyright © 2012 Elsevier B.V. All rights reserved.

A segmental chronic pain syndrome in rats associated with intrathecal infusion of NMDA: evidence for selective action in the dorsal horn.

PubMed

Zochodne, D W; Murray, M; Nag, S; Riopelle, R J

1994-02-01

We explored the effects of chronic lumbar intrathecal NMDA infusion (mini-osmotic pumps) in Sprague-Dawley rats on motor and sensory axon integrity. Several different infusion protocols, each given over a 4 week period were examined: 0.15 M NMDA in phosphate buffered saline; phosphate buffered saline without NMDA; and 0.20 M magnesium sulfate plus 0.15 M NMDA; 0.35 M NMDA. In two additional protocols, 0.15 M NMDA or phosphate buffered saline were infused for a total of 8 weeks. Within 1-2 weeks of the onset of NMDA, but not phosphate buffered saline infusions, the rats exhibited irritability, circling, biting and excessive grooming resulting in loss of hair, and skin ulcerations from autotomy localized to lumbar and sacral innervated dermatomes. Co-infusion of NMDA with magnesium sulfate almost completely prevented these findings. The behavioural changes were not associated with abnormalities of sensory or motor conduction. Intrathecal infusion of NMDA induces a chronic "central" experimental pain disorder in rats, localized to the cord segment with the greatest exposure to the infusion, without involvement of peripheral sensory axons and sparing the axonal integrity of anterior horn cells.

The Biocompatibility of Degradable Magnesium Interference Screws: An Experimental Study with Sheep

PubMed Central

Thormann, Ulrich; Alt, Volker; Heimann, Lydia; Gasquere, Cyrille; Heiss, Christian; Szalay, Gabor; Franke, Jörg; Schnettler, Reinhard; Lips, Katrin Susanne

2015-01-01

Screws for ligament reconstruction are nowadays mostly made of poly-L-lactide (PLLA). However, magnesium-based biomaterials are gathering increased interest in this research field because of their good mechanical property and osteoanabolic influence on bone metabolism. The aim of this pilot study was to evaluate the biocompatibility of an interference screw for ligament reconstruction made of magnesium alloy W4 by diecasting and milling and using different PEO-coatings with calcium phosphates. PLLA and titanium screws were used as control samples. The screws were implanted in the femur condyle of the hind leg of a merino sheep. The observation period was six and twelve weeks and one year. Histomorphometric, immunohistochemical, immunofluorescence, and molecular biological evaluation were conducted. Further TEM analysis was done. In all magnesium screws a clinically relevant gas formation in the vicinity of the biomaterial was observed. Except for the PLLA and titanium control samples, no screw was fully integrated in the surrounding bone tissue. Regarding the fabrication process, milling seems to produce less gas liberation and has a better influence on bone metabolism than diecasting. Coating by PEO with calcium phosphates could not reduce the initial gas liberation but rather reduced the bone metabolism in the vicinity of the biomaterial. PMID:25717474

Precipitation and streamwater chemistry in an undisturbed watershed in southeast Alaska.

Treesearch

John D. Stednick

1981-01-01

Water chemistry samples have been taken from streamflow since 1976 and precipitation since 1978 in Indian River, an undisturbed watershed on Chichagof Island in Southeast Alaska. Volume weighted concentrations of total nitrogen, ammonium nitrogen, nitrate nitrogen, total phosphorus, orthophosphate, sulfate sulfur, chloride, bicarbonate, silica, calcium, magnesium,...

LOW-LEVEL DETERMINATION OF PERCHLORATE IN DRINKING WATER USING ION CHROMATOGRAPHY MASS SPECTROMETRY

EPA Science Inventory

Perchlorate is a drinking water contaminant originating from the dissolution of the salts of ammonium, potassium, magnesium, or sodium in water. It is used primarily as an oxidant in solid propellant for rockets, missiles, pyrotechnics, as a component in air bag inflators, and i...

Effect of sintering conditions on the microstructural and mechanical characteristics of porous magnesium materials prepared by powder metallurgy.

PubMed

Čapek, Jaroslav; Vojtěch, Dalibor

2014-02-01

There has recently been an increased demand for porous magnesium materials in many applications, especially in the medical field. Powder metallurgy appears to be a promising approach for the preparation of such materials. Many works have dealt with the preparation of porous magnesium; however, the effect of sintering conditions on material properties has rarely been investigated. In this work, we investigated porous magnesium samples that were prepared by powder metallurgy using ammonium bicarbonate spacer particles. The effects of the purity of the argon atmosphere and sintering time on the microstructure (SEM, EDX and XRD) and mechanical behaviour (universal loading machine and Vickers hardness tester) of porous magnesium were studied. The porosities of the prepared samples ranged from 24 to 29 vol.% depending on the sintering conditions. The purity of atmosphere played a significant role when the sintering time exceeded 6h. Under a gettered argon atmosphere, a prolonged sintering time enhanced diffusion connections between magnesium particles and improved the mechanical properties of the samples, whereas under a technical argon atmosphere, oxidation at the particle surfaces caused deterioration in the mechanical properties of the samples. These results suggest that a refined atmosphere is required to improve the mechanical properties of porous magnesium. © 2013.

Magnesium prevents phosphate-induced calcification in human aortic vascular smooth muscle cells.

PubMed

Louvet, Loïc; Büchel, Janine; Steppan, Sonja; Passlick-Deetjen, Jutta; Massy, Ziad A

2013-04-01

Vascular calcification (VC) is prevalent in patients suffering from chronic kidney disease. Factors promoting calcification include abnormalities in mineral metabolism, particularly high phosphate levels. Inorganic phosphate (Pi) is a classical inducer of in vitro VC. Recently, an inverse relationship between serum magnesium concentrations and VC has been reported. The present study aimed to investigate the effects of magnesium on Pi-induced VC at the cellular level using primary HAVSMC. Alive and fixed HAVSMC were assessed during 14 days in the presence of Pi with increasing concentrations of magnesium (Mg(2+)) chloride. Mineralization was measured using quantification of calcium, von Kossa and alizarin red stainings. Cell viability and secretion of classical VC markers were also assessed using adequate tests. Involvement of transient receptor potential melastatin (TRPM) 7 was assessed using 2-aminoethoxy-diphenylborate (2-APB) inhibitor. Co-incubation with Mg(2+) significantly decreased Pi-induced VC in live HAVSMC, no effect was found in fixed cells. At potent concentrations in Pi-induced HAVSMC, Mg(2+) significantly improved cell viability and restored to basal level increased secretions of osteocalcin and matrix gla protein, whereas a decrease in osteopontin secretion was partially restored. The block of TRPM7 with 2-APB at 10(-4) M led to the inefficiency of Mg(2+) to prevent VC. Increasing Mg(2+) concentrations significantly reduced VC, improved cell viability and modulated secretion of VC markers during cell-mediated matrix mineralization clearly pointing to a cellular role for Mg(2+) and 2-APB further involved TRPM7 and a potential Mg(2+) entry to exert its effects. Further investigations are needed to shed light on additional cellular mechanism(s) by which Mg(2+) is able to prevent VC.

An extended chemical analysis of gallstone.

PubMed

Chandran, P; Kuchhal, N K; Garg, P; Pundir, C S

2007-09-01

Chemical composition of gall stones is essential for aetiopathogensis of gallstone disease. We have reported quantitative chemical analysis of total cholesterol bilirubin, calcium, iron and inorganic phosphate in 120 gallstones from haryana. To extend this chemical analysis of gall stones by studying more cases and by analyzing more chemical constituents. A quantitative chemical analysis of total cholesterol, total bilirubin, fatty acids, triglycerides, phospholipids, bile acids, soluble proteins, sodium potassium, magnesium, copper, oxalate and chlorides of biliary calculi (52 cholesterol, 76 mixed and 72 pigment) retrieved from surgical operation of 200 patients from Haryana state was carried out. Total cholesterol as the major component and total bilirubin, phospholipids, triglycerides, bile acids, fatty acids (esterified), soluble protein, calcium, magnesium, iron, copper, sodium, potassium, inorganic phosphate, oxalate and chloride as minor components were found in all types of calculi. The cholesterol stones had higher content of total cholesterol, phospholipids, fatty acids (esterified), inorganic phosphate and copper compared to mixed and pigment stones. The mixed stones had higher content of iron and triglycerides than to cholesterol and pigment stones. The pigment stones were richer in total bilirubin, bile acids, calcium, oxalate, magnesium, sodium, potassium, chloride and soluble protein compared to cholesterol and mixed stones. Although total cholesterol was a major component of cholesterol, mixed and pigment gall stone in Haryana, the content of most of the other lipids, cations and anions was different in different gall stones indicating their different mechanism of formation.

Should acidification of urine be performed before the analysis of calcium, phosphate and magnesium in the presence of crystals?

PubMed

Pratumvinit, Busadee; Reesukumal, Kanit; Wongkrajang, Preechaya; Khejonnit, Varanya; Klinbua, Cherdsak; Dangneawnoi, Weerapol

2013-11-15

Acidification of urine has been recommended before testing for calcium, phosphate, and magnesium. We investigated the necessity of pre-analytical acidification in both crystallized and non-crystallized urine samples. From 130 urine samples obtained via routine urine analysis, 65 (50%) samples were classified as non-crystallized. All samples were divided into three groups: untreated samples, acidified samples with HCl, and acidified samples after 1h room-temperature incubation. Urine samples were measured for calcium, phosphate, magnesium, and creatinine using Modular P800 and were examined for crystals using light microscopy. In crystallized samples, acidified samples with 1h incubation had significantly higher Ca/Cr, P/Cr, and Mg/Cr than did untreated samples with mean differences of 0.04, 0.03, and 0.01 mg/mg, respectively (P<0.001). In acidified samples that were analyzed immediately, crystallized samples had lower calcium concentrations than those of acidified samples with 1h incubation and a mean difference of 0.21 mg/dl (P = 0.025). None of the sample differences which exceeded the critical difference of urinary Ca, P and Mg was observed. Acidification of urine should be performed before the measurement of Ca, P, and Mg in the presence of urinary crystals. However, the lack of an acidification process does not result in a clinically significant change. © 2013.

On the mineral characteristics and geochemistry of the Florida phosphate of Four Corners and Hardee County mines

NASA Astrophysics Data System (ADS)

Baghdady, Ashraf R.; Howari, Fares M.; Al-Wakeel, Mohamed I.

2016-08-01

The Florida phosphate deposits in Four Corners and Hardee County mines are composed mainly of phosphate minerals and quartz in addition to subordinate proportions of feldspars, dolomite, calcite, gypsum, kaolinite, attapulgite and montmorillonite. These phosphorites contain three structurally different types of mudclasts: massive mudclasts, mudclasts with concentric structure and mudclasts consisting of agglomerates of apatite microparticles. The latter are represented by particles resembling phosphatized fossil bacteria associated with microbial filaments, and hollow apatite particles having surfacial coatings and connected to microbial filaments. The Florida phosphate particles are reworked and vary in mineral composition, color and shape. They are composed of a mixture of well-crystalline species including carbonate fluorapatite (francolite), carbonate apatite and fluorapatite. The color variation of the phosphate particles is related to difference in mineral composition, extent of diagenetic effects and reworking. The light-colored mudclasts are characterized by the presence of carbonate apatite and aluminum hydroxide phosphate minerals, whereas the dark mudclasts are rich in iron aluminum hydroxide phosphate minerals. The Florida phosphorites are suggested to be formed partially by authigenetic precipitation, replacement of the sea floor carbonate and diatomite, and microbial processes. With respect to elemental geochemistry, the analyzed particles contain small percentages of sulfur and iron which are related to the occurrence of pyrite. Traces of silica and alumina are recorded which may be attributed to the diagenetic. Some of the tested particles are relatively rich in phosphorous, fluorine, calcium, and magnesium, while poor in silicon, potassium and sulfur. Whereas, the bioclasts (especially teeth) are relatively rich in calcium, phosphorous and fluorine while poor in silicon, aluminum, magnesium and potassium. Hence, the microchemical analyses revealed that differential diagenesis affected mudclasts more than bioclasts. There is a complete compositional gradation between clay and phosphate particles which reflects their interaction. This involved kaolinitization of the phosphate particles, phosphatization of the clay mineral particles and production of silica.

Microwave assisted preparation of magnesium phosphate cement (MPC) for orthopedic applications: a novel solution to the exothermicity problem.

PubMed

Zhou, Huan; Agarwal, Anand K; Goel, Vijay K; Bhaduri, Sarit B

2013-10-01

There are two interesting features of this paper. First, we report herein a novel microwave assisted technique to prepare phosphate based orthopedic cements, which do not generate any exothermicity during setting. The exothermic reactions during the setting of phosphate cements can cause tissue damage during the administration of injectable compositions and hence a solution to the problem is sought via microwave processing. This solution through microwave exposure is based on a phenomenon that microwave irradiation can remove all water molecules from the alkaline earth phosphate cement paste to temporarily stop the setting reaction while preserving the active precursor phase in the formulation. The setting reaction can be initiated a second time by adding aqueous medium, but without any exothermicity. Second, a special emphasis is placed on using this technique to synthesize magnesium phosphate cements for orthopedic applications with their enhanced mechanical properties and possible uses as drug and protein delivery vehicles. The as-synthesized cements were evaluated for the occurrences of exothermic reactions, setting times, presence of Mg-phosphate phases, compressive strength levels, microstructural features before and after soaking in (simulated body fluid) SBF, and in vitro cytocompatibility responses. The major results show that exposure to microwaves solves the exothermicity problem, while simultaneously improving the mechanical performance of hardened cements and reducing the setting times. As expected, the cements are also found to be cytocompatible. Finally, it is observed that this process can be applied to calcium phosphate cements system (CPCs) as well. Based on the results, this microwave exposure provides a novel technique for the processing of injectable phosphate bone cement compositions. © 2013.

Evolution of the magnesium incorporated amorphous calcium phosphate to nano-crystallized hydroxyapatite in alkaline solution

NASA Astrophysics Data System (ADS)

Zhang, Xiao-Juan; Lin, Dong-Yang; Yan, Xiao-Hui; Wang, Xiao-Xiang

2011-12-01

A homogeneous amorphous calcium phosphate (ACP) coating containing magnesium was achieved on titanium substrates by electrochemical deposition (ECD). Its amorphous structure is confirmed by transmission electron microscope (TEM) together with grazing reflection absorption infrared spectroscopy (IR) spectrometer. In the images of high-resolution transmission electron microscope (HRTEM), the ACP spheres are assembled by nano-particles with the diameter of 5-10 nm. In the alkaline environment, nucleation of hydroxyapatite (HAP) occurs on the surfaces of ACP spheres. By consuming the Ca and PO 4 ions inside the ACP spheres, the HAP nuclei grow outward. Confirmed by TEM, the ACP spheres converse to hollow HAP spheres composed of HAP nano-needles. The coating is finally constructed by the HAP nano-needles, which are themselves aggregated by numerous nano-particles.

Evaluation of the Properties Magnesium Phosphate Cement with Emulsified Asphalt

NASA Astrophysics Data System (ADS)

Du, Jia-Chong; Shen, Ruei-Siang; Zhou, Yu-Zhun

2017-10-01

Three type mixtures of magnesium phosphate cement with emulsified asphalt for evaluation their properties. The mixtures of the samples were fabricated and allowed them 2 hours, seven and twenty eight days curing before tested by compressive strength, Marshall stability and indirect tensile strength to probe into their engineering properties. The test results show that all tests have the greatest values at the 28 days curing and too much asphalt emulsion may cause too soft as result of low stability. The compressive strength of Type-III mixture has the greatest value, no matter what curing time is. The Marshall stability test and indirect tensile strength of the Type-III mixture are qualified by the specification required for fast maintenance. The more asphalt emulsion added, the less compressive strength has.

Effects of near-bottom water oxygen concentration on biogeochemical cycling of C, N and S in sediments of the Gulf of Gdansk (southern Baltic)

NASA Astrophysics Data System (ADS)

Lukawska-Matuszewska, Katarzyna; Kielczewska, Joanna

2016-04-01

Sediments from four sampling sites in the Gulf of Gdansk were sampled to test how different oxygen concentrations in near-bottom water affects biogeochemical cycling of C, N and S. Vertical distributions of content of organic carbon (OC), total nitrogen (TN) and total sulfur (TS) and number of sulfate-reducing bacteria (SRB) in sediments were determined. Pore water total alkalinity (TA), dissolved inorganic carbon (DIC), sulfate, hydrogen sulfide, ammonium and phosphate were analyzed and benthic fluxes of DIC, hydrogen sulfide and ammonium were calculated. Concentrations of OC and TN decreased and concentration of TS increased with sediment depth. Highest concentrations of OC, TN and TS were observed in silty clay sediments from hypoxic and anoxic sediments below the permanent halocline. Organic matter (OM) accumulation in sediments and oxygen deficiency in near-bottom water stimulate preservation of OC and burial of TS in this area. Concentrations of TA, DIC, hydrogen sulfide, ammonium and phosphate in pore water increased, while concentration of sulfate decreased with sediment depth. Hydrogen sulfide, ammonium and phosphate was a significant additional source of TA in pore water under hypoxic and anoxic conditions. Mineralization of OM at oxygen concentrations <2 ml l-1 occurred mainly via bacterial sulfate reduction. Diurnal hydrogen sulfide fluxes under hypoxic conditions ranged from 400 to 1240 μmol m-2 d-1. Ammonium fluxes were estimated on 534 - 924 μmol m-2 d-1. Corresponding fluxes measured under anoxic conditions were 266 μmol m-2 d-1 and 106 μmol m-2 d-1. Sediments under oxic conditions became a place of the intensive regeneration of carbon - DIC flux from sediment reached 2775 μmol m-2 day-1. Sediment-water DIC fluxes under hypoxic and anoxic conditions were much lower and ranged from 1015 to 1208 μmol m-2 d-1.

Iron-Magnesium Hydroxycarbonate (Fermagate): A Novel Non-Calcium-Containing Phosphate Binder for the Treatment of Hyperphosphatemia in Chronic Hemodialysis Patients

PubMed Central

McIntyre, Christopher W.; Pai, Pearl; Warwick, Graham; Wilkie, Martin; Toft, Alex J.; Hutchison, Alastair J.

2009-01-01

Background and objectives: This phase II study tested the safety and efficacy of fermagate, a calcium-free iron and magnesium hydroxycarbonate binder, for treating hyperphosphatemia in hemodialysis patients. Design, setting, participants, & measurements: A randomized, double-blind, three-arm, parallel-group study compared two doses of fermagate (1 g three times daily or 2 g three times daily with placebo). Sixty-three patients who had been on a stable hemodialysis regimen for ≥3 mo were randomized to the treatment phase. Study medication was administered three times daily just before meals for 21 d. The primary endpoint was reduction in serum phosphate over this period. Results: In the intention-to-treat analysis, mean baseline serum phosphate was 2.16 mmol/L. The fermagate 1- and 2-g three-times-daily treatment arms were associated with statistical reductions in mean serum phosphate to 1.71 and 1.47 mmol/L, respectively. Adverse event (AE) incidence in the 1-g fermagate arm was statistically comparable to the placebo group. The 2-g arm was associated with a statistically higher number of patients reporting AEs than the 1-g arm, particularly gastrointestinal AEs, as well as a higher number of discontinuations, complicating interpretation of this dose's efficacy. Both doses were associated with elevations of prehemodialysis serum magnesium levels. Conclusions: The efficacy and tolerability of fermagate were dose dependent. Fermagate showed promising efficacy in the treatment of hyperphosphatemia in chronic hemodialysis patients as compared with placebo in this initial phase II study. The optimal balance between efficacy and tolerability needs to be determined from future dose-titration studies, or fixed-dose comparisons of more doses. PMID:19158369

Synthesis, characterization, and in-vitro cytocompatibility of amorphous β-tri-calcium magnesium phosphate ceramics.

PubMed

Singh, Satish S; Roy, Abhijit; Lee, Boeun; Banerjee, Ipsita; Kumta, Prashant N

2016-10-01

Biphasic mixtures of crystalline β-tricalcium magnesium phosphate (β-TCMP) and an amorphous calcium magnesium phosphate have been synthesized and reported to support enhanced hMSC differentiation in comparison to β-tricalcium phosphate (β-TCP) due to the release of increased amounts of bioactive ions. In the current study, completely amorphous β-TCMP has been synthesized which is capable of releasing increased amounts of Mg(2+) and PO4(3-) ions, rather than a biphasic mixture as earlier reported. The amorphous phase formed was observed to crystallize between temperatures of 400-600°C. The scaffolds prepared with amorphous β-TCMP were capable of supporting enhanced hMSC proliferation and differentiation in comparison to commercially available β-TCP. However, a similar gene expression of mature osteoblast markers, OCN and COL-1, in comparison to biphasic β-TCMP was observed. To further study the role of Mg(2+) and PO4(3-) ions in regulating hMSC osteogenic differentiation, the capability of hMSCs to mineralize in growth media supplemented with Mg(2+) and PO4(3-) ions was studied. Interestingly, 5mM PO4(3-) supported mineralization while the addition of 5mM Mg(2+) to 5mM PO4(3-) inhibited mineralization. It was therefore concluded that the release of Ca(2+) ions from β-TCMP scaffolds also plays a role in regulating osteogenic differentiation on these scaffolds and it is noted that further work is required to more accurately determine the exact role of Mg(2+) in regulating hMSC osteogenic differentiation. Copyright © 2016 Elsevier B.V. All rights reserved.

METHOD FOR REMOVING CONTAMINATION FROM PRECIPITATES

DOEpatents

Stahl, G.W.

1959-01-01

An improvement in the bismuth phosphate carrier precipitation process is presented for the recovery and purification of plutonium. When plutonium, in the tetravalent state, is carried on a bismuth phosphate precipitate, amounts of centain of the fission products are carried along with the plutonium. The improvement consists in washing such fission product contaminated preeipitates with an aqueous solution of ammonium hydrogen fluoride. since this solution has been found to be uniquely effective in washing fission production contamination from the bismuth phosphate precipitate.

Interaction between vitamin B6 metabolism, nitrogen metabolism and autoimmunity.

PubMed

Colinas, Maite; Fitzpatrick, Teresa B

2016-01-01

The essential micronutrient vitamin B6 is best known in its enzymatic cofactor form, pyridoxal 5'-phosphate (PLP). However, vitamin B6 comprises the amine pyridoxamine 5'-phosphate (PMP) and the alcohol pyridoxine 5'-phosphate (PNP) in addition to PLP, as well as their corresponding non-phosphorylated forms. The different B6 forms (called vitamers) are enzymatically interconverted in a ubiquitous salvage pathway. Recently, we have shown that balancing the ratio of the different B6 vitamers in particular PMP by the PMP/PNP oxidase PDX3 is essential for growth and development in Arabidopsis thaliana. Intriguingly, nitrate to ammonium conversion is impaired in pdx3 mutants, such that the mutants become ammonium-dependent, suggesting an interaction between vitamin B6 and nitrogen metabolism. In addition, we found a strong up-regulation of genes related to plant defense. Here, we further show that pdx3 mutants display a temperature-sensitive phenotype that is typical of autoimmune mutants and is possibly connected to the impaired nitrogen metabolism.

Atmospheric deposition in coniferous and deciduous tree stands in Poland

NASA Astrophysics Data System (ADS)

Kowalska, Anna; Astel, Aleksander; Boczoń, Andrzej; Polkowska, Żaneta

2016-05-01

The objective of this study was to assess the transformation of precipitation in terms of quantity and chemical composition following contact with the crown layer in tree stands with varied species composition, to investigate the effect of four predominant forest-forming species (pine, spruce, beech, and oak) on the amount and composition of precipitation reaching forest soils, and to determine the sources of pollution in atmospheric precipitation in forest areas in Poland. The amount and chemical composition (pH, electric conductivity, alkalinity, and chloride, nitrate, sulfate, phosphate, ammonium, calcium, magnesium, sodium, potassium, iron aluminum, manganese, zinc, copper, total nitrogen, and dissolved organic carbon contents) of atmospheric (bulk, BP) and throughfall (TF) precipitation were studied from January to December 2010 on twelve forest monitoring plots representative of Polish conditions. The study results provided the basis for the determination of the fluxes of pollutants in the forest areas of Poland and allowed the comparison of such fluxes with values provided in the literature for European forest areas. The transformation of precipitation in the canopy was compared for different tree stands. The fluxes of substances in an open field and under canopy were influenced by the location of the plot, including the regional meteorological conditions (precipitation amounts), vicinity of the sea (effect of marine aerosols), and local level of anthropogenic pollution. Differences between the plots were higher in TF than in BP. The impact of the vegetation cover on the chemical composition of precipitation depended on the region of the country and dominant species in a given tree stand. Coniferous species tended to cause acidification of precipitation, whereas deciduous species increased the pH of TF. Pine and oak stands enriched precipitation with components that leached from the canopy (potassium, manganese, magnesium) to a higher degree than spruce and beech stands.

MEASUREMENT OF PERCHLORATE IN WATER USING AN OXYGEN-18 ENRICHED ISOTOPE STANDARD AND ION CHROMATOGRAPHY MASS SPECTROMETRIC DETECTION

EPA Science Inventory

Perchlorate (ClO4 -) is a drinking water contaminant originating from the dissolution of the salts of ammonium, potassium, magnesium, or sodium in water. It is used primarily as an oxidant in solid propellant for rockets, missiles, pyrotechnics, as a component in air bag infla...

PERCHLORATE ENVIRONMENTAL CONTAMINATION: TOXICOLOGICAL REVIEW AND RISK CHARACTERIZATION BASED ON EMERGING INFORMATION (EXTERNAL REVIEW DRAFT) 1998

EPA Science Inventory

Perchlorate (ClO4-) is an anion that originates as a contaminant in ground water and surface waters from the dissolution of ammonium, potassium, magnesium, or sodium salts. Because perchlorate is nonlabile kinetically (i.e., the reduction of the central chlorine atom occurs extre...

Clearcutting affects stream chemistry in the White Mountains of New Hampshire

Treesearch

C. Wayne Martin; Robert S. Pierce; Gene E. Likens; F. Herbert Bormann; F. Herbert Bormann

1986-01-01

Commercial clearcutting of northern hardwood forests changed the chemistry of the streams that drained from them. By the second year after cutting, specific conductance doubled, nitrate increased tenfold, calcium tripled, and sodium, magnesium, and potassium doubled. Chloride and ammonium did not change; sulfate decreased. Concentrations of most ions returned to...

Crystallization of Chicken Egg White Lysozyme from Assorted Sulfate Salts

NASA Technical Reports Server (NTRS)

Forsythe, Elizabeth L.; Snell, Edward H.; Malone, Christine C.; Pusey, Marc L.

1998-01-01

Chicken egg white lysozyme has been found to crystallize from ammonium, sodium, potassium, rubidium, magnesium, and manganese sulfates at acidic and basic pH, with protein concentrations from 60 to 190 mg/ml. Four different crystal morphologies have been obtained, depending upon the temperature, protein concentration, and precipitating salt employed, Crystals grown at 15 C were generally tetragonal, with space group P43212. Crystallization at 20 C typically resulted in the formation of orthorhombic crystals, space group P21212 1. The tetragonal much less than orthorhombic morphology transition appeared to be a function of both the temperature and protein concentration, occurring between 15 and 20 C and between 100 and 125 mg/ml protein concentration. Crystallization from 0.8 -1.2M magnesium sulfate at pH 7.6 - 8.0 gave a hexagonal (trigonal) crystal form, space group P3121, which diffracted to 2.8 A. Ammonium sulfate was also found to result in a monoclinic form, space group C2. Small twinned monoclinic crystals of approx. 0.2 mm on edge were grown by dialysis followed by seeded sitting drop crystallization.

