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Fulltext Magnesium sulfate for acute exacerbations of chronic obstructive pulmonary disease

Ni H, Aye SZ, Naing C

Cochrane Database Syst Rev, 2022 May 26;5(5):CD013506.
PMID: 35616126 DOI: 10.1002/14651858.CD013506.pub2

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a chronic and progressive disease, often punctuated by recurrent flare-ups or exacerbations. Magnesium sulfate, having a bronchodilatory effect, may have a potential role as an adjunct treatment in COPD exacerbations. However, comprehensive evidence of its effects is required to facilitate clinical decision-making.
OBJECTIVES: To assess the effects of magnesium sulfate for acute exacerbations of chronic obstructive pulmonary disease in adults.
SEARCH METHODS: We searched the Cochrane Airways Trials Register, CENTRAL, MEDLINE, Embase, ClinicalTrials.gov, the World Health Organization (WHO) trials portal, EU Clinical Trials Register and Iranian Registry of Clinical Trials. We also searched the proceedings of major respiratory conferences and reference lists of included studies up to 2 August 2021.
SELECTION CRITERIA: We included single- or double-blind parallel-group randomised controlled trials (RCTs) assessing magnesium sulfate in adults with COPD exacerbations. We excluded cross-over trials.
DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. Two review authors independently selected trials for inclusion, extracted data and assessed risk of bias. The primary outcomes were: hospital admissions (from the emergency room); need for non-invasive ventilation (NIV), assisted ventilation or admission to intensive-care unit (ICU); and serious adverse events. Secondary outcomes were: length of hospital stay, mortality, adverse events, dyspnoea score, lung function and blood gas measurements. We assessed confidence in the evidence using GRADE methodology. For missing data, we contacted the study investigators.
MAIN RESULTS: We identified 11 RCTs (10 double-blind and 1 single-blind) with a total 762 participants. The mean age of participants ranged from 62 to 76 years. Trials were single- or two-centre trials conducted in Iran, New Zealand, Nepal, Turkey, the UK, Tunisia and the USA between 2004 and 2018. We judged studies to be at low or unclear risk of bias for most of the domains. Three studies were at high risk for blinding and other biases. Intravenous magnesium sulfate versus placebo Seven studies (24 to 77 participants) were included. Fewer people may require hospital admission with magnesium infusion compared to placebo (odds ratio (OR) 0.45, 95% CI 0.23 to 0.88; number needed to treat for an additional beneficial outcome (NNTB) = 7; 3 studies, 170 participants; low-certainty evidence). Intravenous magnesium may result in little to no difference in the requirement for non-invasive ventilation (OR 0.74, 95% CI 0.31 to 1.75; very low-certainty evidence). There were no reported cases of endotracheal intubation (2 studies, 107 participants) or serious adverse events (1 study, 77 participants) in either group. Included studies did not report intensive care unit (ICU) admission or deaths. Magnesium infusion may reduce the length of hospital stay by a mean difference (MD) of 2.7 days (95% CI 4.73 days to 0.66 days; 2 studies, 54 participants; low-certainty evidence) and improve dyspnoea score by a standardised mean difference of -1.40 (95% CI -1.83 to -0.96; 2 studies, 101 participants; low-certainty evidence). We were uncertain about the effect of magnesium infusion on improving lung function or oxygen saturation. For all adverse events, the Peto OR was 0.14 (95% CI 0.02 to 1.00; 102 participants); however, the event rate was too low to reach a robust conclusion. Nebulised magnesium sulfate versus placebo Three studies (20 to 172 participants) were included. Magnesium inhalation may have little to no impact on hospital admission (OR 0.77, 95% CI 0.21 to 2.82; very low-certainty evidence) or need for ventilatory support (NIV or mechanical ventilation) (OR 0.33, 95% CI 0.01 to 8.20; very low-certainty evidence). It may result in fewer ICU admissions compared to placebo (OR 0.39, 95% CI 0.15 to 1.00; very low-certainty evidence) and improvement in dyspnoea (MD -14.37, 95% CI -26.00 to -2.74; 1 study, 20 participants; very low-certainty evidence). There were no serious adverse events reported in either group. There was one reported death in the placebo arm in one trial, but the number of participants was too small for a conclusion. There was limited evidence about the effect of magnesium inhalation on length of hospital stay, lung function outcomes or oxygen saturation. Included studies did not report adverse events. Magnesium sulfate versus ipratropium bromide A single study with 124 participants assessed nebulised magnesium sulfate plus intravenous magnesium infusion versus nebulised ipratropium plus intravenous normal saline. There was little to no difference between these groups in terms of hospital admission (OR 1.62, 95% CI 0.78 to 3.37), endotracheal intubation (OR 1.69, 95% CI 0.61 to 4.71) and length of hospital stay (MD 1.10 days, 95% CI -0.22 to 2.42), all with very low-certainty evidence. There were no data available for non-invasive ventilation, ICU admission and serious adverse events. Adverse events were not reported. AUTHORS' CONCLUSIONS: Intravenous magnesium sulfate may be associated with fewer hospital admissions, reduced length of hospital stay and improved dyspnoea scores compared to placebo. There is no evidence of a difference between magnesium infusion and placebo for NIV, lung function, oxygen saturation or adverse events. We found no evidence for ICU admission, endotracheal intubation, serious adverse events or mortality. For nebulised magnesium sulfate, we are unable to draw conclusions about its effects in COPD exacerbations for most of the outcomes. Studies reported possibly lower ICU admissions and a lesser degree of dyspnoea with magnesium inhalation compared to placebo; however, larger studies are required to yield a more precise estimate for these outcomes. Similarly, we could not identify any robust evidence for magnesium sulfate compared to ipratropium bromide. Future well-designed multicentre trials with larger samples are required, including subgroups according to severity of exacerbations and COPD phenotypes.

