Assessment of Mechanical Properties and Damage of High Performance Concrete Subjected to Magnesium Sulfate Environment

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Sheng Cang

2017-01-01

Full Text Available Sulfate attack is one of the most important problems affecting concrete structures, especially magnesium sulfate attack. This paper presents an investigation on the mechanical properties and damage evolution of high performance concrete (HPC with different contents of fly ash exposure to magnesium sulfate environment. The microstructure, porosity, mass loss, dimensional variation, compressive strength, and splitting tensile strength of HPC were investigated at various erosion times up to 392 days. The ultrasonic pulse velocity (UPV propagation in HPC at different erosion time was determined by using ultrasonic testing technique. A relationship between damage and UPV of HPC was derived according to damage mechanics, and a correlation between the damage of HPC and erosion time was obtained eventually. The results indicated that (1 the average increasing amplitude of porosity for HPCs was 34.01% before and after exposure to magnesium sulfate solution; (2 the damage evolution of HPCs under sulfate attack could be described by an exponential fitting; (3 HPC containing 20% fly ash had the strongest resistance to magnesium sulfate attack.

Magnesium sulfate differentially modulates fetal membrane inflammation in a time-dependent manner.

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Cross, Sarah N; Nelson, Rachel A; Potter, Julie A; Norwitz, Errol R; Abrahams, Vikki M

2018-04-30

Chorioamnionitis and infection-associated inflammation are major causes of preterm birth. Magnesium sulfate (MgSO 4 ) is widely used in obstetrics as a tocolytic; however, its mechanism of action is unclear. This study sought to investigate how MgSO 4 modulates infection-associated inflammation in fetal membranes (FMs), and whether the response was time dependent. Human FM explants were treated with or without bacterial lipopolysaccharide (LPS); with or without MgSO 4 added either: 1 hour before LPS; at the same time as LPS; 1 hour post-LPS; or 2 hours post-LPS. Explants were also treated with or without viral dsRNA and LPS, alone or in combination; and MgSO 4 added 1 hour post-LPS After 24 hours, supernatants were measured for cytokines/chemokines; and tissue lysates measured for caspase-1 activity. Lipopolysaccharide-induced FM inflammation by upregulating the secretion of a number of inflammatory cytokines/chemokines. Magnesium sulfate administered 1-hour post-LPS inhibited FM secretion of IL-1β, IL-6, G-CSF, RANTES, and TNFα. Magnesium sulfate administered 2 hours post-LPS augmented FM secretion of these factors as well as IL-8, IFNγ, VEGF, GROα and IP-10. Magnesium sulfate delivered 1- hour post-LPS inhibited LPS-induced caspase-1 activity, and inhibited the augmented IL-1β response triggered by combination viral dsRNA and LPS. Magnesium sulfate differentially modulates LPS-induced FM inflammation in a time-dependent manner, in part through its modulation of caspase-1 activity. Thus, the timing of MgSO 4 administration may be critical in optimizing its anti-inflammatory effects in the clinical setting. MgSO 4 might also be useful at preventing FM inflammation triggered by a polymicrobial viral-bacterial infection. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Influence of recycled fine aggregates on the resistance of mortars to magnesium sulfate attack

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Lee, Seung-Tae

2009-01-01

The influence of recycled fine aggregates, which had been reclaimed from field-demolished concretes, on the resistance of mortar specimens to magnesium sulfate attack was investigated. Mortar specimens were prepared with recycled fine aggregates at different replacement levels (0%, 25%, 50%, 75% and 100% of natural fine aggregate by mass). The mortar specimens were exposed to 4.24% magnesium sulfate solution for about 1 year at ambient temperature, and regularly monitored for visual appearance, compressive strength loss and expansion. Additionally, in order to identify products of magnesium sulfate attack, mortar samples incorporating 0%, 25% and 100% replacement levels of the recycled fine aggregates were examined by X-ray diffraction (XRD) technique. Experimental results confirmed that the use of recycled fine aggregates up to a maximum 50% replacement level is effective under severe magnesium sulfate environment, irrespective of type of recycled fine aggregates. However, the worse performance was observed in mortar specimens incorporating 100% replacement level. It was found that the water absorption of recycled fine aggregates affected deterioration of mortar specimens, especially at a higher replacement level. XRD results indicated that the main cause of deterioration of the mortar specimens was primarily due to the formation of gypsum and thaumasite by magnesium sulfate attack. In addition, it appeared that the conversion of C-S-H into M-S-H by the attack probably influenced mechanical deterioration of mortar specimens with recycled fine aggregates.

Antenatal Magnesium Sulfate and Neurologic Outcome in Preterm Infants

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Doyle, Lex W.; Crowther, Caroline A.; Middleton, Philippa; Marret, Stephane

OBJECTIVE: To systematically review rates of neurologic outcomes reported in childhood for the preterm fetus exposed to antenatal magnesium sulfate. DATA SOURCES: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register, CENTRAL (The Cochrane Library 2008, Issue 3), relevant

Suppression of exercise-induced angina by magnesium sulfate in patients with variant angina

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Kugiyama, K.; Yasue, H.; Okumura, K.

1988-01-01

The effects of intravenous magnesium on exercise-induced angina were examined in 15 patients with variant angina and in 13 patients with stable effort angina and were compared with those of placebo. Symptom-limited bicycle exercise and thallium-201 myocardial scintigraphy were performed after intravenous administration of 0.27 mmol/kg body weight of magnesium sulfate and after placebo on different days. In all patients, serum magnesium levels after administration of magnesium sulfate were about twofold higher than levels after placebo. Exercise-induced angina associated with transient ST segment elevation occurred in 11 patients with variant angina receiving placebo and in only 2 of these patients receiving magnesium (p less than 0.005). On the other hand, exercise-induced angina was not suppressed by magnesium in any patient with stable effort angina. In these patients there was no significant difference in exercise duration after administration of placebo versus after administration of magnesium. The size of the perfusion defect as measured by thallium-201 scintigraphy was significantly less in patients with variant angina receiving magnesium than that in those receiving placebo (p less than 0.001), whereas it was not significantly different in patients with stable effort angina receiving placebo versus magnesium. In conclusion, exercise-induced angina is suppressed by intravenous magnesium in patients with variant angina but not in patients with stable effort angina. This beneficial effect of magnesium in patients with variant angina is most likely due to improvement of regional myocardial blood flow by suppression of coronary artery spasm

Influence of Sulfate-Reducing Bacteria on the Corrosion Residual Strength of an AZ91D Magnesium Alloy

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Zhu, Xianyong; Liu, Yaohui; Wang, Qiang; Liu, Jiaan

2014-01-01

In this paper, the corrosion residual strength of the AZ91D magnesium alloy in the presence of sulfate-reducing bacteria is studied. In the experiments, the chemical composition of corrosion film was analyzed by a scanning electron microscope with energy dispersive X-ray spectroscopy. In addition, a series of instruments, such as scanning electronic microscope, pH-meter and an AG-10TA materials test machine, were applied to test and record the morphology of the corrosion product, fracture texture and mechanical properties of the AZ91D magnesium alloy. The experiments show that the sulfate-reducing bacteria (SRB) play an important role in the corrosion process of the AZ91D magnesium alloy. Pitting corrosion was enhanced by sulfate-reducing bacteria. Corrosion pits are important defects that could lead to a significant stress concentration in the tensile process. As a result, sulfate-reducing bacteria influence the corrosion residual strength of the AZ91D magnesium alloy by accelerating pitting corrosion. PMID:28788236

Effect of Low-Dose (Single-Dose Magnesium Sulfate on Postoperative Analgesia in Hysterectomy Patients Receiving Balanced General Anesthesia

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Arman Taheri

2015-01-01

Full Text Available Background and Aim. Aparallel, randomized, double blinded, placebo-controlled trial study was designed to assess the efficacy of single low dose of intravenous magnesium sulfate on post-total abdominal hysterectomy (TAH pain relief under balanced general anesthesia. Subject and Methods. Forty women undergoing TAH surgery were assigned to two magnesium sulfate (N=20 and normal saline (N=20 groups randomly. The magnesium group received magnesium sulfate 50 mg·kg−1 in 100 mL of normal saline solution i.v as single-dose, just 15 minutes before induction of anesthesia whereas patients in control group received 100 mL of 0.9% sodium chloride solution at the same time. The same balanced general anesthesia was induced for two groups. Pethidine consumption was recorded over 24 hours precisely as postoperative analgesic. Pain score was evaluated with Numeric Rating Scale (NRS at 0, 6, 12, and 24 hours after the surgeries. Results. Postoperative pain score was lower in magnesium group at 6, 12, and 24 hours after the operations significantly (P<0.05. Pethidine requirement was significantly lower in magnesium group throughout 24 hours after the surgeries (P=0.0001. Conclusion. Single dose of magnesium sulfate during balanced general anesthesia could be considered as effective and safe method to reduce postoperative pain and opioid consumption after TAH.

The Effect of Magnesium Sulfate on Renal Colic Pain Relief; a Randomized Clinical Trial

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Abolfazl Jokar

2016-12-01

Full Text Available Introduction: Renal colic can be managed by preventing the contraction movements of ureter muscles. By reducing acetylcholine in the nerve terminals, magnesium sulfate could be effective in this regard. The aim of this study is to investigate the effect of magnesium sulfate on acute renal colic pain relief. Method: The present study was a double-blind clinical trial in which the patients suffering from acute renal colic were randomly divided into 2 groups of who either received standard protocol (intravenous infusion of 0.1 mg/Kg morphine sulfate, 30 mg of Ketorolac, and 100 ml normal saline as placebo/15 minutes or standard protocol plus 15 mg/Kg of intravenous magnesium sulfate 50%/100 ml normal saline/15 minutes. Severity of patients’ pain was measured by visual analogue scale (VAS at baseline, and 30 and 60 minutes after infusion. The collected data were analyzed using STATA statistical software. Results: 100 cases were randomly allocated to intervention or control group. The two groups were similar in baseline pain score and demographic characteristics. At 30 and 60 minutes, mean pain score was less in the intervention group compared to the control group. Moreover, the difference between the two groups was statistically significant regarding the additional amount of morphine, suggesting that the intervention group needed less additional morphine than the control group. Conclusion: The results of this study showed that Magnesium sulfate can be used as an adjunct drug in treatment of patients suffering from renal colic. It not only alleviates the pain in the patients, but also diminishes the need for pain medications.

Growth performance and root transcriptome remodeling of Arabidopsis in response to Mars-like levels of magnesium sulfate.