Multi-scale individual-based model of microbial and bioconversion dynamics in aerobic granular sludge.

PubMed

Xavier, Joao B; De Kreuk, Merle K; Picioreanu, Cristian; Van Loosdrecht, Mark C M

2007-09-15

Aerobic granular sludge is a novel compact biological wastewater treatment technology for integrated removal of COD (chemical oxygen demand), nitrogen, and phosphate charges. We present here a multiscale model of aerobic granular sludge sequencing batch reactors (GSBR) describing the complex dynamics of populations and nutrient removal. The macro scale describes bulk concentrations and effluent composition in six solutes (oxygen, acetate, ammonium, nitrite, nitrate, and phosphate). A finer scale, the scale of one granule (1.1 mm of diameter), describes the two-dimensional spatial arrangement of four bacterial groups--heterotrophs, ammonium oxidizers, nitrite oxidizers, and phosphate accumulating organisms (PAO)--using individual based modeling (IbM) with species-specific kinetic models. The model for PAO includes three internal storage compounds: polyhydroxyalkanoates (PHA), poly phosphate, and glycogen. Simulations of long-term reactor operation show how the microbial population and activity depends on the operating conditions. Short-term dynamics of solute bulk concentrations are also generated with results comparable to experimental data from lab scale reactors. Our results suggest that N-removal in GSBR occurs mostly via alternating nitrification/denitrification rather than simultaneous nitrification/denitrification, supporting an alternative strategy to improve N-removal in this promising wastewater treatment process.

Formation of a Spinel Coating on AZ31 Magnesium Alloy by Plasma Electrolytic Oxidation

NASA Astrophysics Data System (ADS)

Sieber, Maximilian; Simchen, Frank; Scharf, Ingolf; Lampke, Thomas

2016-03-01

Plasma electrolytic oxidation (PEO) is a common means for the surface modification of light metals. However, PEO of magnesium substrates in dilute electrolytes generally leads to the formation of coatings consisting of unfavorable MgO magnesium oxide. By incorporation of electrolyte components, the phase constitution of the oxide coatings can be modified. Coatings consisting exclusively of MgAl2O4 magnesium-aluminum spinel are produced by PEO in an electrolyte containing hydroxide, aluminate, and phosphate anions. The hardness of the coatings is 3.5 GPa on Martens scale on average. Compared to the bare substrate, the coatings reduce the corrosion current density in dilute sodium chloride solution by approx. one order of magnitude and slightly shift the corrosion potential toward more noble values.

Utilization of struvite recovered from high-strength ammonium-containing simulated wastewater as slow-release fertilizer and fire-retardant barrier.

PubMed

Yetilmezsoy, Kaan; Kocak, Emel; Akbin, Havva Melda; Özçimen, Didem

2018-06-28

Sustainable uses of the struvite (magnesium ammonium phosphate hexahydrate, MgNH 4 PO 4 ·6H 2 O, MAP) recovered from the synthetic wastewater, as a high-quality slow-release fertilizer for the growth of nine medicinal plants and a fire-retardant barrier on the flammability of cotton fabric and wooden plate, were explored in this study. The previous experimental results demonstrated that under the optimal conditions, about 98.7% of [Formula: see text] (initial [Formula: see text] = 1000 mg/L) could be effectively and successfully recovered from simulated wastewater in the form of MAP precipitate. Rates of increase in total fresh weights, total dry weights, and fresh heights of plants grown in soil fertilized with the struvite were determined as 67%, 52%, and 12% for valerian; 121%, 75%, and 18% for cucumber; 421%, 260%, and 47% for dill; 314%, 318%, and 27% for coriander; 432%, 566%, and 30% for tomato; 285%, 683%, and 26% for parsley; 200%, 225%, and 9% for basil; 857%, 656%, and 92% for rocket; and 146%, 115%, and 28% for cress, respectively, compared to the control pots. The microstructure, elemental composition, surface area, thermal behaviour, and functional groups of the grown crystals were characterized using SEM, EDS, BET, TGA-DTG-DSC, and FTIR analyses, respectively. Flammability tests and thermal analyses concluded that the dried and crumbled/implanted form of struvite used as a fire-retardant barrier demonstrated a remarkable flame-resistant behaviour for both cotton fabric and wooden plate. Findings of this experimental study clearly corroborated the versatility of struvite as non-polluting and environmentally friendly clean product for the sustainable usage in different fields.

Final report on the safety assessment of sodium cetearyl sulfate and related alkyl sulfates as used in cosmetics.

PubMed

Fiume, Monice; Bergfeld, Wilma F; Belsito, Donald V; Klaassen, Curtis D; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Alan Andersen, F

2010-05-01

Sodium cetearyl sulfate is the sodium salt of a mixture of cetyl and stearyl sulfate. The other ingredients in this safety assessment are also alkyl salts, including ammonium coco-sulfate, ammonium myristyl sulfate, magnesium coco-sulfate, sodium cetyl sulfate, sodium coco/hydrogenated tallow sulfate, sodium coco-sulfate, sodium decyl sulfate, sodium ethylhexyl sulfate, sodium myristyl sulfate, sodium oleyl sulfate, sodium stearyl sulfate, sodium tallow sulfate, sodium tridecyl sulfate, and zinc coco-sulfate. These ingredients are surfactants used at concentrations from 0.1% to 29%, primarily in soaps and shampoos. Many of these ingredients are not in current use. The Cosmetic Ingredient Review (CIR) Expert Panel previously completed a safety assessment of sodium and ammonium lauryl sulfate. The data available for sodium lauryl sulfate and ammonium lauryl sulfate provide sufficient basis for concluding that sodium cetearyl sulfate and related alkyl sulfates are safe in the practices of use and concentration described in the safety assessment.

Magnesium-aspartate-based crystallization switch inspired from shell molt of crustacean

PubMed Central

Tao, Jinhui; Zhou, Dongming; Zhang, Zhisen; Xu, Xurong; Tang, Ruikang

2009-01-01

Many animals such as crustacean periodically undergo cyclic molt of the exoskeleton. During this process, amorphous calcium mineral phases are biologically stabilized by magnesium and are reserved for the subsequent rapid formation of new shell tissue. However, it is a mystery how living organisms can regulate the transition of the precursor phases precisely. We reveal that the shell mineralization from the magnesium stabilized precursors is associated with the presence of Asp-rich proteins. It is suggested that a cooperative effect of magnesium and Asp-rich compound can result into a crystallization switch in biomineralization. Our in vitro experiments confirm that magnesium increases the lifetime of amorphous calcium carbonate and calcium phosphate in solution so that the crystallization can be temporarily switched off. Although Asp monomer alone inhibits the crystallization of pure amorphous calcium minerals, it actually reduces the stability of the magnesium-stabilized precursors to switch on the transformation from the amorphous to crystallized phases. These modification effects on crystallization kinetics can be understood by an Asp-enhanced magnesium desolvation model. The interesting magnesium-Asp-based switch is a biologically inspired lesson from nature, which can be developed into an advanced strategy to control material fabrications. PMID:20007788

Magnesium-aspartate-based crystallization switch inspired from shell molt of crustacean.

PubMed

Tao, Jinhui; Zhou, Dongming; Zhang, Zhisen; Xu, Xurong; Tang, Ruikang

2009-12-29

Many animals such as crustacean periodically undergo cyclic molt of the exoskeleton. During this process, amorphous calcium mineral phases are biologically stabilized by magnesium and are reserved for the subsequent rapid formation of new shell tissue. However, it is a mystery how living organisms can regulate the transition of the precursor phases precisely. We reveal that the shell mineralization from the magnesium stabilized precursors is associated with the presence of Asp-rich proteins. It is suggested that a cooperative effect of magnesium and Asp-rich compound can result into a crystallization switch in biomineralization. Our in vitro experiments confirm that magnesium increases the lifetime of amorphous calcium carbonate and calcium phosphate in solution so that the crystallization can be temporarily switched off. Although Asp monomer alone inhibits the crystallization of pure amorphous calcium minerals, it actually reduces the stability of the magnesium-stabilized precursors to switch on the transformation from the amorphous to crystallized phases. These modification effects on crystallization kinetics can be understood by an Asp-enhanced magnesium desolvation model. The interesting magnesium-Asp-based switch is a biologically inspired lesson from nature, which can be developed into an advanced strategy to control material fabrications.

Zinc speciation in proximity to phosphate application points in a lead/zinc smelter-contaminated soil.

PubMed

Baker, Lucas R; Pierzynski, Gary M; Hettiarachchi, Ganga M; Scheckel, Kirk G; Newville, Matthew

2012-01-01

The use of P to immobilize Pb in contaminated soils has been well documented. However, the influence of P on Zn speciation in soils has not been extensively examined, and these two metals often occur as co-contaminants. We hypothesized that additions of P to a Pb/Zn-contaminated soil would induce Zn phosphate mineral formation and fluid P sources would be more effective than granular P amendments. A combination of different synchrotron-based techniques, namely, spatially resolved micro-X-ray fluorescence (μ-XRF), micro-extended X-ray absorption fine structure spectroscopy (μ-EXAFS), and micro-X-ray diffraction (μ-XRD), were used to speciate Zn at two incubation times in the proximity of application points (0 to 4 mm) for fluid and granular P amendments in a Pb/Zn smelter-contaminated soil. Phosphate rock (PR), triple super phosphate (TSP), monoammonium phosphate (MAP), and fluid ammonium polyphosphate induced Zn phosphate formation. Ammonium polyphosphate was more effective at greater distances (up to 3.7 mm) from the point of P application. Phosphoric acid increased the presence of soluble Zn species because of increased acidity. Soluble Zn has implications with respect to Zn bioavailability, which may negatively impact vegetation and other sensitive organisms. Although additions of P immobilize Pb, this practice needs close monitoring due to potential increases in Zn solubility in a Pb/Zn smelter-contaminated soil. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Characterisation of magnesium potassium phosphate cements blended with fly ash and ground granulated blast furnace slag

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gardner, Laura J.; Bernal, Susan A.; Walling, Samuel A.

Magnesium potassium phosphate cements (MKPCs), blended with 50 wt.% fly ash (FA) or ground granulated blast furnace slag (GBFS) to reduce heat evolution, water demand and cost, were assessed using compressive strength, X-ray diffraction (XRD), scanning electron microscopy (SEM) and nuclear magnetic resonance (NMR) spectroscopy on {sup 25}Mg, {sup 27}Al, {sup 29}Si, {sup 31}P and {sup 39}K nuclei. We present the first definitive evidence that dissolution of the glassy aluminosilicate phases of both FA and GBFS occurred under the pH conditions of MKPC. In addition to the main binder phase, struvite-K, an amorphous orthophosphate phase was detected in FA/MKPC andmore » GBFS/MKPC systems. It was postulated that an aluminium phosphate phase was formed, however, no significant Al–O–P interactions were identified. High-field NMR analysis of the GBFS/MKPC system indicated the potential formation of a potassium-aluminosilicate phase. This study demonstrates the need for further research on these binders, as both FA and GBFS are generally regarded as inert fillers within MKPC.« less

Renal ammonium production--une vue canadienne.

PubMed

Brosnan, J T; Lowry, M; Vinay, P; Gougoux, A; Halperin, M L

1987-04-01

The purpose of this review is to examine the factors regulating ammonium production in the kidney and to place these factors in the perspective of acid-base balance. Renal ammonium production and excretion are required to maintain acid-base balance. However, only a portion of renal ammonium production is specifically stimulated by metabolic acidosis. One should examine urinary ammonium excretion at three levels: distribution of ammonium between blood and urine, augmented glutamine metabolism, and an energy constraint due to ATP balance considerations. With respect to the biochemical regulation of acid-base renal ammonium production, an acute stimulation of alpha-ketoglutarate dehydrogenase by a fall in pH seems to be important but this may not be the entire story. In chronic metabolic acidosis augmented glutamine entry into mitochondria (dog) or increased phosphate-dependent glutaminase activity (rat) become critical to support a high flux rate. Metabolic alterations, which diminish the rate of oxidation of alternate fuels, might also be important. The above principles are discussed in the ketoacidosis of fasting, the clinically important situation of high rates of renal ammonium production.

The Role of Magnesium Ion Substituted Biphasic Calcium Phosphate Spherical Micro-Scaffolds in Osteogenic Differentiation of Human Adipose Tissue-Derived Mesenchymal Stem Cells.

PubMed

Kim, Dong-Hyun; Shin, Keun-Koo; Jung, Jin Sup; Chun, Ho Hwan; Park, Seong Soo; Lee, Jong Kook; Park, Hong-Chae; Yoon, Seog-Young

2015-08-01

This study was investigated the role of magnesium (Mg2+) ion substituted biphasic calcium phosphate (Mg-BCP) spherical micro-scaffolds in osteogenic differentiation of human adipose tissue-derived mesenchymal stem cells (hAT-MSCs). Mg-BCP micro-scaffolds with spherical morphology were successfully prepared using in situ co-precipitation and spray drying atomization process. The in vitro cell proliferation and differentiation of hAT-MSCs were determined up to day 14. After in vitro biological tests, Mg-BCP micro-scaffolds with hAT-MSCs showed more enhanced osteogenicity than pure hAT-MSCs as control group by unique biodegradation of TCP phase and influence of substituted Mg2+ ion in biphasic nanostructure. Therefore, these results suggest that Mg-BCP micro-scaffolds promote osteogenic differentiation of hAT-MSCs.

SEPARATION OF SCANDIUM VALUES FORM IRON VALUES BY SOLVENT EXTRACTION

DOEpatents

Kuhlman, C.W. Jr.; Lang, G.P.

1961-12-19

A process is given for separating scandium from trivalent iron values. In this process, an aqueous nitric acid solution is contacted with a water- immiscible alkyl phosphate solution, the aqueous solution containing the values to be separated, whereby the scandium is taken up by the alkyl phosphate. The aqueous so1ution is preferably saturated with magnesium nitrate to retain the iron in the aqueous solution. (AEC)

Environmental benefits of using magnesium carbonate minerals as new wildfire retardants instead of commercially available, phosphate-based compounds.

PubMed

Liodakis, S; Tsoukala, M

2010-10-01

A serial batch leaching experiment has been carried out to evaluate the release of elements from the ash of Pinus halepensis needles burned under two test conditions-with and without treatment of the forest species with the carbonate minerals (huntite and hydromagnesite) in aqueous solution (pH 6). The ash (before and after leaching) and leachates were analyzed using atomic absorption spectroscopy and X-ray diffraction. Compared with data from samples treated with the commercially available, phosphate-based fire retardant diammonium phosphate (DAP), we found that use of huntite or hydromagnesite was much more successful in obstructing the release of the toxic elements present in the ash, probably because of the alkaline conditions resulting from decomposition of the minerals during burning. In contrast, DAP tended to be more able to facilitate the extraction of some toxic metals (e.g., Zn, Cu, Mn), probably because of the acidic conditions resulting from its decomposition to phosphoric acid. Data from this study thus lend strong support to the use of magnesium carbonate minerals as new wildfire retardants, because they were shown to be more friendly to the environment (e.g., soil, ground, and underground water streams) than those currently in use (e.g., phosphate or sulfate salt type).

Removal of ammonia from landfill leachate by struvite precipitation with the use of low-cost phosphate and magnesium sources.

PubMed

Huang, Haiming; Xiao, Dean; Zhang, Qingrui; Ding, Li

2014-12-01

This paper presents a study concerning ammonia removal from landfill leachate by struvite precipitation with the use of waste phosphoric acid as the phosphate source. The results indicated that the Al(3+) ions present in the waste phosphoric acid significantly affected the struvite precipitation, and a removal ratio of ammonia close to that of pure phosphate salts could be achieved. Nevertheless, large amounts of NaOH were necessary to neutralize the H(+) present in the waste phosphoric acid. To overcome this problem, a low-cost magnesium source was proposed to be used as well as an alkali reagent in the struvite precipitation. The ammonia removal ratios were found to be 83%, with a remaining phosphate of 56 mg/L, by dosing the low-cost MgO in the Mg:N:P molar ratio of 3:1:1. An economic analysis showed that using waste phosphoric acid plus the low-cost MgO could save chemical costs by 68% compared with the use of pure chemicals. Post-treatment employment of a biological anaerobic filter process demonstrated that the high concentration of Mg(2+) remaining in the effluent of the struvite precipitation has no inhibitory effect on the performance of the biological treatment. Copyright © 2014 Elsevier Ltd. All rights reserved.

In vitro production of azadirachtin from cell suspension cultures of Azadirachta indica.

PubMed

Sujanya, S; Devi, B Poornasri; Sai, Isha

2008-03-01

The present study aimed to elucidate the effect of nutritional alteration on biomass content and azadirachtin production in cell suspensions of the elite neem variety crida-8. Variations in total nitrogen availability in the medium in terms of different ratios of nitrate: ammonium showed that the ratio 4:1 revealed a profound effect, leading to a 1.5-fold increase in the total extracellular azadirachtin production (5.59 mg/l) over the standard MS medium. Reduction in sucrose (15 mg/l) in the medium exhibited a reduction in biomass and absence of azadirachtin, whereas total phosphate reduction raised intracellular azadirachtin production (6.98 mg/l). An altered medium with a nitrate: ammonium ratio of 4:1 coupled with complete elimination of phosphate enhanced biomass by 36% (59.36 g/l).

Solubility of ammonium acid urate nephroliths from bottlenose dolphins (Tursiops truncatus).

PubMed

Argade, Sulabha; Smith, Cynthia R; Shaw, Timothy; Zupkas, Paul; Schmitt, Todd L; Venn-Watson, Stephanie; Sur, Roger L

2013-12-01

Nephrolithiasis has been identified in managed populations of bottlenose dolphins (Tursiops truncatus); most of these nephroliths are composed of 100% ammonium acid urate (AAU). Several therapies are being investigated to treat and prevent nephrolithiasis in dolphins including the alkalization of urine for dissolution of nephroliths. This study evaluates the solubility of AAU nephroliths in a phosphate buffer, pH range 6.0-8.0, and in a carbonate-bicarbonate buffer, pH range 9.0-10.8. AAU nephroliths were obtained from six dolphins and solubility studies were conducted using reverse-phase high performance liquid chromatography with ultraviolet detection at 290 nm. AAU nephroliths were much more soluble in a carbonate-bicarbonate buffer, pH range 9.0-10.8 compared to phosphate buffer pH range 6.0-8.0. In the pH range 6.0-8.0, the solubility was 45% lower in potassium phosphate buffer compared to sodium phosphate buffer. When citrate was used along with phosphate in the same pH range, the solubility was improved by 13%. At pH 7 and pH 8, 150 mM ionic strength buffer was optimum for dissolution. In summary, adjustment of urinary pH alone does not appear to be a useful way to treat AAU stones in bottlenose dolphins. Better understanding of the pathophysiology of AAU nephrolithiasis in dolphins is needed to optimize kidney stone prevention and treatment.

Photometric Determination of Ammonium and Phosphate in Seawater Medium Using a Microplate Reader.

PubMed

Ruppersberg, Hanna S; Goebel, Maren R; Kleinert, Svea I; Wünsch, Daniel; Trautwein, Kathleen; Rabus, Ralf

2017-01-01

To more efficiently process the large sample numbers for quantitative determination of ammonium (NH4+) and phosphate (orthophosphate, PO43-) generated during comprehensive growth experiments with the marine Roseobacter group member Phaeobacter inhibens DSM 17395, specific colorimetric assays employing a microplate reader (MPR) were established. The NH4+ assay is based on the reaction of NH4+ with hypochlorite and salicylate, yielding a limit of detection of 14 µM, a limit of quantitation of 36 µM, and a linear range for quantitative determination up to 200 µM. The PO43-assay is based on the complex formation of PO43- with ammonium molybdate in the presence of ascorbate and zinc acetate, yielding a limit of detection of 13 µM, a limit of quantitation of 50 µM, and a linear range for quantitative determination up to 1 mM. Both MPR-based assays allowed for fast (significantly lower than 1 h) analysis of 21 samples plus standards for calibration (all measured in triplicates) and showed only low variation across a large collection of biological samples. © 2017 S. Karger AG, Basel.

Increase in serum magnesium level in haemodialysis patients receiving sevelamer hydrochloride.

PubMed

Mitsopoulos, Efstathios; Griveas, Ioannis; Zanos, Stavros; Anagnostopoulos, Konstantinos; Giannakou, Anastasia; Pavlitou, Aikaterini; Sakellariou, Georgios

2005-01-01

Clinical studies have shown that sevelamer hydrochloride improves lipid profiles and attenuates the progression of the cardiovascular calcifications in haemodialysis patients. It is known that both of these properties are associated with increased magnesium levels. The effect of sevelamer on serum magnesium level is not well documented. The aim of this study was to determine the effects of sevelamer treatment on serum magnesium in haemodialysis patients and to assess the association of magnesium levels with lipid profiles and intact parathyroid hormone (iPTH). Phosphate binders were discontinued during a two week washout period. Forty-seven patients, whose serum phosphate was greater than 6.0 mg/dl at the end of washout, received sevelamer hydrochloride for eight weeks. The patients were then washed off sevelamer for another two weeks. Mean serum phosphorus concentration declined from 7.5 +/- 1.3 to 6.4 +/- 1.2 mg/dl (P < 0.001), mean serum magnesium levels increased from 2.75 +/- 0.35 to 2.90 +/- 0.41 mg/dl (P < 0.001) and median serum iPTH levels decreased from 297 to 213 pg/ml (P=0.001) during the eight weeks of sevelamer treatment. After the two week post-treatment washout phosphorus levels increased to 7.3 +/- 1.3 mg/dl (P < 0.001), magnesium levels were reduced to 2.77 +/- 0.39 mg/dl (P < 0.001) and iPTH levels increased to 240 pg/ml (P=0.012). No change was observed in serum calcium levels during the sevelamer treatment period and the subsequent washout period. The mean decline in total and low density lipoprotein (LDL) cholesterol during sevelamer treatment was 16.3 and 28.3 (P < 0.001), respectively. The mean increase in high density lipoprotein (HDL) cholesterol and in apolipoprotein A1 was 2.9 +/- 5.8 mg/dl (P=0.004) and 6.8 +/- 11.1 mg/dl (P=0.001), respectively. Multivariate analysis showed that the rise in serum magnesium concentration significantly correlated with reductions in iPTH levels (r=-0.40, P=0.016), but did not have any significant correlation with the changes in lipid profiles. Our findings indicate that patients on haemodialysis receiving sevelamer have a significant increase in serum magnesium concentrations. This increase in serum magnesium is associated with reduction in iPTH levels. The changes in lipid profiles of these patients however are not related to changes in serum magnesium levels.

DETERMINATION OF PERCHLORATE BY ION CHROMATOGRAPHY, SUPPRESSED CONDUCTIVITY AND MASS SPECTROMETRIC DETECTION USING AN OXYGEN-18 ENRICHED ISOTROPIC INTERNAL STANDARD

EPA Science Inventory

Perchlorate (ClO4 -) is a drinking water contaminant originating from the dissolution of the salts of ammonium, potassium, magnesium, or sodium in water. It is used primarily as an oxidant in solid propellant for rockets, missiles, pyrotechnics, as a component in air bag infla...

SUB-PPB QUANTITATION AND CONFIRMATION OF PERCHLORATE IN DRINKING WATERS CONTAINING HIGH TOTAL DISSOLVED SOLIDS USING ION CHROMATOGRAPHY WITH MASS SPECTROMETRIC DETECTION

EPA Science Inventory

Perchlorate (ClO4 -) is a drinking water contaminant originating from the dissolution of the salts of ammonium, potassium, magnesium, or sodium in water. It is used primarily as an oxidant in solid propellant for rockets, missiles, pyrotechnics, as a component in air bag infla...

MEASUREMENT OF PERCHLORATE IN WATER BY USE OF AN 18O-ENRICHED ISOTOPIC STANDARD AND ION CHROMATOGRAPHY WITH MASS SPECTROMETRIC DETECTION

EPA Science Inventory

Perchlorate (ClO₄^-) is a drinking water contaminant originating from the dissolution of the salts of ammonium, potassium, magnesium, or sodium in water. It is used primarily as an oxidant in solid propellant for rockets, missiles, pyrotechnics, as a compone...

ELUTION OF URANIUM VALUES FROM ION EXCHANGE RESINS

DOEpatents

Kennedy, R.H.

1959-11-24

A process is described for eluting complex uranium ions absorbed on ion exchange resins. The resin is subjected to the action of an aqueous eluting solution contuining sulfuric acid and an alkali metal, ammonium, or magnesium chloride or nitrate, the elution being carried out until the desired amount of the uranium is removed from the resin.

Structural and spectroscopic investigations on deuteron glasses belonging to the potassium dihydrogen phosphate family

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choudhury, Rajul Ranjan, E-mail: rajul@barc.gov.in; Chitra, R.; Abraham, Geogy J.

2015-06-24

X-ray powder diffraction and Raman measurements were performed on the mixed crystals of deuterated potassium dihydrogen phosphate (DKDP) and deuterated ammonium dihydrogen phosphate (DADP) grown at our lab. These crystals are known to behave like deuteron glasses due to frustration between ferroelectric and antiferroelectric ordering. Both spectral as well as structural studies indicate that crystals belonging to the glassy regions of the crystal composition have stronger O-D-O hydrogen bonds as compared to those belong to the ferroelectric or antiferroelectric regions of the crystal composition.

Influence of silica nanospheres on corrosion behavior of magnesium matrix syntactic foam

NASA Astrophysics Data System (ADS)

Qureshi, W.; Kannan, S.; Vincent, S.; Eddine, N. N.; Muhammed, A.; Gupta, M.; Karthikeyan, R.; Badari, V.

2018-04-01

Over the years, the development of Magnesium alloys as biodegradable implants has seen significant advancements. Magnesium based materials tend to provide numerous advantages in the field of biomedical implants over existing materials such as titanium or stainless steel. The present research focuses on corrosive behavior of Magnesium reinforced with different volume percentages of Hollow Silica Nano Spheres (HSNS). These behaviors were tested in two different simulated body fluids (SBF) namely, Hank’s Buffered Saline Solution (HBSS) and Phosphate Buffered Solution (PBS). This corrosion study was done using the method of electrochemical polarization with a three-electrode configuration. Comparative studies were established by testing pure Mg which provided critical information on the effects of the reinforcing material. The HSNS reinforced Mg displayed desirable characteristics after corrosion experiments; increased corrosion resistance was witnessed with higher volume percentage of HSNS.

In vitro and in vivo evaluation of sanguinarine liposomes prepared by a remote loading method with three different ammonium salts.

PubMed

Ke, X; Bei, J H; Zhang, Y; Li, J

2011-04-01

Sanguinarine liposomes were prepared by a remote loading method using three different ammonium salts. A series of studies, including in vitro release, in vitro and in vivo anti-tumor effects and pharmacokinetics in rats, were conducted. The three liposomes showed pH-sensitive release characteristics in vitro, but there were obvious variations in their release profiles. Among the three liposomes, the liposomes made using ammonium citrate and phosphate possessed better anti-tumor activity in vitro and in vivo, compared with the liposome using ammonium sulfate. Pharmacokinetics test results in rats indicated that sanguinarine liposomes have notably elevated AUC (P<0.05) and markedly lower CL (P<0.05) compared with the solution, but there were no obvious differences between the three liposomes. The present study may be useful for better understanding and better choice of a suitable ammonium salt for the remote loading method.