Matched MeSH terms: Magnesium/therapeutic use
Variation of Ca, Sr, Ba and Mg in the otolith of mudskipper in west coast of Peninsular Malaysia

Sarimin AS, Ghaffar MA, Mohamed CA

Pak J Biol Sci, 2009 Feb 01;12(3):231-8.
PMID: 19579951

A study on elemental composition in the otolith of giant mudskipper, Periophthalmodon schlosseri, was done from June to October 2003. Specimens were obtained from the mangrove areas of Kuala Selangor, Sepang and Melaka in the west coast of Peninsular Malaysia. A total of 70 sagitta otoliths were analyzed to detect variation of Sr, Ba and Mg, replacing the natural chemical composition of the otolith, which is the calcium carbonate (CaCO3). The average ratio of Sr:Ca was 0.11 x 10(-4), Ba:Ca was 5.7 x 10(-3) and Mg:Ca was 0.2 x 10(-3). Strong correlation (R > 0.8) between fish body size and otolith weight ofmudskipper (p < 0.01) also found during this study.

Matched MeSH terms: Magnesium/analysis*
Fulltext The Perilous PPI: Proton Pump Inhibitor as a Cause of Clinically Significant Hypomagnesaemia

Tai YT, Tong CV

J ASEAN Fed Endocr Soc, 2020;35(1):109-113.
PMID: 33442177 DOI: 10.15605/jafes.035.01.18

Proton pump inhibitors (PPIs) are the mainstay of therapy for all gastric acid related diseases and are commonly used in current clinical practice. Although widely regarded as safe, PPIs have been associated with a variety of adverse effects, including hypomagnesaemia. The postulated mechanism of PPI-related hypomagnesaemia involves inhibition of intestinal magnesium absorption via transient receptor potential melastin (TRPM) 6 and 7 cation channels. PPIinduced hypomagnesaemia (PPIH) has become a well recognized phenomenon since it was first reported in 2006. Clinical concerns arise from growing number of case reports presenting PPIH as a consequence of long-term PPI use, with more than 30 cases published to date. In this article, we report 2 cases of PPIH associated with the use of pantoprazole. Both patients presented with severe hypomagnesaemia and hypocalcaemia. One of them had associated hypokalemia and cardiac arrhythmia. A casual relation with PPIs postulated and supported by resolution of electrolyte abnormalities after discontinuation of PPIs.

Matched MeSH terms: Magnesium; Magnesium Deficiency
Functional expression, purification, biochemical and biophysical characterizations, and molecular dynamics simulation of a histidine acid phosphatase from Saccharomyces cerevisiae

Nezhad NG, Jamaludin SZB, Rahman RNZRA, Yahaya NM, Oslan SN, Shariff FM, et al.

World J Microbiol Biotechnol, 2024 Apr 17;40(6):171.
PMID: 38630327 DOI: 10.1007/s11274-024-03970-8

A histidine acid phosphatase (HAP) (PhySc) with 99.50% protein sequence similarity with PHO5 from Saccharomyces cerevisiae was expressed functionally with the molecular mass of ∼110 kDa through co-expression along with the set of molecular chaperones dnaK, dnaJ, GroESL. The purified HAP illustrated the optimum activity of 28.75 ± 0.39 U/mg at pH 5.5 and 40 ˚C. The Km and Kcat values towards calcium phytate were 0.608 ± 0.09 mM and 650.89 ± 3.6 s- 1. The half-lives (T1/2) at 55 and 60 ˚C were 2.75 min and 55 s, respectively. The circular dichroism (CD) demonstrated that PhySc includes 30.5, 28.1, 21.3, and 20.1% of random coils, α-Helix, β-Turns, and β-Sheet, respectively. The Tm recorded by CD for PhySc was 56.5 ± 0.34˚C. The molecular docking illustrated that His59 and Asp322 act as catalytic residues in the PhySc. MD simulation showed that PhySc at 40 ˚C has higher structural stability over those of the temperatures 60 and 80 ˚C that support the thermodynamic in vitro investigations. Secondary structure content results obtained from MD simulation indicated that PhySc consists of 34.03, 33.09, 17.5, 12.31, and 3.05% of coil, helix, turn, sheet, and helix310, respectively, which is almost consistent with the experimental results.