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Anne M Visscher

Full Text Available BACKGROUND: Martian regolith (unconsolidated surface material is a potential medium for plant growth in bioregenerative life support systems during manned missions on Mars. However, hydrated magnesium sulfate mineral levels in the regolith of Mars can reach as high as 10 wt%, and would be expected to be highly inhibitory to plant growth. METHODOLOGY AND PRINCIPAL FINDINGS: Disabling ion transporters AtMRS2-10 and AtSULTR1;2, which are plasma membrane localized in peripheral root cells, is not an effective way to confer tolerance to magnesium sulfate soils. Arabidopsis mrs2-10 and sel1-10 knockout lines do not mitigate the growth inhibiting impacts of high MgSO(4.7H(2O concentrations observed with wildtype plants. A global approach was used to identify novel genes with potential to enhance tolerance to high MgSO(4.7H(2O (magnesium sulfate stress. The early Arabidopsis root transcriptome response to elevated concentrations of magnesium sulfate was characterized in Col-0, and also between Col-0 and the mutant line cax1-1, which was confirmed to be relatively tolerant of high levels of MgSO(4.7H(2O in soil solution. Differentially expressed genes in Col-0 treated for 45 min. encode enzymes primarily involved in hormone metabolism, transcription factors, calcium-binding proteins, kinases, cell wall related proteins and membrane-based transporters. Over 200 genes encoding transporters were differentially expressed in Col-0 up to 180 min. of exposure, and one of the first down-regulated genes was CAX1. The importance of this early response in wildtype Arabidopsis is exemplified in the fact that only four transcripts were differentially expressed between Col-0 and cax1-1 at 180 min. after initiation of treatment. CONCLUSIONS/SIGNIFICANCE: The results provide a solid basis for the understanding of the metabolic response of plants to elevated magnesium sulfate soils; it is the first transcriptome analysis of plants in this environment. The results foster

Magnesium sulfate infusion for acute asthma in the emergency department

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Jose Enrique Irazuzta

Full Text Available Abstract Objectives: To describe the role of intravenous magnesium sulfate (MgSO4 as therapy for acute severe asthma in the pediatric emergency department (ED. Source: Publications were searched in the PubMed and Cochrane databases using the following keywords: magnesium AND asthma AND children AND clinical trial. A total of 53 publications were retrieved using this criteria. References of relevant articles were also screened. The authors included the summary of relevant publications where intravenous magnesium sulfate was studied in children (age <18 years with acute asthma. The NAEPP and Global Initiative for Asthma expert panel guidelines were also reviewed. Summary of the data: There is a large variability in the ED practices on the intravenous administration of MgSO4 for severe asthma. The pharmacokinetics of MgSO4 is often not taken into account with a consequent impact in its pharmacodynamics properties. The cumulative evidence points to the effectiveness of intravenous MgSO4 in preventing hospitalization, if utilized in a timely manner and at an appropriate dosage (50-75 mg/kg. For every five children treated in the ED, one hospital admission could be prevented. Another administration modality is a high-dose continuous magnesium sulfate infusion (HDMI as 50 mg/kg/h/4 h (200 mg/kg/4 h. The early utilization of HDMI for non-infectious mediated asthma may be superior to a MgSO4 bolus in avoiding admissions and expediting discharges from the ED. HDMI appears to be cost-effective if applied early to a selected population. Intravenous MgSO4 has a similar safety profile than other asthma therapies. Conclusions: Treatment with intravenous MgSO4 reduces the odds of hospital admissions. The use of intravenous MgSO4 in the emergency room was not associated with significant side effects or harm. The authors emphasize the role of MgSO4 as an adjunctive therapy, while corticosteroids and beta agonist remain the primary acute therapeutic agents.

Effect of Nitrogen, Potassium, Magnesium and Zinc Sulfates on Yield and Some Characteristics of Biodiesel Produced from Safflower

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M. Ranjbar

2012-08-01

Full Text Available In order to evaluate the effect of different amounts of nitrogen fertilizer, potassium sulfate, magnesium sulfate and zinc sulfate on biodiesel produced from safflower, a field experiment was carried out as completely randomized blocks design with three replications, at Research Farm of Shahrekord University in 2010. Treatments included nitrogen fertilizer at three levels (150, 200 and 300 kg/ha, potassium, magnesium and zinc sulfates at 150, 100 and 50 kg/ha, respectively, and control (no fertilizer application. By nourishing the safflower plants, the seed yield and biodiesel traits such as density, iodine value and saponification value were measured. The results showed that the seed yield under treatment of 300 kg/ha nitrogen (913 kg/ha was greater than other treatments. Magnesium sulfate and potassium sulfate produced the highest oil percentage (32.84 and 32.5, respectively. The biodiesel production under utilization of potassium sulfate had greater density, iodine value and saponification value (867.25 kg/m3, 139.7 mg iodine per 100 g oil, and 190.6 mg sodium hydroxide per g oil, respectively compared to other treatments. In general, it was concluded that application of micronutrient fertilizers (especially potassium sulfate improves seed-oil and biodiesel characteristics of safflower.

Effect of pancreatic kallikrein combined with magnesium sulfate therapy on disease severity of patients with severe preeclampsia

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Yi Yang

2016-10-01

Full Text Available Objective: To study the clinical effect of pancreatic kallikrein combined with magnesium sulfate therapy on severe preeclampsia. Methods: A total of 47 patients with severe preeclampsia treated in our hospital from May 2013 to October 2015 were retrospectively analyzed, patients who received pancreatic kallikrein combined with magnesium sulfate therapy were selected as observation group, patients who received magnesium sulfate therapy were selected as control group, and then blood pressure level, renal function, uterine artery and umbilical artery blood flow state, and hypoxia indexes in serum and placenta were compared between two groups. Results: After treatment, systolic pressure and diastolic pressure levels as well as serum CysC level and 24 h urine protein level of observation group were significantly lower than those of control group, the uterine artery and umbilical artery S/ D and PI were significantly lower than those of control group, PIGF and NO levels in serum as well as Xiap and Survivin levels in placenta were significantly higher than those of control group, and sVEGFR1 level in serum as well as Caspase-3 and Caspase-7 levels in placenta was significantly lower than those of control group. Conclusions: Pancreatic kallikrein combined with magnesium sulfate therapy can alleviate the disease severity, lower blood pressure and vascular resistance, and improve renal function and the apoptosis caused by placental hypoxia in patients with severe preeclampsia.

Effect of magnesium sulfate with propofol induction of anesthesia on succinylcholine-induced fasciculations and myalgia

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Mahendra Kumar

2012-01-01

Full Text Available Background: Magnesium sulfate and propofol have been found to be effective against succinylcholine-induced fasciculations and myalgia, respectively, in separate studies. A prospective randomized double blind controlled study was designed to assess the effect of a combination of magnesium sulfate with propofol for induction of anesthesia on succinylcholine-induced fasciculations and myalgia. Materials and Methods: Randomly selected 60 adult patients scheduled for elective surgery under general anesthesia were allocated to one of the two equal groups by draw of lots. The patients of MG Group were pretreated with magnesium sulfate 40 mg/kg body weight in 10 ml volume, while patients of NS group were given isotonic saline 0.9% in the same volume (10 ml intravenously slowly over a period of 10 min. Anesthesia was induced with fentanyl 1.5 mcg/kg and propofol 2 mg/kg, followed by administration of succinylcholine 2 mg/kg intravenously. Muscle fasciculations were observed and graded as nil, mild, moderate, or severe. Postoperative myalgia was assessed after 24 h of surgery and graded as nil, mild, moderate, or severe. Observations were made in double blind manner. Results: Demographic data of both groups were comparable (P> 0.05. Muscle fasciculations occurred in 50% patients of MG group versus in 100% patients of NS group with a significant difference (P< 0.001. After 24 h of surgery, no patient of MG group and 30% patients of NS group had myalgia with a significant difference (P< 0.002. Conclusion: Magnesium sulfate 40 mg/kg intravenously may be used with propofol for induction of anesthesia to control succinylcholine-induced fasciculations and myalgia.

Magnesium Sulfate as a Key Mineral for the Detection of Organic Molecules on Mars Using Pyrolysis

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Francois, P.; Szopa, C.; Buch, A.; Coll, P.; McAdam, A. C.; Mahaffy, P. R.; Freissinet, C.; Glavin, D. P.; Navarro-Gonzalez, R.; Cabane, M.

2016-01-01

Pyrolysis of soil or rock samples is the preferred preparation technique used on Mars to search for organic molecules up today. During pyrolysis, oxichlorines present in the soil of Mars release oxidant species that alter the organic molecules potentially contained in the samples collected by the space probes.This process can explain the difficulty experienced by in situ exploration probes to detect organic materials in Mars soil samples until recently. Within a few months, the Curiosity rover should reach and analyze for the first time soils rich in sulfates which could induce a different behavior of the organics during the pyrolysis compared with the types of soils analyzed up today. For this reason, we systematically studied the pyrolysis of organic molecules trapped in magnesium sulfate, in the presence or absence of calcium perchlorate. Our results show that organics trapped in magnesium sulfate can undergo some oxidation and sulfuration during the pyrolysis. But these sulfates are also shown to protect organics trapped inside the crystal lattice and/or present in fluid inclusions from the oxidation induced by the decomposition of calcium perchlorate and probably other oxychlorine phases currently detected on Mars. Trapped organics may also be protected from degradation processes induced by other minerals present in the sample, at least until these organics are released from the pyrolyzed sulfate mineral (700C in our experiment). Hence, we suggest magnesium sulfate as one of the minerals to target in priority for the search of organic molecules by the Curiosity and ExoMars 2018 rovers.

Situational analysis of facilitators and barriers to availability and utilization of magnesium sulfate for eclampsia and severe preeclampsia in the public health system in Brazil.

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Lotufo, Fátima Aparecida; Parpinelli, Mary Angela; Osis, Maria José; Surita, Fernanda Garanhani; Costa, Maria Laura; Cecatti, José Guilherme

2016-08-30

Eclampsia is the main cause of maternal death in Brazil. Magnesium sulfate is the drug of choice for seizure prevention and control in the management of severe preeclampsia and eclampsia. Despite scientific evidence demonstrating its effectiveness and safety, there have been delays in managing hypertensive disorders, including timely access to magnesium sulfate. To conduct a general situational analysis on availability and use of magnesium sulfate for severe preeclampsia and eclampsia in the public health system. A situational analysis was conducted with two components: a documental analysis on information available at the official websites on the policy, regulation and availability of the medication, plus a cross sectional study with field analysis and interviews with local managers of public obstetric health services in Campinas, in the southeast of Brazil. We used the fishbone cause and effect diagram to organize study components. Interviews with managers were held during field observations using specific questionnaires. There was no access to magnesium sulfate in primary care facilities, obstetric care was excluded from urgency services and clinical protocols for professional guidance on the adequate use of magnesium sulfate were lacking in the emergency mobile care service. Magnesium sulfate is currently only administered in referral maternity hospitals. The lack of processes that promote the integration between urgency/emergency care and specialized obstetric care possibly favors the untimely use of magnesium sulfate and contributes to the high maternal morbidity/mortality rates.

Total and ionized serum magnesium and calcium levels during magnesium sulfate administration for preterm labor

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Kim, Won Hee; An, Yuna; Moon, Jong Ho; Noh, Eun Ji; Kim, Jong Woon

2018-01-01

Objective This study aimed to estimate the association between total and ionized magnesium, and the changes in serum magnesium and calcium levels in patients with preterm labor during magnesium sulfate (MgSO4) administration. Methods The study population included 64 women who were candidates for intravenous MgSO4 treatment for preterm labor. Serial blood samples were taken and measured total magnesium (T-Mg), ionized magnesium (I-Mg), total calcium (T-Ca), and ionized calcium (I-Ca) levels every one-week interval (1st, 2nd, 3rd). Results There was no significant difference in T-Mg and I-Mg levels during MgSO4 administration (P>0.05). There was no significant difference in T-Ca and I-Ca levels during MgSO4 administration (P>0.05). Compared before and after administration of MgSO4, T-Mg and I-Mg levels and T-Ca levels were changed allow statistically significant (P0.05). There was significant correlation between levels of I-Mg and T-Mg (I-Mg=0.395×T-Mg+0.144, P<0.01). Conclusion There were no significant differences in serum Mg and Ca levels during MgSO4 administration for preterm labor. Compared to the before and after administration of MgSO4, only I-Ca levels were not substantially changed. There are significant correlations between I-Mg and T-Mg levels during administration of MgSO4 and I-Mg level seemed to have more correlation with adverse effect than T-Mg. PMID:29372150

TREATMENT AND PREVENTION OF ATRIAL TACHYARRHYTHMIAS IN CRITICALLY ILL PATIENT: THE ROLEOF MAGNESIUM SULFATE

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M. MOJTAHEDZADEH

1999-09-01

Full Text Available In this prospective, randomized study, in the general intensive care unit at Shanatee teaching hospital, we evaluated twenty patients, mean age 52+18 years and mean acute physiology and chronic health evaluation II score of 20±8, who were experiencing atrial tachyarrhythmias for more than 1 hour. After correction of their plasma potassium concentration to more than 4.0 mmof/1, patients were randomized to receive either 40 mg/kg magnesium sulfate bolus followed by 30 mg/kg/hr or 5mg/kg amiodarone bolus and 10 mg/kg/24hr infusion. Therapeutic end point was conversion to sinus rhythm over 24 hours. By logistic regression, the probability of conversion to sinus rhythm was significantly better for magnesium than for amiodarone at time 0-4 (0.6 vs.0.4, 12 (0.72 vs 0.45, and 24 (0.72vs.0.45 hours. In patients not converting to sinus rhythm, a significant decrease in ventricular response rate occurred at time zero to 0.5 hour (mean decrease 22 beats/min, P=0.0001, but there was no specific treatment effect between the magnesium and the amiodarone groups. Magnesium sulfate is superior to amiodarone in the conversion of acute atrial tachyarrhythmias, while initial slowing of ventricular response rate in non-converters appears equally efficacious with both agents.