Influence of injected caffeine on the metabolism of calcium and the retention and excretion of sodium, potassium, phosphorus, magnesium, zinc and copper in rats.

PubMed

Yeh, J K; Aloia, J F; Semla, H M; Chen, S Y

1986-02-01

Mineral metabolism was studied by the metabolic balance technique in rats with and without administration of caffeine. Caffeine was injected subcutaneously each day at either 2.5 mg or 10 mg/100 g body weight for 2 wk before the balance studies. Urinary volume excretion was higher in the group given caffeine than in the control group, but the creatinine clearance was not different. Urinary excretion of potassium, sodium, inorganic phosphate, magnesium and calcium, but not of zinc and copper, was also higher in the rats given caffeine. The rank order of the difference was the same as the percent of ingested mineral excreted in urine in the absence of caffeine. Caffeine caused a negative balance of potassium, sodium and inorganic phosphate. There was no significant difference from the control levels and in the apparent metabolic balance of calcium and magnesium. The urinary and fecal excretion of zinc and copper were found to be unaffected by caffeine. It is suggested that chronic administration of caffeine may lead to a tendency toward deficiency of those minerals that are excreted primarily in urine.

In vivo corrosion of four magnesium alloys and the associated bone response.

PubMed

Witte, F; Kaese, V; Haferkamp, H; Switzer, E; Meyer-Lindenberg, A; Wirth, C J; Windhagen, H

2005-06-01

Degrading metal alloys are a new class of implant materials suitable for bone surgery. The aim of this study was to investigate the degradation mechanism at the bone-implant interface of different degrading magnesium alloys in bone and to determine their effect on the surrounding bone. Sample rods of four different magnesium alloys and a degradable polymer as a control were implanted intramedullary into the femora of guinea pigs. After 6 and 18 weeks, uncalcified sections were generated for histomorphologic analysis. The bone-implant interface was characterized in uncalcified sections by scanning electron microscopy (SEM), element mapping and X-ray diffraction. Results showed that metallic implants made of magnesium alloys degrade in vivo depending on the composition of the alloying elements. While the corrosion layer of all magnesium alloys accumulated with biological calcium phosphates, the corrosion layer was in direct contact with the surrounding bone. The results further showed high mineral apposition rates and an increased bone mass around the magnesium rods, while no bone was induced in the surrounding soft tissue. From the results of this study, there is a strong rationale that in this research model, high magnesium ion concentration could lead to bone cell activation.

Recovery of phosphate from aqueous solution by magnesium oxide decorated magnetic biochar and its potential as phosphate-based fertilizer substitute.

PubMed

Li, Ronghua; Wang, Jim J; Zhou, Baoyue; Awasthi, Mukesh Kumar; Ali, Amjad; Zhang, Zengqiang; Lahori, Altaf Hussain; Mahar, Amanullah

2016-09-01

The present study deals with the preparation of a novel MgO-impregnated magnetic biochar (MMSB) for phosphate recovery from aqueous solution. The MMSB was evaluated against sugarcane harvest residue biochar (SB) and magnetic biochar without Mg (MSB). The results showed that increasing Mg content in MMSB greatly improved the phosphate adsorption compared to SB and MSB, with 20% Mg-impregnated MMSB (20MMSB) recovering more than 99.5% phosphate from aqueous solution. Phosphate adsorption capacity of 20MMSB was 121.25mgP/g at pH 4 and only 37.53% of recovered phosphate was desorbed by 0.01mol/L HCl solutions. XRD and FTIR analysis showed that phosphate sorption mechanisms involved predominately with surface electrostatic attraction and precipitation with impregnated MgO and surface inner-sphere complexation with Fe oxide. The 20MMSB exhibited both maximum phosphate sorption and strong magnetic separation ability. Overall, phosphate-loaded 20MMSB significantly enhanced plant growth and could be used as a potential substitute for phosphate-based fertilizer. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effects of impurities on the biodegradation behavior of pure magnesium

NASA Astrophysics Data System (ADS)

Lee, Ji-Young; Han, Gilsoo; Kim, Yu-Chan; Byun, Ji-Young; Jang, Jae-il; Seok, Hyun-Kwang; Yang, Seok-Jo

2009-12-01

The corrosion behavior of pure magnesium that has different content ratio of impurities (such as Fe/Mn ratio) in Hanks' solution was investigated in order to tailor the lifetime of biodegradable implant made of pure magnesium. Two distinct stages of corrosion were observed: a slow corrosion rate stage and a subsequent fast corrosion rate stage. The first stage was characterized by uniform corrosion that produced magnesium hydroxide and calcium phosphate film on a magnesium surface, resulting in a slow corrosion rate. The second stage with an abrupt increase in the corrosion rate was induced by Fe precipitates and was stimulated by an increase in the Fe/Mn ratio. This corrosion was developed to a preferred crystallographic pitting corrosion where the pits propagated along the preferred crystallographic plane and several layers of Mg planes with narrow interplanar space remained uncorroded. From this study, it is expected that the lifetime of the biodegradable implant made of pure Mg can be tailored by controlling the amount and ratio of the impurities.

Solid-state reaction kinetics and optical studies of cadmium doped magnesium hydrogen phosphate crystals

NASA Astrophysics Data System (ADS)

Verma, Madhu; Gupta, Rashmi; Singh, Harjinder; Bamzai, K. K.

2018-04-01

The growth of cadmium doped magnesium hydrogen phosphate was successfully carried out by using room temperature solution technique i.e., gel encapsulation technique. Grown crystals were confirmed by single crystal X-ray diffraction (XRD). The structure of the grown crystal belongs to orthorhombic crystal system and crystallizes in centrosymmetric space group. Kinetics of the decomposition of the grown crystals were studied by non-isothermal analysis. Thermo gravimetric / differential thermo analytical (TG/DTA) studies revealed that the grown crystal is stable upto 119 °C. The various steps involved in the thermal decomposition of the material have been analysed using Horowitz-Metzger, Coats-Redfern and Piloyan-Novikova equations for evaluating various kinetic parameters. The optical studies shows that the grown crystals possess wide transmittance in the visible region and significant optical band gap of 5.5ev with cut off wavelength of 260 nm.

Effect of Thickness on the Morphology and Corrosion Behavior of Cerium-Based Conversion Coatings on AZ31B Magnesium Alloy

NASA Astrophysics Data System (ADS)

Castano, Carlos E.; Maddela, Surender; O'Keefe, Matthew J.; Wang, Yar-Ming

Cerium-based conversion coatings (CeCCs) were deposited onto AZ31B magnesium alloy substrates using a spontaneous reaction of CeCl3, H2O2 and gelatin in a water-based solution. The coating thickness was adjusted by controlling the immersion time in the deposition solution. Prior to deposition, the AZ31B substrates were treated using an acid pickling in nitric acid and then an alkaline cleaning in sodium metasilicate pentahydrate. After deposition, the coated samples were immersed in a phosphate bath that converted cerium oxide/hydroxide into cerium phosphate. Electrochemical impedance spectroscopy, potentiodynamic polarization and neutral salt spray testing studies indicated that 100 nm thick CeCC had better corrosion performance than 400 nm coatings. Characterization of the CeCCs by transmission electron microscopy (TEM) revealed a three layer structure with different compositions.

21 CFR 184.1141a - Ammonium phosphate, monobasic.

Code of Federal Regulations, 2012 CFR

2012-04-01

... Academy Press, 2101 Constitution Ave. NW., Washington, DC 20418, or available for inspection at the... at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal...

21 CFR 184.1141b - Ammonium phosphate, dibasic.

Code of Federal Regulations, 2012 CFR

2012-04-01

..., 2101 Constitution Ave. NW., Washington, DC 20418, or available for inspection at the National Archives... 202-741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr...

Assessment of bacterial and fungal growth on natural substrates: consequences for preserving caves with prehistoric paintings.

PubMed

Stomeo, Francesca; Portillo, Maria C; Gonzalez, Juan M

2009-09-01

The most representative bacterium (Pseudonocardia sp.) and fungus (Fusarium sp.) from the microbial communities of a cave containing paleolithic paintings were isolated and their growth on natural substrates assessed. Growth was tested at the in situ and optimal, laboratory growth temperature. Development was analyzed with and without supplemented nutrients (glucose, ammonium, phosphate, peptone). Results showed that the assayed bacterium on natural substrate was able to develop best at in situ temperature and the addition of organic nutrients and/or phosphate enhanced its growth. The growth of the assayed fungus, however, was limited by low temperature and the availability of ammonium. These results confirm a differential behavior of microorganisms between the laboratory and the natural environments and could explain previous invasion of fungi reported for some caves with prehistoric paintings.

Winter nutrient behaviours in the Pearl River estuary

NASA Astrophysics Data System (ADS)

Wang, G.; Jin, S.; Du, M.

2017-12-01

Nutrient (nitrate, nitrite, ammonium, phosphate, and silicate) mapping and time-series investigation were carried out in winter in the Pearl River estuary, China. These nutrients behaved non-conservatively in the upper estuary. In the middle and lower estuary, however, nitrate and silicate seemed to be controled by physical mixing, while additions of nitrite, ammonium, and phosphate were found in the middle estuary. Nitrate was the dominant disslved inorganic nitrogen, with a fraction of more than 2/3. From the upper to the lower estuary the N:P ratio decreased from more than 200 to near the Redfield ratio of 16. Nutrients near the surface behaved almost the same as near the bottom in the water column at both the uppper and lower estuary. During a tidal cycle these nutrients seemed to be regulated more by physical mixing than by other processes.

Ammonium and phosphate enrichment across the dry-wet transition and their ecological relevance in a subtropical reservoir, China.

PubMed

Mo, Qiongli; Chen, Nengwang; Zhou, Xingpeng; Chen, Jixin; Duan, Shuiwang

2016-07-13

Small river reservoirs are widespread and can be ecologically sensitive across the dry-wet transition under monsoon climate with respect to nutrient loading and phenology. Monthly sampling and high-frequency in situ measurements were conducted for a river reservoir (southeast China) in 2013-2014 to examine the seasonal pattern of nutrients and phytoplankton. We found that nutrient concentrations were runoff-mediated and determined by watershed inputs and, in some cases, by internal cycling depending on hydrology and temperature. Ammonium and phosphate were relatively enriched in February-March (a transitional period from dry/cold to wet/hot climate), which can be ascribed to initial flushing runoff from human/animal waste and spring fertilizer use. A phytoplankton bloom (mainly Chlorophyta) occurred during April after a surge of water temperature, probably due to the higher availability of inorganic nutrients and sunlight and suitable hydraulic residence time (medium flow) in the transitional period. The concentration of phytoplankton was low during May-June (wet-hot climate) when the concentrations of total suspended matter (TSM) were highest, likely owing to the "shading" effect of TSM and turbulence of high flow conditions. Nutrient-algae shifts across the dry-wet season and vertical profiles suggested that algal blooms seem to be fueled primarily by phosphate and ammonium rather than nitrate. Current findings of a strong temporal pattern and the relationship between physical parameters, nutrient and biota would improve our understanding of drivers of change in water quality and ecosystem functions with dam construction.

Ammonium phosphate as a sole nutritional supplement for the fermentative production of 2,3-butanediol from sugar cane juice.

PubMed

Berbert-Molina, M A; Sato, S; Silveira, M M

2001-01-01

The production of 2,3-butanediol by Klebsiella pneumoniae from sugar cane juice supplemented with different salts was studied. This microorganism is able to degrade sucrose present in sugar cane juice containing ammonium phosphate as the sole nutritional supplement. With a sugar cane juice-based medium containing approximately 180 g sucrose/l and 8.0 g (NH4)2HPO4/l, over 70 g 2,3-butanediol plus acetoin/l were formed. This result is comparable to that achieved with a sugar cane juice-based medium containing several nutrients, although the kinetic profiles of these runs presented significant differences. With the ammonium phosphate-enriched medium, cell growth was initially favoured by both the strong oxygen supply and the higher water activity due to the lower concentration of nutrients. After 14 h, the limitation in some nutrients led to the interruption of cell growth, and decreasing rates for product formation and substrate consumption were observed. During the stationary phase of this run, sucrose was preferentially converted to product, and the substrate was completely depleted after 35 h of the process. With the complete medium, the substrate was totally consumed after 36 h of run. In this case, the higher initial concentration of nutrients reduced the overall process rate but sustained the cell growth for 27 h. Conversion yields of 0.40 g product/g sucrose and productivities close to 2.0 g/l x h were obtained under both conditions.

Nephrolithiasis, stone composition, meteorology, and seasons in Malta: Is there any connection?

PubMed

Buttigieg, Jesmar; Attard, Stephanie; Carachi, Alexander; Galea, Ruth; Fava, Stephen

2016-01-01

The effect of seasons and meteorology on the incidence of nephrolithiasis has been studied in various regions around the globe, but seldom in the Mediterranean. This retrospective analysis aims at investigating these putative effects in the Maltese Islands, whose climate is typically Mediterranean, followed by a systematic review of the literature. Submission rate and chemical composition of all kidney stones after spontaneous passage or surgical removal between January 2009 and December 2011 were analyzed according to seasons and corresponding meteorology. A total of 389 stones were analyzed. A higher stone submission rate was observed in summer compared to winter (31.6% vs. 20.8%, P = 0.0008) and in the warm period compared to the cold period (57.1% vs. 42.9%, P = 0.0001). Significant correlation was established between the monthly number of stones and mean monthly maximum temperature (r = 0.50, P = 0.002), mean monthly temperature (r = 0.49, P = 0.003) and mean monthly Humidex (r = 0.49, P = 0.007). Humidex was found to be an independent predictor for stone submission (β = 0.49, P = 0.007). The majority of stones contained calcium (83.3%), combined with oxalate (77.6%), phosphate (14.7%), and carbonate (2.8%). Some stones (11.8%) contained a mixture of >1 negatively charged molecules. Urate (11.6%), cysteine (4.6%), and ammonium-magnesium-phosphate (0.5%) constituted the rest. There was no association between chemical composition and seasons. Literature review included 25 articles. Higher ambient temperature and warm seasons were the most commonly encountered risk factors for both presentation and etiology of nephrolithiasis. A significant positive correlation was noted between ambient temperature and stone submission rate, which was significantly higher during the warm months in Malta.

Nitrate-induced genes in tomato roots. Array analysis reveals novel genes that may play a role in nitrogen nutrition.

PubMed

Wang, Y H; Garvin, D F; Kochian, L V

2001-09-01

A subtractive tomato (Lycopersicon esculentum) root cDNA library enriched in genes up-regulated by changes in plant mineral status was screened with labeled mRNA from roots of both nitrate-induced and mineral nutrient-deficient (-nitrogen [N], -phosphorus, -potassium [K], -sulfur, -magnesium, -calcium, -iron, -zinc, and -copper) tomato plants. A subset of cDNAs was selected from this library based on mineral nutrient-related changes in expression. Additional cDNAs were selected from a second mineral-deficient tomato root library based on sequence homology to known genes. These selection processes yielded a set of 1,280 mineral nutrition-related cDNAs that were arrayed on nylon membranes for further analysis. These high-density arrays were hybridized with mRNA from tomato plants exposed to nitrate at different time points after N was withheld for 48 h, for plants that were grown on nitrate/ammonium for 5 weeks prior to the withholding of N. One hundred-fifteen genes were found to be up-regulated by nitrate resupply. Among these genes were several previously identified as nitrate responsive, including nitrate transporters, nitrate and nitrite reductase, and metabolic enzymes such as transaldolase, transketolase, malate dehydrogenase, asparagine synthetase, and histidine decarboxylase. We also identified 14 novel nitrate-inducible genes, including: (a) water channels, (b) root phosphate and K(+) transporters, (c) genes potentially involved in transcriptional regulation, (d) stress response genes, and (e) ribosomal protein genes. In addition, both families of nitrate transporters were also found to be inducible by phosphate, K, and iron deficiencies. The identification of these novel nitrate-inducible genes is providing avenues of research that will yield new insights into the molecular basis of plant N nutrition, as well as possible networking between the regulation of N, phosphorus, and K nutrition.

Structural wood panels with improved fire resistance

NASA Technical Reports Server (NTRS)

Sawko, P. M. (Inventor)

1980-01-01

Structural wood paneling or other molded wood compositions consisting of finely divided wood chips, flour, or strands are bound together and hot pressed with a modified novolac resin which is the cured product of a prepolymer made from an aralkyl ether or halide with a phenol and a hardening agent such as hexamethylene tetramine. The fire resistance of these articles is further improved by incorporating in the binder certain inorganic fillers, especially a mixture of ammonium oxalate and ammonium phosphate.

Ability of various plant species to prevent leakage of N, P, and metals from sewage sludge.

PubMed

Neuschütz, Clara; Greger, Maria

2010-01-01

The preventive effect of vegetation on nutrient and metal leakage from sewage sludge (SS) used in treatment of mine waste was investigated. In a 10-week greenhouse study, the release of ammonium, nitrate, phosphate, Cd, Cu, and Zn from SS was analyzed in the absence (control) and presence of basket willow, fireweed, reed Canary grass (RCG), and Scots pine. Plants significantly decreased the leakage by reducing the amount of leachate, and lowered the concentrations of phosphate (to 0.1 mg L(-1)), Cu (0.8 mg L(-1)), and Zn (2.2 mg L(-1)); and plants increased the pH in the leachate towards the end of the experiment. The most efficient plant was RCG that significantly decreased the total leakage of all pollutants. However, plants could not counteract high initial concentrations of ammonium and nitrate (< 400 mg L(-1) of both) and drop in pH (to 4.5), or increasing Cd release (< 9.7 microg L(-1)). RCG and fireweed used both ammonium and nitrate as nitrogen source and were more efficient in preventing nitrate leakage, compared with willow and pine that mainly used ammonium. This study indicates that introduction of RCG is a promising method for phytostabilization of SS, but that alkaline additives are needed to prevent an initial decrease in pH.

Dietary magnesium supplementation prevents and reverses vascular and soft tissue calcifications in uremic rats.

PubMed

Diaz-Tocados, Juan M; Peralta-Ramirez, Alan; Rodríguez-Ortiz, María E; Raya, Ana I; Lopez, Ignacio; Pineda, Carmen; Herencia, Carmen; Montes de Oca, Addy; Vergara, Noemi; Steppan, Sonja; Pendon-Ruiz de Mier, M Victoria; Buendía, Paula; Carmona, Andrés; Carracedo, Julia; Alcalá-Díaz, Juan F; Frazao, Joao; Martínez-Moreno, Julio M; Canalejo, Antonio; Felsenfeld, Arnold; Rodriguez, Mariano; Aguilera-Tejero, Escolástico; Almadén, Yolanda; Muñoz-Castañeda, Juan R

2017-11-01

Although magnesium has been shown to prevent vascular calcification in vitro, controlled in vivo studies in uremic animal models are limited. To determine whether dietary magnesium supplementation protects against the development of vascular calcification, 5/6 nephrectomized Wistar rats were fed diets with different magnesium content increasing from 0.1 to 1.1%. In one study we analyzed bone specimens from rats fed 0.1%, 0.3%, and 0.6% magnesium diets, and in another study we evaluated the effect of intraperitoneal magnesium on vascular calcification in 5/6 nephrectomized rats. The effects of magnesium on established vascular calcification were also evaluated in uremic rats fed on diets with either normal (0.1%) or moderately increased magnesium (0.6%) content. The increase in dietary magnesium resulted in a marked reduction in vascular calcification, together with improved mineral metabolism and renal function. Moderately elevated dietary magnesium (0.3%), but not high dietary magnesium (0.6%), improved bone homeostasis as compared to basal dietary magnesium (0.1%). Results of our study also suggested that the protective effect of magnesium on vascular calcification was not limited to its action as an intestinal phosphate binder since magnesium administered intraperitoneally also decreased vascular calcification. Oral magnesium supplementation also reduced blood pressure in uremic rats, and in vitro medium magnesium decreased BMP-2 and p65-NF-κB in TNF-α-treated human umbilical vein endothelial cells. Finally, in uremic rats with established vascular calcification, increasing dietary magnesium from 0.1% magnesium to 0.6% reduced the mortality rate from 52% to 28%, which was associated with reduced vascular calcification. Thus, increasing dietary magnesium reduced both vascular calcification and mortality in uremic rats. Copyright © 2017 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

A multiregional Italian cohort of 24-hour urine metabolic evaluation in renal stone formers.

PubMed

Esperto, Francesco; Marangella, Martino; Trinchieri, Alberto; Petrarulo, Michele; Miano, Roberto

2018-02-01

Nephrolithiasis is a common condition with several studies documenting an increased prevalence over the past four decades. EAU and AUA guidelines recommend 24-hour urine metabolic evaluation in high-risk stone formers. Aim of this study is to retrospectively evaluate the first three years of experience with LithoTest® (Biohealth Italia Srl, Turin, Italy) through the analysis of demographic, clinical and biochemical data collected from a large cohort of patients with kidney stones. We retrospectively analyzed data from the LithoCenter database, including data from outpatient consultations, between January 2007 and December 2009 from all over Italy. LithoTest® was performed through a 24-hour urine collection and included measurements of urine volume and pH, 24-hour excretion of creatinine as well as main cations and anions, including calcium, magnesium sodium potassium, ammonium, uric acid, oxalate, citrate, phosphate, inorganic sulphate and chloride. Urine state of saturation for calcium oxalate (βCaOx), calcium hydrogen phosphate or brushite (βbsh) and uric acid (βUA) were also calculated by means of the computer program LithoRisk. Brand's test for cystinuria was also carried out. Statistical analysis was performed using the S-PSS software v. 22.0. The number of patients with data available for analysis was 435, of whom 236 were male (54%) and 199 female (46%). Complete 24-hour urine measurements were available for all 435 patients. Compared to men, women had significantly lower values for creatinine, urate, oxalate, phosphate, sodium, potassium, magnesium and chloride excretion, whereas 24-hour pH and citrate excretion were higher. No significant differences were found for the other examined variables. βCaOx and βUA were significantly higher in men than women, whereas no significant difference was found for βbsh. There was a direct relationship between calcium and sodium urine excretion. Excessive sodium excretion was recorded in 191 patients (44%) and low urine volumes in 201 (46.2%). Hyperoxaluria was observed in 118 patients (27.3%), hypercalciuria in 115 (26.6%), hyperuricosuria in 153 (35.4%), hypomagnesuria in 96 (22.2%), and hypocitraturia in 134 patients (31%). Hyperexcretion of sodium, hypocitraturia and hyperoxaluria were most frequent in males. βCaOx was significantly higher in the setting of hypercalciuria, hypocitraturia, hyperoxaluria and urine pH below 5.5. Our findings in a large cohort of high-risk stone-forming patients show significant differences in urinary metabolic profiles between men and women. Carrying on the collection and analysis of data by LithoTest® from 2009 to 2015 and matching urinary and dietary data could eventually improve our understanding on the metabolic profile of stone-formers in Italy.

Mesocarbon Microbead Carbon-Supported Magnesium Hydroxide Nanoparticles: Turning Spent Li-ion Battery Anode into a Highly Efficient Phosphate Adsorbent for Wastewater Treatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Yan; Guo, Xingming; Wu, Feng

Phosphorus in water eutrophication has become a serious problem threatening the environment. However, the development of efficient adsorbents for phosphate removal from water is lagging. In this work, we recovered the waste material, graphitized carbon, from spent lithium ion batteries and modified it with nanostructured Mg(OH)2 on the surface to treat excess phosphate. This phosphate adsorbent shows one of the highest phosphate adsorption capacities to date, 588.4 mg/g (1 order of magnitude higher than previously reported carbon-based adsorbents), and exhibits decent stability. A heterogeneous multilayer adsorption mechanism was proposed on the basis of multiple adsorption results. This highly efficient adsorbentmore » from spent Li-ion batteries displays great potential to be utilized in industry, and the mechanism study paved a way for further design of the adsorbent for phosphate adsorption.« less

Novel biodegradable calcium phosphate/polymer composite coating with adjustable mechanical properties formed by hydrothermal process for corrosion protection of magnesium substrate.

PubMed

Kaabi Falahieh Asl, Sara; Nemeth, Sandor; Tan, Ming Jen

2016-11-01

Ceramic type coatings on metallic implants, such as calcium phosphate (Ca-P), are generally stiff and brittle, potentially leading to the early failure of the bone-implant interface. To reduce material brittleness, polyacrylic acid and carboxymethyl cellulose were used in this study to deposit two types of novel Ca-P/polymer composite coatings on AZ31 magnesium alloy using a one-step hydrothermal process. X-ray diffraction and scanning electron microscopy showed that the deposited Ca-P crystal phase and morphology could be controlled by the type and concentration of polymer used. Incorporation of polymer in the Ca-P coatings reduced the coating elastic modulus bringing it close to that of magnesium and that of human bone. Nanoindentation test results revealed significantly decreased cracking tendency with the incorporation of polymer in the Ca-P coating. Apart from mechanical improvements, the protective composite layers had also enhanced the corrosion resistance of the substrate by a factor of 1000 which is sufficient for implant application. Cell proliferation studies indicated that the composite coatings induced better cell attachment compared with the purely inorganic Ca-P coating, confirming that the obtained composite materials could be promising candidates for surface protection of magnesium for implant application with the multiple functions of corrosion protection, interfacial stress reduction, and cell attachment/cell growth promotion. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1643-1657, 2016. © 2015 Wiley Periodicals, Inc.

Major element concentrations in six Alaskan arctic rivers from melt to freeze-up

NASA Astrophysics Data System (ADS)

Douglas, T. A.; Barker, A.; Jacobson, A. D.; McClelland, J. W.; Khosh, M. S.; Lehn, G. O.

2010-12-01

It is increasingly evident that permafrost in the Arctic is responding to climate warming. An expected response to this warming is permafrost degradation and the downward migration of the seasonally thawed (active) layer into previously frozen material. This could allow weathering of previously frozen soils and influence surface water biogeochemistry in Arctic rivers. The weathering signal would most likely be evident in surface waters during summer and early fall base flow when the active layer is at its deepest extent. Studies collecting water samples from spring through late fall could capture these flows. Fieldwork in remote regions often requires long storage times for samples prior to analysis. One aspect of our study was to investigate whether waters collected for major element analyses should be preserved by acidification. We collected up to 60 surface water samples from each of six rivers between April and October, 2009. Two rivers were underlain by organic rich permafrost, two of the rivers drained mountainous bedrock, and two rivers were underlain by a combination of both bedrock and organic rich permafrost. We collected duplicate samples from each river. Samples were filtered in the field to less than 0.45 microns and collected into high density polyethylene bottles. Waters were stored for six months prior to analysis. One set of samples was analyzed without acidification while the second set was acidified with nitric acid to a pH of 2 after 6 months of storage. Concentrations of sodium, potassium, magnesium, calcium, ammonium, fluoride, chloride, nitrate, sulfate and phosphate were measured from all samples by ion chromatography. Sulfate, calcium, magnesium, sodium and potassium concentrations increase steadily through the summer from the end of spring melt into early fall. In all six rivers the potassium concentrations are unaffected by acidification. In the two streams underlain by organic rich permafrost and in one of the bedrock streams the calcium, magnesium, and sodium values are similar for both the acidified and unacidified samples. In the other rivers, however, the calcium, magnesium and sodium concentrations yield complex behavior. From spring melt into early summer the cation values are identical in the acidified and unacidified samples. However, in late summer and early fall calcium, magnesium, and sodium concentrations are roughly ten percent higher in the acidified samples than in the unacidified ones. Our results suggest an enhanced mineral weathering signal in the watersheds in the late summer which is evidenced by steadily increasing sulfate and cation concentrations throughout the summer. Potassium does not appear to be affected by acidification. Some cation species respond to acidification, especially in waters representing baseflow. However, the cause(s) for the higher values in some acidified samples is unknown.