Matched MeSH terms: Magnesium*
Origin of formation water salinity variation and its geological significance in Chang 9 Stratum, Jiyuan Oilfield

Hua Yang, Jinhua Fu, Yujiang Shi, Yumei Cheng, Haitao Zhang, Zhiqiang Mao, et al.

Sains Malaysiana, 2016;45:9-18.

The origin of formation water salinity variation in Chang 9 stratum, Jiyuan oilfield, Ordos basin is studied here. 91 formation water samples show that water salinity is characterized by a wide range and a complex plane distribution. In order to find out the main cause of such distribution complexity and reveal the relationship between formation water and evolution of reservoir traps, core data, chemical analysis result of formation water and log data are analyzed from perspectives of diagenesis and tectonism. And then, their characteristics are presented as the followings. In high salinity area, tuffaceous mudstone interlayer is found growing. Besides, the condition of Na++K+ is opposite to that of Ca2+, for its rate of concentration increase slows down with total salinity accumulating. In low salinity area, while, with fracture and faults developing, some formation water of CaCl2 type turns into MgCl2, NaHCO3 or Na2SO4 type. The cause is thus proposed to be composed of two aspects. One covers tuff alteration and later diagenesis for the high salinity. To be specific, montmorillonite, developed from tuff alteration, absorbs cation selectively and then ions migrate, during which more Na++K+ get lost, while more Ca2+ reserved. Afterwards, those reserved Ca2+ get released with montmorillonite transforming to illite, which results in a loss of Na++K+ and accumulation of Ca2+. Lots of ions are released into formation water during that process and later diagenetic process, which leads to the high water salinity. The other aspect is the development of faults and fractures, through which, the upper low salinity formation water gets connected. And that is the main cause of low salinity. At last, geological significance is discussed from two angles. Firstly, tuff alteration and later diagenesis are pivotal to reservoir reconstruction; and secondly, faults and fractures play an important role in oil transportation and storage.

Matched MeSH terms: Magnesium Chloride
Diagenesis dan Asal Mula Dolomit dan Kuarza di dalam Batu Kapur Kodiang, Kedah (Diagenetic and Origin of Dolomite and Quartz in Kodiang Limestone, Kedah)

Che Aziz Ali, Kamal Roslan Mohamed

Sains Malaysiana, 1996;25(4):47-68.

The Kodiang Formation which outcrops in Kodiang and Alor Setar areas has been well studied and documented. Various geological aspects of the limestone formation have been reported in detail including its stratigraphy, sequence startigraphy, sedimentology and paleontology. Diagenetic aspect of this rock formation, however, had not been specifically discussed before. The Kodiang limestone has undergone a complicated diagenetic history which started immediately after the sediments were laid down on the sea bed. Various diagenetic products have been identified including, early marine cement, meteoric cement, and deeper subsurface cement. The diagenetic features identified are as follows; Fibrous calcite cement, sparry and poikilotopic calcites, calcite overgrowth, dolomite, silica cements and evaporites. Close examination at outcrops shows that dolomite occurs at several levels in the sequence. Their systematic occurrences can be correlated across the area. Petrographic studies show that dolomite occurs in several modes as stratified dolomite and as non-stratified dolomite. The two dolomite groups are attributed to two phases of dolomitizations. The stratified dolomites are interpreted to have been formed early in the limestone diagenetic history. The non-stratified dolomite type is, however, attributed to dolomitization during deep burial under the control of deeper subsurface physico-chemical conditions.
Batu Kapur Kodiang yang tersingkap di Kodiang dan Alor Setar telah banyak dikaji dan didokumentasikan. Berbagai aspek geologi formasi batu kapur ini telah dilaporkan termasuk stratigrafi, startigrafi jujukan, sedimentologi dan paleontologi. Walau bagaimanapun aspek diagenesis formasi batuan ini tidak pernah dibincangkan secara khusus. Batu kapur Kodiang ini telah melalui sejarah diagenesis yang rumit yang bermula sebaik saja sedimen dimendapkan di atas permukaan dasar laut. Berbagai hasil diagenesis telah dikenal pasti termasuk penyimenan samudera awal, penyimenan meterorik dan penyimenan di bawah permukaan yang lebih dalam. Secara asas fitur-fitur yang dikenalpasti adalah seperti berikut; simen kalsit berserat, kalsit spar dan poikilotopik, tumbuhlampau kalsit, dolomit, simen silika dan evaporit. Pemeriksaan rapi pada singkapan menunjukkan dolomit hadir pada beberapa aras di dalam jujukan. Kehadirannya secara bersistematik boleh dikorelasikan pada setiap singkapan. Kajian petrografi menunjukkan dolomit wujud dalam berbagai mod yang boleh diklaskan sebagai dolomit berstrata dan dolomit tidak berstrata. Dua klas ini boleh dikaitkan dengan dua fasa pendolomitan. Dolomit berstrata ditafsirkan telah terbentuk awal di dalam sejarah diagenesis batu kapur. Dolomit tidak berstrata pula dikaitkan dengan pendolomitan semasa timbusan dalam di bawah keadaan fiziko-kimia bawah permukaan.