Double-blind, randomized crossover study of intravenous infusion of magnesium sulfate versus 5% dextrose on depressive symptoms in adults with treatment-resistant depression.

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Mehdi, Syed M A; Atlas, Steven E; Qadir, Sidra; Musselman, Dominique; Goldberg, Sharon; Woolger, Judi M; Corredor, Raul; Abbas, Muhammad H; Arosemena, Leopoldo; Caccamo, Simone; Campbell, Carmen S G; Farooqi, Ashar; Gao, Jinrun; Konefal, Janet; Lages, Lucas C; Lantigua, Laura; Lopez, Johanna; Padilla, Vanessa; Rasul, Ammar; Ray, Anna M; Simões, Herbert G; Tiozzo, Eduard; Lewis, John E

2017-03-01

Treatment-resistant depression patients are more likely to suffer from comorbid physical and mental disorders, experience marked and protracted functional impairment, and incur higher health-care costs than non-affected individuals. Magnesium sulfate is a treatment option that may offer great potential for patients with treatment-resistant depression based on prior work in animals and humans. Twelve subjects with mild or moderate treatment-resistant depression were randomized into a double-blind crossover trial to receive an infusion of 4 g of magnesium sulfate in 5% dextrose or placebo infusion of 5% dextrose with a 5-day washout in between the 8-day intervention period. Subjects were assessed before and after the intervention for serum and urine magnesium, lipid panel, the Hamilton Rating Scale for Depression, and the Patient Health Questionnaire-9. We found a difference in serum magnesium from day 2 to 8 (pre-infusion) (P < 0.002) and from baseline to day 8 (P < 0.02). No changes were noted on the Hamilton Rating Scale for Depression or the Patient Health Questionnaire-9 24 h post-treatment, but as serum magnesium increased from baseline to day 7, the Patient Health Questionnaire-9 decreased from baseline to day 7 (P = 0.02). Magnesium sulfate did not significantly affect depression 24 h post-infusion, but other results were consistent with the literature. The association between changes in serum magnesium and the Patient Health Questionnaire-9 supports the idea that magnesium sulfate may be used to address treatment-resistant depression, an ongoing medical challenge. © 2016 The Authors Psychiatry and Clinical Neurosciences © 2016 Japanese Society of Psychiatry and Neurology.

Effect of magnesium sulfate administration for neuroprotection on latency in women with preterm premature rupture of membranes.

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Horton, Amanda L

2015-03-01

This study aims to evaluate whether magnesium sulfate administration for neuroprotection prolongs latency in women with preterm premature rupture of membranes (PPROM) between 24 and 31(6\\/7) weeks\\' gestation.

Comparison of anesthetic efficacy between lidocaine with and without magnesium sulfate USP 50% for inferior alveolar nerve blocks in patients with symptomatic irreversible pulpitis.

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Shetty, Krishna Prasad; Satish, Sarvepalli Venkata; Kilaru, Krishna Rao; Sardar, Poonam; Luke, Alexander M

2015-04-01

The purpose of this prospective, randomized, double-blind, placebo-controlled study was to compare the anesthetic efficacy between lidocaine with and without magnesium sulfate USP 50% for inferior alveolar nerve (IAN) blocks in patients with symptomatic irreversible pulpitis. One hundred patients with symptomatic irreversible pulpitis of mandibular posterior teeth were selected for the study. The patients received 1 mL magnesium sulfate USP 50% or distilled water (placebo) 1 hour before administration of conventional IAN block. Endodontic access cavity preparation was initiated 15 minutes after the IAN block injection. Lip numbness was recorded for all the patients. Success of IAN block was defined as no or mild pain on the visual analogue scale during access cavity preparation and initial instrumentation. The success rate for the IAN block was 58% for magnesium sulfate group and 32% for the placebo group, with statistically significant difference between the 2 groups (P = .016). In mandibular posterior teeth diagnosed with symptomatic irreversible pulpitis, preoperative administration of 1 mL magnesium sulfate USP 50% resulted in statistically significant increase in success of IAN block compared with placebo. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Comparative study of attenuation of the pain caused by propofol intravenous injection, by granisetron, magnesium sulfate and nitroglycerine

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Dhananjay Kumar Singh

2011-01-01

Full Text Available Background: Propofol has the disadvantage of causing pain or discomfort on injection. The aim of the study was to assess the efficacy of pretreatment with various drugs to alleviate the propofol injection pain. Methods: One hundred American Society of Anesthesiology (ASA I and II adults, scheduled for various elective surgical procedures under general anesthesia (GA, were included in the study. They were randomly divided into four groups having 25 patients in each group. Group A received pretreatment with intravenous (i.v. magnesium sulfate, group B received i.v. granisetron, group C received i.v. nitroglycerine and group D was the control group. One-fourth of the total calculated induction dose of propofol was administered over a period of 5 seconds. The patients were asked about the pain on injection. The intensity of pain was assessed using verbal response. A score of 0-3 which corresponds to no, mild, moderate and severe pain was recorded. Results: All the three drugs reduced the incidence and intensity of pain on propofol injection but the order of efficacy in attenuation of pain on the propofol injection was granisetron > nitroglycerine > magnesium sulfate > control. Conclusion: Granisetron was the most effective followed by nitroglycerine and magnesium sulfate in attenuating pain on propofol intravenous injection.

Effect of Salicylic Acid and Chelated Magnesium Sulfate on Fruit Quality Improvement (Physical Characteristics in Pear (cv. Louise Bonne

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mahjabin adel

2017-02-01

Full Text Available Introduction: Fruit quality is described based on the crop functions (for industry or table and/or difference of the consumer tastes in different societies. The conformity of the quality with consumer demands has an effective role in improvement of the marketing process. For example, elongated pears are preferred for the processing industries and conserving productions. The lack of attention to retaining of quality and/or improvement of apparent situation of gardening product in proportion to consumer demands decreases especial consumer acceptance. The necessity of having desired quality characteristics in pear fruits from the characters viewpoint of fruit specific gravity (major rating criterion of pears and proportion of length to diameter (minor rating, because of their role in market acceptance and pricing, is evident. Fruit quality, while harvesting, as one of the components of plants fertility influenced under different parameters like nourishment and could be managed during growth season. In other words, the gain of qualities proportionated to consumers demands and/or processing industries is possible by the use of acquired method such as the kind of mother plant nutrition, and control of pests and diseases, etc. In the current research, the effect of salicylic acid and chelated magnesium sulfate was studied on physical indexes of fruits quality of pear fruit. Materials and Methods: In order to study the effect of treatment agents, an experiment was conducted in the ecological conditions of Qazvinon Pear trees belonging to Louise Bonne cultivar in the Randomized Complete Block Design. The treatments includecontrol group (with andwithout water,chelated magnesium sulfate with concentration of 0.5 gram in a liter, chelated magnesium sulfate with concentration of 0.7gram in a liter, salicylic acid with concentration of0.1 gram in a liter,the compound treatment of salicylic acid with concentration of 0.1 andchelated magnesium sulfate with

Physical Compatibility of Magnesium Sulfate and Sodium Bicarbonate in a Pharmacy-compounded Bicarbonate-buffered Hemofiltration Solution

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Moriyama, Brad; Henning, Stacey A.; Jin, Haksong; Kolf, Mike; Rehak, Nadja N.; Danner, Robert L.; Walsh, Thomas J.; Grimes, George J.

2011-01-01

PURPOSE To assess the physical compatibility of magnesium sulfate and sodium bicarbonate in a pharmacy-compounded bicarbonate-buffered hemofiltration solution used at the National Institutes of Health Clinical Center (http://www.cc.nih.gov). METHODS Two hemofiltration fluid formulations with a bicarbonate of 50 mEq/L and a magnesium of 1.5 mEq/L or 15 mEq/L were prepared in triplicate with an automated compounding device. The hemofiltration solution with a bicarbonate of 50 mEq/L and a magnesium of 1.5 mEq/L contains the maximum concentration of additives that we use in clinical practice. The hemofiltration solution of 15 mEq/L of magnesium and 50 mEq/L of bicarbonate was used to study the physicochemical properties of this interaction. The solutions were stored without light protection at 22 to 25 °C for 48 hours. Physical compatibility was assessed by visual inspection and microscopy. The pH of the solutions was assayed at 3 to 4 hours and 52 to 53 hours after compounding. In addition, electrolyte and glucose concentrations in the solutions were assayed at two time points after preparation: 3 to 4 hours and 50 to 51 hours. RESULTS No particulate matter was observed by visual and microscopic inspection in the compounded hemofiltration solutions at 48 hours. Electrolyte and glucose concentrations and pH were similar at both time points after solution preparation. CONCLUSION Magnesium sulfate (1.5 mEq/L) and sodium bicarbonate (50 mEq/L) were physically compatible in a pharmacy-compounded bicarbonate-buffered hemofiltration solution at room temperature without light protection at 48 hours. PMID:20237384

Is magnesium sulfate effective for pain in chronic postherpetic neuralgia patients comparing with ketamine infusion therapy?

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Kim, Yang Hyun; Lee, Pyung Bok; Oh, Tak Kyu

2015-06-01

Postherpetic neuralgia (PHN) is a frequent debilitating complication and one of the most intractable pain disorders, particularly in elderly patients. Although tricyclic antidepressants, topical capsaicin, gabapentin, and oxycodone are effective for alleviating PHN, many patients remain refractory to current therapies. Here, the analgesic effects of ketamine or magnesium for PHN were assessed in an open prospective study. Thirty patients with severe, intractable PHN who were unresponsive to conservative therapy participated. The effects of ketamine hydrochloride (Ketara, Parke Davis) 1 mg/kg and magnesium sulfate (Magnesin) 30 mg/kg were investigated. The patients were randomly divided into 2 groups of 15 patients each, and ketamine 1 mg/kg or magnesium 30 mg/kg was administered intravenously for 1 hour after midazolam sedation. Pain was rated on a visual analog scale (VAS) during a 2-week follow-up. All patients also completed the Doleur Neuropathique 4 questionnaire at baseline and final visits. Response to treatment, defined as a 50% reduction in VAS score 2 weeks after, was recorded in 10 of 15 patients in the ketamine group and 7 of 15 patients in the magnesium group. The difference in VAS reduction was not significant between the 2 groups. Ketamine and magnesium showed significant analgesic effects in patients with PHN. Copyright © 2015 Elsevier Inc. All rights reserved.

Effects of Cheap Antidotes; Sodium Bicarbonate and Magnesium Sulfate in Organophosphorous Poisoning

International Nuclear Information System (INIS)

Balali-Mood, M.; Afshari, R.

2007-01-01

Organophosphorous (OP) compounds have been used as pesticides and chemical warfare nerve agents. Despite administration of well known antidotes (atropine and oximes), morbidity and mortality of OP poisoning were still high. Besides, oximes are very expensive and not available in most developing countries. It was thus aimed to study the effects of cheap available antidotes; sodium bicarbonate and magnesium sulfate in OP poisoning. In addition to the standard antidotal treatment, out of 117 patients (63M, 47F) aged 25.2 ± 9.5 years with moderate to severe acute OP pesticide poisoning 59 were given sodium bicarbonate 5 mEq/kg in 60 min. followed by 5-6 mEq/kg/day to obtain arterial blood pH of 7.45 to 7.55. Arterial blood pH increased significantly (p less than 0.01) to 7.48 ± 0.05 compared to the controls (7.32 ± 0.06). Morbidity based on hospitalization days reduced significantly (p less than 0.05) from 5.62 ± 3.4 in the controls to 3.1 ± 2.6 days in the sodium bicarbonate group. Total atropine dose was also significantly (p less than 0.05) lower in the test group. Mortality was lower, but not significantly due to the low numbers (5 and 2 of the controls and test group, respectively). Sodium bicarbonate appeared to be effective and could be added to the treatment regime of OP poisoning. Magnesium sulfate was administered four gram intravenously only for the first 24 hr of hospitalization day for the patients with moderate to severe OP poisoning in a pilot study. The results were promising and thus further investigations are continued.(author)

Effects of enteral and intravenous fluid therapy, magnesium sulfate, and sodium sulfate on colonic contents and feces in horses.