Differential magnesium implant corrosion coat formation and contribution to bone bonding.

PubMed

Rahim, Muhammad Imran; Weizbauer, Andreas; Evertz, Florian; Hoffmann, Andrea; Rohde, Manfred; Glasmacher, Birgit; Windhagen, Henning; Gross, Gerhard; Seitz, Jan-Marten; Mueller, Peter P

2017-03-01

Magnesium alloys are presently under investigation as promising biodegradable implant materials with osteoconductive properties. To study the molecular mechanisms involved, the potential contribution of soluble magnesium corrosion products to the stimulation of osteoblastic cell differentiation was examined. However, no evidence for the stimulation of osteoblast differentiation could be obtained when cultured mesenchymal precursor cells were differentiated in the presence of metallic magnesium or in cell culture medium containing elevated magnesium ion levels. Similarly, in soft tissue no bone induction by metallic magnesium or by the corrosion product magnesium hydroxide could be observed in a mouse model. Motivated by the comparatively rapid accumulation solid corrosion products physicochemical processes were examined as an alternative mechanism to explain the stimulation of bone growth by magnesium-based implants. During exposure to physiological solutions a structured corrosion coat formed on magnesium whereby the elements calcium and phosphate were enriched in the outermost layer which could play a role in the established biocompatible behavior of magnesium implants. When magnesium pins were inserted into avital bones, corrosion lead to increases in the pull out force, suggesting that the expanding corrosion layer was interlocking with the surrounding bone. Since mechanical stress is a well-established inducer of bone growth, volume increases caused by the rapid accumulation of corrosion products and the resulting force development could be a key mechanism and provide an explanation for the observed stimulatory effects of magnesium-based implants in hard tissue. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 697-709, 2017. © 2016 Wiley Periodicals, Inc.

FEDS Smoke Dispersion.

DTIC Science & Technology

1979-08-31

flameless smoke material. Mixtures of HC smoke incorporating such flame re- tardants as magnesium carbonate, calcium oxalate, hydrated alumina and ammonium...aluminum materials should moderate the heat of combustion and still provide sufficient heat intensity to generate a smoke reaction in an anthracene...of preliminary tests, it appears that the problem of confining the combustion of a rapid smoke dis- persion and safe operation of the prototype

Structural and Biochemical Studies of the Ovarian Tumor Domain

DTIC Science & Technology

2007-05-01

solution containing Bis-Tris pH 5.5-6.5, 16-20% PEG 3350 , and 100-200 mM of a magnesium cation. These crystals belong to spacegroup P64 with unit...drop method using a reservoir solution containing Bis-Tris pH 5.5-6.5, 16-20% PEG 3350 , and 50-200 mM ammonium acetate . Orthorhombic crystals

Complete staghorn calculus in polycystic kidney disease: infection is still the cause

PubMed Central

2013-01-01

Background Kidney stones in patients with autosomal dominant polycystic kidney disease are common, regarded as the consequence of the combination of anatomic abnormality and metabolic risk factors. However, complete staghorn calculus is rare in polycystic kidney disease and predicts a gloomy prognosis of kidney. For general population, recent data showed metabolic factors were the dominant causes for staghorn calculus, but for polycystic kidney disease patients, the cause for staghorn calculus remained elusive. Case presentation We report a case of complete staghorm calculus in a polycystic kidney disease patient induced by repeatedly urinary tract infections. This 37-year-old autosomal dominant polycystic kidney disease female with positive family history was admitted in this hospital for repeatedly upper urinary tract infection for 3 years. CT scan revealed the existence of a complete staghorn calculus in her right kidney, while there was no kidney stone 3 years before, and the urinary stone component analysis showed the composition of calculus was magnesium ammonium phosphate. Conclusion UTI is an important complication for polycystic kidney disease and will facilitate the formation of staghorn calculi. As staghorn calculi are associated with kidney fibrosis and high long-term renal deterioration rate, prompt control of urinary tract infection in polycystic kidney disease patient will be beneficial in preventing staghorn calculus formation. PMID:24070202

Complete staghorn calculus in polycystic kidney disease: infection is still the cause.

PubMed

Mao, Zhiguo; Xu, Jing; Ye, Chaoyang; Chen, Dongping; Mei, Changlin

2013-08-01

Kidney stones in patients with autosomal dominant polycystic kidney disease are common, regarded as the consequence of the combination of anatomic abnormality and metabolic risk factors. However, complete staghorn calculus is rare in polycystic kidney disease and predicts a gloomy prognosis of kidney. For general population, recent data showed metabolic factors were the dominant causes for staghorn calculus, but for polycystic kidney disease patients, the cause for staghorn calculus remained elusive. We report a case of complete staghorm calculus in a polycystic kidney disease patient induced by repeatedly urinary tract infections. This 37-year-old autosomal dominant polycystic kidney disease female with positive family history was admitted in this hospital for repeatedly upper urinary tract infection for 3 years. CT scan revealed the existence of a complete staghorn calculus in her right kidney, while there was no kidney stone 3 years before, and the urinary stone component analysis showed the composition of calculus was magnesium ammonium phosphate. UTI is an important complication for polycystic kidney disease and will facilitate the formation of staghorn calculi. As staghorn calculi are associated with kidney fibrosis and high long-term renal deterioration rate, prompt control of urinary tract infection in polycystic kidney disease patient will be beneficial in preventing staghorn calculus formation.

Femtosecond laser lithotripsy: feasibility and ablation mechanism.

PubMed

Qiu, Jinze; Teichman, Joel M H; Wang, Tianyi; Neev, Joseph; Glickman, Randolph D; Chan, Kin Foong; Milner, Thomas E

2010-01-01

Light emitted from a femtosecond laser is capable of plasma-induced ablation of various materials. We tested the feasibility of utilizing femtosecond-pulsed laser radiation (lambda=800 nm, 140 fs, 0.9 mJ/pulse) for ablation of urinary calculi. Ablation craters were observed in human calculi of greater than 90% calcium oxalate monohydrate (COM), cystine (CYST), or magnesium ammonium phosphate hexahydrate (MAPH). Largest crater volumes were achieved on CYST stones, among the most difficult stones to fragment using Holmium:YAG (Ho:YAG) lithotripsy. Diameter of debris was characterized using optical microscopy and found to be less than 20 microm, substantially smaller than that produced by long-pulsed Ho:YAG ablation. Stone retropulsion, monitored by a high-speed camera system with a spatial resolution of 15 microm, was negligible for stones with mass as small as 0.06 g. Peak shock wave pressures were less than 2 bars, measured by a polyvinylidene fluoride (PVDF) needle hydrophone. Ablation dynamics were visualized and characterized with pump-probe imaging and fast flash photography and correlated to shock wave pressures. Because femtosecond-pulsed laser ablates urinary calculi of soft and hard compositions, with micron-sized debris, negligible stone retropulsion, and small shock wave pressures, we conclude that the approach is a promising candidate technique for lithotripsy.

An exploratory study on seawater-catalysed urine phosphorus recovery (SUPR).

PubMed

Dai, Ji; Tang, Wen-Tao; Zheng, Yi-Se; Mackey, Hamish R; Chui, Ho Kwong; van Loosdrecht, Mark C M; Chen, Guang-Hao

2014-12-01

Phosphorus (P) is a crucial and non-renewable resource, while it is excessively discharged via sewage, significant amounts originating from human urine. Recovery of P from source-separated urine presents an opportunity not only to recover this precious resource but also to improve downstream sewage treatment works. This paper proposes a simple and economic method to recover urine derived P by using seawater as a low-cost precipitant to form struvite, as Hong Kong has practised seawater toilet flushing as an alternative water resource since 1958. Chemical reactions, process conditions and precipitate composition for P precipitation in urine have been investigated to develop this new urine P recovery approach. This study concluded that ureolysis extent in a urine-seawater mixture determines the reaction pH that in turn influences the P recovery efficiency significantly; 98% of urine P can precipitate with seawater within 10 min when 40-75% of the urea in urine is ureolysed; the urine to seawater ratio alters the composition of the precipitates. The P content in the precipitates was found to be more than 9% when the urine fraction was 40% or higher. Magnesium ammonium phosphate (MAP) was confirmed to be the predominant component of the precipitates. Copyright © 2014 Elsevier Ltd. All rights reserved.

Proteus mirabilis viability after lithotripsy of struvite calculi

NASA Astrophysics Data System (ADS)

Prabakharan, Sabitha; Teichman, Joel M. H.; Spore, Scott S.; Sabanegh, Edmund; Glickman, Randolph D.; McLean, Robert J. C.

2000-05-01

Urinary calculi composed of struvite harbor urease-producing bacteria within the stone. The photothermal mechanism of holmium:YAG lithotripsy is uniquely different than other lithotripsy devices. We postulated that bacterial viability of struvite calculi would be less for calculi fragmented with holmium:YAG irradiation compared to other lithotripsy devices. Human calculi of known struvite composition (greater than 90% magnesium ammonium phosphate hexahydrate) were incubated with Proteus mirabilis. Calculi were fragmented with no lithotripsy (controls), or shock wave, intracorporeal ultrasonic, electrohydraulic, pneumatic, holmium:YAG or pulsed dye laser lithotripsy. After lithotripsy, stone fragments were sonicated and specimens were serially plated for 48 hours at 38 C. Bacterial counts and the rate of bacterial sterilization were compared. Median bacterial counts (colony forming units per ml) were 8 X 106 in controls and 3 X 106 in shock wave, 3 X 107 in ultrasonic, 4 X 105 in electrohydraulic, 8 X 106 in pneumatic, 5 X 104 in holmium:YAG and 1 X 106 in pulsed dye laser lithotripsy, p less than 0.001. The rate of bacterial sterilization was 50% for holmium:YAG lithotripsy treated stones versus 0% for each of the other cohorts, p less than 0.01. P. mirabilis viability is less after holmium:YAG irradiation compared to other lithotripsy devices.

Influence of lead on stabilization/solidification by ordinary Portland cement and magnesium phosphate cement.

PubMed

Wang, Yan-Shuai; Dai, Jian-Guo; Wang, Lei; Tsang, Daniel C W; Poon, Chi Sun

2018-01-01

Inorganic binder-based stabilization/solidification (S/S) of Pb-contaminated soil is a commonly used remediation approach. This paper investigates the influences of soluble Pb species on the hydration process of two types of inorganic binders: ordinary Portland cement (OPC) and magnesium potassium phosphate cement (MKPC). The environmental leachability, compressive strength, and setting time of the cement products are assessed as the primary performance indicators. The mechanisms of Pb involved in the hydration process are analyzed through X-ray diffraction (XRD), hydration heat evolution, and thermogravimetric analyses. Results show that the presence of Pb imposes adverse impact on the compressive strength (decreased by 30.4%) and the final setting time (prolonged by 334.7%) of OPC, but it exerts much less influence on those of MKPC. The reduced strength and delayed setting are attributed to the retarded hydration reaction rate of OPC during the induction period. These results suggest that the OPC-based S/S of soluble Pb mainly depends on physical encapsulation by calcium-silicate-hydrate (CSH) gels. In contrast, in case of MKPC-based S/S process, chemical stabilization with residual phosphate (pyromorphite and lead phosphate precipitation) and physical fixation of cementitious struvite-K are the major mechanisms. Therefore, MKPC is a more efficient and chemically stable inorganic binder for the Pb S/S process. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ceramic Adhesive for High Temperatures

NASA Technical Reports Server (NTRS)

Stevens, Everett G.

1987-01-01

Fused-silica/magnesium-phosphate adhesive resists high temperatures and vibrations. New adhesive unaffected by extreme temperatures and vibrations. Assuring direct bonding of gap filters to tile sidewalls, adhesive obviates expensive and time-consuming task of removal, treatment, and replacement of tiles.

Maxillary sinus floor elevation using a tissue-engineered bone with calcium-magnesium phosphate cement and bone marrow stromal cells in rabbits.

PubMed

Zeng, Deliang; Xia, Lunguo; Zhang, Wenjie; Huang, Hui; Wei, Bin; Huang, Qingfeng; Wei, Jie; Liu, Changsheng; Jiang, Xinquan

2012-04-01

The objective of this study was to assess the effects of maxillary sinus floor elevation with a tissue-engineered bone constructed with bone marrow stromal cells (bMSCs) and calcium-magnesium phosphate cement (CMPC) material. The calcium (Ca), magnesium (Mg), and phosphorus (P) ions released from calcium phosphate cement (CPC), magnesium phosphate cement (MPC), and CMPC were detected by inductively coupled plasma atomic emission spectroscopy (ICP-AES), and the proliferation and osteogenic differentiation of bMSCs seeded on CPC, MPC, and CMPC or cultured in CPC, MPC, and CMPC extracts were measured by MTT analysis, alkaline phosphatase (ALP) activity assay, alizarin red mineralization assay, and real-time PCR analysis of the osteogenic genes ALP and osteocalcin (OCN). Finally, bMSCs were combined with CPC, MPC, and CMPC and used for maxillary sinus floor elevation in rabbits, while CPC, MPC, or CMPC without cells served as control groups. The new bone formation in each group was detected by histological finding and fluorochrome labeling at weeks 2 and 8 after surgical operation. It was observed that the Ca ion concentrations of the CMPC and CPC scaffolds was significantly higher than that of the MPC scaffold, while the Mg ions concentration of CMPC and MPC was significantly higher than that of CPC. The bMSCs seeded on CMPC and MPC or cultured in their extracts proliferated more quickly than the cells seeded on CPC or cultured in its extract, respectively. The osteogenic differentiation of bMSCs seeded on CMPC and CPC or cultured in the corresponding extracts was significantly enhanced compared to that of bMSCs seeded on MPC or cultured in its extract; however, there was no significant difference between CMPC and CPC. As for maxillary sinus floor elevation in vivo, CMPC could promote more new bone formation and mineralization compared to CPC and MPC, while the addition of bMSCs could further enhance its new bone formation ability significantly. Our data suggest that CMPC possesses moderate biodegradability and excellent osteoconductivity, which may be attributed to its Ca and Mg ion composition, and the tissue-engineered bone constructed of CMPC and bMSCs might be a potential alterative graft for maxillofacial bone regeneration.

Phosphate Mines, Jordan

NASA Technical Reports Server (NTRS)

2008-01-01

Jordan's leading industry and export commodities are phosphate and potash, ranked in the top three in the world. These are used to make fertilizer. The Jordan Phosphate Mines Company is the sole producer, having started operations in 1935. In addition to mining activities, the company produces phosphoric acid (for fertilizers, detergents, pharmaceuticals), diammonium phosphate (for fertilizer), sulphuric acid (many uses), and aluminum fluoride (a catalyst to make aluminum and magnesium).

The image covers an area of 27.5 x 49.4 km, was acquired on September 17, 2005, and is located near 30.8 degrees north latitude, 36.1 degrees east longitude.

The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

Preliminary research on a novel bioactive silicon doped calcium phosphate coating on AZ31 magnesium alloy via electrodeposition.

PubMed

Qiu, Xun; Wan, Peng; Tan, Lili; Fan, Xinmin; Yang, Ke

2014-03-01

A silicon doped calcium phosphate coating was obtained successfully on AZ31 alloy substrate via pulse electrodeposition. A novel dual-layer structure was observed with a porous lamellar-like and outer block-like apatite layer. In vitro immersion tests were adopted in simulated body fluid within 28 days of immersion. Slow degradation rate obtained from weight loss was observed for the Si-doped Ca-P coating, which was also consistent with the results of electrochemical experiments showing an enhanced corrosion resistance for the coating. Further formation of an apatite-like layer on the surface after immersion proved better integrity and biomineralization performance of the coating. Biological characterization was carried out for viability, proliferation and differentiation of MG63 osteoblast-like cells. The coating showed a good cell growth and an enhanced cell proliferation. Moreover, an increased activity of osteogenic marker ALP was found. All the results demonstrated that the Si-doped calcium phosphate was perspective to be used as a coating for magnesium alloy implants to control the degradation rate and enhance the bioactivity, which would facilitate the rapidity of bone tissue repair. Copyright © 2013 Elsevier B.V. All rights reserved.

Chloroplast Phosphofructokinase

PubMed Central

Kelly, Grahame J.; Latzko, Erwin

1977-01-01

Chloroplast phosphofructokinase from spinach (Spinacia oleracea L.) was purified approximately 40-fold by a combination of fractionations with ammonium sulfate and acetone followed by chromatography on DEAE-Sephadex A-50. Positive cooperative kinetics was observed for the interaction between the enzyme and the substrate fructose 6-phosphate. The optimum pH shifted from 7.7 toward 7.0 as the fructose 6-phosphate concentration was taken below 0.5 mm. The second substrate was MgATP2− (Michaelis constant 30 μm). Free ATP inhibited the enzyme. Chloroplast phosphofructokinase was sensitive to inhibition by low concentration of phosphoenolpyruvate and glycolate 2-phosphate (especially at higher pH); these compounds inhibited in a positively cooperative fashion. Inhibitions by glycerate 2-phosphate (and probably glycerate 3-phosphate), citrate, and inorganic phosphate were also recorded; however, inorganic phosphate effectively relieved the inhibitions by phosphoenolpyruvate and glycolate 2-phosphate. These regulatory properties are considered to complement those of ADP-glucose pyrophosphorylase and fructosebisphosphatase in the regulation of chloroplast starch metabolism. PMID:16660079

Formation of glycolaldehyde phosphate from glycolaldehyde in aqueous solution

NASA Technical Reports Server (NTRS)

Krishnamurthy, R.; Arrhenius, G.; Eschenmoser, A.; Bada, J. L. (Principal Investigator)

1999-01-01

Amidotriphosphate (0.1 M) in aqueous solution at near neutral pH in the presence of magnesium ions (0.25 M) converts glycolaldehyde (0.025 M) within days at room temperature into glycolaldehyde phosphate in (analytically) nearly quantitative yields (76% in isolated product). This robust phosphorylation process was observed to proceed at concentrations as low as 30 microM glycolaldehyde and 60 microM phosphorylation reagent under otherwise identical conditions. In sharp contrast, attempts to achieve a phosphorylation of glycolaldehyde with cyclotriphosphate ('trimetaphosphate') as phosphorylating reagent were unsuccessful. Mechanistically, the phosphorylation of glycolaldehyde with amidotriphosphate is an example of intramolecular delivery of the phosphate group.

Interconversion of large packets and small groups of cells of Micrococcus rubens: dependence upon magnesium and phosphate.

PubMed Central

Yamada, M; Koyama, T; Matsuhashi, M

1977-01-01

Micrococcus rubens, a gram-positive occus, usually forms large, cubic packets of more than 500 cells that are regularly arranged in three-dimensional cell groups. In medium with extremely low concentration of Mg2+ and phosphate, in which the cells can only grow on a agar surface, it formed small groups of 2 to 20 cells. Irregularly arraged cell groups of intermediated size were obtained in culture media containing intermediated concentrations of Mg2+ and phosphate. Mutants that formed irregular cell groups of intermediate size under normal culture conditions were also obtained. Images PMID:845123

Phosphorus K-edge XANES spectroscopy of mineral standards

PubMed Central

Ingall, Ellery D.; Brandes, Jay A.; Diaz, Julia M.; de Jonge, Martin D.; Paterson, David; McNulty, Ian; Elliott, W. Crawford; Northrup, Paul

2011-01-01

Phosphorus K-edge X-ray absorption near-edge structure (XANES) spectroscopy was performed on phosphate mineral specimens including (a) twelve specimens from the apatite group covering a range of compositional variation and crystallinity; (b) six non-apatite calcium-rich phosphate minerals; (c) 15 aluminium-rich phosphate minerals; (d) ten phosphate minerals rich in either reduced iron or manganese; (e) four phosphate minerals rich in either oxidized iron or manganese; (f) eight phosphate minerals rich in either magnesium, copper, lead, zinc or rare-earth elements; and (g) four uranium phosphate minerals. The identity of all minerals examined in this study was independently confirmed using X-ray powder diffraction. Minerals were distinguished using XANES spectra with a combination of pre-edge features, edge position, peak shapes and post-edge features. Shared spectral features were observed in minerals with compositions dominated by the same specific cation. Analyses of apatite-group minerals indicate that XANES spectral patterns are not strongly affected by variations in composition and crystallinity typical of natural mineral specimens. PMID:21335905

Osmotic pressures and second virial coefficients for aqueous saline solutions of lysozyme

DOE PAGES

Moon, Y. U.; Anderson, C. O.; Blanch, H. W.; ...

2000-03-27

Experimental data at 25 °C are reported for osmotic pressures of aqueous solutions containing lysozyme and any one of the following salts: ammonium sulfate, ammonium oxalate and ammonium phosphate at ionic strength 1 or 3M. Data were obtained using a Wescor Colloid Membrane Osmometer at lysozyme concentrations from about 4 to 20 grams per liter at pH 4, 7 or 8. Osmotic second virial coefficients for lysozyme were calculated from the osmotic-pressure data. All coefficients were negative, increasing in magnitude with ionic strength. Furthermore, tesults are insensitive to the nature of the anion, but rise slightly in magnitude as themore » size of the anion increases.« less

Magnesium reduces calcification in bovine vascular smooth muscle cells in a dose-dependent manner

PubMed Central

Peter, Mirjam E.; Sevinc Ok, Ebru; Celenk, Fatma Gul; Yilmaz, Mumtaz; Steppan, Sonja; Asci, Gulay; Ok, Ercan; Passlick-Deetjen, Jutta

2012-01-01

Background. Vascular calcification (VC), mainly due to elevated phosphate levels, is one major problem in patients suffering from chronic kidney disease. In clinical studies, an inverse relationship between serum magnesium and VC has been reported. However, there is only few information about the influence of magnesium on calcification on a cellular level available. Therefore, we investigated the effect of magnesium on calcification induced by β-glycerophosphate (BGP) in bovine vascular smooth muscle cells (BVSMCs). Methods. BVSMCs were incubated with calcification media for 14 days while simultaneously increasing the magnesium concentration. Calcium deposition, transdifferentiation of cells and apoptosis were measured applying quantification of calcium, von Kossa and Alizarin red staining, real-time reverse transcription–polymerase chain reaction and annexin V staining, respectively. Results. Calcium deposition in the cells dramatically increased with addition of BGP and could be mostly prevented by co-incubation with magnesium. Higher magnesium levels led to inhibition of BGP-induced alkaline phosphatase activity as well as to a decreased expression of genes associated with the process of transdifferentiation of BVSMCs into osteoblast-like cells. Furthermore, estimated calcium entry into the cells decreased with increasing magnesium concentrations in the media. In addition, higher magnesium concentrations prevented cell damage (apoptosis) induced by BGP as well as progression of already established calcification. Conclusions. Higher magnesium levels prevented BVSMC calcification, inhibited expression of osteogenic proteins, apoptosis and further progression of already established calcification. Thus, magnesium is influencing molecular processes associated with VC and may have the potential to play a role for VC also in clinical situations. PMID:21750166

Alkali corrosion resistant coatings and ceramic foams having superfine open cell structure and method of processing

DOEpatents

Brown, Jr., Jesse J.; Hirschfeld, Deidre A.; Li, Tingkai

1993-12-07

Alkali corrosion resistant coatings and ceramic foams having superfine open cell structure are created using sol-gel processes. The processes have particular application in creating calcium magnesium zirconium phosphate, CMZP, coatings and foams.

Factors affecting the hydrochemistry of a mangrove tidal creek, sepetiba bay, Brazil

NASA Astrophysics Data System (ADS)

Ovalle, A. R. C.; Rezende, C. E.; Lacerda, L. D.; Silva, C. A. R.

1990-11-01

We studied the porewater chemistry, and spatial and temporal variation of mangrove creek hydrochemistry. Except for nitrate porewater, the concentrations of nutrients we analysed were higher than for creek water. Groundwater is a source of silica and phosphate, whereas total alkalinity and ammonium are related to mangrove porewater migration to the creek. Open bay waters contribute chlorine, dissolved oxygen and elevated pH. The results also suggest that nitrate is related to nitrification inside the creek. During flood tides, salinity, chlorine, dissolved oxygen and pH increase, whereas total alkalinity decreases. This pattern is reversed at ebb tides. Silica, phosphate, nitrate and ammonium show an erratic behaviour during the tidal cycle. Tidal dynamics, precipitation events and nitrification inside the creek were identified as major control factors and an estimate of tidal exchanges indicate that the system is in an equilibrium state.

Predicting stability of DNA duplexes in solutions containing magnesium and monovalent cations.

PubMed

Owczarzy, Richard; Moreira, Bernardo G; You, Yong; Behlke, Mark A; Walder, Joseph A

2008-05-13

Accurate predictions of DNA stability in physiological and enzyme buffers are important for the design of many biological and biochemical assays. We therefore investigated the effects of magnesium, potassium, sodium, Tris ions, and deoxynucleoside triphosphates on melting profiles of duplex DNA oligomers and collected large melting data sets. An empirical correction function was developed that predicts melting temperatures, transition enthalpies, entropies, and free energies in buffers containing magnesium and monovalent cations. The new correction function significantly improves the accuracy of predictions and accounts for ion concentration, G-C base pair content, and length of the oligonucleotides. The competitive effects of potassium and magnesium ions were characterized. If the concentration ratio of [Mg (2+)] (0.5)/[Mon (+)] is less than 0.22 M (-1/2), monovalent ions (K (+), Na (+)) are dominant. Effects of magnesium ions dominate and determine duplex stability at higher ratios. Typical reaction conditions for PCR and DNA sequencing (1.5-5 mM magnesium and 20-100 mM monovalent cations) fall within this range. Conditions were identified where monovalent and divalent cations compete and their stability effects are more complex. When duplexes denature, some of the Mg (2+) ions associated with the DNA are released. The number of released magnesium ions per phosphate charge is sequence dependent and decreases surprisingly with increasing oligonucleotide length.

Calcium Solubility and Cation Exchange Properties in Zeoponic Soil

NASA Technical Reports Server (NTRS)

Beiersdorfer, Raymond E.