Matched MeSH terms: Magnesium
Prediction of copper ions adsorption by attapulgite adsorbent using tuned-artificial intelligence model

Bhagat SK, Pyrgaki K, Salih SQ, Tiyasha T, Beyaztas U, Shahid S, et al.

Chemosphere, 2021 Aug;276:130162.
PMID: 34088083 DOI: 10.1016/j.chemosphere.2021.130162

Copper (Cu) ion in wastewater is considered as one of the crucial hazardous elements to be quantified. This research is established to predict copper ions adsorption (Ad) by Attapulgite clay from aqueous solutions using computer-aided models. Three artificial intelligent (AI) models are developed for this purpose including Grid optimization-based random forest (Grid-RF), artificial neural network (ANN) and support vector machine (SVM). Principal component analysis (PCA) is used to select model inputs from different variables including the initial concentration of Cu (IC), the dosage of Attapulgite clay (Dose), contact time (CT), pH, and addition of NaNO3 (SN). The ANN model is found to predict Ad with minimum root mean square error (RMSE = 0.9283) and maximum coefficient of determination (R2 = 0.9974) when all the variables (i.e., IC, Dose, CT, pH, SN) were considered as input. The prediction accuracy of Grid-RF model is found similar to ANN model when a few numbers of predictors are used. According to prediction accuracy, the models can be arranged as ANN-M5> Grid-RF-M5> Grid-RF-M4> ANN-M4> SVM-M4> SVM-M5. Overall, the applied statistical analysis of the results indicates that ANN and Grid-RF models can be employed as a computer-aided model for monitoring and simulating the adsorption from aqueous solutions by Attapulgite clay.

Matched MeSH terms: Magnesium Compounds
Evolution of groundwater chemistry in the shallow aquifer of a small tropical island in Sabah, Malaysia

Ahmad Zaharin Aris, Mohd Harun Abdullah, Praveena SM

Sains Malaysiana, 2009;38.

Groundwater is the prime source of freshwater in most small islands. A detailed groundwater and seawater chemistry study was undertaken from March 2006 to January 2007 to examine the evolution of groundwater in the shallow aquifer of Manukan Island, Sabah, Malaysia. Coastal groundwater aquifers especially for small islands are often exposed to heavy pumping and consequently to risks of seawater intrusion. Major ion chemistry analysis showed that the groundwater quality of the island experienced changes attributed to seawater intrusion. The groundwater has undergone a compositional change from Ca-rich to Na-rich which can be explained mostly by simple mixing process and cation exchange process. From the PHREEQC simulation model, calcite, dolomite and aragonite solubility showed positive mean values (0.65; 1.11; 0.51, respectively) of the saturation indices (SI) indicating supersaturation which attributed from the simple mixing and eventually cation exchange process. This information is important in protecting and remediating the disturbed aquifer situation.

Matched MeSH terms: Magnesium
Hydrogen-rich gas production via steam gasification of food waste over basic oxides (MgO/CaO/SrO) promoted-Ni/Al2O3 catalysts

Moogi S, Jang SH, Rhee GH, Ko CH, Choi YJ, Lee SH, et al.

Chemosphere, 2022 Jan;287(Pt 2):132224.
PMID: 34826918 DOI: 10.1016/j.chemosphere.2021.132224