Science.gov (United States)

Lopes, Marco A F; White, Nathaniel A; Donaldson, Lydia; Crisman, Mark V; Ward, Daniel L

2004-05-01

To assess changes in systemic hydration, concentrations of electrolytes in plasma, hydration of colonic contents and feces, and gastrointestinal transit in horses treated with IV fluid therapy or enteral administration of magnesium sulfate (MgSO4), sodium sulfate (NaSO4), water, or a balanced electrolyte solution. 7 horses with fistulas in the right dorsal colon (RDC). In a crossover design, horses alternately received 1 of 6 treatments: no treatment (control); IV fluid therapy with lactated Ringer's solution; or enteral administration of MgSO4, Na2SO4, water, or a balanced electrolyte solution via nasogastric intubation. Physical examinations were performed and samples of blood, RDC contents, and feces were collected every 6 hours during the 48 hour-observation period. Horses were muzzled for the initial 24 hours but had access to water ad libitum. Horses had access to hay, salt, and water ad libitum for the last 24 hours. Enteral administration of a balanced electrolyte solution and Na2SO4 were the best treatments for promoting hydration of RDC contents, followed by water. Sodium sulfate was the best treatment for promoting fecal hydration, followed by MgSO4 and the balanced electrolyte solution. Sodium sulfate caused hypocalcemia and hypernatremia, and water caused hyponatremia. Enteral administration of a balanced electrolyte solution promoted hydration of RDC contents and may be useful in horses with large colon impactions. Enteral administration of either Na2SO4 or water may promote hydration of RDC contents but can cause severe electrolyte imbalances.

Use of magnesium sulfate before 32 weeks of gestation

DEFF Research Database (Denmark)

Wolf, H. T.; Weber, T.; Piedvache, A.

2017-01-01

Objectives: The use of magnesium sulfate (MgSO4) in European obstetric units is unknown. We aimed to describe reported policies and actual use of MgSO4 in women delivering before 32 weeks of gestation by indication. Methods: We used data from the European Perinatal Intensive Care in Europe (EPICE......) population-based cohort study of births before 32 weeks of gestation in 19 regions in 11 European countries. Data were collected from April 2011 to September 2012 from medical records and questionnaires. The study population comprised 720 women with severe preeclampsia, eclampsia or HELLP and 3658 without...... preeclampsia delivering from 24 to 31 weeks of gestation in 119 maternity units with 20 or more very preterm deliveries per year. Results: Among women with severe pre-eclampsia, eclampsia or HELLP, 255 (35.4%) received MgSO4 before delivery. 41% of units reported use of MgSO4 whenever possible for pre...

Protective Effect of Forced Hydration with Isotonic Saline, Potassium Chloride and Magnesium Sulfate on Cisplatin Nephrotoxicity: An Initial Evaluation

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Seyed Seifollah Beladi Mousavi

2013-12-01

How to cite this article: Beladi Mousavi SS, Hossainzadeh M, Khanzadeh A, Hayati F, Beladi Mousavi M, Zeraati AA, et al. Protective Effect of Forced Hydration with Isotonic Saline, Potassium Chloride and Magnesium Sulfate on Cisplatin Nephrotoxicity: An Initial Evaluation. Asia Pac J Med Toxicol 2013;2:136-9.

Ganymede's internal structure including thermodynamics of magnesium sulfate oceans in contact with ice

Science.gov (United States)

Vance, Steve; Bouffard, Mathieu; Choukroun, Mathieu; Sotin, Christophe

2014-06-01

The large icy moons of Jupiter contain vast quantities of liquid water, a key ingredient for life. Ganymede and Callisto are weaker candidates for habitability than Europa, in part because of the model-based assumption that high-pressure ice layers cover their seafloors and prevent significant water-rock interaction. Water-rock interactions may occur, however, if heating at the rock-ice interface melts the high pressure ice. Highly saline fluids would be gravitationally stable, and might accumulate under the ice due to upward migration, refreezing, and fractionation of salt from less concentrated liquids. To assess the influence of salinity on Ganymede's internal structure, we use available phase-equilibrium data to calculate activity coefficients and predict the freezing of water ice in the presence of aqueous magnesium sulfate. We couple this new equation of state with thermal profiles in Ganymede's interior-employing recently published thermodynamic data for the aqueous phase-to estimate the thicknesses of layers of ice I, III, V, and VI. We compute core and silicate mantle radii consistent with available constraints on Ganymede's mass and gravitational moment of inertia. Mantle radii range from 800 to 900 km for the values of salt and heat flux considered here (4-44 mW m-2 and 0 to 10 wt% MgSO4). Ocean concentrations with salinity higher than 10 wt% have little high pressure ice. Even in a Ganymede ocean that is mostly liquid, achieving such high ocean salinity is permissible for the range of likely S/Si ratios. However, elevated salinity requires a smaller silicate mantle radius to satisfy mass and moment-of-inertia constraints, so ice VI is always present in Ganymede's ocean. For lower values of heat flux, oceans with salinity as low as 3 wt% can co-exist with ice III. Available experimental data indicate that ice phases III and VI become buoyant for salinity higher than 5 wt% and 10 wt%, respectively. Similar behavior probably occurs for ice V at salinities

Surface modification and characterization of magnesium hydroxide sulfate hydrate nanowhiskers

Energy Technology Data Exchange (ETDEWEB)

Gao Chuanhui [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100 (China); Li Xianguo, E-mail: chuanhuigao@foxmail.com [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100 (China); Feng Lijuan; Lu Shaoyan; Liu Jinyan [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100 (China)

2010-03-01

In order to enhance the compatibility with plastic polymers, magnesium hydroxide sulfate hydrate (MHSH) nanowhiskers were modified through grafting methyl methacrylate (MMA) on the surface of the nanowhiskers by emulsion polymerization. The influences of the reaction time, MMA monomer content, adding speed of monomer and the reaction temperature on the grafting ratio were investigated. Thermogravimetry (TG), Fourier transform infrared (FT-IR) spectroscopy, X-ray powder diffraction (XRD), scanning electron microscope (SEM), energy-dispersive X-ray (EDX) spectroscopy and surface contact angle measurement were used to characterize the effect of surface modification. The results showed that the MHSH nanowhiskers were uniformly coated by polymethyl methacrylate (PMMA), and a well-defined core-shell hybrid structure of MHSH/PMMA was obtained. The surface contact angle of the hybrid whiskers increased to 87.32 deg. from 12.71 deg. and the whiskers surface was changed from hydrophilic to lipophilic.

Determination of thermodynamic parameters for complexation of calcium and magnesium with chondroitin sulfate isomers using isothermal titration calorimetry: Implications for calcium kidney-stone research

Science.gov (United States)

Rodgers, Allen L.; Jackson, Graham E.

2017-04-01

Chondroitin sulfate (CS) occurs in human urine. It has several potential binding sites for calcium and as such may play an inhibitory role in calcium oxalate and calcium phosphate (kidney stone disease by reducing the supersaturation (SS) and crystallization of these salts. Urinary magnesium is also a role player in determining speciation in stone forming processes. This study was undertaken to determine the thermodynamic parameters for binding of the disaccharide unit of two different CS isomers with calcium and magnesium. These included the binding constant K. Experiments were performed using an isothermal titration calorimeter (ITC) at 3 different pH levels in the physiological range in human urine. Data showed that interactions between the CS isomers and calcium and magnesium occur via one binding site, thought to be sulfate, and that log K values are 1.17-1.93 and 1.77-1.80 for these two metals respectively. Binding was significantly stronger in Mg-CS than in Ca-CS complexes and was found to be dependent on pH in the latter but not in the former. Furthermore, binding in Ca-CS complexes was dependent on the location of the sulfate binding site. This was not the case in the Mg-CS complexes. Interactions were shown to be entropy driven and enthalpy unfavourable. These findings can be used in computational modeling studies to predict the effects of the calcium and magnesium CS complexes on the speciation of calcium and the SS of calcium salts in real urine samples.

Effect of continuous magnesium sulfate infusion on spinal block characteristics: A prospective study

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Akansha Agrawal

2014-01-01

Full Text Available Background: Spinal anesthesia is an established mode of anesthesia for lower limb orthopedic surgeries. The limitations of the technique are short duration of action and limited post-operative analgesia. Concomitant use of intravenous infusion of magnesium sulfate may have an effect on the block characteristics and duration of action of intrathecal bupivacaine. Methods: A total of 80 American Society of Anesthesiologists I and II patients, either sex, 20-60 years of age scheduled for elective orthopedic fixation of fracture of long bones of lower limbs under spinal anesthesia were included. Spinal anesthesia administered with 2.5 ml heavy bupivacaine mixed with 10 mcg fentanyl. The groups were then divided to receive an infusion of injection magnesium sulfate 50 mg/kg/h over 15 min followed by 15 mg/kg/h until the end of the surgery (Group M and 15 ml of Normal Saline over 15 min followed by 100 ml/h until the end of surgery (Group S. Onset, duration of sensory and motor block and amount of post-operative analgesic were noted. Results: A total of 6 patients (Group M and seven patients (Group S had inadequate block and excluded from the study. Mean block height was T6. Time required to achieve block height was 8.82 min versus 7.42 min in Groups M and S respectively (P = 0.04. Mean duration of motor block was longer in group M (160.63 ± 17.76 min compared with Group S (130.12 ± 20.70 min (P = 0.000. Time for regression of sensory block to T12/L1was 206.88 ± 20.96 min (Group M and 163.88 ± 15.46 min (Group S (P = 0.000. Hemodynamic parameters were similar and statistically not significant. Need for first analgesic requirement was after 262.88 ± 21.11 min in group M and 193.25 ± 17.74 min in the group S (P = 0.000. Mean dosage of tramadol needed in first 24 h was less in group M (190 ± 30.38 mg vs. 265 ± 48.30 mg, P = 0.000. Conclusion: Use of intravenous magnesium with spinal anesthesia reduces post-operative pain and analgesic consumption.

A facile synthesis of phenazine and quinoxaline derivatives using magnesium sulfate heptahydrate as a catalyst

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BAHADOR KARAMI

2011-09-01

Full Text Available Convenient and simple procedures for the synthesis of phenazine and quinoxaline derivatives were developed via a reaction of o-phenylenediamines and 1,2-dicarbonyl compounds. In addition, the synthesis of two new 1,4-benzodiazine derivatives and the catalytic activity of magnesium sulfate heptahydrate (MgSO4·7H2O in the room temperature condensation of o-phenylenediamines and 1,2-dicarbonyl compounds in ethanol as solvent are reported. This method has many appealing attributes, such as excellent yields, short reaction times, and simple work-up procedures.