1999-01-01

An important aspect of a regenerative life support system at a Lunar or Martian outpost is the ability to produce food. Essential plant nutrients, as well as a solid support substrate, can be provided by: (1) treated Lunar or Martian regolith; (2) a synthetic soil or (3) some combination of both. A synthetic soil composed of ammonium- and potassium-saturated chinoptlolite (a zeolite mineral) and apatite, can provide slow-release fertilization of plants via dissolution and ion-exchange reactions. Previous equilibrium studies (Beiersdorfer, 1997) on mixtures of synthetic hydroxyapatite and saturated-clinoptilolite indicate that the concentrations of macro-nutrients such as ammonium, phosphorous, potassium, magnesium, and calcium are a function of the ratio of chinoptilolite to apatite in the sample and to the ratio of potassium to ammonium on the exchange sites in the clinoptilolite. Potassium, ammonium, phosphorous, and magnesium are available to plants at sufficient levels. However, calcium is deficient, due to the high degree of calcium adsorption by the clinoptilolite. Based on a series of batch-equilibration experiments, this calcium deficiency can be reduced by (1) treating the clinoptilolite with CaNO3 or (2) adding a second Ca-bearing mineral (calcite, dolomite or wollastonite) to the soil. Treating the Cp with CaNO3 results in increased Ca in solution, decreased P in solution and decreased NH4 in solution. Concentrations of K were not effected by the CaNO3 treatment. Additions of Cal, Dol and Wol changed the concentrations of Ca and P in solution in a systematic fashion. Cal has the greatest effect, Dol the least and Wol is intermediate. The changes are consistent with changes expected for a common ion effect with Ca. Higher concentrations of Ca in solution with added Cal, Dol or Wol do not result in changes in K or NH4 concentrations.

Quality of drinking water from the agricultural area treated with pitcher water filters

PubMed

Królak, Elżbieta; Raczuk, Jolanta; Sakowicz, Danuta; Biardzka, Elżbieta

Home methods of drinking water treatment through filtration have recently become quite popular. The aim of the study was to compare chemical composition of unfiltered water with water filtered in households with pitcher water filters. Obtained results were discussed in view of the effect of analysed chemical components of water on human health. Water samples were taken from water works supplies and from home dug wells from the agricultural area. Unfiltered water and water filtered through filters filled with active carbon and ion-exchanging resin and placed in a pitcher were analysed. Electrolytic conductivity, pH, hardness and the concentrations of calcium, magnesium, nitrate, phosphate and chloride ions were determined in water samples. Results of analyses were statistically processed. As a result of water filtration, the concentration of phosphates significantly increased and the concentrations of calcium, magnesium, electrolytic conductivity and pH decreased. No changes were noted in the concentration of chloride ions. Filtering water decreased the concentration of nitrates in dug wells samples. Using water purification devices is justified in the case of water originating from home dug wells contaminated with nitrates when, at the same time, consumers’ diet is supplemented with calcium and magnesium. Filtration of water from water works supplies, controlled by sanitary inspection seems aimless.

Curing and Characterization of Siloxanecarbonate Polymers

DTIC Science & Technology

1980-01-01

to 93 percent yields of p-bromophenol-Z-tetrahydropyranyl ether. The Grignard reagent made from the protected phenol in tetrahydrofuran was added to...iodomethane and heating. When all of the magnesium appeared to have been consumed, the resulting Grignard reagent was added via a double-tipped needle...7-dichlorooctamethyltetrasiloxane via the Grignard reaction. Workup of the reaction product with aqueous ammonium chloride solution kept the molecule

Elevated dietary magnesium during pregnancy and postnatal life prevents ectopic mineralization in Enpp1asj mice, a model for generalized arterial calcification of infancy.

PubMed

Kingman, Joshua; Uitto, Jouni; Li, Qiaoli

2017-06-13

Generalized arterial calcification of infancy (GACI) is an autosomal recessive disorder caused by mutations in the ENPP1 gene. It is characterized by mineralization of the arterial blood vessels, often diagnosed prenatally, and associated with death in early childhood. There is no effective treatment for this devastating disorder. We previously characterized the Enpp1asjmutant mouse as a model of GACI, and we have now explored the effect of elevated dietary magnesium (five-fold) in pregnant mothers and continuing for the first 14 weeks of postnatal life. The mothers were kept on either control diet or experimental diet supplemented with magnesium. Upon weaning at 4 weeks of age the pups were placed either on control diet or high magnesium diet. The degree of mineralization was assessed at 14 weeks of age by histopathology and a chemical calcium assay in muzzle skin, kidney and aorta. Mice placed on high magnesium diet showed little, if any, evidence of mineralization when their corresponding mothers were also placed on diet enriched with magnesium during pregnancy and nursing. The reduced ectopic mineralization in these mice was accompanied by increased calcium and magnesium content in the urine, suggesting that magnesium competes calcium-phosphate binding thereby preventing the mineral deposition. These results have implications for dietary management of pregnancies in which the fetus is suspected of having GACI. Moreover, augmenting a diet with high magnesium may be beneficial for other ectopic mineralization diseases, including nephrocalcinosis.

Increased water hardness and magnesium levels may increase occurrence of urolithiasis in cows from the Burdur region (Turkey).

PubMed

Sahinduran, S; Buyukoglu, T; Gulay, M S; Tasci, F

2007-08-01

Objectives of the study were to measure water hardness in Burdur, and to establish its possible association with urolithiasis in cattle. Water samples were obtained from different stables (n = 15). Water hardness and the concentrations of potassium, calcium, magnesium, sodium, iron, zinc, manganese and copper ions were calculated from these water samples. Total hardness of the samples (mean 285 ppm) exceeded the standards and the water was characterized by high content of magnesium ions. Kidneys (n = 500) were collected randomly from slaughterhouses and examined for urolithiasis. Urolithiasis was observed in 102 kidneys (20.4%). The weights of the stones were between 0.02 and 237.44 g and the colour varied from white to brown. The calculi collected had various shapes and composed of calcium apatite (42.45%), struvite (20.15%), magnesium carbonate (15.15%), calcium carbonate (12.12%), and calcium phosphate cystine (10.13%). It was concluded that high water hardness with high magnesium ion concentrations in water may contribute to urolithiasis and needs to be investigated further in future studies.

A Study on Factors Affecting the Degradation of Magnesium and a Magnesium-Yttrium Alloy for Biomedical Applications

PubMed Central

Johnson, Ian; Liu, Huinan

2013-01-01

Controlling degradation of magnesium or its alloys in physiological saline solutions is essential for their potential applications in clinically viable implants. Rapid degradation of magnesium-based materials reduces the mechanical properties of implants prematurely and severely increases alkalinity of the local environment. Therefore, the objective of this study is to investigate the effects of three interactive factors on magnesium degradation, specifically, the addition of yttrium to form a magnesium-yttrium alloy versus pure magnesium, the metallic versus oxide surfaces, and the presence versus absence of physiological salt ions in the immersion solution. In the immersion solution of phosphate buffered saline (PBS), the magnesium-yttrium alloy with metallic surface degraded the slowest, followed by pure magnesium with metallic or oxide surfaces, and the magnesium-yttrium alloy with oxide surface degraded the fastest. However, in deionized (DI) water, the degradation rate showed a different trend. Specifically, pure magnesium with metallic or oxide surfaces degraded the slowest, followed by the magnesium-yttrium alloy with oxide surface, and the magnesium-yttrium alloy with metallic surface degraded the fastest. Interestingly, only magnesium-yttrium alloy with metallic surface degraded slower in PBS than in DI water, while all the other samples degraded faster in PBS than in DI water. Clearly, the results showed that the alloy composition, presence or absence of surface oxide layer, and presence or absence of physiological salt ions in the immersion solution all influenced the degradation rate and mode. Moreover, these three factors showed statistically significant interactions. This study revealed the complex interrelationships among these factors and their respective contributions to degradation for the first time. The results of this study not only improved our understanding of magnesium degradation in physiological environment, but also presented the key factors to consider in order to satisfy the degradation requirements for next-generation biodegradable implants and devices. PMID:23799028

Effect of pH on uranium(VI) biosorption and biomineralization by Saccharomyces cerevisiae.

PubMed

Zheng, X Y; Shen, Y H; Wang, X Y; Wang, T S

2018-07-01

Biosorption of radionuclides by microorganisms is a promising and effective method for the remediation of contaminated areas. pH is the most important factor during uranium biosorption by Saccharomyces cerevisiae because the pH value not only affects the biosorption rate but also affects the precipitation structure. This study investigated the effect of pH on uranium (VI) biosorption and biomineralization by S. cerevisiae. Cells have the ability to buffer the solution to neutral, allowing the biosorption system to reach an optimal level regardless of the initial pH value. This occurs because there is a release of phosphate and ammonium ions during the interaction between cells and uranium. The uranyl and phosphate ions formed nano-particles, which is chernikovite H 2 (UO 2 ) 2 (PO 4 ) 2 ·8H 2 O (PDF #08-0296), on cell surface under the initial acidic conditions. However, under the initial alkaline conditions, the uranyl, phosphate and ammonium ions formed a large amount of scale-like precipitation, which is uramphite (NH 4 )(UO 2 )PO 4 ·3H 2 O (PDF #42-0384), evenly over on cell surface. Copyright © 2018 Elsevier Ltd. All rights reserved.

Magnesium modification up-regulates the bioactivity of bone morphogenetic protein-2 upon calcium phosphate cement via enhanced BMP receptor recognition and Smad signaling pathway.

PubMed

Ding, Sai; Zhang, Jing; Tian, Yu; Huang, Baolin; Yuan, Yuan; Liu, Changsheng

2016-09-01

Efficient presentation of growth factors is one of the great challenges in tissue engineering. In living systems, bioactive factors exist in soluble as well as in matrix-bound forms, both of which play an integral role in regulating cell behaviors. Herein, effect of magnesium on osteogenic bioactivity of recombinant human bone morphogenetic protein-2 (rhBMP-2) was investigated systematically with a series of Mg modified calcium phosphate cements (xMCPCs, x means the content of magnesium phosphate cement wt%) as matrix model. The results indicated that the MCPC, especially 5MCPC, could promote the rhBMP-2-induced in vitro osteogenic differentiation via Smad signaling of C2C12 cells. Further studies demonstrated that all MCPC substrates exhibited similar rhBMP-2 release rate and preserved comparable conformation and biological activity of the released rhBMP-2. Also, the ionic extracts of MCPC made little difference to the bioactivity of rhBMP-2, either in soluble or in matrix-bound forms. However, with the quartz crystal microbalance (QCM), we observed a noticeable enhancement of rhBMP-2 mass-uptake on 5MCPC as well as a better recognition of the bound rhBMP-2 to BMPR IA and BMPR II. In vivo results demonstrated a better bone regeneration capacity of 5MCPC/rhBMP-2. From the above, our results demonstrated that it was the Mg anchored on the underlying substrates that tailored the way of rhBMP-2 bound on MCPC, and thus facilitated the recognition of BMPRs to stimulate osteogenic differentiation. The study will guide the development of Mg-doped bioactive bone implants for tissue regeneration. Copyright © 2016 Elsevier B.V. All rights reserved.

Nanostructured calcium phosphate coatings on magnesium alloys: characterization and cytocompatibility with mesenchymal stem cells.

PubMed

Iskandar, Maria Emil; Aslani, Arash; Tian, Qiaomu; Liu, Huinan

2015-05-01

This article reports the deposition and characterization of nanostructured calcium phosphate (nCaP) on magnesium-yttrium alloy substrates and their cytocompatibility with bone marrow derived mesenchymal stem cells (BMSCs). The nCaP coatings were deposited on magnesium and magnesium-yttrium alloy substrates using proprietary transonic particle acceleration process for the dual purposes of modulating substrate degradation and BMSC adhesion. Surface morphology and feature size were analyzed using scanning electron microscopy and quantitative image analysis tools. Surface elemental compositions and phases were analyzed using energy dispersive X-ray spectroscopy and X-ray diffraction, respectively. The deposited nCaP coatings showed a homogeneous particulate surface with the dominant feature size of 200-500 nm in the long axis and 100-300 nm in the short axis, and a Ca/P atomic ratio of 1.5-1.6. Hydroxyapatite was the major phase identified in the nCaP coatings. The modulatory effects of nCaP coatings on the sample degradation and BMSC behaviors were dependent on the substrate composition and surface conditions. The direct culture of BMSCs in vitro indicated that multiple factors, including surface composition and topography, and the degradation-induced changes in media composition, influenced cell adhesion directly on the sample surface, and indirect adhesion surrounding the sample in the same culture. The alkaline pH, the indicator of Mg degradation, played a role in BMSC adhesion and morphology, but not the sole factor. Additional studies are necessary to elucidate BMSC responses to each contributing factor.

Effect of Ramadan fasting on urinary risk factors for calculus formation.

PubMed

Miladipour, Amir Hossein; Shakhssalim, Nasser; Parvin, Mahmoud; Azadvari, Mohaddeseh

2012-01-01

Even though dehydration could aggravate formation of urinary calculi, the effects of fluid and food restriction on calculus formation is not thoroughly defined. The purpose of this study is to evaluate the effects of fluid and food restriction in Ramadan fasting on urinary factors in kidney and urinary calculus formation. Fifty-seven men aged 30 to 55 years old, including 37 recurrent calcium calculus formers and 20 with no history of kidney calculi were evaluated for blood tests, ultrasonography investigations, urinalysis, urine culture, and also 24-hour urine collection test. Metabolites including calcium, oxalate, citrate, uric acid, magnesium, phosphate, potassium, sodium, and creatinine were measured before and during Ramadan fasting. The values of calculus-precipitating solutes as well as inhibitory factors were documented thoroughly. Total excretion of calcium, phosphate, and magnesium in 24-hour urine and also urine volume during fasting were significantly lower than those in the nonfasting period. Urine concentration of calcium during fasting was significantly lower than nonfasting (P < .001). Urine concentrations of uric acid, citrate, phosphate, sodium, and potassium during fasting were significantly higher than nonfasting. Uric acid supersaturation was accentuated, and calcium phosphate supersaturation was decreased significantly during fasting. There was no significant increase in calcium oxalate supersaturation during the fasting period. Fasting during Ramadan has different effects on total excretion and concentrations of urinary precipitate and inhibitory factors contributing to calculus formation. We did not find enough evidence in favor of increased risks of calculus formation during Ramadan fasting.

Recovery of ammonia and phosphate minerals from swine wastewater using gas-permeable membranes

USDA-ARS?s Scientific Manuscript database

Gas-permeable membrane technology is useful to recover ammonia from liquid manures. In this study, phosphorus (P) recovery via magnesium chloride precipitation was enhanced by combining it with ammonia recovery through gas-permeable membranes. Anaerobically digested swine effluent containing approx...

Enzymatic, urease-mediated mineralization of gellan gum hydrogel with calcium carbonate, magnesium-enriched calcium carbonate and magnesium carbonate for bone regeneration applications.

PubMed

Douglas, Timothy E L; Łapa, Agata; Samal, Sangram Keshari; Declercq, Heidi A; Schaubroeck, David; Mendes, Ana C; der Voort, Pascal Van; Dokupil, Agnieszka; Plis, Agnieszka; De Schamphelaere, Karel; Chronakis, Ioannis S; Pamuła, Elżbieta; Skirtach, Andre G

2017-12-01

Mineralization of hydrogel biomaterials is considered desirable to improve their suitability as materials for bone regeneration. Calcium carbonate (CaCO 3 ) has been successfully applied as a bone regeneration material, but hydrogel-CaCO 3 composites have received less attention. Magnesium (Mg) has been used as a component of calcium phosphate biomaterials to stimulate bone-forming cell adhesion and proliferation and bone regeneration in vivo, but its effect as a component of carbonate-based biomaterials remains uninvestigated. In the present study, gellan gum (GG) hydrogels were mineralized enzymatically with CaCO 3 , Mg-enriched CaCO 3 and magnesium carbonate to generate composite biomaterials for bone regeneration. Hydrogels loaded with the enzyme urease were mineralized by incubation in mineralization media containing urea and different ratios of calcium and magnesium ions. Increasing the magnesium concentration decreased mineral crystallinity. At low magnesium concentrations calcite was formed, while at higher concentrations magnesian calcite was formed. Hydromagnesite (Mg 5 (CO 3 ) 4 (OH) 2 .4H 2 O) formed at high magnesium concentration in the absence of calcium. The amount of mineral formed and compressive strength decreased with increasing magnesium concentration in the mineralization medium. The calcium:magnesium elemental ratio in the mineral formed was higher than in the respective mineralization media. Mineralization of hydrogels with calcite or magnesian calcite promoted adhesion and growth of osteoblast-like cells. Hydrogels mineralized with hydromagnesite displayed higher cytotoxicity. In conclusion, enzymatic mineralization of GG hydrogels with CaCO 3 in the form of calcite successfully reinforced hydrogels and promoted osteoblast-like cell adhesion and growth, but magnesium enrichment had no definitive positive effect. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Microwave assisted coating of bioactive amorphous magnesium phosphate (AMP) on polyetheretherketone (PEEK).

PubMed

Ren, Yufu; Sikder, Prabaha; Lin, Boren; Bhaduri, Sarit B

2018-04-01

Polyetheretherketone (PEEK) with great thermal and chemical stability, desirable mechanical properties and promising biocompatibility is being widely used as orthopedic and dental implant materials. However, the bioinert surface of PEEK can hinder direct osseointegration between the host tissue and PEEK based implants. The important signatures of this paper are as follows. First, we report for the formation of osseointegrable amorphous magnesium phosphate (AMP) coating on PEEK surface using microwave energy. Second, coatings consist of nano-sized AMP particles with a stacked thickness of 800nm. Third, coatings enhance bioactivity in-vitro and induce significantly high amount of bone-like apatite coating, when soaked in simulated body fluid (SBF). Fourth, the as-deposited AMP coatings present no cytotoxicity effects and are beneficial for cell adhesion at early stage. Finally, the high levels of expression of osteocalcin (OCN) in cells cultured on AMP coated PEEK samples indicate that AMP coatings can promote new bone formation and hence osseointegration. Copyright © 2017 Elsevier B.V. All rights reserved.

Growth of calcium phosphates on magnesium substrates for corrosion control in biomedical applications via immersion techniques.

PubMed

Shadanbaz, Shaylin; Walker, Jemimah; Staiger, Mark P; Dias, George J; Pietak, Alexis

2013-01-01

Magnesium (Mg) has been suggested as a revolutionary biodegradable replacement for current permanent metals used in orthopedic applications. Current investigations concentrate on the control of the corrosion rate to match bone healing. Calcium phosphate coatings have been a recent focus of these investigations through various coating protocols. Within this investigation, an in situ crystallization technique was utilized as an inexpensive and relatively simple method to produce a brushite and monetite coating on pure Mg. Coatings were characterized using energy dispersive spectroscopy, glancing angle X-ray diffraction and field emission scanning electron microscopy. Corrosion protection properties of the coatings were assessed in physiological buffers, Earles balanced salt solution, minimum essential media, and minimum essential media containing serum albumin, over a 4-week period. Using this novel coating protocol, our findings indicate brushite and monetite coated Mg to have significant corrosive protective effects when compared with its uncoated counterpart whilst maintaining high coating substrate adhesion, homogeneity, and reproducibility. Copyright © 2012 Wiley Periodicals, Inc.

URINE SOURCE SEPARATION AND TREATMENT: NUTRIENT RECOVERY USING LOW-COST MATERIALS

EPA Science Inventory

Successful completion of this P3 Project will achieve the following expected outputs: identification of low-cost materials that can effectively recover ammonium, phosphate, and potassium from urine; material balance calculations for different urine separation and treatment scheme...

A magnesium based phosphate binder reduces vascular calcification without affecting bone in chronic renal failure rats.

PubMed

Neven, Ellen; De Schutter, Tineke M; Dams, Geert; Gundlach, Kristina; Steppan, Sonja; Büchel, Janine; Passlick-Deetjen, Jutta; D'Haese, Patrick C; Behets, Geert J

2014-01-01

The alternative phosphate binder calcium acetate/magnesium carbonate (CaMg) effectively reduces hyperphosphatemia, the most important inducer of vascular calcification, in chronic renal failure (CRF). In this study, the effect of low dose CaMg on vascular calcification and possible effects of CaMg on bone turnover, a persistent clinical controversy, were evaluated in chronic renal failure rats. Adenine-induced CRF rats were treated daily with 185 mg/kg CaMg or vehicle for 5 weeks. The aortic calcium content and area% calcification were measured to evaluate the effect of CaMg. To study the effect of CaMg on bone remodeling, rats underwent 5/6th nephrectomy combined with either a normal phosphorus diet or a high phosphorus diet to differentiate between possible bone effects resulting from either CaMg-induced phosphate deficiency or a direct effect of Mg. Vehicle or CaMg was administered at doses of 185 and 375 mg/kg/day for 8 weeks. Bone histomorphometry was performed. Aortic calcium content was significantly reduced by 185 mg/kg/day CaMg. CaMg ameliorated features of hyperparathyroid bone disease. In CRF rats on a normal phosphorus diet, the highest CaMg dose caused an increase in osteoid area due to phosphate depletion. The high phosphorus diet combined with the highest CaMg dose prevented the phosphate depletion and thus the rise in osteoid area. CaMg had no effect on osteoblast/osteoclast or dynamic bone parameters, and did not alter bone Mg levels. CaMg at doses that reduce vascular calcification did not show any harmful effect on bone turnover.

The composition of bulk precipitation on a coastal island with agriculture compared to an urban region

NASA Astrophysics Data System (ADS)

Weijers, E. P.; Vugts, H. F.

Results of chemical analyses of monthly bulk samples from Schiermonnikoog, one of the islands in the northern part of The Netherlands, are interpreted. The continuous record covers a period of more than 15 years. A comparison (10 years) is made with Ouderkerk, a village near Amsterdam. Non-sea salt contributions, relations between ion species, long-time trends, annual cycles and meteorological influence are discussed. The study reveals enhanced levels of ammonium in the Schiermonnikoog samples with respect to Ouderkerk. Also, concentrations of sulfate and nitrate were higher. The high concentrations of ammonium are ascribed to dry-deposited NH 3 caused by cattle breeding, the only economical activity on the island. A significant positive trend reflects its intensifying nature. Annual cycles and statistical computations indicate prior combination of parts of ammonium and excess sulfate as ammonium sulfate. The nitrate content appears to be strongly related to ammonium ( r = 079). In the Ouderkerk dataset this correspondence is much weaker (0.37), whereas its pH values are systematically lower. It is therefore believed that on Schiermonnikoog concentrations of nitrate are increased by nitrification of ammonium in the collector. Annual cycles of sodium, magnesium and chloride, and to a lesser extent potassium, are very similar (maximum concentrations in November, December and January, and a relative maximum in April). The other annual patterns peak in the first half of the year: maximum concentrations are found in February (ammonium, excess sulfate), June (nitrate), January (potassium) and in April (excess calcium). A combination of frequently occurring offshore winds and low precipitation amounts will account for this behavior.

Degradability, biocompatibility, and osteogenesis of biocomposite scaffolds containing nano magnesium phosphate and wheat protein both in vitro and in vivo for bone regeneration.

PubMed

Xia, Yan; Zhou, Panyu; Wang, Fei; Qiu, Chao; Wang, Panfeng; Zhang, Yuntong; Zhao, Liming; Xu, Shuogui

2016-01-01

In this study, bioactive scaffold of nano magnesium phosphate (nMP)/wheat protein (WP) composite (MWC) was fabricated. The results revealed that the MWC scaffolds had interconnected not only macropores (sized 400-600 μm) but also micropores (sized 10-20 μm) on the walls of macropores. The MWC scaffolds containing 40 w% nMP had an appropriate degradability in phosphate-buffered saline and produced a weak alkaline microenvironment. In cell culture experiments, the results revealed that the MWC scaffolds significantly promoted the MC3T3-E1 cell proliferation, differentiation, and growth into the scaffolds. The results of synchrotron radiation microcomputed tomography and analysis of the histological sections of the in vivo implantation revealed that the MWC scaffolds evidently improved the new bone formation and bone defects repair as compared with WP scaffolds. Moreover, it was found that newly formed bone tissue continued to increase with the gradual reduction of materials residual in the MWC scaffolds. Furthermore, the immunohistochemical analysis further offered the evidence of the stimulatory effects of MWC scaffolds on osteogenic-related cell differentiation and new bone regeneration. The results indicated that MWC scaffolds with good biocompability and degradability could promote osteogenesis in vivo, which would have potential for bone tissue repair.

Behavior of Osteoblast-Like Cells on a β-Tricalcium Phosphate Synthetic Scaffold Coated With Calcium Phosphate and Magnesium.

PubMed

Park, Ki-Deog; Jung, Young-Suk; Lee, Kyung-Ku; Park, Hong-Ju

2016-06-01

Tricalcium phosphate (TCP) is one of the most useful synthetic scaffolds for bone grafts and has several advantages. However, the rapid degradation of TCP makes it less osteoconductive than the other candidates, and represents a major shortcoming. To overcome this problem, the authors investigated magnesium (Mg) and/or hydroxyapatite (HA) coating on a β-TCP substrate using a sputtering technique. Biocompatibility tests were carried out on β-TCP discs that were either uncoated (TCP), coated with HA by radio frequency magnetron sputtering (HA-TCP), coated with Mg by DC sputtering (Mg-TCP), or multicoated with Mg and HA by DC and radio frequency magnetron sputtering (MgHA-TCP). Cells showed similar morphology in all 4 groups, and were widely spread, had flattened elongated shapes, and were connected to adjacent cells by pseudopods. An MTT assay revealed higher cell proliferation on HA-TCP, Mg-TCP, and MgHA-TCP compared with TCP at 3 and 5 days. MgHA-TCP also showed significantly higher alkaline phosphatase activity levels compared with TCP, HA-TCP, and Mg-TCP (P < 0.05). Results suggest that Mg-coated β-TCP could have great potential as a bone graft material for future applications in hard tissue regeneration.

The determination of calcium in phosphate, carbonate, and silicate rocks by flame photometer

USGS Publications Warehouse

Kramer, Henry

1956-01-01

A method has been developed for the determination of calcium in phosphate, carbonate, and silicate rocks using the Beckman flame photometer, with photomultiplier attachement. The sample is dissolved in hydrofluoric, nitric, and perchloric acids, the hydrofluoric and nitric acids are expelled, a radiation buffer consisting of aluminum, magnesium, iron, sodium, potassium, phosphoric acid, and nitric acid is added, and the solution is atomized in an oxy-hydrogen flame with an instrument setting of 554 mµ. Measurements are made by comparison against calcium standards, prepared in the same manner, in the 0 to 50 ppm range. The suppression of calcium emission by aluminum and phosphate was overcome by the addition of a large excess of magnesium. This addition almost completely restores the standard curve obtained from a solution of calcium nitrate. Interference was noted when the iron concentration in the aspirated solution (including the iron from the buffer) exceeded 100 ppm iron. Other common rock-forming elements did not interfere. The results obtained by this procedure are within ± 2 percent of the calcium oxide values obtained by other methods in the range 1 to 95 percent calcium oxide. In the 0 to 1 percent calcium oxide range the method compares favorably with standard methods.

Use of ammonium formate in QuEChERS for high-throughput analysis of pesticides in food by fast, low-pressure gas chromatography and liquid chromatography tandem mass spectrometry

USDA-ARS?s Scientific Manuscript database

The “quick, easy, cheap, effective, rugged, and safe” (QuEChERS) approach to sample preparation is widely applied in pesticide residue analysis, but the use of magnesium sulfate for salting out in the method is not ideal for mass spectrometry. In this study we developed and evaluated three new diffe...