Food waste, a renewable resource, was converted to H2-rich gas via a catalytic steam gasification process. The effects of basic oxides (MgO, CaO, and SrO) with 10 wt% Ni/Al2O3 on the gasification properties of food waste were investigated using a U-shaped gasifier. All catalysts prepared by the precipitation method were analyzed by X-ray diffraction, H2-temperature-programmed reduction, NH3-temperature-programmed desorption, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The Ni/Al2O3 catalyst was reduced incompletely, and low nickel concentrations were detected on the surface of the alumina. The basic oxides minimized the number of acid sites and suppressed the formation of nickel-aluminate (NiAlxOy) phase in catalyst. In addition, the basic oxides shifted nickel-aluminate reduction reaction to lower temperatures. It resulted in enhancing nickel concentration on the catalyst surface and increasing gas yield and hydrogen selectivity. The low gas yield of the Ni/Al2O3 catalyst was attributed to the low nickel concentration on the surface. The maximum gas yield (66.0 wt%) and hydrogen selectivity (63.8 vol%) of the 10 wt% SrO- 10 wt% Ni/Al2O3 catalyst correlated with the highly dispersed nickel on the surface and low acidity. Furthermore, coke deposition during steam gasification varied with the surface acidity of the catalysts and less coke was formed on 10 wt% SrO- 10 wt% Ni/Al2O3 due to efficient tar cracking. This study showed that the steam gasification efficiency of the Ni/Al2O3 catalyst could be improved significantly by the addition of SrO.

Matched MeSH terms: Magnesium Oxide
Enhancement of CO2 adsorption on biochar sorbent modified by metal incorporation

Zubbri NA, Mohamed AR, Kamiuchi N, Mohammadi M

Environ Sci Pollut Res Int, 2020 Apr;27(11):11809-11829.
PMID: 31975005 DOI: 10.1007/s11356-020-07734-3

This work is scrutinizing the development of metallized biochar as a low-cost bio-sorbent for low temperature CO2 capture with high adsorption capacity. Accordingly, single-step pyrolysis process was carried out in order to synthesize biochar from rambutan peel (RP) at different temperatures. The biochar product was then subjected to wet impregnation with several magnesium salts including magnesium nitrate, magnesium sulphate, magnesium chloride and magnesium acetate which then subsequently heat-treated with N2. The impregnation of magnesium into the biochar structure improved the CO2 capture performance in the sequence of magnesium nitrate > magnesium sulphate > magnesium chloride > magnesium acetate. There is an enhancement in CO2 adsorption capacity of metallized biochar (76.80 mg g-1) compare with pristine biochar (68.74 mg g-1). It can be justified by the synergetic influences of physicochemical characteristics. Gas selectivity study verified the high affinity of biochar for CO2 capture compared with other gases such as air, methane, and nitrogen. This investigation also revealed a stable performance of the metallized biochar in 25 cycles of CO2 adsorption and desorption. Avrami kinetic model accurately predicted the dynamic CO2 adsorption performance for pristine and metallized biochar.

Matched MeSH terms: Magnesium Compounds
Fulltext The effect of calcium silicate and ground magnesium limestone (GML) on the chemical characteristics of acid sulfate soil

Azman EA, Ismail R, Ninomiya S, Jusop S, Tongkaemkaew U

PLoS One, 2023;18(9):e0290703.
PMID: 37713375 DOI: 10.1371/journal.pone.0290703

Acid sulfate soil characterized by pyrite (FeS2) which produces high acidity (soil pH < 3.5) and release high amount of Al3+ and Fe2+. Application of 4 t ha-1 Ground Magnesium Limestone (GML), is a common rate used for acid sulfate soil by the rice farmers in Malaysia. Therefore, this study was conducted to evaluate the integral effect of ground magnesium limestone (GML) and calcium silicate and to determine the optimal combination on acid sulfate soils in Malaysia. The acid sulfate soils were incubated under the submerged condition for 120 days with GML (0, 2, 4, 6 t ha-1) in combination with calcium silicate (0, 1, 2, 3 t ha-1) arranged in a Completely Randomized Design (CRD). The soil was sampled after 30, 60, 90 and 120 days of incubation and analyzed for soil pH, exchangeable Al, Ca, Mg, K and available Si. A total of 2 out of 16 combinations met the desired soil requirement for rice cultivation. The desired chemical soil characteristics for rice cultivation are soil pH > 4, exchangeable Al < 2 cmolc Kg-1, exchangeable Ca > 2 cmolc kg-1, exchangeable Mg > 1 cmolc kg-1 and Si content > 43 mg kg-1. The combinations are i) 2 t ha-1 calcium silicate + 2 t ha-1 GML, and ii) 3 t ha-1 calcium silicate + 2 t ha-1 GML, respectively. These combination rates met the desired requirement of soil chemical characteristics for rice cultivation. Soil acidity was reduced by a gradual release of Ca2+ and SiO32- from calcium silicate continuously filling the exchange sites and reducing the potential of extra (free) H+ availability in the soil system. Combination of calcium silicate and GML, shows the ameliorative effect with; i) release of Ca, ii) binding of Al3+ making it inert Al-hydroxides and, iii) bind H+ to produce water molecules.