Studies on sulfate attack: Mechanisms, test methods, and modeling

Science.gov (United States)

Santhanam, Manu

The objective of this research study was to investigate various issues pertaining to the mechanism, testing methods, and modeling of sulfate attack in concrete. The study was divided into the following segments: (1) effect of gypsum formation on the expansion of mortars, (2) attack by the magnesium ion, (3) sulfate attack in the presence of chloride ions---differentiating seawater and groundwater attack, (4) use of admixtures to mitigate sulfate attack---entrained air, sodium citrate, silica fume, and metakaolin, (5) effects of temperature and concentration of the attack solution, (6) development of new test methods using concrete specimens, and (7) modeling of the sulfate attack phenomenon. Mortar specimens using portland cement (PC) and tricalcium silicate (C 3S), with or without mineral admixtures, were prepared and immersed in different sulfate solutions. In addition to this, portland cement concrete specimens were also prepared and subjected to complete and partial immersion in sulfate solutions. Physical measurements, chemical analyses and microstructural studies were performed periodically on the specimens. Gypsum formation was seen to cause expansion of the C3S mortar specimens. Statistical analyses of the data also indicated that the quantity of gypsum was the most significant factor controlling the expansion of mortar bars. The attack by magnesium ion was found to drive the reaction towards the formation of brucite. Decalcification of the C-S-H and its subsequent conversion to the non-cementitious M-S-H was identified as the mechanism of destruction in magnesium sulfate attack. Mineral admixtures were beneficial in combating sodium sulfate attack, while reducing the resistance to magnesium sulfate attack. Air entrainment did not change the measured physical properties, but reduced the visible distress of the mortars. Sodium citrate caused a substantial reduction in the rate of damage of the mortars due to its retarding effect. Temperature and

The Effect of Salicylic Acid and Chelated Magnesium Sulfate on Matters Allocation in Vegetative and Reproductive Parts in Pear cv. Louise Bonne Infected to Fire Blight Disease

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mahjabin adel

2017-10-01

Full Text Available Introduction: Distribution of photosynthetic substances between vegetative and reproductive parts is influenced by the environmental factors as well as plant nutrition status. Therefore, application of nutrient substances (such as chelated magnesium sulfate and salicylic acid combination can influence the distribution of photosynthetic substances which in turn result in changes in allocation of photo-assimilates between vegetative and reproductive parts. Since the investigation of partitioning of photo- assimilates is complex and the interpretation of treatments effects on partitioning of substances is difficult in garden plants, this examination has been focused on external application of nutritional treatments on different organs growth by comparing the effects of salicylic acid and chelated magnesium sulfate on the allocation of photo- assimilates. Materials and Methods: This experiment was performed in a commercial 10-year old orchard of Qazvin in 2013. Initially, 60 uniform pears (cv. Louise Bonne which were infected to fire blight disease were selected. Before treatment imposing, agronomic practices such as removing and pruning infected shoots were applied. Treatments were combination of salicylic acid and chelated magnesium sulfate at different levels, which were applied on foliage under the conditions of neutral pollution to fire blight. In the present research, vegetative parameters (current shoot growth, leaf weight, leaf area, relative water content and so on and reproductive parameters (length: diameter ratio and density of fruit and so on were measured. The fully expanded leaves were collected randomly from each replicate. After washing the samples were weighed and these values referred to as initial readings (fresh weight. Then, the leaf samples were placed in distilled water for 24 h in the dark at room temperature. The turgid leaves were blotted dry and weighed (saturation weight. After weighing, the material was oven-dried at 70

Theoretical investigation of zero field splitting parameter of Cr{sup 3+} doped diammonium hexaaqua magnesium sulfate

Energy Technology Data Exchange (ETDEWEB)

Kripal, Ram, E-mail: ram_kripal2001@rediffmail.com; Yadav, Awadhesh Kumar, E-mail: aky.physics@gmail.com

2015-01-01

The zero field splitting parameter D of Cr{sup 3+} doped diammonium hexaaqua magnesium sulfate (DHMS) are calculated with perturbation formula using crystal field (CF) parameters from superposition model. The theoretically calculated ZFS parameters for Cr{sup 3+} in DHMS single crystal are compared with the experimental value obtained by electron paramagnetic resonance (EPR). The theoretical ZFS parameter D is similar to that from experiment. The energy band positions of optical absorption spectra of Cr{sup 3+} doped DHMS single crystal are calculated with CFA package, which are in good match with experimental values.

Adding different doses of intrathecal magnesium sulfate for spinal anesthesia in the cesarean section: A prospective double blind randomized trial

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Mitra Jabalameli

2012-01-01

Conclusions: In patients undergoing the caesarean section under hyperbaric bupivacaine spinal anesthesia, the addition of 50, 75, or 100 mg magnesium sulfate provides safe and effective anesthesia, but 75 mg of this drug was enough to lead a significant delay in the onset of both sensory and motor blockade, and prolonged the duration of sensory and motor blockade, without increasing major side effects.

Magnesium protects cognitive functions and synaptic plasticity in streptozotocin-induced sporadic Alzheimer's model.

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Zhi-Peng Xu

Full Text Available Alzheimer's disease (AD is characterized by profound synapse loss and impairments of learning and memory. Magnesium affects many biochemical mechanisms that are vital for neuronal properties and synaptic plasticity. Recent studies have demonstrated that the serum and brain magnesium levels are decreased in AD patients; however, the exact role of magnesium in AD pathogenesis remains unclear. Here, we found that the intraperitoneal administration of magnesium sulfate increased the brain magnesium levels and protected learning and memory capacities in streptozotocin-induced sporadic AD model rats. We also found that magnesium sulfate reversed impairments in long-term potentiation (LTP, dendritic abnormalities, and the impaired recruitment of synaptic proteins. Magnesium sulfate treatment also decreased tau hyperphosphorylation by increasing the inhibitory phosphorylation of GSK-3β at serine 9, thereby increasing the activity of Akt at Ser473 and PI3K at Tyr458/199, and improving insulin sensitivity. We conclude that magnesium treatment protects cognitive function and synaptic plasticity by inhibiting GSK-3β in sporadic AD model rats, which suggests a potential role for magnesium in AD therapy.

Liquid-liquid equilibrium of water + PEG 8000 + magnesium sulfate or sodium sulfate aqueous two-phase systems at 35°C: experimental determination and thermodynamic modeling

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B. D. Castro

2005-09-01

Full Text Available Liquid-liquid extraction using aqueous two-phase systems is a highly efficient technique for separation and purification of biomolecules due to the mild properties of both liquid phases. Reliable data on the phase behavior of these systems are essential for the design and operation of new separation processes; several authors reported phase diagrams for polymer-polymer systems, but data on polymer-salt systems are still relatively scarce. In this work, experimental liquid-liquid equilibrium data on water + polyethylene glycol 8000 + magnesium sulfate and water + polyethylene glycol 8000 + sodium sulfate aqueous two-phase systems were obtained at 35°C. Both equilibrium phases were analyzed by lyophilization and ashing. Experimental results were correlated with a mass-fraction-based NRTL activity coefficient model. New interaction parameters were estimated with the Simplex method. The mean deviations between the experimental and calculated compositions in both equilibrium phases is about 2%.

Timeline (Bioavailability) of Magnesium Compounds in Hours: Which Magnesium Compound Works Best?

Science.gov (United States)

Uysal, Nazan; Kizildag, Servet; Yuce, Zeynep; Guvendi, Guven; Kandis, Sevim; Koc, Basar; Karakilic, Aslı; Camsari, Ulas M; Ates, Mehmet

2018-04-21

Magnesium is an element of great importance functioning because of its association with many cellular physiological functions. The magnesium content of foods is gradually decreasing due to food processing, and magnesium supplementation for healthy living has become increasingly popular. However, data is very limited on the bioavailability of various magnesium preparations. The aim of this study is to investigate the bioavailability of five different magnesium compounds (magnesium sulfate, magnesium oxide, magnesium acetyl taurate, magnesium citrate, and magnesium malate) in different tissues. Following a single dose 400 mg/70 kg magnesium administration to Sprague Dawley rats, bioavailability was evaluated by examining time-dependent absorption, tissue penetration, and the effects on the behavior of the animals. Pharmacokinetically, the area under the curve calculation is highest in the magnesium malate. The magnesium acetyl taurate was found to have the second highest area under the curve calculation. Magnesium acetyl taurate was rapidly absorbed, able to pass through to the brain easily, had the highest tissue concentration level in the brain, and was found to be associated with decreased anxiety indicators. Magnesium malate levels remained high for an extended period of time in the serum. The commonly prescribed dietary supplements magnesium oxide and magnesium citrate had the lowest bioavailability when compared to our control group. More research is needed to investigate the bioavailability of magnesium malate and acetyl taurate compounds and their effects in specific tissues and on behavior.

Theoretical Study of Infrared and Raman Spectra of Hydrated Magnesium Sulfate Salts

Science.gov (United States)

Chaban, Galina M.; Huo, Winifred M.; Lee, Timothy J.; Kwak, Dochan (Technical Monitor)

2002-01-01

Harmonic and anharmonic vibrational frequencies, as well as infrared and Raman intensities, are calculated for MgSO4.nH20 (n=1-3). Electronic structure theory at the second order Moller-Plesset perturbation theory (MP2) level with a triple-zeta + polarization (TZP) basis set is used to determine the geometry, properties, and vibrational spectra of pure and hydrated MgSO4 salts. The direct vibrational self-consistent field (VSCF) method and its correlation corrected (CC-VSCF) extension are used to determine anharmonic corrections to vibrational frequencies and intensities for the pure MgSO4 and its complex with one water molecule. Very significant differences are found between vibrational of water molecules in complexes with MgSO4 and pure water. Some of the O-H stretching frequencies are shifted to the red very significantly (by up to 1500-2000/cm) upon complexation with magnesium sulfate. They should be observed between 1700 and 3000/cm in a region very different from the corresponding O-H stretch frequency region of pure water (3700-3800/cm). In addition, the SO2 stretching vibrations are found at lower frequency regions than the water vibrations. They can serve as unique identifiers for the presence of sulfate salts. The predicted infrared and Raman spectra should be of valuable help in the design of future missions and analysis of observed data from the ice surface of Jupiter's moon Europa that possibly contains hydrated MgSO4 salts.

Reversal with sugammadex for rocuronium-induced deep neuromuscular block after pretreatment of magnesium sulfate in rabbits.

Science.gov (United States)

Kang, Woon Seok; Kim, Kyo Sang; Song, Shin Mi

2017-04-01

Magnesium sulfate (MgSO 4 ) has been used in the treatment of pre-eclampsia, hypertension and arrhythmia. Magnesium enhances the neuromuscular block of rocuronium. This study has been conducted to evaluate the reversal efficacy of sugammadex from deep rocuronium-induced neuromuscular block (NMB) during consistent pretreatment of MgSO 4 in rabbits. Twenty-eight rabbits were randomly assigned to four groups, a control group or study groups (50% MgSO 4 150-200 mg/kg and 25 mg/kg/h IV), and received rocuronium 0.6 mg/kg. When post-tetanic count 1-2 appeared, sugammadex 2, 4, and 8 mg/kg was administered in the 2-mg group, control and 4-mg group, and 8-mg group, respectively. The recovery course after reversal of sugammadex administration was evaluated in each group. The mean serum concentration of magnesium was maintained at more than 2 mmol/L in the study groups, and the total dose of MgSO 4 was more than 590 mg. The reversal effect of sugammadex on rocuronium-induced NMB in pretreated MgSO 4 was not different from that in the group without MgSO 4 . The recovery time to train-of-four ratio 0.9 after sugammadex administration in the 2-mg group was longer than in the other groups (P rocuronium-induced NMB during large pretreatment of MgSO 4 was not affected. However, we should consider that the reversal effect of sugammadex varied depending on the dose.

Combined treatment with progesterone and magnesium sulfate positively affects traumatic brain injury in immature rats.

Science.gov (United States)

Uysal, Nazan; Baykara, Basak; Kiray, Muge; Cetin, Ferihan; Aksu, Ilkay; Dayi, Ayfer; Gurpinar, Tugba; Ozdemir, Durgul; Arda, M Nuri

2013-01-01

It is well known that head trauma results in damage in hippocampal and cortical areas of the brain and impairs cognitive functions. The aim of this study is to explore the neuroprotective effect of combination therapy with magnesium sulphate (MgSO4) and progesterone in the 7-days-old rat pups subjected to contusion injury. Progesterone (8 mg/kg) and MgSO4 (150 mg/kg) were injected intraperitoneally immediately after induction of traumatic brain injury. Half of groups were evaluated 24 hours later, the remaining animals 3 weeks after trauma or sham surgery. Anxiety levels were assessed with open field activity and elevated plus maze; learning and memory performance were evaluated with Morris Water maze in postnatal 27 days. Combined therapy with progesterone and magnesium sulfate significantly attenuated trauma-induced neuronal death, increased brain VEGF levels and improved spatial memory deficits that appear later in life. Brain VEGF levels were higher in rats that received combined therapy compared to rats that received either medication alone. Moreover, rats that received combined therapy had reduced hipocampus and prefrontal cortex apoptosis in the acute period. These results demonstrate that combination of drugs with different mechanisms of action may be preferred in the treatment of head trauma.