Sonochemical synthesis of 1,2,4,5-tetrasubstituted imidazoles using nanocrystalline MgAl2O4 as an effective catalyst☆

PubMed Central

Safari, Javad; Gandomi-Ravandi, Soheila; Akbari, Zahra

2012-01-01

An efficient four-component synthesis of 1,2,4,5-tetrasubstituted imidazoles is described by one-step condensation of an aldehyde, benzil, ammonium acetate and primary aromatic amine with nanocrystalline magnesium aluminate in ethanol under ultrasonic irradiation. High yields, short reaction times, mild conditions, simplicity of operation and easy work-up are some advantages of this protocol. PMID:25685459

Bright carbonate deposits as evidence of aqueous alteration on (1) Ceres

NASA Astrophysics Data System (ADS)

de Sanctis, M. C.; Raponi, A.; Ammannito, E.; Ciarniello, M.; Toplis, M. J.; McSween, H. Y.; Castillo-Rogez, J. C.; Ehlmann, B. L.; Carrozzo, F. G.; Marchi, S.; Tosi, F.; Zambon, F.; Capaccioni, F.; Capria, M. T.; Fonte, S.; Formisano, M.; Frigeri, A.; Giardino, M.; Longobardo, A.; Magni, G.; Palomba, E.; McFadden, L. A.; Pieters, C. M.; Jaumann, R.; Schenk, P.; Mugnuolo, R.; Raymond, C. A.; Russell, C. T.

2016-08-01

The typically dark surface of the dwarf planet Ceres is punctuated by areas of much higher albedo, most prominently in the Occator crater. These small bright areas have been tentatively interpreted as containing a large amount of hydrated magnesium sulfate, in contrast to the average surface, which is a mixture of low-albedo materials and magnesium phyllosilicates, ammoniated phyllosilicates and carbonates. Here we report high spatial and spectral resolution near-infrared observations of the bright areas in the Occator crater on Ceres. Spectra of these bright areas are consistent with a large amount of sodium carbonate, constituting the most concentrated known extraterrestrial occurrence of carbonate on kilometre-wide scales in the Solar System. The carbonates are mixed with a dark component and small amounts of phyllosilicates, as well as ammonium carbonate or ammonium chloride. Some of these compounds have also been detected in the plume of Saturn’s sixth-largest moon Enceladus. The compounds are endogenous and we propose that they are the solid residue of crystallization of brines and entrained altered solids that reached the surface from below. The heat source may have been transient (triggered by impact heating). Alternatively, internal temperatures may be above the eutectic temperature of subsurface brines, in which case fluids may exist at depth on Ceres today.

Correlation between chemical components of billary calculi and bile & sera and bile of gallstone patients.

PubMed

Chandran, Prasheeda; Garg, Pradeep; Pundir, Chandra S

2005-07-01

Total cholesterol, total bilirubin, calcium, oxalate, inorganic phosphate, magnesium, iron, copper, sodium and potassium were analyzed quantitatively in gallstones, bile of gall bladder and sera of 200 patients of cholelithiasis (52 cholesterol, 76 mixed and 72 pigment stone patients) and their contents were correlated between calculi and bile and sera and bile in these three type of stone patients. A significant positive correlation was observed between total cholesterol, total bilirubin of calculi and bile, copper of bile and sera of cholesterol stone patients, copper of calculi and bile, total bilirubin, oxalate, magnesium, potassium of sera and bile of pigment stone patients and oxalate and iron of stone and bile, total bilirubin, oxalate, sodium of sera and bile of mixed stone patients. A significant negative correlation was found between magnesium of serum and bile of cholesterol stone patients, oxalate of calculi and bile of pigment stone patients and magnesium of serum and bile of mixed stone patients.

Influence of Magnesium Ion Substitution on Structural and Thermal Behavior of Nanodimensional Hydroxyapatite

NASA Astrophysics Data System (ADS)

Batra, Uma; Kapoor, Seema; Sharma, Sonia

2013-06-01

Hydroxyapatite (HA), incorporating small amount of magnesium, shows attractive biological performance in terms of improved bone metabolism, osteoblast and osteoclast activity, and bone in-growth. This article reports a systematic investigation on the influence of magnesium (Mg) substitution on structural and thermal behavior of nanodimensional HA. HA and Mg-substituted HA nanopowders were synthesized through sol-gel route. The morphology and size of nanopowders were characterized by transmission electron microscopy. The BET surface area was evaluated from N2 adsorption isotherms. Structural analysis and thermal behavior were investigated by means of Fourier transform infrared spectroscopy, x-ray diffraction, thermogravimetry, and differential thermal analysis. As-synthesized powders consisted of flake-like agglomerates of HA and calcium-deficient HA. The incorporation of magnesium in HA resulted in decrease of crystallite size, crystallinity, and lattice parameters a and c and increase in BET surface area. β-tricalcium phosphate formation occured at lower calcination temperature in Mg-substituted HA than HA.

Magnesium carbonate for phosphate control in patients on hemodialysis. A randomized controlled trial

PubMed Central

Papadaki, Antonia N.; Wei, Mingxin; Kagia, Stella; Spadidakis, Vlassios V.; Kallivretakis, Nikolaos E.; Oreopoulos, Dimitrios G.

2008-01-01

Background Magnesium salts bind dietary phosphorus, but their use in renal patients is limited due to their potential for causing side effects. The aim of this study was to evaluate the efficacy and safety of magnesium carbonate (MgCO3) as a phosphate-binder in hemodialysis patients. Methods Forty-six stable hemodialysis patients were randomly allocated to receive either MgCO3 (n = 25) or calcium carbonate (CaCO3), (n = 21) for 6 months. The concentration of Mg in the dialysate bath was 0.30 mmol/l in the MgCO3 group and 0.48 mmol/l in the CaCO3 group. Results Only two of 25 patients (8%) discontinued ingestion of MgCO3 due to complications: one (4%) because of persistent diarrhea, and the other (4%) because of recurrent hypermagnesemia. In the MgCO3 and CaCO3 groups, respectively, time-averaged (months 1–6) serum concentrations were: phosphate (P), 5.47 vs. 5.29 mg/dl, P = ns; Ca, 9.13 vs. 9.60 mg/dl, P < 0.001; Ca × P product, 50.35 vs. 50.70 (mg/dl)2, P = ns; Mg, 2.57 vs. 2.41 mg/dl, P = ns; intact parathyroid hormone (iPTH), 285 vs. 235 pg/ml, P < 0.01. At month 6, iPTH levels did not differ between groups: 251 vs. 212 pg/ml, P = ns. At month 6 the percentages of patients with serum levels of phosphate, Ca × P product and iPTH that fell within the Kidney Disease Outcomes Quality Initiative (K/DOQI) guidelines were similar in both groups, whereas more patients in the MgCO3 group (17/23; 73.91%) than in the CaCO3 group (5/20, 25%) had serum Ca levels that fell within these guidelines, with the difference being significant at P < 0.01. Conclusion Our study shows that MgCO3 administered for a period of 6 months is an effective and inexpensive agent to control serum phosphate levels in hemodialysis patients. The administration of MgCO3 in combination with a low dialysate Mg concentration avoids the risk of severe hypermagnesemia. PMID:18193489

Phosphate Recovery from Human Waste via the Formation of Hydroxyapatite during Electrochemical Wastewater Treatment

PubMed Central

2018-01-01

Electrolysis of toilet wastewater with TiO2-coated semiconductor anodes and stainless steel cathodes is a potentially viable onsite sanitation solution in parts of the world without infrastructure for centralized wastewater treatment. In addition to treating toilet wastewater, pilot-scale and bench-scale experiments demonstrated that electrolysis can remove phosphate by cathodic precipitation as hydroxyapatite at no additional energy cost. Phosphate removal could be predicted based on initial phosphate and calcium concentrations, and up to 80% total phosphate removal was achieved. While calcium was critical for phosphate removal, magnesium and bicarbonate had only minor impacts on phosphate removal rates at concentrations typical of toilet wastewater. Optimal conditions for phosphate removal were 3 to 4 h treatment at about 5 mA cm–2 (∼3.4 V), with greater than 20 m2 m–3 electrode surface area to reactor volume ratios. Pilot-scale systems are currently operated under similar conditions, suggesting that phosphate removal can be viewed as an ancillary benefit of electrochemical wastewater treatment, adding utility to the process without requiring additional energy inputs. Further value may be provided by designing reactors to recover precipitated hydroxyapatite for use as a low solubility phosphorus-rich fertilizer. PMID:29607266

Phosphate Recovery from Human Waste via the Formation of Hydroxyapatite during Electrochemical Wastewater Treatment.

PubMed

Cid, Clément A; Jasper, Justin T; Hoffmann, Michael R

2018-03-05

Electrolysis of toilet wastewater with TiO 2 -coated semiconductor anodes and stainless steel cathodes is a potentially viable onsite sanitation solution in parts of the world without infrastructure for centralized wastewater treatment. In addition to treating toilet wastewater, pilot-scale and bench-scale experiments demonstrated that electrolysis can remove phosphate by cathodic precipitation as hydroxyapatite at no additional energy cost. Phosphate removal could be predicted based on initial phosphate and calcium concentrations, and up to 80% total phosphate removal was achieved. While calcium was critical for phosphate removal, magnesium and bicarbonate had only minor impacts on phosphate removal rates at concentrations typical of toilet wastewater. Optimal conditions for phosphate removal were 3 to 4 h treatment at about 5 mA cm -2 (∼3.4 V), with greater than 20 m 2 m -3 electrode surface area to reactor volume ratios. Pilot-scale systems are currently operated under similar conditions, suggesting that phosphate removal can be viewed as an ancillary benefit of electrochemical wastewater treatment, adding utility to the process without requiring additional energy inputs. Further value may be provided by designing reactors to recover precipitated hydroxyapatite for use as a low solubility phosphorus-rich fertilizer.

Kinetics of struvite to newberyite transformation in the precipitation system MgCl2-NH4H2PO4NaOH-H2O.

PubMed

Babić-Ivancić, Vesna; Kontrec, Jasminka; Brecević, Ljerka; Kralj, Damir

2006-10-01

The influence of the initial reactant concentrations on the composition of the solid phases formed in the precipitation system MgCl(2)-NH(4)H(2)PO(4)-NaOH-H(2)O was investigated. The precipitation diagram constructed shows the approximate concentration regions within which struvite, newberyite, and their mixtures exist at 25 degrees C and an aging time of 60 min. It was found that immediately after mixing the reactant solutions, struvite (MgNH(4)PO(4).6H(2)O) precipitated in nearly the whole concentration area, while newberyite (MgHPO(4).3H(2)O) appeared mostly within the region of the excess of magnesium concentration. It was also found that after aging time of 60 min the precipitation domain of struvite alone is much broader than that of newberyite or the domain of their coexistence, and shows that struvite is more abundant in the systems in which the initial concentration of ammonium phosphate is higher than that of magnesium. The kinetics of struvite to newberyite transformation (conversion) was systematically studied under the conditions of different initial reactant concentrations and different initial pH in the systems in which a mixture of both phases precipitated spontaneously. The struvite to newberyite conversion period was found to be strongly related to the ratio of initial supersaturations, S(N)/S(S), rather than to the any particular physical quantity that can describe and predict the behavior of the precipitation system. Experimental data suggest a solution-mediated process as a most possible transformation mechanism. Along with a continuous monitoring of the changes in the liquid phase, the content of struvite in the solid phase was estimated by means of a Fourier transform infrared (FT-IR) method, developed for this particular precipitation system.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ren Limei; Schuchardt, Frank; Shen Yujun

An absorbent mixture of magnesium hydroxide (Mg(OH){sub 2}) and phosphoric acid (H{sub 3}PO{sub 4}) was added to compost mixtures of pig manure with cornstalk in different molar ratios (T1, 1:1; T2, 1:2; T3, 1:3) in order to examine its effect on controlling ammonia losses during composting. Based on the principle of struvite precipitation, and with an unamended trial as control (CK), an in-vessel composting experiment was conducted in fermenters (60 L with forced aeration) in which the absorbent mixture was added with proportions of 3.8%, 7.3% and 8.9% of dry weight for T1, T2 and T3, respectively. The results showedmore » that the total nitrogen loss was reduced from 35% to 12%, 5% and 1% of initial N mass, respectively. In the final compost, the total nitrogen content in T1, T2 and T3 was improved by 10, 14, 12 g kg{sup -1}, and NH{sub 4}{sup +}-N in T1, T2 and T3 was improved by 8, 9, and 10 g kg{sup -1}, respectively, compared with the unamended trial. The results of the germination index test showed that the maturity of treatment T2 was best among the four treatments in the final compost, followed by T1, CK and T3. The results of X-ray diffraction (XRD) confirmed the formation of magnesium ammonium phosphate hexahydrate (MgNH{sub 4}PO{sub 4}.6H{sub 2}O:MAP) in the T1, T2 and T3 compost. Based on these results, the adsorbent mixture of Mg(OH){sub 2} + H{sub 3}PO{sub 4} could control nitrogen loss effectively during composting via struvite crystallization. However, an excess of phosphoric acid (1:3) had a negative influence on composting properties. The pH value decreased which led to reduced microorganism activity, and which finally resulted in reduced biodegradation of the organic matter.« less

Proton-pump inhibitor use is associated with low serum magnesium concentrations

PubMed Central

Danziger, John; William, Jeffrey H.; Scott, Daniel J.; Lee, Joon; Lehman, Li-wei; Mark, Roger G.; Howell, Michael D.; Celi, Leo A.; Mukamal, Kenneth J.

2017-01-01

Although case reports link proton-pump inhibitor (PPI) use and hypomagnesemia, no large-scale studies have been conducted. Here we examined the serum magnesium concentration and the likelihood of hypomagnesemia (< 1.6 mg/dl) with a history of PPI or histamine-2 receptor antagonist used to reduce gastric acid, or use of neither among 11,490 consecutive adult admissions to an intensive care unit of a tertiary medical center. Of these, 2632 patients reported PPI use prior to admission, while 657 patients were using a histamine-2 receptor antagonist. PPI use was associated with 0.012 mg/dl lower adjusted serum magnesium concentration compared to users of no acid-suppressive medications, but this effect was restricted to those patients taking diuretics. Among the 3286 patients concurrently on diuretics, PPI use was associated with a significant increase of hypomagnesemia (odds ratio 1.54) and 0.028 mg/dl lower serum magnesium concentration. Among those not using diuretics, PPI use was not associated with serum magnesium levels. Histamine-2 receptor antagonist use was not significantly associated with magnesium concentration without or with diuretic use. The use of PPI was not associated with serum phosphate concentration regardless of diuretic use. Thus, we verify case reports of the association between PPI use and hypomagnesemia in those concurrently taking diuretics. Hence, serum magnesium concentrations should be followed in susceptible individuals on chronic PPI therapy. PMID:23325090

Fluid and Electrolyte Balance

MedlinePlus

... work the way they should Sodium, calcium, potassium, chlorine, phosphate, and magnesium are all electrolytes. You get them from the foods you eat and the fluids you drink. The levels of electrolytes in your body can become too low or too high. This can happen when the amount of water ...

Short-term starvation effects on nitrogen and phosphorus excretion by the chaetognath Sagitta enflata

NASA Astrophysics Data System (ADS)

Szyper, James P.

1981-12-01

Freshly captured Sagitta enflata exhibited specific excretion rates of ammonium and phosphate (expressed as percentage body content of N or P per hour) that were not significantly related to the size of individual animals. The degree of crowding in experimental vessels was positively correlated with specific excretion rates of ammonium. Excretion rates, under conditions that precluded feeding, decreased sharply during the first several hours' incubation time, approaching the rates exhibited by animals starved overnight. The practice of holding freshly captured zooplankton for a time before determining excretion rates may seriously affect those rates, if the animals are unable to feed. Animals captured during the day in Kaneohe Bay, Hawaii, having no food items in their guts, had mean specific excretion rates (± S.D.) of 0·81±0·51% body content of N h -1 for ammonium, and 1·29±1·24% body content of P h -1 for phosphate. Minimal estimates of natural excretion rates, made from the first hour of incubation in further experiments, were 1·19±0·47% h -1 for nitrogen and 3·8±3·95% h -1 for phosphorus. Sagitta is not a large contributor to nutrient regeneration in Kaneohe Bay.

Elevated dietary magnesium during pregnancy and postnatal life prevents ectopic mineralization in Enpp1asj mice, a model for generalized arterial calcification of infancy

PubMed Central

Kingman, Joshua; Uitto, Jouni; Li, Qiaoli

2017-01-01

Generalized arterial calcification of infancy (GACI) is an autosomal recessive disorder caused by mutations in the ENPP1 gene. It is characterized by mineralization of the arterial blood vessels, often diagnosed prenatally, and associated with death in early childhood. There is no effective treatment for this devastating disorder. We previously characterized the Enpp1asjmutant mouse as a model of GACI, and we have now explored the effect of elevated dietary magnesium (five-fold) in pregnant mothers and continuing for the first 14 weeks of postnatal life. The mothers were kept on either control diet or experimental diet supplemented with magnesium. Upon weaning at 4 weeks of age the pups were placed either on control diet or high magnesium diet. The degree of mineralization was assessed at 14 weeks of age by histopathology and a chemical calcium assay in muzzle skin, kidney and aorta. Mice placed on high magnesium diet showed little, if any, evidence of mineralization when their corresponding mothers were also placed on diet enriched with magnesium during pregnancy and nursing. The reduced ectopic mineralization in these mice was accompanied by increased calcium and magnesium content in the urine, suggesting that magnesium competes calcium-phosphate binding thereby preventing the mineral deposition. These results have implications for dietary management of pregnancies in which the fetus is suspected of having GACI. Moreover, augmenting a diet with high magnesium may be beneficial for other ectopic mineralization diseases, including nephrocalcinosis. PMID:28402956

Ammonium removal from aqueous solutions by using natural Chinese (Chende) zeolite as adsorbent.

PubMed

Huang, Haiming; Xiao, Xianming; Yan, Bo; Yang, Liping

2010-03-15

This paper presents a study of the removal of ammonium ion from aqueous solutions using natural Chinese (Chende) zeolite. A series of experiments was conducted to examine the effects of solution pH, particle size, contact time, adsorbent dosage, and the presence of other cation- and anion species on ammonium removal. The findings indicated that these parameters named had a significant effect on the removal of ammonium by the zeolite. The effect of other cations on the removal of ammonium followed the order of preference Na(+)>K(+)>Ca(2+)>Mg(2+) at identical mass concentrations, and the effect of the presence of individual anions followed the order of preference carbonate>chloride>sulfate>phosphate at identical mass concentrations of ammonium ions. Kinetic analysis showed that the adsorption of ammonium on zeolite at different ranges of particle size well followed the pseudo-second-order model and followed the intra-particle diffusion model only during the initial 60 min of the adsorption process. Equilibrium isotherm data was fitted to the linear Langmuir- and Freundlich models with the latter model providing the better description of the process (R(2)=0.991-0.997) compared to the former (R(2)=0.902-0.989). (c) 2009 Elsevier B.V. All rights reserved.

Determination of ammonium on an integrated microchip with LED-induced fluorescence detection.

PubMed

Xue, Shuhua; Uchiyama, Katsumi; Li, Hai-Fang

2012-01-01

A simply fabricated microfluidic device integrated with a fluorescence detection system has been developed for on-line determination of ammonium in aqueous samples. A 365-nm light-emitting diode (LED) as an excitation source and a minor band pass filter were mounted into a polydimethylsiloxane (PDMS)-based microchip for the purpose of miniaturization of the entire analytical system. The ammonium sample reacted with o-phthaldialdehyde (OPA) on-chip with sodium sulfite as reducing reagent to produce a fluorescent isoindole derivative, which can emit fluorescence signal at about 425 nm when excited at 365 nm. Effects of pH, flow rate of solutions, concentrations of OPA-reagent, phosphate and sulfite salt were investigated. The calibration curve of ammonium in the range of 0.018-1.8 microg/mL showed a good linear relationship with R2 = 0.9985, and the detection limit was (S/N = 3) 3.6 x 10(-4) microg/mL. The relative standard deviation was 2.8% (n = 11) by calculating at 0.18 microg/mL ammonium for repeated detection. The system was applied to determine the ammonium concentration in rain and river waters, even extent to other analytes fluorescence detection by the presented device.

Influence of the environmental factors on the intensity of the oxygen, ammonium, and phosphate metabolism in the agar-containing seaweed Ahnfeltia tobuchiensis (Ahnfeltiales, Rhodophyta)

NASA Astrophysics Data System (ADS)

Cherbadgy, I. I.; Sabitova, L. I.

2011-02-01

A complex study of the influence of various environmental factors on the rate of the oxygen (MO 2), ammonium (MNH 4), and phosphate (MPO 4) metabolism in Ahnfeltia tobuchiensis has been carried out in situ in the Izmena Bay of Kunashir Island. The following environmental factors have been included into the investigation: the photosynthetically active radiation (PAR); the ammonium (NH4); the phosphate (PO4); and the tissue content of carbon (C), nitrogen (N), phosphorus (P), and chlorophyll a (Chl). The population of agar-containing seaweed A. tobuchiensis forms a layer with a thickness up to 0.5 m, which occupies about 23.3 km2; the population's biomass is equal to 125000 tons. The quantitative assessment of the organic matter production and nutrient consumption during the oxygen metabolism (MO 2) has been carried out for the whole population. It has been shown that the daily rate depends on the PAR intensity, the seawater concentrations of PO4 and NH4, and the tissue content of N and P ( r 2 = 0.78, p < 0.001). The daily NH4 consumption averages 0.21 μmol/(gDW h) and depends on the NH4 and O2 concentrations in the seawater and on the C and Chl a content in the algal tissues ( r 2 = 0.64, p < 0.001). The daily PO4 consumption averages 0.01 μmol/(gDW h) and depends on the NH4 concentration in the seawater and on the P content in the algal tissues ( r 2 = 0.40, p < 0.001).

Tetracalcium phosphate composite containing quaternary ammonium dimethacrylate with antibacterial properties

PubMed Central

Cheng, Lei; Weir, Michael D.; Limkangwalmongkol, Penwadee; Hack, Gary D.; Xu, Hockin H. K.; Chen, Qianming; Zhou, Xuedong

2012-01-01

Tooth caries is a carbohydrate-modified bacterial infectious disease, and recurrent caries is a frequent reason for restoration failure. The objective of this study was to develop a novel antibacterial composite using tetracalcium phosphate (TTCP) fillers and bis(2-methacryloyloxy-ethyl) dimethyl-ammonium bromide, which is a quaternary ammonium dimethacrylate (QADM). QADM was synthesized using 2-(N,N-dimethylamino)ethyl methacrylate and 2-bromoethyl methacrylate and incorporated into a resin. The resin was filled with 40% TTCP and 30% glass particles. The following QADM mass fractions in the composite were tested: 0%, 6%, 12%, and 18%. Streptococcus mutans biofilms were formed on the composites and the colony-forming units (CFUs), metabolic activity, and lactic acid production were measured. The TTCP-QADM composite had flexural strength and elastic modulus similar to those of two commercial composites (p > 0.1). Increasing the QADM content in TTCP composite greatly decreased the bacteria growth and biofilm matrix production. There were significantly more dead bacteria with increasing QADM content. TTCP composite containing 18% QADM had biofilm CFU, metabolic activity, and acid production about half of those without QADM. Inversely linear relationships were established between QADM mass fraction and S. mutans biofilm CFU, metabolic activity, and acid production, with correlation coefficients R2 ≥ 0.98. In conclusion, TTCP-QADM composites were developed and the effect of QADM mass fraction on the antibacterial properties of the composite was determined for the first time. The novel TTCP-QADM composites possessing a strong antibacterial capability, together with calcium phosphate ion release and good mechanical properties, are promising for dental restorations to reduce biofilm growth and recurrent caries. PMID:22190356

In vitro investigation of biodegradable polymeric coating for corrosion resistance of Mg-6Zn-Ca alloy in simulated body fluid.

PubMed

Gaur, Swati; Singh Raman, R K; Khanna, A S

2014-09-01

A silane-based biodegradable coating was developed and investigated to improve corrosion resistance of an Mg-6Zn-Ca magnesium alloy to delay the biodegradation of the alloy in the physiological environment. Conditions were optimized to develop a stable and uniform hydroxide layer on the alloys surface-known to facilitate silane-substrate adhesion. A composite coating of two silanes, namely, diethylphosphatoethyltriethoxysilane (DEPETES) and bis-[3-(triethoxysilyl) propyl] tetrasulfide (BTESPT), was developed, by the sol-gel route. Corrosion resistance of the coated alloy was characterized in a modified-simulated body fluid (m-SBF), using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The silane coating provided significant and durable corrosion resistance. During the course of this, hydrogen evolution and pH variation, if any, were monitored for both bare and coated alloys. The coating morphology was characterized using scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX) and the cross-linking in the coating was studied using Fourier transform infrared spectroscopy (FTIR). As indicated by X-ray diffraction (XRD) results, an important finding was the presence of hydrated magnesium phosphate on the sample that was subjected to immersion in m-SBF for 216h. Magnesium phosphate is reported to support osteoblast formation and tissue healing. Copyright © 2014 Elsevier B.V. All rights reserved.

Protective layer formation on magnesium in cell culture medium.

PubMed

Wagener, V; Virtanen, S

2016-06-01

In the past, different studies showed that hydroxyapatite (HA) or similar calcium phosphates can be precipitated on Mg during immersion in simulated body fluids. However, at the same time, in most cases a dark grey or black layer is built under the white HA crystals. This layer seems to consist as well of calcium phosphates. Until now, neither the morphology nor its influence on Mg corrosion have been investigated in detail. In this work commercially pure magnesium (cp) was immersed in cell culture medium for one, three and five days at room temperature and in the incubator (37 °C, 5% CO2). In addition, the influence of proteins on the formation of a corrosion layer was investigated by adding 20% of fetal calf serum (FCS) to the cell culture medium in the incubator. In order to analyze the formed layers, SEM images of cross sections, X-ray Photoelectron Spectroscopy (XPS), X-ray diffraction (XRD), Energy Dispersive X-ray Spectroscopy (EDX) and Fourier Transformed Infrared Spectroscopy (FTIR) measurements were carried out. Characterization of the corrosion behavior was achieved by electrochemical impedance spectroscopy (EIS) and by potentio-dynamic polarization in Dulbecco's Modified Eagle's Medium (DMEM) at 37°C. Surface analysis showed that all formed layers consist mainly of amorphous calcium phosphate compounds. For the immersion at room temperature the Ca/P ratio indicates the formation of HA, while in the incubator probably pre-stages to HA are formed. The different immersion conditions lead to a variation in layer thicknesses. However, electrochemical characterization shows that the layer thickness does not influence the corrosion resistance of magnesium. The main influencing factor for the corrosion behavior is the layer morphology. Thus, immersion at room temperature leads to the highest corrosion protection due to the formation of a compact outer layer. Layers formed in the incubator show much worse performances due to completely porous structures. The existence of proteins in DMEM seems to hinder the formation of a corrosion layer. However, protein adsorption leads to similar results as concerns corrosion protection as the formed calcium phosphate layer. Copyright © 2016 Elsevier B.V. All rights reserved.

An effective and novel pore sealing agent to enhance the corrosion resistance performance of Al coating in artificial ocean water

NASA Astrophysics Data System (ADS)

Lee, Han-Seung; Singh, Jitendra Kumar; Ismail, Mohamed A.