Matched MeSH terms: Magnesium
In vitro degradation and cell viability assessment of Zn-3Mg alloy for biodegradable bone implants

Dambatta MS, Murni NS, Izman S, Kurniawan D, Froemming GR, Hermawan H

Proc Inst Mech Eng H, 2015 May;229(5):335-42.
PMID: 25991712 DOI: 10.1177/0954411915584962

This article reports the in vitro degradation and cytotoxicity assessment of Zn-3Mg alloy developed for biodegradable bone implants. The alloy was prepared using casting, and its microstructure was composed of Mg2Zn11 intermetallic phase distributed within a Zn-rich matrix. The degradation assessment was done using potentiodynamic polarization and electrochemical impedance spectrometry. The cell viability and the function of normal human osteoblast cells were assessed using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium and alkaline phosphatase extracellular enzyme activity assays. The results showed that the degradation rate of the alloy was slower than those of pure Zn and pure Mg due to the formation of a high polarization resistance oxide film. The alloy was cytocompatible with the normal human osteoblast cells at low concentrations (<0.5 mg/mL), and its alkaline phosphatase activity was superior to pure Mg. This assessment suggests that Zn-3Mg alloy has the potential to be developed as a material for biodegradable bone implants, but the toxicity limit must be carefully observed.

Matched MeSH terms: Magnesium/toxicity; Magnesium/chemistry*
Uranium in well drinking water of Kabul, Afghanistan and its effective, low-cost depuration using Mg-Fe based hydrotalcite-like compounds

Kato M, Azimi MD, Fayaz SH, Shah MD, Hoque MZ, Hamajima N, et al.

Chemosphere, 2016 Dec;165:27-32.
PMID: 27619645 DOI: 10.1016/j.chemosphere.2016.08.124

Toxic elements in drinking water have great effects on human health. However, there is very limited information about toxic elements in drinking water in Afghanistan. In this study, levels of 10 elements (chromium, nickel, copper, arsenic, cadmium, antimony, barium, mercury, lead and uranium) in 227 well drinking water samples in Kabul, Afghanistan were examined for the first time. Chromium (in 0.9% of the 227 samples), arsenic (7.0%) and uranium (19.4%) exceeded the values in WHO health-based guidelines for drinking-water quality. Maximum chromium, arsenic and uranium levels in the water samples were 1.3-, 10.4- and 17.2-fold higher than the values in the guidelines, respectively. We next focused on uranium, which is the most seriously polluted element among the 10 elements. Mean ± SD (138.0 ± 1.4) of the (238)U/(235)U isotopic ratio in the water samples was in the range of previously reported ratios for natural source uranium. We then examined the effect of our originally developed magnesium (Mg)-iron (Fe)-based hydrotalcite-like compounds (MF-HT) on adsorption for uranium. All of the uranium-polluted well water samples from Kabul (mean ± SD = 190.4 ± 113.9 μg/L; n = 11) could be remediated up to 1.2 ± 1.7 μg/L by 1% weight of our MF-HT within 60 s at very low cost (<0.001 cents/day/family) in theory. Thus, we demonstrated not only elevated levels of some toxic elements including natural source uranium but also an effective depurative for uranium in well drinking water from Kabul. Since our depurative is effective for remediation of arsenic as shown in our previous studies, its practical use in Kabul may be encouraged.

Matched MeSH terms: Magnesium/pharmacology; Magnesium/chemistry*; Magnesium Hydroxide/pharmacology; Magnesium Hydroxide/chemistry*
Fulltext In vitro inhibition of histamine release behavior of cetirizine intercalated into Zn/Al- and Mg/Al-layered double hydroxides

Hussein-Al-Ali SH, Al-Qubaisi M, Hussein MZ, Ismail M, Zainal Z, Hakim MN

Int J Mol Sci, 2012;13(5):5899-916.
PMID: 22754339 DOI: 10.3390/ijms13055899

The intercalation of cetirizine into two types of layered double hydroxides, Zn/Al and Mg/Al, has been investigated by the ion exchange method to form CTZAN and CTMAN nanocomposites, respectively. The basal spacing of the nanocomposites were expanded to 31.9 Å for CTZAN and 31.2 Å for CTMAN, suggesting that cetirizine anion was intercalated into Layered double hydroxides (LDHs) and arranged in a tilted bilayer fashion. A Fourier transform infrared spectroscopy (FTIR) study supported the formation of both the nanocomposites, and the intercalated cetirizine is thermally more stable than its counterpart in free state. The loading of cetirizine in the nanocomposite was estimated to be about 57.2% for CTZAN and 60.7% CTMAN. The cetirizine release from the nanocomposites show sustained release manner and the release rate of cetirizine from CTZAN and CTMAN nanocomposites at pH 7.4 is remarkably lower than that at pH 4.8, presumably due to the different release mechanism. The inhibition of histamine release from RBL2H3 cells by the free cetirizine is higher than the intercalated cetirizine both in CTZAN and CTMAN nanocomposites. The viability in human Chang liver cells at 1000 μg/mL for CTZAN and CTMAN nanocomposites are 74.5 and 91.9%, respectively.