Standard test method for laboratory evaluation of magnesium sacrificial anode test specimens for underground applications

CERN Document Server

American Society for Testing and Materials. Philadelphia

1997-01-01

1.1 This test method covers a laboratory procedure that measures the two fundamental performance properties of magnesium sacrificial anode test specimens operating in a saturated calcium sulfate, saturated magnesium hydroxide environment. The two fundamental properties are electrode (oxidation potential) and ampere hours (Ah) obtained per unit mass of specimen consumed. Magnesium anodes installed underground are usually surrounded by a backfill material that typically consists of 75 % gypsum (CaSO4·2H2O), 20 % bentonite clay, and 5 % sodium sulfate (Na2SO4). The calcium sulfate, magnesium hydroxide test electrolyte simulates the long term environment around an anode installed in the gypsum-bentonite-sodium sulfate backfill. 1.2 This test method is intended to be used for quality assurance by anode manufacturers or anode users. However, long term field performance properties may not be identical to property measurements obtained using this laboratory test. Note 1—Refer to Terminology G 15 for terms used ...

The efficacy of nebulized magnesium sulfate alone and in combination with salbutamol in acute asthma

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Sarhan HA

2016-06-01

Full Text Available Hatem A Sarhan,1 Omar H EL-Garhy,1 Mohamed A Ali,2 Nouran A Youssef1 1Department of Pharmaceutics, Faculty of Pharmacy, 2Department of Chest Diseases, Faculty of Medicine, Minia University, Minia, Egypt Objective: Evaluation of the efficacy of nebulized magnesium sulfate (MgSO4 alone and in combination with salbutamol in acute asthma.Methods: A double-blind randomized controlled study was conducted in Chest and Emergency Departments. Thirty patients of acute attack of bronchial asthma were randomized into three groups: MgSO4 nebulization (group A, salbutamol nebulization (group B, and their combination (group C. All patients were monitored before and after nebulization (each 20 minutes for peak expiratory flow rate (PEFR, respiratory rate (RR, heart rate (HR, blood pressure, pulsus paradoxus, oxygen saturation, clinical examination, and Fischl index.Results: A highly significant improvement in PEFR, PEFR percentage, and Fischl index and significant decrease in RR and HR was observed in all groups. A similar improvement in PEFR was observed in group A and group B (P=0.389. The difference in peak expiratory flow (PEF improvement was insignificant between group B and group C (P=0.101, while there was a significant differ­ence between group A and group C (P=0.014 in favor of group C.Conclusion: Nebulized MgSO4 alone or combined with salbutamol has a clinically significant bronchodilator effect in acute asthma and leads to clinical improvement, increase in PEFR, reduction in HR, and reduction in RR. The response to nebulized MgSO4 alone (PEFR improvement 54±35.6 L/min, P=0.001 is comparable (P=0.389 to that of nebulized salbutamol (PEFR improvement 67.0±41.9 L/min, P=0.001 and is significantly less than (P=0.014 that of nebulized combination (PEFR improvement 92.0±26.9 L/min, P=0.000. Keywords: nebulized magnesium sulfate, salbutamol, acute asthma, peak expiratory flow rate, Fischl index

Tratamento da Eclâmpsia: Estudo Comparativo entre o Sulfato de Magnésio e a Fenitoína Treatment of Eclampsia: Comparative Study on the Use of Magnesium Sulfate and Phenytoin

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João de Deus Valadares Neto

2000-10-01

Full Text Available Objetivos: comparar a eficácia do sulfato de magnésio e da fenitoína no controle das convulsões em pacientes com eclâmpsia e avaliar os efeitos de sulfato de magnésio e da fenitoína sobre o prognóstico materno e perinatal em pacientes com eclâmpsia. Métodos: estudo prospectivo, randômico e controlado no qual foram analisados, de forma comparativa, os resultados obtidos no tratamento anticonvulsivante da eclâmpsia em 77 mulheres tratadas com sulfato de magnésio ou fenitoína. As drogas que constituíram os dois esquemas terapêuticos foram distribuídas, na proporção de um para um, em caixas numeradas aleatoriamente que apresentavam características semelhantes. À medida que cada paciente era admitida, uma caixa era aberta e o esquema nela contido administrado à paciente. Resultados: observou-se que, no grupo tratado com sulfato de magnésio, 19,5% das pacientes apresentaram recidiva de convulsões, ao passo que no grupo que usou fenitoína, 36,1% manifestaram novas crises (p0,05. Conclusões: o sulfato de magnésio mostrou-se mais eficaz que a fenitoína no controle e prevenção da recidiva de convulsões em pacientes com eclâmpsia, embora sua utilização esteja associada a maior prevalência materna de hemorragia pós-parto e desconforto respiratório neonatal. A fenitoína apresenta-se como droga alternativa para o tratamento de eclâmpsia nos casos em que houver contra-indicação ao uso do sulfato de magnésio.Purpose: to compare the efficiency between magnesium sulfate and phenytoin in the control of convulsions in patients with eclampsia and to evaluate the effects of magnesium sulfate and phenytoin on the maternal and perinatal prognosis in patients with eclampsia. Methods: this is a prospective, randomized and controlled study in which the results obtained with the use of anticonvulsive treatment in 77 women with eclampsia, treated with either magnesium sulfate or phenytoin, were analyzed comparatively. The drugs

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

Science.gov (United States)

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 sulfate salts and historic building materials: experimental simulation of limestone flaking by relative humidity cycling and crystallization of salts

Directory of Open Access Journals (Sweden)

Pinchin, S.

2008-06-01

Full Text Available Magnesium sulfate salts often result from the combination of incompatible construction materials, such as stone or mortar with high magnesium content and sulfates from adjacent mortars or polluted air. When combined with a source of moisture, these materials react to form soluble salts, often leading to significant damage by flaking of the stone, as the magnesium sulfate responds to fluctuating environmental conditions. Several laboratory experiments were performed to reproduce surface flaking on different types of limestone from Spain and the UK to evaluate the effects of humidity cycling on the damage of stone by salt crystallization. The two salt solutions used for the experiments were a single salt of magnesium sulfate and a mixture of magnesium sulfate, calcium sulfate and sodium chloride, a typical salt mixture found in damaged stone at the site of Howden Minster (UK. A climate chamber with precise and programmable temperature and humidity control was used to test the hypothesis that salt damage in the stone can be readily caused by humidity fluctuations. Damage was monitored using Linear Variable Differential Transformer (LVDT, which measure transducers displacement by dimensional change on the order of microns. In addition, Ion Chromatography, Environmental Scanning Electron Microscopy with energy dispersive X-ray spectroscopy (ESEM-EDX and X-ray Diffraction analyses (XRD were also carried out to analyze salt behavior. Damage by flaking took place in two types of magnesian limestone cubes impregnated with the salt mixture, from Cadeby quarry and York Minster, apparently by deliquescent salts of low equilibrium relative humidity (RHeq, while the rest of the samples developed a salt crust over the surface, but no damage was observed in the stone. It is important to verify hypotheses developed from field observations with laboratory experiments. By combining both field and laboratory data, a clearer understanding the different mechanisms of

Influences of doping mesoporous magnesium silicate on water absorption, drug release, degradability, apatite-mineralization and primary cells responses to calcium sulfate based bone cements

International Nuclear Information System (INIS)

Gu, Zhengrong; Wang, Sicheng; Weng, Weizong; Chen, Xiao; Cao, Liehu; Wei, Jie; Shin, Jung-Woog; Su, Jiacan

2017-01-01

In this study, composite cements containing mesoporous magnesium silicate (m-MS) and calcium sulfate (CS) were fabricated. The results revealed that the setting time of the m-MS/CS composite cements (m-MSC) slightly prolonged with the increase of m-MS content while the compressive strength suffered a little loss. The doping of m-MS improved the water absorption, drug release (vancomycin) and degradability of the m-MSC in Tris-HCl solution (pH = 7.4). In addition, addition of m-MS facilitated the apatite-mineralization of m-MSC in simulated body fluid (SBF), indicating good bioactivity. For cell cultural experiments, the results revealed that the m-MSC promoted the cells adhesion and proliferation, and improved the alkaline phosphatase (ALP) activity of MC3T3-E1 cells, revealing good cytocompatibility. It could be suggested that the m-MSC might be promising cements biomaterials for bone tissue regeneration. - Highlights: • The mesoporous magnesium silicate and calcium sulfate composite was fabricated. • The composite possessed good water absorption and drug release of vancomycin. • The bioactive composite could enhance the in vivo apatite formation in SBF. • The composite promoted cell adhesion, proliferation and osteogenic differentiation.

Influences of doping mesoporous magnesium silicate on water absorption, drug release, degradability, apatite-mineralization and primary cells responses to calcium sulfate based bone cements

Energy Technology Data Exchange (ETDEWEB)

Gu, Zhengrong [Department of Trauma Orthopaedics, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China); The Department of Orthopaedics, Jing' an District Centre Hospital of Shanghai (Huashan Hospital Fudan University Jing' An Branch), 200040 (China); Wang, Sicheng [Department of Trauma Orthopaedics, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China); Department of Orthopaedics, Zhongye Hospital, Shanghai 200941 (China); Weng, Weizong; Chen, Xiao; Cao, Liehu [Department of Trauma Orthopaedics, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China); Wei, Jie [Key Laboratory for Ultrafine Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); Shin, Jung-Woog [Department of Biomedical Engineering, Inje University, Gimhae, 621749 (Korea, Republic of); Su, Jiacan, E-mail: jiacansu@sina.com [Department of Trauma Orthopaedics, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China)

2017-06-01

In this study, composite cements containing mesoporous magnesium silicate (m-MS) and calcium sulfate (CS) were fabricated. The results revealed that the setting time of the m-MS/CS composite cements (m-MSC) slightly prolonged with the increase of m-MS content while the compressive strength suffered a little loss. The doping of m-MS improved the water absorption, drug release (vancomycin) and degradability of the m-MSC in Tris-HCl solution (pH = 7.4). In addition, addition of m-MS facilitated the apatite-mineralization of m-MSC in simulated body fluid (SBF), indicating good bioactivity. For cell cultural experiments, the results revealed that the m-MSC promoted the cells adhesion and proliferation, and improved the alkaline phosphatase (ALP) activity of MC3T3-E1 cells, revealing good cytocompatibility. It could be suggested that the m-MSC might be promising cements biomaterials for bone tissue regeneration. - Highlights: • The mesoporous magnesium silicate and calcium sulfate composite was fabricated. • The composite possessed good water absorption and drug release of vancomycin. • The bioactive composite could enhance the in vivo apatite formation in SBF. • The composite promoted cell adhesion, proliferation and osteogenic differentiation.

The corrosion properties of phosphate coating on AZ31 magnesium alloy: The effect of sodium dodecyl sulfate (SDS) as an eco-friendly accelerating agent

Energy Technology Data Exchange (ETDEWEB)

Amini, R. [Department of Polymer Engineering and Color Technology, AmirKabir University of Technology, P.O. Box 15875-4413, Tehran (Iran, Islamic Republic of); Sarabi, A.A., E-mail: sarabi@aut.ac.ir [Department of Polymer Engineering and Color Technology, AmirKabir University of Technology, P.O. Box 15875-4413, Tehran (Iran, Islamic Republic of)

2011-06-01

Sodium nitrite has been used as an accelerating agent in phosphating bath to improve its properties. However, it is well known that sodium nitrite is a carcinogenic component in phosphating sludge. In this study, it has been aimed to replace sodium nitrite by an environmentally friendly accelerating agent. To this end, sodium dodecyl sulfate (SDS) was used in phosphating bath to improve the phosphate coating formation on an AZ31 magnesium alloy. The effect of SDS/sodium nitrite ratio on the phosphated samples properties was also studied. Using field emission scanning electron microscope (FE-SEM), X-ray diffraction (XRD), direct current (DC) polarization and electrochemical impedance spectroscopy (EIS) the properties of phosphated magnesium samples were studied. Results showed uniform phosphate coating formation on the magnesium sample mostly in hopeite phase composition. In addition, a denser and less permeable coating can be obtained at these conditions. The corrosion resistance of the phosphated samples was superiorly improved using higher SDS concentration in the phosphating bath.

The corrosion properties of phosphate coating on AZ31 magnesium alloy: The effect of sodium dodecyl sulfate (SDS) as an eco-friendly accelerating agent

International Nuclear Information System (INIS)

Amini, R.; Sarabi, A.A.