2017-02-01

A new technique was accepted to fill the porosity of Al coating applied by arc thermal spray process to enhance corrosion resistance performance in artificial ocean water. The porosity is the inherent property of arc thermal spray coating process. In this study, applied coating was treated with different concentrations of ammonium phosphate mono basic (NH4H2PO4: AP) solution thereafter dried at room temperature and kept in humidity chamber for 7d to deposit uniform film. The corrosion resistance of Al coating and treated samples have been evaluated using electrochemical impedance spectroscopy (EIS) and potentiodynamic techniques with exposure periods in artificial ocean water. Electrochemical techniques, X-ray diffraction (XRD), Raman spectroscopy, atomic force microscopy (AFM) and field emission-scanning electron microscopy (FE-SEM) indicated that phosphate ion would have been retarding corrosion of Al coating effectively. The formation of AHP (Ammonium Aluminum Hydrogen Phosphate Hydrate: NH4)3Al5H6(PO4)8.18H2O) on Al coating surface after treatment with AP is nano sized, crystalline and uniformly deposited but after exposure them in artificial ocean water, they form AHPH (Aluminum hydroxide phosphate hydrate Al3(PO4)2(OH)3(H2O)5) that is very protective, adherent, uniform and plate like morphology of corrosion products. The AHPH is sparingly soluble and adherent to surface and imparted improved corrosion resistance.

Effects of nutrient input on phytoplankton productivity and community structure in the Grand Bay estuary in Mississippi

NASA Astrophysics Data System (ADS)

Baine, G. C., II; Caffrey, J. M.

2016-02-01

The estuarine system at Grand Bay National Estuarine Research Reserve in Mississippi is a near pristine wetland home to a diversity of flora and fauna. While seasonal fluctuations in water quality are well understood, less is known about the coupled dynamics of water quality and phytoplankton production. Light availability and nutrient levels are key factors regulating phytoplankton. Previous studies have revealed Grand Bay to primarily be limited by nitrogen rather than phosphorus or light. Since then, extended phosphate inputs from the neighboring Mississippi Phosphates fertilizer plant have occurred provoking the question: will the phosphate inputs affect the growth and structure of the phytoplankton communities? This study is investigating the effects of inputs of an array of nutrients (ammonium, nitrate, silicon, and phosphate) on phytoplankton growth, community structure, and production over an annual cycle. Phytoplankton production is being monitored by accumulation of biomass (chlorophyll a concentration) and C14 incorporation. We are also evaluating changes in the phytoplankton community composition using Flowcam imaging over the course of the incubation. Currently the summer months have shown nitrogen limitation as previously observed, with little difference between nitrate and ammonium additions. Flowcam images have revealed increases in ciliate abundance in all treatments. C14 experiments show significant decreases in efficiency for all treatments compared to the initial condition, however there is no significant variation among treatments. The results of this study will provide a strong foundation in understanding the nature of phytoplankton response to various nutrient inputs in Grand Bay.

An effective and novel pore sealing agent to enhance the corrosion resistance performance of Al coating in artificial ocean water

PubMed Central

Lee, Han-Seung; Singh, Jitendra Kumar; Ismail, Mohamed A.

2017-01-01

A new technique was accepted to fill the porosity of Al coating applied by arc thermal spray process to enhance corrosion resistance performance in artificial ocean water. The porosity is the inherent property of arc thermal spray coating process. In this study, applied coating was treated with different concentrations of ammonium phosphate mono basic (NH4H2PO4: AP) solution thereafter dried at room temperature and kept in humidity chamber for 7d to deposit uniform film. The corrosion resistance of Al coating and treated samples have been evaluated using electrochemical impedance spectroscopy (EIS) and potentiodynamic techniques with exposure periods in artificial ocean water. Electrochemical techniques, X-ray diffraction (XRD), Raman spectroscopy, atomic force microscopy (AFM) and field emission-scanning electron microscopy (FE-SEM) indicated that phosphate ion would have been retarding corrosion of Al coating effectively. The formation of AHP (Ammonium Aluminum Hydrogen Phosphate Hydrate: NH4)3Al5H6(PO4)8.18H2O) on Al coating surface after treatment with AP is nano sized, crystalline and uniformly deposited but after exposure them in artificial ocean water, they form AHPH (Aluminum hydroxide phosphate hydrate Al3(PO4)2(OH)3(H2O)5) that is very protective, adherent, uniform and plate like morphology of corrosion products. The AHPH is sparingly soluble and adherent to surface and imparted improved corrosion resistance. PMID:28157233

Hydrolysis of p-nitrophenyl esters promoted by semifluorinated quaternary ammonium polymer latexes and films.

PubMed

Kaur, Baljinder; McBride, Sean P; Paul, Abhijit; Ford, Warren T

2010-10-19

Semifluorinated polymer latexes were prepared by emulsion polymerization of 2.5-25% of a fluoroalkyl methacrylate, 25% chloromethylstyrene, 1% styrylmethyl(trimethyl)ammonium chloride, and the remainder 2-ethylhexyl methacrylate under surfactant-free conditions. The chloromethylstyrene units were converted to quaternary ammonium ions with trimethylamine. In aqueous dispersions at particle concentrations of less than 1 mg mL(-1) the quaternary ammonium ion latexes promoted hydrolyses of p-nitrophenyl hexanoate (PNPH) in pH 9.4 borate buffer and of diethyl p-nitrophenyl phosphate (Paraoxon) in 0.1 M NaOH at 30 °C with half-lives of less than 10 min. Thin 0.7-2 μm films of the latexes on glass promoted fast hydrolysis of Paraoxon but not of PNPH under the same conditions. Even after annealing the quaternary ammonium ion polymer films at temperatures well above their glass transition temperatures, AFM images of the film surfaces had textures of particles. Contact angle measurements of the annealed films against water and against hexadecane showed that the surfaces were not highly fluorinated.

Recovery of ammonia and production of high-grade phosphates from digester effluents (municipal and livestock)

USDA-ARS?s Scientific Manuscript database

Phosphorus (P) recovery of anaerobically digested swine wastewater and side-stream municipal wastewater via magnesium precipitation was enhanced by combining it with the recovery of ammonia (NH3) through gas-permeable membranes and low-rate aeration. The low-rate aeration stripped the natural carbon...

Determination of ammonium in wastewaters by capillary electrophoresis on a column-coupling chip with conductivity detection.

PubMed

Luc, Milan; Kruk, Pavol; Masár, Marián

2011-07-01

Analytical potentialities of a chip-based CE in determination of ammonium in wastewaters were investigated. CZE with the electric field and/or ITP sample stacking was performed on a column-coupling (CC) chip with integrated conductivity detectors. Acetate background electrolytes (pH ∼3) including 18-crown-6-ether (18-crown-6) and tartaric acid were developed to reach rapid (in 7-8 min) CZE and ITP-CZE resolutions of ammonium from other cations (sodium, potassium, calcium and magnesium) present in wastewater samples. Under preferred working conditions (suppressed hydrodynamic flow (HDF) and EOF on the column-coupling chip), both the employed methods did provide very good repeatabilities of the migration (RSD of 0.2-0.8% for the migration time) and quantitative (RSD of 0.3-4.9% for the peak area) parameters in the model and wastewater samples. Using a 900-nL sample injection volume, LOD for ammonium were obtained at 20 and 40 μg/L concentrations in CZE and ITP-CZE separations, respectively. Very good agreements of the CZE and ITP-CZE determinations of ammonium in six untreated wastewater samples (only filtration and dilution) with the results obtained by a reference spectrometric method indicate a very good accuracy of both the CE methods presented. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Monosodium glutamate (MSG) consumption is associated with urolithiasis and urinary tract obstruction in rats.

PubMed

Sharma, Amod; Prasongwattana, Vitoon; Cha'on, Ubon; Selmi, Carlo; Hipkaeo, Wiphawi; Boonnate, Piyanard; Pethlert, Supattra; Titipungul, Tanin; Intarawichian, Piyapharom; Waraasawapati, Sakda; Puapiroj, Anucha; Sitprija, Visith; Reungjui, Sirirat

2013-01-01

The peritoneal injection of monosodium glutamate (MSG) can induce kidney injury in adult rats but the effects of long-term oral intake have not been determined. We investigated the kidney histology and function in adult male Wistar rats that were fed ad libitum with a standard rat chow pellet and water with or without the addition of 2 mg/g body weight MSG/day in drinking water (n=10 per group). Both MSG-treated and control animals were sacrificed after 9 months when renal function parameters, blood and urine electrolytes, and tissue histopathology were determined. MSG-treated rats were more prone to kidney stone formation, as represented by the alkaline urine and significantly higher activity product of calcium phosphate. Accordingly, 3/10 MSG-treated rats developed kidney stones over 9 months versus none of the control animals. Further, 2/10 MSG-treated rats but none (0/10) of the controls manifested hydronephrosis. MSG-treated rats had significantly higher levels of serum creatinine and potassium including urine output volume, urinary excretion sodium and citrate compared to controls. In contrast, MSG-treated rats had significantly lower ammonium and magnesium urinary excretion. Oral MSG consumption appears to cause alkaline urine and may increase the risks of kidney stones with hydronephrosis in rats. Similar effects in humans must be verified by dedicated studies.

The Use of a Fractional Factorial Design to Determine the Factors That Impact 1,3-Propanediol Production from Glycerol by Halanaerobium hydrogeniformans.

PubMed

Kalia, Shivani; Trager, Jordan; Sitton, Oliver C; Mormile, Melanie R

2016-08-20

In recent years, biodiesel, a substitute for fossil fuels, has led to the excessive production of crude glycerol. The resulting crude glycerol can possess a high concentration of salts and an alkaline pH. Moreover, current crude glycerol purification methods are expensive, rendering this former commodity a waste product. However, Halanaerobium hydrogeniformans, a haloalkaliphilic bacterium, possesses the metabolic capability to convert glycerol into 1,3-propanediol, a valuable commodity compound, without the need for salt dilution or adjusting pH when grown on this waste. Experiments were performed with different combinations of 24 medium components to determine their impact on the production of 1,3-propanediol by using a fractional factorial design. Tested medium components were selected based on data from the organism's genome. Analysis of HPLC data revealed enhanced production of 1,3-propanediol with additional glycerol, pH, vitamin B12, ammonium ions, sodium sulfide, cysteine, iron, and cobalt. However, other selected components; nitrate ions, phosphate ions, sulfate ions, sodium:potassium ratio, chloride, calcium, magnesium, silicon, manganese, zinc, borate, nickel, molybdenum, tungstate, copper and aluminum, did not enhance 1,3-propanediol production. The use of a fractional factorial design enabled the quick and efficient assessment of the impact of 24 different medium components on 1,3-propanediol production from glycerol from a haloalkaliphilic bacterium.

Determination of urine ionic composition with potentiometric multisensor system.

PubMed

Yaroshenko, Irina; Kirsanov, Dmitry; Kartsova, Lyudmila; Sidorova, Alla; Borisova, Irina; Legin, Andrey

2015-01-01

The ionic composition of urine is a good indicator of patient's general condition and allows for diagnostics of certain medical problems such as e.g., urolithiasis. Due to environmental factors and malnutrition the number of registered urinary tract cases continuously increases. Most of the methods currently used for urine analysis are expensive, quite laborious and require skilled personnel. The present work deals with feasibility study of potentiometric multisensor system of 18 ion-selective and cross-sensitive sensors as an analytical tool for determination of urine ionic composition. In total 136 samples from patients of Urolithiasis Laboratory and healthy people were analyzed by the multisensor system as well as by capillary electrophoresis as a reference method. Various chemometric approaches were implemented to relate the data from electrochemical measurements with the reference data. Logistic regression (LR) was applied for classification of samples into healthy and unhealthy producing reasonable misclassification rates. Projection on Latent Structures (PLS) regression was applied for quantitative analysis of ionic composition from potentiometric data. Mean relative errors of simultaneous prediction of sodium, potassium, ammonium, calcium, magnesium, chloride, sulfate, phosphate, urate and creatinine from multisensor system response were in the range 3-13% for independent test sets. This shows a good promise for development of a fast and inexpensive alternative method for urine analysis. Copyright © 2014 Elsevier B.V. All rights reserved.

Monosodium Glutamate (MSG) Consumption Is Associated with Urolithiasis and Urinary Tract Obstruction in Rats

PubMed Central

Sharma, Amod; Prasongwattana, Vitoon; Cha’on, Ubon; Selmi, Carlo; Hipkaeo, Wiphawi; Boonnate, Piyanard; Pethlert, Supattra; Titipungul, Tanin; Intarawichian, Piyapharom; Waraasawapati, Sakda; Puapiroj, Anucha; Sitprija, Visith; Reungjui, Sirirat

2013-01-01

Background The peritoneal injection of monosodium glutamate (MSG) can induce kidney injury in adult rats but the effects of long-term oral intake have not been determined. Methods We investigated the kidney histology and function in adult male Wistar rats that were fed ad libitum with a standard rat chow pellet and water with or without the addition of 2 mg/g body weight MSG/day in drinking water (n=10 per group). Both MSG-treated and control animals were sacrificed after 9 months when renal function parameters, blood and urine electrolytes, and tissue histopathology were determined. Results MSG-treated rats were more prone to kidney stone formation, as represented by the alkaline urine and significantly higher activity product of calcium phosphate. Accordingly, 3/10 MSG-treated rats developed kidney stones over 9 months versus none of the control animals. Further, 2/10 MSG-treated rats but none (0/10) of the controls manifested hydronephrosis. MSG-treated rats had significantly higher levels of serum creatinine and potassium including urine output volume, urinary excretion sodium and citrate compared to controls. In contrast, MSG-treated rats had significantly lower ammonium and magnesium urinary excretion. Conclusion Oral MSG consumption appears to cause alkaline urine and may increase the risks of kidney stones with hydronephrosis in rats. Similar effects in humans must be verified by dedicated studies. PMID:24086562

Immobilization of Mn and NH4 (+)-N from electrolytic manganese residue waste.

PubMed

Chen, Hongliang; Liu, Renlong; Liu, Zuohua; Shu, Jiancheng; Tao, Changyuan

2016-06-01

The objective of this work was the immobilization of soluble manganese (Mn) and ammonium nitrogen (NH4 (+)-N) leached from electrolytic manganese residue (EMR). Immobilization of Mn was investigated via carbonation using carbon dioxide (CO2) and alkaline additives. NH4 (+)-N immobilization was evaluated via struvite precipitation using magnesium and phosphate sources. Results indicated that the immobilization efficiency of Mn using CO2 and quicklime (CaO) was higher than using CO2 and sodium hydroxide (NaOH). This higher efficiency was likely due to the slower release of OH(-) during CaO hydrolysis. The immobilization efficiency of Mn was >99.99 % at the CaO:EMR mass ratio of 0.05:1 for 20-min reaction time. The struvite precipitation of NH4 (+)-N was conducted in the carbonated EMR slurry and the immobilization efficiency was 89 % using MgCl2 · 6H2O + Na3PO4 · 12H2O at the Mg:P:N molar ratio of 1.5:1.5:1 for 90-min reaction time. A leaching test showed that the concentrations of Mn and NH4 (+)-N in the filtrate of the treated EMR were 0.2 and 9 mg/L, respectively. The combined immobilization of Mn and NH4 (+)-N was an effective pretreatment method in the harmless treatment of the EMR.

Potential Application of Silica Mineral from Dieng Mountain in Agriculture Sector to Control the Release Rate of Fertilizer Elements

NASA Astrophysics Data System (ADS)

Solihin; Mursito, Anggoro Tri; Dida, Eki N.; Erlangga, Bagus D.; Widodo

2017-07-01

Silica mineral, which comes along with geothermal fluid in Dieng, is a product of erosion, decomposition and dissolution of silicon oxide based mineral, which is followed by precipitation to form silica mineral. This silica cell structure is non crystalline, and it contains 85,60 % silicon oxide, 6.49 volatile elements, and also other oxide elements. Among the direct potential application of this silica is as raw material in slow release fertilizer. Silica in compacted slow release fertilizer is able control the release rate of fertilizer elements. Two type of slow release fertilizer has been made by using silica as the matrix in these slow release fertilizer. The first type is the mixing of ordinary solid fertilizer with Dieng silica, whereas the second one is the mixing of disposal leach water with Dieng silica. The release test shows that both of these modified fertilizers have slow release fertilizer characteristic. The release rate of fertilizer elements (magnesium, potassium, ammonium, and phosphate) can be significantly reduced. The addition of kaolin in the first type of slow release fertilizer makes the release rate of fertilizer elements can be more slowed down. Meanwhile in the second type of slow release fertilizer, the release rate is determined by ratio of silica/hydrogel. The lowest release rate is achieved by sample that has highest ratio of silica/hydrogel.

[Effect of pilot UASB-SFSBR-MAP process for the large scale swine wastewater treatment].

PubMed

Wang, Liang; Chen, Chong-Jun; Chen, Ying-Xu; Wu, Wei-Xiang

2013-03-01

In this paper, a treatment process consisted of UASB, step-fed sequencing batch reactor (SFSBR) and magnesium ammonium phosphate precipitation reactor (MAP) was built to treat the large scale swine wastewater, which aimed at overcoming drawbacks of conventional anaerobic-aerobic treatment process and SBR treatment process, such as the low denitrification efficiency, high operating costs and high nutrient losses and so on. Based on the treatment process, a pilot engineering was constructed. It was concluded from the experiment results that the removal efficiency of COD, NH4(+) -N and TP reached 95.1%, 92.7% and 88.8%, the recovery rate of NH4(+) -N and TP by MAP process reached 23.9% and 83.8%, the effluent quality was superior to the discharge standard of pollutants for livestock and poultry breeding (GB 18596-2001), mass concentration of COD, TN, NH4(+) -N, TP and SS were not higher than 135, 116, 43, 7.3 and 50 mg x L(-1) respectively. The process developed was reliable, kept self-balance of carbon source and alkalinity, reached high nutrient recovery efficiency. And the operating cost was equal to that of the traditional anaerobic-aerobic treatment process. So the treatment process could provide a high value of application and dissemination and be fit for the treatment pf the large scale swine wastewater in China.

Growth of single crystals from solutions using semi-permeable membranes

NASA Astrophysics Data System (ADS)

Varkey, A. J.; Okeke, C. E.

1983-05-01

A technique suitable for growth of single crystals from solutions using semi-preamble membranes is described. Using this technique single crystals of copper sulphate, potassium bromide and ammonium dihydrogen phosphate have been successfully grown. Advantages of this technique over other methods are discussed.

Nitrogen

USGS Publications Warehouse

Kramer, D.A.

2007-01-01

Ammonia was produced by 15 companies at 25 plants in 16 states in the United States during 2006. Fifty-seven percent of U.S. ammonia production capacity was centered in Louisiana, Oklahoma and Texas because of their large reserves of natural gas, the dominant domestic feedstock. In 2006, U.S. producers operated at about 72 percent of their rated capacity (excluding plants that were idle for the entire year). Five companies, Koch Nitrogen, Terra Industries, CF Industries, PCS Nitro-gen, and Agrium, in descending order, accounted for 79 percent U.S. ammonia production capacity. The United States was the world's fourth-ranked ammonia producer and consumer following China, India and Russia. Urea, ammonium nitrate, ammonium phosphates, nitric acid and ammonium sulfate were the major derivatives of ammonia in the United States, in descending order of importance.

Selections From Kung-Jen JIH-PAO (Source Span: 9 May-30 June 1961) Number 7 -Communist China.

DTIC Science & Technology

1961-08-17

sulphate Ammonium hydrogen carbonate Sodium borate Titaniüm-iron powder Sodium fluoride Silicon dioxide Barium chloride beryllium carbonate ...Vinzenstrasse, 22a :■ P. 0. Box 3521 Aachen, Germany Washington 7> B.C. , Institute de Sociologie Solvay Rue du Chatelain, k9 Brussels, Belgium State... Sodium nitrite Specifications Pure n industrial Boric Acid " A^ua ammonia " Magnesium sulphate Industrial Manganese tedroxide Pure

Effect of a magnesium-based phosphate binder on medial calcification in a rat model of uremia.

PubMed

De Schutter, Tineke M; Behets, Geert J; Geryl, Hilde; Peter, Mirjam E; Steppan, Sonja; Gundlach, Kristina; Passlick-Deetjen, Jutta; D'Haese, Patrick C; Neven, Ellen

2013-06-01

Calcium-based phosphate binders are used to control hyperphosphatemia; however, they promote hypercalcemia and may accelerate aortic calcification. Here we compared the effect of a phosphate binder containing calcium acetate and magnesium carbonate (CaMg) to that of sevelamer carbonate on the development of medial calcification in rats with chronic renal failure induced by an adenine diet for 4 weeks. After 1 week, rats with chronic renal failure were treated with vehicle, 375 or 750 mg/kg CaMg, or 750 mg/kg sevelamer by daily gavage for 5 weeks. Renal function was significantly impaired in all groups. Vehicle-treated rats with chronic renal failure developed severe hyperphosphatemia, but this was controlled in treated groups, particularly by CaMg. Neither CaMg nor sevelamer increased serum calcium ion levels. Induction of chronic renal failure significantly increased serum PTH, dose-dependently prevented by CaMg but not sevelamer. The aortic calcium content was significantly reduced by CaMg but not by sevelamer. The percent calcified area of the aorta was significantly lower than vehicle-treated animals for all three groups. The presence of aortic calcification was associated with increased sox9, bmp-2, and matrix gla protein expression, but this did not differ in the treatment groups. Calcium content in the carotid artery was lower with sevelamer than with CaMg but that in the femoral artery did not differ between groups. Thus, treatment with either CaMg or sevelamer effectively controlled serum phosphate levels in CRF rats and reduced aortic calcification.

Effect of a magnesium-based phosphate binder on medial calcification in a rat model of uremia

PubMed Central

De Schutter, Tineke M; Behets, Geert J; Geryl, Hilde; Peter, Mirjam E; Steppan, Sonja; Gundlach, Kristina; Passlick-Deetjen, Jutta; D'Haese, Patrick C; Neven, Ellen

2013-01-01

Calcium-based phosphate binders are used to control hyperphosphatemia; however, they promote hypercalcemia and may accelerate aortic calcification. Here we compared the effect of a phosphate binder containing calcium acetate and magnesium carbonate (CaMg) to that of sevelamer carbonate on the development of medial calcification in rats with chronic renal failure induced by an adenine diet for 4 weeks. After 1 week, rats with chronic renal failure were treated with vehicle, 375 or 750 mg/kg CaMg, or 750 mg/kg sevelamer by daily gavage for 5 weeks. Renal function was significantly impaired in all groups. Vehicle-treated rats with chronic renal failure developed severe hyperphosphatemia, but this was controlled in treated groups, particularly by CaMg. Neither CaMg nor sevelamer increased serum calcium ion levels. Induction of chronic renal failure significantly increased serum PTH, dose-dependently prevented by CaMg but not sevelamer. The aortic calcium content was significantly reduced by CaMg but not by sevelamer. The percent calcified area of the aorta was significantly lower than vehicle-treated animals for all three groups. The presence of aortic calcification was associated with increased sox9, bmp-2, and matrix gla protein expression, but this did not differ in the treatment groups. Calcium content in the carotid artery was lower with sevelamer than with CaMg but that in the femoral artery did not differ between groups. Thus, treatment with either CaMg or sevelamer effectively controlled serum phosphate levels in CRF rats and reduced aortic calcification. PMID:23486515

Revealing the role of the product metal in DNA polymerase β catalysis

PubMed Central

Freudenthal, Bret D.; Beard, William A.; Pedersen, Lee G.; Wilson, Samuel H.

2017-01-01

Abstract DNA polymerases catalyze a metal-dependent nucleotidyl transferase reaction during extension of a DNA strand using the complementary strand as a template. The reaction has long been considered to require two magnesium ions. Recently, a third active site magnesium ion was identified in some DNA polymerase product crystallographic structures, but its role is not known. Using quantum mechanical/ molecular mechanical calculations of polymerase β, we find that a third magnesium ion positioned near the newly identified product metal site does not alter the activation barrier for the chemical reaction indicating that it does not have a role in the forward reaction. This is consistent with time-lapse crystallographic structures following insertion of Sp-dCTPαS. Although sulfur substitution deters product metal binding, this has only a minimal effect on the rate of the forward reaction. Surprisingly, monovalent sodium or ammonium ions, positioned in the product metal site, lowered the activation barrier. These calculations highlight the impact that an active site water network can have on the energetics of the forward reaction and how metals or enzyme side chains may interact with the network to modulate the reaction barrier. These results also are discussed in the context of earlier findings indicating that magnesium at the product metal position blocks the reverse pyrophosphorolysis reaction. PMID:28108654

Nonflammable potting, encapsulating and/or conformal coating compound

NASA Technical Reports Server (NTRS)

Kline, H. F.; Dawn, F.

1972-01-01

Compound formed from dimethylpolysiloxane, ammonium phosphate, and ground glass is nonflammable in air environment and self-extingushing in atmosphere of 60 percent oxygen and 40 percent nitrogen. Material may have applications for reducing industrial fire hazards and should interest aircraft industry, machinery manufacturers, and automotive industry.

Common stock solutions, buffers, and media.

PubMed

2001-05-01

This collection of recipes describes the preparation of buffers and reagents used in Current Protocols in Pharmacology for cell culture, manipulation of neural tissue, molecular biological methods, and neurophysiological/neurochemical measurements. RECIPES: Acid, concentrated stock solutions Ammonium hydroxide, concentrated stock solution EDTA (ethylenediaminetetraacetic acid), 0.5 M (pH 8.0) Ethidium bromide staining solution Fetal bovine serum (FBS) Gel loading buffer, 6× LB medium (Luria broth) and LB plates Potassium phosphate buffer, 0.1 M Sodium phosphate buffer, 0.1 M TE (Tris/EDTA) buffer Tris⋅Cl, 1 M.

Intra- and extracellular magnesium levels and atheromatosis in haemodialysis patients.

PubMed

Tzanakis, Ioannis; Virvidakis, Kyriakos; Tsomi, Aggeliki; Mantakas, Emmanouel; Girousis, Nikolaos; Karefyllakis, Nektarios; Papadaki, Antonia; Kallivretakis, Nikolaos; Mountokalakis, Theodoros

2004-06-01

Traditional risk factors do not adequately explain the high prevalence of cardiovascular disease in patients with chronic renal insufficiency. Currently, there is a lot of evidence that hypomagnesaemia may play a significant role in the pathogenesis of cardiovascular diseases in general population. The aim of this study was to test the hypothesis that magnesium status in haemodialysis patients is related to the degree of atheromatosis of carotid arteries, as assessed by B-mode ultrasound. Intima-media thickness of both common carotids was assessed by B-mode ultrasound in 93 stable chronic haemodialysis patients and in 182 age- and sex-matched healthy controls. Intracellular magnesium as well as serum magnesium levels were obtained in the haemodialysis patients. Intracellular magnesium was estimated by determination of this ion in isolated peripheral lymphocytes. Haemodialysis patients had also a significantly higher mean common carotid intima-media thickness than controls (0.87+/-0.16 vs 0.76+/-0.13 mm, p < 0.001). Multivariate analysis revealed that in haemodialysis patients both serum magnesium and intracellular magnesium were negatively associated with common carotid intima-media thickness (p = 0.001 and p = 0.003 respectively). Significant associations between the age of the haemodialysis patients, the existence of diabetes mellitus as well as the serum calcium x serum phosphate product with common carotid intima-media thickness of haemodialysis patients were also observed. A strong negative association of both extracellular and intracellular magnesium with common carotid intima-media thickness exists in haemodialysis patients. The above finding suggests that magnesium may play an important protective role in the development and/or acceleration of arterial atherosclerosis in patients with chronic renal insufficiency.