Matched MeSH terms: Magnesium/pharmacology; Magnesium/chemistry*
Synthesis and characterization of magnesium doped biphasic calcium phosphate

Toibah AR, Sopyan I, Mel M

Med J Malaysia, 2008 Jul;63 Suppl A:83-4.
PMID: 19024995

The incorporation of magnesium ions into the calcium phosphate structure is of great interest for the development of artificial bone implants. This paper investigates the preparation of magnesium-doped biphasic calcium phosphate (Mg-BCP) via sol gel method at various concentrations of added Mg. The effect of calcinations temperature (ranging from 500 degrees C to 900 degrees C) and concentrations of Mg incorporated into BCP has been studied by the aid of XRD, TGA and infrared spectroscopy (IR) in transmittance mode analysis. The study indicated that the powder was pure BCP and Mg-BCP with 100% purity and high crystallinity. The results also indicated that beta-tricalcium phosphate (beta-TCP) phase can be observed when the powder was calcined at 800 degrees C and above.

Matched MeSH terms: Magnesium Compounds/chemical synthesis; Magnesium Compounds/chemistry*
Fulltext Transport and retention of engineered Al2O3, TiO2, and SiO2 nanoparticles through various sedimentary rocks

Bayat AE, Junin R, Shamshirband S, Chong WT

Sci Rep, 2015;5:14264.
PMID: 26373598 DOI: 10.1038/srep14264

Engineered aluminum oxide (Al2O3), titanium dioxide (TiO2), and silicon dioxide (SiO2) nanoparticles (NPs) are utilized in a broad range of applications; causing noticeable quantities of these materials to be released into the environment. Issues of how and where these particles are distributed into the subsurface aquatic environment remain as major challenges for those in environmental engineering. In this study, transport and retention of Al2O3, TiO2, and SiO2 NPs through various saturated porous media were investigated. Vertical columns were packed with quartz-sand, limestone, and dolomite grains. The NPs were introduced as a pulse suspended in aqueous solutions and breakthrough curves in the column outlet were generated using an ultraviolet-visible spectrophotometer. It was found that Al2O3 and TiO2 NPs are easily transported through limestone and dolomite porous media whereas NPs recoveries were achieved two times higher than those found in the quartz-sand. The highest and lowest SiO2-NPs recoveries were also achieved from the quartz-sand and limestone columns, respectively. The experimental results closely replicated the general trends predicted by the filtration and DLVO calculations. Overall, NPs mobility through a porous medium was found to be strongly dependent on NP surface charge, NP suspension stability against deposition, and porous medium surface charge and roughness.

Matched MeSH terms: Magnesium
Waste bones ash as an alternative source of P for struvite precipitation

Darwish M, Aris A, Puteh MH, Jusoh MNH, Abdul Kadir A

J Environ Manage, 2017 Dec 01;203(Pt 2):861-866.
PMID: 26935149 DOI: 10.1016/j.jenvman.2016.02.033

Struvite precipitation has been widely applied for the removal of ammonium-nitrogen (NH4-N) from wastewater. Due to the high cost of phosphorus (P) reagents, the current research trend was directed to find alternative sources of P, in order to maintain a sustainable NH4-N removal process. The current study investigated waste bones ashes as alternative sources of P. Different types of bones' ashes were characterized, in which the ash produced from waste fish bones was the highest in P content (17%wt.). The optimization of the factors affecting P extraction from ash by acidic leaching showed that applying 2M H2SO4 and 1.25 kg H2SO4/kg ash achieved the highest P recovery (95%). Thereafter, the recovered P was successfully used in struvite precipitation, which achieved more than 90% NH4-N removal and high purity struvite.

Matched MeSH terms: Magnesium Compounds
Rainwater chemistry of acid precipitation occurrences due to long-range transboundary haze pollution and prolonged drought events during southwest monsoon season: climate change driven

Payus CM, Jikilim C, Sentian J

Heliyon, 2020 Sep;6(9):e04997.
PMID: 33005801 DOI: 10.1016/j.heliyon.2020.e04997

The purposes of this research were to study the characteristics chemistry of pH, anions and cations in rainwater, and to identify the possible sources that contributing to the acid precipitation during southwest monsoon season with occurrence of extreme drought event. During the southwest monsoon season, it normally occurs along with haze phenomenon that every year will hit Southeast Asia. This condition will aggravate with high acidic particles in the atmosphere due to the prolonged drought. The analysed parameters which involved pH, anions (NO3-, SO42- and Cl-) and cations (Ca2+, Mg2+, Na+ and K+) were analysed using pH meter, Hach DR 2800, argentometric method and ICP-OES. From the findings, it showed that acid rain occurred during the southwest monsoon season with the range of pH values from 4.95 ± 0.13 to 6.40 ± 0.03 and the total average of pH 5.71 ± 0.32. Anions NO3-, SO42- and Cl- were found to be the dominant compositions of the acid rain occurrences with higher concentrations detected. In overall, rural area recorded with higher acidity of precipitation at total average of pH 5.54 ± 0.39 compared to urban area at pH 5.77 ± 0.26. Rural area surprisingly recorded higher frequency occurrences of acid rain with pH lesser than 5.6 and below compared to urban area. As for public health and safety, all rainwater samples during the acid rain event were found exceeded the allowable limits of NWQS and WHO standards, that shown not suitable for skin contact, recreational purposes even for drinking purposes.