2011-01-01

Sodium nitrite has been used as an accelerating agent in phosphating bath to improve its properties. However, it is well known that sodium nitrite is a carcinogenic component in phosphating sludge. In this study, it has been aimed to replace sodium nitrite by an environmentally friendly accelerating agent. To this end, sodium dodecyl sulfate (SDS) was used in phosphating bath to improve the phosphate coating formation on an AZ31 magnesium alloy. The effect of SDS/sodium nitrite ratio on the phosphated samples properties was also studied. Using field emission scanning electron microscope (FE-SEM), X-ray diffraction (XRD), direct current (DC) polarization and electrochemical impedance spectroscopy (EIS) the properties of phosphated magnesium samples were studied. Results showed uniform phosphate coating formation on the magnesium sample mostly in hopeite phase composition. In addition, a denser and less permeable coating can be obtained at these conditions. The corrosion resistance of the phosphated samples was superiorly improved using higher SDS concentration in the phosphating bath.

Regeneration of sulfated metal oxides and carbonates

Science.gov (United States)

Hubble, Bill R.; Siegel, Stanley; Cunningham, Paul T.

1978-03-28

Alkali metal or alkaline earth metal carbonates such as calcium carbonate and magnesium carbonate found in dolomite or limestone are employed for removal of sulfur dioxide from combustion exhaust gases. The sulfated carbonates are regenerated to oxides through use of a solid-solid reaction, particularly calcium sulfide with calcium sulfate to form calcium oxide and sulfur dioxide gas. The regeneration is performed by contacting the sulfated material with a reductant gas such as hydrogen within an inert diluent to produce calcium sulfide in mixture with the sulfate under process conditions selected to permit the sulfide-sulfate, solid-state reaction to occur.

Intravenous magnesium sulfate for vaso-occlusive episodes in sickle cell disease.

Science.gov (United States)

Goldman, Ran D; Mounstephen, William; Kirby-Allen, Melanie; Friedman, Jeremy N

2013-12-01

Vaso-occlusive episodes (VOEs) are the most common complication of sickle cell disease in children. Treatment with magnesium seems to improve cellular hydration and may result in reduced vaso-occlusion. This study aimed to determine if intravenous (IV) magnesium sulfate (MgSO4) reduces length of stay (LOS) in hospital, pain scores, and cumulative analgesia when compared with placebo. Randomized, double-blind, placebo-controlled trial in children aged 4 to 18 years requiring admission to hospital with a sickle cell disease VOE requiring IV analgesia. Participating children received IV MgSO4 (100 mg/kg) every 8 hours or placebo in addition to standard therapy. We used a t test or Mann-Whitney test (continuous variables), Fisher's exact test, or χ2 test (frequencies). P values were considered significant if <.05, and 95% confidence intervals were calculated for the difference between groups. One hundred six children were randomly assigned to the study, and 104 were included. Fifty-one (49%) received MgSO4. Children's mean age was 12.4 years (range: 4-18 years; SD: 3.8 years), and 56 (54%) were females. There was no significant difference in the primary outcome measure, LOS in hospital, with a mean of 132.6 and 117.7 hours in the MgSO4 and placebo groups, respectively (P = .41). There was no significant difference between groups for the secondary outcomes of mean pain scores (4.9 ± 2.6 vs 4.8 ± 2.6, respectively; P = .92) or analgesic requirements (continuous morphine infusion [P = .928], boluses of IV morphine [P = .82], acetaminophen [P = .34], ibuprofen [P = .15], naproxen [P = .10]). Only minor adverse events were recorded in both groups. Pain at the infusion site was more common in the MgSO4 group. IV MgSO4 was well tolerated but had no effect on the LOS in hospital, pain scores, or cumulative analgesia use in admitted children with a VOE.

Unphysiologically high magnesium concentrations support chondrocyte proliferation and redifferentiation.

Science.gov (United States)

Feyerabend, Frank; Witte, Frank; Kammal, Michael; Willumeit, Regine

2006-12-01

The effect of unphysiologically high extracellular magnesium concentrations on chondrocytes, induced by the supplementation of magnesium sulfate, was studied using a 3-phase tissue engineering model. The experiments showed that chondrocyte proliferation and redifferentiation, on the gene and protein expression level, are enhanced. A negative influence was found during chondrogenesis where an inhibition of extracellular matrix formation was observed. In addition, a direct impact on chondrocyte metabolism, elevated magnesium concentrations also affected growth factor effectiveness by consecutive influences during chondrogenesis. All observations were dosage dependent. The results of this study indicate that magnesium may be a useful tool for cartilage tissue engineering.

A Novel Injectable Magnesium/Calcium Sulfate Hemihydrate Composite Cement for Bone Regeneration

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Shanchuan Zhang

2015-01-01

Full Text Available Objective. A novel injectable magnesium/calcium sulfate hemihydrate (Mg/CSH composite with improved properties was reported here. Methods. Composition, setting time, injectability, compressive strength, and bioactivity in simulated body fluid (SBF of the Mg/CSH composite were evaluated. Furthermore, the cellular responses of canine bone marrow stromal cells (cBMSCs and bone formation capacity after the implantation of Mg/CSH in tibia defects of canine were investigated. Results. Mg/CSH possessed a prolonged setting time and markedly improved injectability and mechanical property p<0.05. Mg/CSH samples showed better degradability than CSH in SBF after 21 days of soaking p<0.05. Moreover, the degrees of cell attachment, proliferation, and capability of osteogenic differentiation on the Mg/CSH specimens were higher than those on CSH, without significant cytotoxicity and with the increased proliferation index, ALP activity, and expression levels of integrin β1 and Coll I in cBMSCs p<0.05. Mg/CSH enhanced the efficiency of new bone formation at the tibia defect area, including the significantly elevated bone mineral density, bone area fraction, and Coll I expression level p<0.05. Conclusions. The results implied that this new injectable bone scaffold exhibited promising prospects for bone repair and had a great potential in bone tissue engineering.

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

Science.gov (United States)

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.

Uso do sulfato de magnésio por via venosa e nebulização para o tratamento da asma aguda na emergência Use of the intravenous and nebulized magnesium sulfate for the treatment of the acute asthma in the emergence

Directory of Open Access Journals (Sweden)

Fabiano Timbó Barbosa

2007-09-01

Full Text Available JUSTIFICATIVA E OBJETIVOS: Tem sido mostrado que o sulfato de magnésio apresenta benefícios em adultos e crianças asmáticos, com fraca resposta aos agentes beta-agonistas e corticóides sistêmicos no departamento de emergência. O objetivo deste estudo foi realizar uma revisão não sistemática acerca do tratamento da asma aguda com sulfato de magnésio por via venosa e nebulização na emergência. CONTEÚDO: As primeiras investigações que demonstraram benefício no uso do sulfato de magnésio na asma são de 1938. Os efeitos do sulfato de magnésio podem ser mediados através da ação antagonista do cálcio ou através da função de co-fator em sistemas enzimáticos envolvendo o fluxo iônico através da membrana celular. Foi realizada uma revisão de literatura através da base de dados MedLine nos últimos seis anos (2000 a 2006 e incluídos os artigos publicados na língua inglesa, através do cruzamento dos unitermos asma e sulfato de magnésio. CONCLUSÕES: A administração de rotina do sulfato de magnésio por via venosa e nebulização em pacientes com asma aguda grave que se apresentam no serviço de emergência não é recomendado; entretanto, como um tratamento adjuvante obtém-se algum benefício.BACKGROUND AND OBJECTIVES: Magnesium sulfate has been shown to benefit asthmatic children and adults with poor responses to initial beta-agonist therapy and systemic corticoids in the emergency department. The aim of this study was to realize a no systematic review about the treatment of the acute asthma with intravenous and nebulized magnesium sulfate in the emergence. CONTENTS: The first investigations that demonstrate the benefit in the use of the magnesium sulfate in asthma date to 1938. The effects of magnesium sulfate may be mediated through its action as a calcium antagonist or through its function as a cofactor in enzyme systems involving ion flux across cell membranes. We realized a literature review using Med

Serum magnesium in the first week of life in extremely low birth weight infants.

LENUS (Irish Health Repository)

Noone, D

2012-01-01

Evidence that antenatal administration of magnesium sulfate (MgSO(4)) to women in preterm labor may confer fetal neuroprotection is growing. MgSO(4) crosses the placenta and can affect the neonate. Magnesium homeostasis in extremely low birth weight (ELBW) infants remains to be clarified.

AC impedance spectroscopy study of the corrosion behavior of an AZ91 magnesium alloy in 0.1 M sodium sulfate solution

International Nuclear Information System (INIS)

Chen, Jian; Wang, Jianqiu; Han, Enhou; Dong, Junhua; Ke, Wei

2007-01-01

The corrosion behavior of an AZ91 magnesium alloy in 0.1 M sodium sulfate solution at the corrosion potential (E corr ) was investigated using electrochemical impedance spectroscopy (EIS), environmental scanning electron microscopy (ESEM), energy dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). The results showed that when the immersion time was less than 18th, general corrosion occurred on the surface and the main corrosion products were hydroxides and sulfates. The film coverage effect was the main mechanism for the corrosion process of AZ91 alloy. At this stage, the matrix had a better corrosion resistance. With the increasing immersion time, pitting occurred on the surface. At this stage, the corrosion process was controlled by three surface state variables: the area fraction θ 1 of the region controlled by the formation of Mg(OH) 2 , the area fraction θ 2 of the region controlled by the precipitation of MgAl 2 (SO 4 ) 4 .2H 2 O, and the metastable Mg + concentration C m

Individual and combined effects of chloride, sulfate, and magnesium ions on hydrated Portland-cement paste

International Nuclear Information System (INIS)

Poole, T.S.; Wakeley, L.D.; Young, C.L.

1994-03-01

Ground water with a high concentration of magnesium ion is known to cause deterioration to portland cement concretes. A proposed mechanism for this deterioration process published previously involves an approximate 1:1 replacement of Ca ions by Mg ions in the crystalline phases of hydrated cement. The current study was undertaken to determine which ions, among magnesium, chloride, and sulfate, cause deterioration; whether their deleterious action is individual or interdependent; and to relate this mechanism of deterioration to the outlook for a 100-yr service life of concretes used in mass placements at the Waste Isolation Pilot Plant. Loss of Ca ion by cement pastes was found to be strongly related to the concentration of Mg ion in simulated ground-water solutions in which the paste samples were aged. This was true of both salt- containing and conventional cement pastes. No other ion in the solutions exerted a strong effect on Ca loss. Ca ion left first from calcium hydroxide in the pastes, depleting all calcium hydroxide by 60 days. Some calcium silicate hydrate remained even after 90 days in the solutions with the highest concentration of Mg ion, while the paste samples deteriorated noticeably. The results indicated a mechanism that involves dissolution of Ca phases and transport of Ca ions to the surface of the sample, followed by formation of Mg-bearing phases at this reaction surface rather than directly by substitution within the microstructure of hydrated cement. Given that calcium hydroxide and calcium silicate hydrate are the principal strength-giving phases of hydrated cement, this mechanism indicates the likelihood of significant loss of integrity of a concrete exposed to Mg-bearing ground water at the WIPP. The rate of deterioration ultimately will depend on Mg-ion concentration, the microstructure materials of the concrete exposed to that groundwater, and the availability of brine

Liquid-liquid phase separation in internally mixed magnesium sulfate/glutaric acid particles

Science.gov (United States)

Wu, Feng-Min; Wang, Xiao-Wei; Jing, Bo; Zhang, Yun-Hong; Ge, Mao-Fa

2018-04-01

The confocal Raman microscopy is utilized to investigate the liquid-liquid phase separation (LLPS) of mixed magnesium sulfate/glutaric acid (MgSO4/GA) droplets deposited on a hydrophobic polytetrafluoroethylene (PTFE) substrate and a hydrophilic quartz substrate. Raman spectra collected from different regions of the mixed droplets provide detailed information of component distributions for MgSO4 and GA. During the dehydration process, the MgSO4/GA mixed particles show the initial liquid-liquid phase separation between 85% and 80% relative humidity (RH) on both the hydrophobic and hydrophilic substrates. For the droplets deposited on the two substrates, the inner phase of droplets is dominated by aqueous MgSO4, which is surrounded by a rich GA organic layer due to the surface tension effects. In addition, the crystallization of GA could be observed in the organic aqueous phase while it is inhibited in the inner MgSO4 phase due to the effects of gel formation of MgSO4 at low RH. The Raman spectra reveal that with decreasing RH the morphology of the mixed droplet evolves from a uniform droplet to the structure of LLPS with the GA crystallizing in the outer layer and MgSO4 gel formed in the inner phase. These findings contribute to the further understanding of the role of interactions between inorganic salts and organic acids on the morphological evolution and environmental effects of atmospheric aerosols under ambient RH conditions.