In Vitro Degradation Behaviors of Manganese-Calcium Phosphate Coatings on an Mg-Ca-Zn Alloy

PubMed Central

Su, Yichang; Su, Yingchao; Zai, Wei

2018-01-01

In order to decrease the degradation rate of magnesium (Mg) alloys for the potential orthopedic applications, manganese-calcium phosphate coatings were prepared on an Mg-Ca-Zn alloy in calcium phosphating solutions with different addition of Mn2+. Influence of Mn content on degradation behaviors of phosphate coatings in the simulated body fluid was investigated to obtain the optimum coating. With the increasing Mn addition, the corrosion resistance of the manganese-calcium phosphate coatings was gradually improved. The optimum coating prepared in solution containing 0.05 mol/L Mn2+ had a uniform and compact microstructure and was composed of MnHPO4·3H2O, CaHPO4·2H2O, and Ca3(PO4)2. The electrochemical corrosion test in simulated body fluid revealed that polarization resistance of the optimum coating is 36273 Ωcm2, which is about 11 times higher than that of phosphate coating without Mn addition. The optimum coating also showed the most stable surface structure and lowest hydrogen release in the immersion test in simulated body fluid. PMID:29643970

Improved Spectra for MALDI MSI of Peptides Using Ammonium Phosphate Monobasic in MALDI Matrix.

PubMed

Ucal, Yasemin; Ozpinar, Aysel

2018-05-10

MALDI mass spectrometry imaging (MSI) enables analysis of peptides along with histology. However, there are several critical steps in MALDI MSI of peptides, one of which is spectral quality. Suppression of MALDI matrix clusters by the aid of ammonium salts in MALDI experiments is well-known. It is asserted that addition of ammonium salts dissociates potential matrix adducts and thereafter decreases matrix cluster formation. Consequently, MALDI MS sensitivity and mass accuracy increases. Up to our knowledge, a limited number of MALDI MSI studies used ammonium salts as matrix additives to suppress matrix clusters and enhance peptide signals. In this work, we investigated the effect of ammonium phosphate monobasic (AmP) as alpha-cyano-4-hydroxycinnamic acid (α-CHCA) matrix additive in MALDI MSI of peptides. Prior to MALDI MSI, the effect of varying concentrations of AmP in α-CHCA were assessed in bovine serum albumin (BSA) tryptic digests and compared with the control (α-CHCA without AmP). Based on our data, the addition of AmP as matrix additive decreased matrix cluster formation regardless of its concentration and, specifically 8 mM AmP and 10 mM AmP increased BSA peptide signal intensities. In MALDI MSI of peptides, both 8 mM, and 10 mM AmP in α-CHCA improved peptide signals especially in the mass range of m/z 2000 to 3000. In particular, 9 peptide signals were found to have differential intensities within the tissues deposited with AmP in α-CHCA (AUC>0.60). To the best of our knowledge, this is the first MALDI MSI of peptides work investigating different concentrations of AmP as α-CHCA matrix additive in order to enhance peptide signals in formalin fixed paraffin embedded (FFPE) tissues. Further, AmP as part of α-CHCA matrix could enhance protein identifications and support MALDI MSI based proteomic approaches. This article is protected by copyright. All rights reserved.

Magnesium coated phosphate glass fibers for unidirectional reinforcement of polycaprolactone composites.

PubMed

Liu, Xiaoling; Grant, David M; Palmer, Graham; Parsons, Andrew J; Rudd, Chris D; Ahmed, Ifty

2015-10-01

Bioresorbable composites have shown much potential for bone repair applications, as they have the ability to degrade completely over time and their degradation and mechanical properties can be tailored to suit the end application. In this study, phosphate glass fiber (from the system 45% P2 O5-16% CaO-24% MgO-11% Na2 O-4% Fe2 O3 (given in mol%)) were used to reinforce polycaprolactone (PCL) with approximately 20% fiber volume fraction. The glass fiber surfaces were coated with magnesium (Mg) through magnetron sputtering to improve the fiber-matrix interfacial properties. The Mg coating provided a rough fiber surface (roughness (Ra) of about 44nm). Both noncoated and Mg-coated fiber-reinforced composites were assessed. The water uptake and mass loss properties for the composites were assessed in phosphate-buffered saline (PBS) at 37°C for up to 28 days, and ion release profiles were also investigated in both water and PBS media. Inhibition of media influx was observed for the Mg-coated composites. The composite mechanical properties were characterized on the basis of both tensile and flexural tests and their retention in PBS media at 37°C was also investigated. A higher retention of the mechanical properties was observed for the Mg-coated composites over the 28 days degradation period. © 2014 Wiley Periodicals, Inc.

Physicochemical characterization of mozzarella cheese wheys and stretchwaters in comparison with several other sweet wheys.

PubMed

Gernigon, G; Piot, M; Beaucher, E; Jeantet, R; Schuck, P

2009-11-01

To better understand the origins of the problems occurring during mozzarella cheese whey concentration, lactose crystallization, and spray-drying steps, a physicochemical characterization was achieved. For this purpose, mozzarella cheese wheys were sampled and their content in different compounds such as total nitrogen, noncasein nitrogen, nonprotein nitrogen, lactate, citrate, chloride, sulfate, phosphate anions, calcium, magnesium, potassium, sodium cations, and the sugars glucose and galactose were measured. In a second step, the results were compared with the corresponding content in cheddar cheese wheys, raclette cheese wheys, soft cheese wheys, and Swiss-type cheese wheys. At the end of this survey, it was shown that mozzarella cheese wheys were more concentrated in lactate and in minerals--especially phosphate, calcium, and magnesium--than the other cheese wheys and that they contained galactose. These constituents are known to be hygroscopic. Complementary surveys are now necessary to compare the hygroscopicity of galactose and lactate and discover whether the amounts of these compounds found in mozzarella cheese wheys are a factor in the problems encountered during the concentration, lactose crystallization, and spray-drying steps.

OPTIMIZATION OF FUROSEMIDE LIQUISOLID TABLETS PREPARATION PROCESS LEADING TO THEIR MASS AND SIZE REDUCTION.

PubMed

Kurek, Mateusz; Woyna-Orlewicz, Krzysztof; Khalid, Mohammad Hassan; Jachowicz, Renata

2016-09-01

The great number of drug substances currently used in solid oral dosage forms is characterized by poor water solubility. Therefore, various methods of dissolution rate enhancement are an important topic of research interest in modem drug technology. The purpose of this study was to enhance the furosemide dissolution rate from liquisolid tablets while maintaining an acceptable size and mass. Two types of dibasic calcium phosphate (Fujicalin®/Emcompress®) and microcrystalline cellulose (Vivapur® 102/Vivapur® 12) were used as carriers and magnesium aluminometasilicate (Neusilin® US2) was used as a coating material. The flowable liquid retention potential for those excipients was tested by measuring the angle of slide. To evaluate the impact of used excipients on tablet properties fourteen tablet formulations were prepared. It was found that LS2 tablets containing spherically granulated dibasic calcium phosphate and magnesium aluminometasilicate exhibit the best dissolution profile and mechanical properties while tablets composed only with Neusilin® US2 was characterized by the smallest size and mass with preserved good mechanical properties and furosemide dissolution.

Biomimetic coating of magnesium alloy for enhanced corrosion resistance and calcium phosphate deposition.

PubMed

Cui, W; Beniash, E; Gawalt, E; Xu, Z; Sfeir, C

2013-11-01

Degradable metals have been suggested as biomaterials with revolutionary potential for bone-related therapies. Of these candidate metals, magnesium alloys appear to be particularly attractive candidates because of their non-toxicity and outstanding mechanical properties. Despite their having been widely studied as orthopedic implants for bone replacement/regeneration, their undesirably rapid corrosion rate under physiological conditions has limited their actual clinical application. This study reports the use of a novel biomimetic peptide coating for Mg alloys to improve the alloy corrosion resistance. A 3DSS biomimetic peptide is designed based on the highly acidic, bioactive bone and dentin extracellular matrix protein, phosphophoryn. Surface characterization techniques (scanning electron microscopy, energy dispersive X-ray spectroscopy and diffuse-reflectance infrared spectroscopy) confirmed the feasibility of coating the biomimetic 3DSS peptide onto Mg alloy AZ31B. The 3DSS peptide was also used as a template for calcium phosphate deposition on the surface of the alloy. The 3DSS biomimetic peptide coating presented a protective role of AZ31B in both hydrogen evolution and electrochemical corrosion tests. Copyright © 2013. Published by Elsevier Ltd.

Fluoride and calcium-phosphate coated sponges of the magnesium alloy AX30 as bone grafts: a comparative study in rabbits.

PubMed

Lalk, Mareike; Reifenrath, Janin; Angrisani, Nina; Bondarenko, Alexandr; Seitz, Jan-Marten; Mueller, Peter P; Meyer-Lindenberg, Andrea

2013-02-01

Biocompatibility and degradation of magnesium sponges (alloy AX30) with a fluoride (MgF(2) sponge, n = 24, porosity 63 ± 6 %, pore size 394 ± 26 μm) and with a fluoride and additional calcium-phosphate coating (CaP sponge, n = 24, porosity 6 ± 4 %, pore size 109 ± 37 μm) were evaluated over 6, 12 and 24 weeks in rabbit femurs. Empty drill holes (n = 12) served as controls. Clinical and radiological examinations, in vivo and ex vivo μ-computed tomographies and histological examinations were performed. Clinically both sponge types were tolerated well. Radiographs and XtremeCT evaluations showed bone changes comparable to controls and mild gas formation. The μCT80 depicted a higher and more inhomogeneous degradation of the CaP sponges. Histomorphometrically, the MgF(2) sponges resulted in the highest bone and osteoid fractions and were integrated superiorly into the bone. Histologically, the CaP sponges showed more inflammation and lower vascularization. MgF(2) sponges turned out to be better biocompatible and promising, biodegradable bone replacements.

Improved osteogenesis and angiogenesis of magnesium-doped calcium phosphate cement via macrophage immunomodulation.

PubMed

Wang, Meng; Yu, Yuanman; Dai, Kai; Ma, Zhengyu; Liu, Yang; Wang, Jing; Liu, Changsheng

2016-10-18

Immune responses are vital for bone regeneration and play an essential role in the fate of biomaterials after implantation. As a kind of plastic cell, macrophages are central regulators of the immune response during the infection and wound healing process including osteogenesis and angiogenesis. Magnesium-calcium phosphate cement (MCPC) has been reported as a promising candidate for bone repair with promoted osteogenesis both in vitro and in vivo. However, relatively little is known about the effects of MCPC on immune response and the following outcome. In this study, we investigated the interactions between macrophages and MCPC. Here we found that the pro-inflammatory cytokines including TNF-α and IL-6 were less expressed and the bone repair related cytokine of TGF-β1 was up-regulated by macrophages in MCPC extract. Furthermore, the enhanced osteogenic capacity of BMSCs and angiogenic potential of HUVECs were acquired in vitro by the MCPC-induced immune microenvironment. These findings suggest that MCPC is able to facilitate bone healing by endowing favorable osteoimmunomodulatory properties and influencing crosstalk behavior between immune cells and osteogenesis-related cells.

Dental plaque microcosm biofilm behavior on calcium phosphate nanocomposite with quaternary ammonium.

PubMed

Cheng, Lei; Weir, Michael D; Zhang, Ke; Wu, Eric J; Xu, Sarah M; Zhou, Xuedong; Xu, Hockin H K

2012-08-01

Half of dental restorations fail in 10 years, with secondary caries as the main reason. Calcium phosphate composites could remineralize tooth lesions. The objectives of this study were to: (1) impart antibacterial activity to a composite with nanoparticles of amorphous calcium phosphate (NACP); and (2) investigate the effect of quaternary ammonium dimethacrylate (QADM) on mechanical and dental plaque microcosm biofilm properties for the first time. The NACP and glass particles were filled into a dental resin that contained bis(2-methacryloyloxy-ethyl) dimethyl-ammonium bromide, the QADM. NACP nanocomposites containing 0%, 7%, 14%, and 17.5% of QADM by mass, respectively, were photo-cured. A commercial composite with no antibacterial activity was used as control. Mechanical properties were measured in three-point flexure. A human saliva microcosm model was used to grow biofilms on composites. Live/dead assay, metabolic activity, colony-forming unit (CFU) counts, and lactic acid production of biofilms on the composites were measured. Increasing QADM mass fraction monotonically reduced the biofilm viability, CFU and lactic acid. Biofilms on NACP nanocomposite with 17.5% QADM had metabolic activity that was 30% that on a commercial composite control (p<0.05). Total microorganisms, total streptococci, and mutans streptococci CFU counts (mean ± sd; n = 6) on composite control was 6-fold those on NACP +17.5% QADM nanocomposite. Composite control had long strings of bacterial cells with normal short-rod shapes, while some cells on NACP-QADM nanocomposites disintegrated into pieces. Adding QADM to NACP did not decrease the composite strength and elastic modulus, which matched (p>0.1) those of a commercial composite without Ca-PO(4) or antibacterial activity. A dental plaque microcosm model was used to evaluate the novel NACP-QADM nanocomposite. The nanocomposite greatly reduced the biofilm viability, metabolic activity and lactic acid, while its mechanical properties matched those of a commercial composite. NACP-QADM nanocomposite with calcium phosphate fillers, good mechanical properties and a strong antibacterial activity may have potential for anti-biofilm and anti-caries restorations. Copyright © 2012 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Dental plaque microcosm biofilm behavior on calcium phosphate nanocomposite with quaternary ammonium

PubMed Central

Cheng, Lei; Weir, Michael D.; Zhang, Ke; Wu, Eric; Xu, Sarah M.; Zhou, Xuedong; Xu, Hockin H. K.

2012-01-01

Objectives Half of dental restorations fail in 10 years, with secondary caries as the main reason. Calcium phosphate composites could remineralize tooth lesions. The objectives of this study were to: (1) Impart antibacterial activity to a composite with nanoparticles of amorphous calcium phosphate (NACP); and (2) investigate the effect of quaternary ammonium dimethacrylate (QADM) on mechanical and dental plaque microcosm biofilm properties for the first time. Methods The NACP and glass particles were filled into a dental resin that contained bis(2-methacryloyloxy-ethyl) dimethyl-ammonium bromide, the QADM. NACP nanocomposites containing 0%, 7%, 14%, and 17.5% of QADM by mass, respectively, were photo-cured. A commercial composite with no antibacterial activity was used as control. Mechanical properties were measured in three-point flexure. A human saliva microcosm model was used to grow biofilms on composites. Live/dead assay, metabolic activity, colony-forming unit (CFU) counts, and lactic acid production of biofilms on the composites were measured. Results Increasing QADM mass fraction monotonically reduced the biofilm viability, CFU and lactic acid. Biofilms on NACP nanocomposite with 17.5% QADM had metabolic activity that was 30% that on a commercial composite control (p<0.05). Total microorganisms, total streptococci, and mutans streptococci CFU counts (mean±sd; n=6) on composite control was 6-fold those on NACP+17.5% QADM nanocomposite. Composite control had long strings of cells with normal short-rod shapes, while some cells on NACP-QADM nanocomposites disintegrated into pieces. Adding QADM to NACP did not decrease the strength and elastic modulus, which matched (p>0.1) those of a commercial composite without Ca-PO4 or antibacterial activity. Significance A dental plaque microcosm model was used to evaluate the novel NACP-QADM nanocomposite. The nanocomposite greatly reduced the biofilm viability, metabolic activity and lactic acid, while its mechanical properties matched those of a commercial composite. NACP-QADM nanocomposite with calcium phosphate fillers, good mechanical properties and a strong antibacterial activity may have potential for anti-biofilm and anti-caries restorations. PMID:22578992

Phosphate-containing dialysis solution prevents hypophosphatemia during continuous renal replacement therapy

PubMed Central

BROMAN, M; CARLSSON, O; FRIBERG, H; WIESLANDER, A; GODALY, G

2011-01-01

Background Hypophosphatemia occurs in up to 80% of the patients during continuous renal replacement therapy (CRRT). Phosphate supplementation is time-consuming and the phosphate level might be dangerously low before normophosphatemia is re-established. This study evaluated the possibility to prevent hypophosphatemia during CRRT treatment by using a new commercially available phosphate-containing dialysis fluid. Methods Forty-two heterogeneous intensive care unit patients, admitted between January 2007 and July 2008, undergoing hemodiafiltration, were treated with a new Gambro dialysis solution with 1.2 mM phosphate (Phoxilium) or with standard medical treatment (Hemosol B0). The patients were divided into three groups: group 1 (n=14) receiving standard medical treatment and intravenous phosphate supplementation as required, group 2 (n=14) receiving the phosphate solution as dialysate solution and Hemosol B0 as replacement solution and group 3 (n=14) receiving the phosphate-containing solution as both dialysate and replacement solutions. Results Standard medical treatment resulted in hypophosphatemia in 11 of 14 of the patients (group 1) compared with five of 14 in the patients receiving phosphate solution as the dialysate solution and Hemosol B0 as the replacement solution (group 2). Patients treated with the phosphate-containing dialysis solution (group 3) experienced stable serum phosphate levels throughout the study. Potassium, ionized calcium, magnesium, pH, pCO2 and bicarbonate remained unchanged throughout the study. Conclusion The new phosphate-containing replacement and dialysis solution reduces the variability of serum phosphate levels during CRRT and eliminates the incidence of hypophosphatemia. PMID:21039362

Microwave assisted synthesis and characterization of magnesium substituted calcium phosphate bioceramics.

PubMed

Khan, Nida Iqbal; Ijaz, Kashif; Zahid, Muniza; Khan, Abdul S; Abdul Kadir, Mohammed Rafiq; Hussain, Rafaqat; Anis-Ur-Rehman; Darr, Jawwad A; Ihtesham-Ur-Rehman; Chaudhry, Aqif A

2015-11-01

Hydroxyapatite is used extensively in hard tissue repair due to its biocompatibility and similarity to biological apatite, the mineral component of bone. It differs subtly in composition from biological apatite which contains other ions such as magnesium, zinc, carbonate and silicon (believed to play biological roles). Traditional methods of hydroxyapatite synthesis are time consuming and require strict reaction parameter control. This paper outlines synthesis of magnesium substituted hydroxyapatite using simple microwave irradiation of precipitated suspensions. Microwave irradiation resulted in a drastic decrease in ageing times of amorphous apatitic phases. Time taken to synthesize hydroxyapatite (which remained stable upon heat treatment at 900°C for 1h) reduced twelve folds (to 2h) as compared to traditionally required times. The effects of increasing magnesium concentration in the precursors on particle size, surface area, phase-purity, agglomeration and thermal stability, were observed using scanning electron microscopy, BET surface area analysis, X-ray diffraction and photo acoustic Fourier transform infra-red spectroscopy. Porous agglomerates were obtained after a brief heat-treatment (1h) at 900°C. Copyright © 2015 Elsevier B.V. All rights reserved.

Coating Systems for Biodegradable Magnesium Applications

NASA Astrophysics Data System (ADS)

Seitz, Jan-Marten; Eifler, Rainer; Vaughan, Matthew; Seal, Chris; Hyland, Margaret; Maier, Hans Jürgen

Current research for degradable magnesium implants has shown a multitude of potential applications for these materials. Within various studies, the research focuses especially on Mg alloys' biocompatibility and also its mechanical and corrosive behaviour in in vitro/in vivo environments. In particular, the corrosive properties of Mg alloys often remain problematic, showing either a rapid or a burst degradation, limiting their applicability. Besides changing the alloy, a magnesium implant's initial corrosion properties can be improved and controllable by means of applied coatings. In general, a multitude of coating solutions (e.g. on basis of phosphates or degradable polymers) are already available for permanent implants. If these are applicable to Mg, the next step requires that they delay corrosion and inhibit burst corrosion. In this study, the applicability and corrosion-delaying properties of PLA and MgF2 coatings on the magnesium alloy LANd442, respecting their singular and combined application, is shown. By means of corrosion tests in a simulated body fluid the use of combined coatings was proven to be advantageous regarding longevity and toughness of the coating system.

Optimal use of phosphate binders in chronic kidney disease.

PubMed

Sonikian, Makrouhi; Papachristou, Evangelos; Goumenos, Dimitrios S

2013-12-01

Hyperphosphatemia is one of the major factors associated with the development of vascular calcification in patients with chronic kidney disease (CKD). Since phosphate is retained in such patients, pharmacological treatment and other measures are necessary to control hyperphosphatemia. Several phosphate binders (calcium salts, magnesium salts, non-calcium-based binders and aluminium) are available for the treatment of hyperphosphatemia. Nevertheless, none of the above mentioned agents has shown an overall superiority over others, while potency and side effects are quite variable among them creating difficulties in choosing the optimal drug for each patient. The authors discuss the disturbed phosphate metabolism, the available phosphate binders, as well as the general therapeutic principles of treating hyperphosphatemia in CKD patients. The literature used for this review had been retrieved from PubMed and covers a large number of original and retrospective studies as well as prospective cohort studies, meta-analyses and international clinical guidelines. Lowering serum phosphate levels in CKD patients may potentially have a positive impact on cardiovascular morbidity and mortality. Factors that should be taken into consideration when selecting a specific drug include CKD stage, cardiovascular disease, severity of secondary hyperparathyroidism, concomitant medications, life expectancy and patient compliance. Therefore, when selecting a specific phosphate binder, individualisation is mandatory.

BENTHIC NUTRIENT FLUX IN A SMALL ESTUARY IN NORTHWESTERNFLORIDA (USA)

EPA Science Inventory

Benthic Nutrient Flux in a Small Estuary in Northwestern Florida(USA).Gulf and Caribbean Research 18, 15-25, 2006.

Benthic nutrient fluxes of ammonium (NH4+), nitrite/nitrate (NO2-+NO3-), phosphate (PO4-), and dissolved silica (DSi) were measured in Escambia Bay, an estuar...

Effects of Phos-Chek® on soil nutrient availability

USDA-ARS?s Scientific Manuscript database

Wildfire frequencies and intensities have been steadily increasing on western US landscapes. Phos-chek® is an aerially-applied fire retardant used to contain and control wildfires. Composed of ammonium and phosphate salts, Phos-chek® has the potential to increase soil nutrient availability of N and ...

21 CFR 184.1141a - Ammonium phosphate, monobasic.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 184.1141a Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS... phosphoric acid at a pH below 5.8. (b) The ingredient meets the specifications of the Food Chemicals Codex...

21 CFR 184.1141a - Ammonium phosphate, monobasic.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 184.1141a Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS... phosphoric acid at a pH below 5.8. (b) The ingredient meets the specifications of the Food Chemicals Codex...

Effect of Poly(Vinyl Alcohol) Addition on the Properties of Hydrothermal Derived Calcium Phosphate Cement for Bone Filling Materials

NASA Astrophysics Data System (ADS)

Razali, N. N.; Sopyan, I.; Mel, M.; Salleh, H. M.; Rahman, M. M.; Singh, R.

2017-06-01

The effect of addition of poly(vinyl alcohol) on hydrothermal derived calcium phosphate cement has been studied. The precursors used to prepare the cement were calcium oxide (CaO) and ammonium dihydrogen phosphate (NH4H2PO4); the reaction was conducted in water at 80-100°C. To improve properties of CPC, poly(vinyl alcohol) (PVA) of 1wt% and 2wt% was added to the liquid phase of CPC and the results were compared to CPC without PVA addition. The addition of PVA was proved to bring remarkable effects on cohesion, setting time and mechanical strength of CPC which make it suitable physically for injectable bone filler applications.

Common buffers, media, and stock solutions.

PubMed

2001-05-01

This appendix describes the preparation of selected bacterial media and of buffers and reagents used in the manipulation of nucleic acids and proteins. Recipes for cell culture media and reagents are located elsewhere in the manual. RECIPES: Acids, concentrated stock solutions; Ammonium acetate, 10 M; Ammonium hydroxide, concentrated stock solution; ATP, 100 mM; BCIP, 5% (w/v); BSA (bovine serum albumin), 10% (100 mg/ml); Denhardt solution, 100x; dNTPs: dATP, dTTP, dCTP, and dGTP; DTT, 1 M; EDTA, 0.5 M (pH 8.0); Ethidium bromide solution; Formamide loading buffer, 2x; Gel loading buffer, 6x; HBSS (Hanks balanced salt solution); HCl, 1 M; HEPES-buffered saline, 2x; KCl, 1 M; LB medium; LB plates; Loading buffer; 2-ME, (2-mercaptoethanol)50 mM; MgCl(2), 1 M; MgSO(4), 1 M; NaCl, 5 M; NaOH, 10 M; NBT (nitroblue tetrazolium chloride), 5% (w/v); PCR amplification buffer, 10x; Phosphate-buffered saline (PBS), pH approximately 7.3; Potassium acetate buffer, 0.1 M; Potassium phosphate buffer, 0.1 M; RNase a stock solution (DNase-free), 2 mg/ml; SDS, 20%; SOC medium; Sodium acetate, 3 M; Sodium acetate buffer, 0.1 M; Sodium phosphate buffer, 0.1 M; SSC (sodium chloride/sodium citrate), 20x; SSPE (sodium chloride/sodium phosphate/EDTA), 20x; T4 DNA ligase buffer, 10x; TAE buffer, 50x; TBE buffer, 10x; TBS (Tris-buffered saline); TCA (trichloroacetic acid), 100% (w/v); TE buffer; Terrific broth (TB); TrisCl, 1 M; TY medium, 2x; Urea loading buffer, 2x.

Green colorants based on energetic azole borates.

PubMed

Glück, Johann; Klapötke, Thomas M; Rusan, Magdalena; Stierstorfer, Jörg

2014-11-24

The investigation of green-burning boron-based compounds as colorants in pyrotechnic formulations as alternative for barium nitrate, which is a hazard to health and to the environment, is reported. Metal-free and nitrogen-rich dihydrobis(5-aminotetrazolyl)borate salts and dihydrobis(1,3,4-triazolyl)borate salts have been synthesized and characterized by NMR spectroscopy, elemental analysis, mass spectrometry, and vibrational spectroscopy. Their thermal and energetic properties have been determined as well. Several pyrotechnic compositions using selected azolyl borate salts as green colorants were investigated. Formulations with ammonium dinitramide and ammonium nitrate as oxidizers and boron and magnesium as fuels were tested. The burn time, dominant wavelength, spectral purity, luminous intensity, and luminous efficiency as well as the thermal and energetic properties of these compositions were measured. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

IONIC EFFECTS ON LIGNIFICATION AND PEROXIDASE IN TISSUE CULTURES

PubMed Central

Lipetz, Jacques; Garro, Anthony J.

1965-01-01

Crown-gall tumor tissue cultures release peroxidase into the medium in response to the concentration of specific ions in the medium. This release is not due to diffusion from cut surfaces or injured cells. Calcium, magnesium, and ammonium were, in that order, most effective in increasing peroxidase release. The enzyme was demonstrated cytochemically on the cell walls and in the cytoplasm. Cell wall fractions, exhaustively washed in buffer, still contained bound peroxidase. This bound peroxidase could be released by treating the wall fractions with certain divalent cations or ammonium. The order of effectiveness for removing the enzyme from the washed cell walls is: Ca++ ≈ Sr++ > Ba++ > Mg++ > NH4 +. These data support the thesis presented that specific ions can control the deposition of lignin on cell walls by affecting the peroxidase levels on these walls. PMID:19866650