Matched MeSH terms: Magnesium
Fulltext Carbon Nanotubes (CNTs)-Reinforced Magnesium-Based Matrix Composites: A Comprehensive Review

Abazari S, Shamsipur A, Bakhsheshi-Rad HR, Ismail AF, Sharif S, Razzaghi M, et al.

Materials (Basel), 2020 Oct 04;13(19).
PMID: 33020427 DOI: 10.3390/ma13194421

In recent years considerable attention has been attracted to magnesium because of its light weight, high specific strength, and ease of recycling. Because of the growing demand for lightweight materials in aerospace, medical and automotive industries, magnesium-based metal matrix nanocomposites (MMNCs) reinforced with ceramic nanometer-sized particles, graphene nanoplatelets (GNPs) or carbon nanotubes (CNTs) were developed. CNTs have excellent material characteristics like low density, high tensile strength, high ratio of surface-to-volume, and high thermal conductivity that makes them attractive to use as reinforcements to fabricate high-performance, and high-strength metal-matrix composites (MMCs). Reinforcing magnesium (Mg) using small amounts of CNTs can improve the mechanical and physical properties in the fabricated lightweight and high-performance nanocomposite. Nevertheless, the incorporation of CNTs into a Mg-based matrix faces some challenges, and a uniform distribution is dependent on the parameters of the fabricating process. The characteristics of a CNTs reinforced composite are related to the uniform distribution, weight percent, and length of the CNTs, as well as the interfacial bonding and alignment between CNTs reinforcement and the Mg-based matrix. In this review article, the recent findings in the fabricating methods, characterization of the composite's properties, and application of Mg-based composites reinforced with CNTs are studied. These include the strategies of fabricating CNT-reinforced Mg-based composites, mechanical responses, and corrosion behaviors. The present review aims to investigate and conclude the most relevant studies conducted in the field of Mg/CNTs composites. Strategies to conquer complicated challenges are suggested and potential fields of Mg/CNTs composites as upcoming structural material regarding functional requirements in aerospace, medical and automotive industries are particularly presented.

Matched MeSH terms: Magnesium
Reduced graphene/nanostructured cobalt oxide nanocomposite for enhanced electrochemical performance of supercapacitor applications

Sagadevan S, Marlinda AR, Johan MR, Umar A, Fouad H, Alothman OY, et al.

J Colloid Interface Sci, 2020 Jan 15;558:68-77.
PMID: 31585223 DOI: 10.1016/j.jcis.2019.09.081

We demonstrate the preparation of nanostructures cobalt oxide/reduced graphene oxide (Co3O4/rGO) nanocomposites by a simple one-step cost-effective hydrothermal technique for possible electrode materials in supercapacitor application. The X-ray diffraction patterns were employed to confirm the nanocomposite crystal system of Co3O4/rGO by demonstrating the existence of normal cubic spinel structure of Co3O4 in the matrix of Co3O4/rGO nanocomposite. FTIR and FT-Raman studies manifested the structural behaviour and quality of prepared Co3O4/rGO nanocomposite. The optical properties of the nanocomposite Co3O4/rGO have been investigated by UV absorption spectra. The SEM/TEM images showed that the Co3O4 nanoparticles in the Co3O4/rGO nanocomposites were covered over the surface of the rGO sheets. The electrical properties were analyzed in terms of real and imaginary permittivity, dielectric loss and AC conductivity. The electrocatalytic activities of synthesized Co3O4/rGO nanocomposites were determined by cyclic voltammetry and charge-discharge cycle to evaluate the supercapacitive performance. The specific capacitance of 754 Fg-1 was recorded for Co3O4/rGO nanocomposite based electrode in three electrode cell system. The electrode material exhibited an acceptable capability and excellent long-term cyclic stability by maintaining 96% after 1000 continuous cycles. These results showed that the prepared sample could be an ideal candidate for high-energy application as electrode materials. The synthesized Co3O4/rGO nanocomposite is a versatile material and can be used in various application such as fuel cells, electrochemical sensors, gas sensors, solar cells, and photocatalysis.

Matched MeSH terms: Magnesium Oxide

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