Inhibitory effect of magnesium sulfate on reaction of lipid hyperoxidation after radiation-induced acute brain injuries

International Nuclear Information System (INIS)

Wang Lili; Zhou Juying; Yu Zhiying; Qin Songbing; Xu Xiaoting; Li Li; Tu Yu

2007-01-01

Objective: To explore the protection of magnesium sulfate (MgSO 4 ) on radiation-induced acute brain injuries. Methods: 60 maturity Sprague-Dawley (SD) rats were randomly divided into 3 groups: blank control group, experimental control group and experimental-therapeutic group. The whole brain of SD rats of experimental control group and experimental-therapeutic group was irradiated to a dose of 20 Gy using 6 MeV electron. MgSO 4 was injected intraperitoneally into the rats of experimental-therapeutic group before and after irradiation for five times. At different time points ranging from the 1 d, 7 d, 14 d, 30 d after irradiation, the brain tissue were taken. The xanthine oxidase and colorimetric examination were used to measure the superoxide dismutase (SOD) and malonyldialdehyde (MDA) respectively in the rat brain respectively. Results: Compared with blank control group, the SOD in brain of experimental control group decreased significantly (P 4 used in early stage can inhibit the lipid peroxidation after radiation-induced acute brain injuries and alleviate the damage induced by free radicals to brain tissue. (authors)

Magnesium sulfate versus esomeprazole impact on the neonates of preeclamptic rats.

Science.gov (United States)

Shafik, Amani N; Khattab, Mahmoud A; Osman, Ahmed H

2018-06-01

Preeclampsia represents a major complication of pregnancy, associated with greater maternal and fetal complications. We compared the effects of esomeprazole (a proton pump inhibitor) and magnesium sulfate (MgSO4) on the deleterious effects observed on the mother and neonates in experimentally induced preeclampsia in rats. Preeclampsia was induced in pregnant rats with NG-nitro-l-arginine methyl ester (L-NAME) starting from day 10-till end of pregnancy. Pregnant rats were divided into four groups: control pregnant; untreated preeclampsia; preeclamptic rats treated with MgSO4 and preeclamptic treated with esomeprazole. Treatment was started on day 14 and continued until end of pregnancy. Systolic blood pressure, gestation duration, the total number of pups/fetal resorption, pups birth weight, and histopathology examination of the pup's organs were recorded. In comparison with the L-NAME group, the MgSO4 and esomeprazole treatment reduced the values of systolic blood pressure; MgSO4 normalized gestational duration while esomeprazole prolonged it (post-term pregnancy); both restored number of delivered pups; with no statistical differences between the numbers of died pups between the four groups studied while with esomeprazole, out of 10 pregnant females, 2 of them had complete intrauterine fetal resorption; esomeprazole normalized birth weight and histological structure of fetal liver, kidney, and brain. On the other side, MgSO4 treatment gave rise to lower than normal birth weight and minimal tissue damage. Esomeprazole and MgSO4 improved systolic blood pressure, prevented preterm labor and restored numbers of pups delivered and fetal weight. Esomeprazole prolonged gestational period post-term with subsequent improving reproductive outcome. Copyright © 2018 Elsevier B.V. All rights reserved.

Effects of Short-term Feeding Magnesium before Slaughter on Blood Metabolites and Postmortem Muscle Traits of Halothane-carrier Pigs

Directory of Open Access Journals (Sweden)

Jing Chen

2013-06-01

Full Text Available Fifty-four, mixed-sex, halothane-carrier crossbred (Yorkshire×Landrace pigs with an average initial BW of 108.2±0.8 kg were randomly allotted to one of three dietary treatments for 5 d before slaughter: i a control corn-soybean meal finisher diet devoid of supplemental magnesium; ii a diet supplemented with 1.5 g/kg of elemental Mg from magnesium acetate; and iii a diet supplemented with 1.5 g/kg of elemental Mg from magnesium sulfate heptahydrate. Serum creatine kinase (CK, lactate and glucose were analyzed at slaughter. Muscles from longissimus (LM were packaged and stored to simulate display storage for muscle lactate and glycogen determinations at 0, 1, 2, 3, and 4 d. Mg supplementation reduced (p0.05 on serum glucose. Daily change of muscle lactate concentration linearly increased (p<0.01, while glucose concentration linearly decreased (p<0.05 as storage time increased in all treatments. However, dietary Mg acetate and Mg sulfate supplementation in pigs elevated (p<0.05 muscle glycogen and reduced (p<0.05 muscle lactate concentrations, especially during the first 2 d of display, compared with pigs fed the control diet. This study suggests that short-term feeding of magnesium acetate and magnesium sulfate to heterozygous carriers of the halothane gene has beneficial effects on stress response and pork quality by improving blood and muscle biochemical indexes.

The confused world of sulfate attack on concrete

International Nuclear Information System (INIS)

Neville, Adam

2004-01-01

External sulfate attack is not completely understood. Part I identifies the issues involved, pointing out disagreements, and distinguishes between the mere occurrence of chemical reactions of sulfates with hydrated cement paste and the damage or deterioration of concrete; only the latter are taken to represent sulfate attack. Furthermore, sulfate attack is defined as deleterious action involving sulfate ions; if the reaction is physical, then, it is physical sulfate attack that takes place. The discussion of the two forms of sulfate attack leads to a recommendation for distinct nomenclature. Sulfate attack on concrete structures in service is not widespread, and the amount of laboratory-based research seems to be disproportionately large. The mechanisms of attack by different sulfates--sodium, calcium, and magnesium--are discussed, including the issue of topochemical and through-solution reactions. The specific aspects of the action of magnesium sulfate are discussed, and the differences between laboratory conditions and field exposure are pointed out. Part II discusses the progress of sulfate attack and its manifestations. This is followed by a discussion of making sulfate-resisting concrete. One of the measures is to use Type V cement, and this topic is extensively discussed. Likewise, the influence of w/c on sulfate resistance is considered. The two parameters are not independent of one another. Moreover, the cation in the sulfate salt has a strong bearing on the efficiency of the Type V cement. Recent interpretations of the Bureau of Reclamation tests, both long term and accelerated, are evaluated, and it appears that they need reworking. Part III reviews the standards and guides for the classification of the severity of exposure of structures to sulfates and points out the lack of calibration of the various classes of exposure. A particular problem is the classification of soils because much depends on the extraction ratio of sulfate in the soil: there is a

Evaluation of sulfate resistance of cement mortars containing black rice husk ash.

Science.gov (United States)

Chatveera, B; Lertwattanaruk, P

2009-03-01

In this paper, black rice husk ashes (BRHAs), which are agrowastes from an electricity generating power plant and a rice mill, were ground and used as a partial cement replacement. The durability of mortars under sulfate attack including expansion and compressive strength loss were investigated. For parametric study, BRHA were used as a Portland cement Type 1 replacement at the levels of 0%, 10%, 30%, and 50% by weight of binder. The water-to-binder ratios were 0.55 and 0.65. For the durability of mortar exposed to sulfate attack, 5% sodium sulfate (Na2SO4) and magnesium sulfate (MgSO4) solutions were used. As a result, when increasing the percentage replacement of BRHA, the expansion and compressive strength loss of mortar decreased. At the replacement levels of 30% and 50% of BRHA, the expansion of the mortars was less than those mixed with sulfate-resistant cement. However, the expansion of the mortars exposed to Na2SO4 was more than those exposed to MgSO4. Increasing the replacement level of BRHA tends to reduce the compressive strength loss of mortars exposed to Na2SO4 attack. In contrary, under MgSO4 attack, when increasing the replacement level of BRHA, the compressive strength loss increases from 0% to 50% in comparison to Portland cement mortar. Results show that ground BRHA can be applied as a pozzolanic material to concrete and also improve resistance to sodium sulfate attack, but it can impair resistance to magnesium sulfate attack.

[Magnesium sulphate in the treatment of ischemic-hypoxic neonatal encephalopathy].

Science.gov (United States)

Kornacka, M K

2001-01-01

Hypoxic-ischaemic encephalopathy (HIE) remains one of the most important neurological complications in full and near full term newborns. During HIE glutamate and other excitatory neurotransmitters are released and progressive energy failure in brain is observed. Toxicity of glutamate plays the main role in brain injury. Glutamate activates the specific receptors that, in turn, mediate an overwhelming influx of calcium into the postsynaptic neuron. The pathological changes are located particularly in hippocampus. Magnesium sulfate has been used safely for years to treat preclampsia. The animal experimental evidence support a neuroprotective role for magnesium in HIE.

Role of Magnesium Sulfate in Prolonging the Analgesic Effect of ...

African Journals Online (AJOL)

antinociceptive effect in animal and human pain models. i.v magnesium ... about 30 min prior to surgery followed by continuous infusion at the rate of 10 mg/kg/h for the next 24 h while the other group received similar ... of analgesia and reduces postoperative analgesic consumption without any significant side effects.

Protection and repair of post-thrombolytic brain tissue with high-dose human albumin and magnesium sulfate: an experimental study

International Nuclear Information System (INIS)

Li Yongdong; Zhao Jungong; Li Minghua; You Xiaofang; Chen Yingsheng

2008-01-01

Objective: To evaluate the neuroprotective effects of high-dose human albumin and magnesium sulfate combined with recombinant tissue plasminogen activator (rt-PA) thrombolysis in a SD rat model of embolic stroke, with the aim to explore the possibility of extention for thrombolytic window. Methods: A thromboembolic stroke model performed on male SD rats (n=40) was randomly assigned into four groups: group A (n=10): rats received an intravenous infusion of 10 mg/kg rt-PA over a period of one hour at 3 h after onset of MCAO; group B (n=10): rats received an intravenous infusion of 10 mg/kg rt-PA over a period of one hour at 6 h after onset of MCAO; group C(n=10): rats received an intravenous infusion of human albumin (2.5 g/kg) and rt-PA(10 mg/kg) at 3 h and 6 h after onset of MCAO; group D(n=10): rats received same dose human albumin and rt-PA as that in group C, in addition, magnesium salfate (500 mg/ kg) was given intraperitoneally 3 h and 18 h after onset of MCAO. MRI was performed in each animal at preischemia, 24 h, 7 d and 14 d after treatment. After the last MR examination, all animals were killed under anesthesia, pathologic study (including electron microscope, light microscope, immuno-histochemistry) was performed in each animal, and LSCM were performed in two animals of each group. Results: The infarct volumes in four groups at 14 d after thrombolysis reduced 5.07% , 2.58%, 10.18% and 35.40% respectively compared with the infarct volume at 3 h after MCAO, with a predominant reduction in group D (P<0.05); increase of rCBV was confirmed at the marginal area of the cerebral infarction from the onset of stroke to 14 d, with significant increase between group A and C from 1 d to 7 d (P<0.05), while no significant difference was found in group B and C. The longest survival exhibited in group D and the shortest in group B, and no significant difference occurred concerning about survival among the four groups (P=0.763, P=0.636). In addition, LSCM showed a slight

Ultrasound-assisted leaching of rare earths from the weathered crust elution-deposited ore using magnesium sulfate without ammonia-nitrogen pollution.

Science.gov (United States)

Yin, Shaohua; Pei, Jiannan; Jiang, Feng; Li, Shiwei; Peng, Jinhui; Zhang, Libo; Ju, Shaohua; Srinivasakannan, Chandrasekar

2018-03-01

The in situ leaching process of China's unique ion-adsorption rare earth ores has caused severe environmental damages due to the use of (NH 4 ) 2 SO 4 solution. This study reports that magnesium sulfate (MgSO 4 ) as a leaching agent would replace (NH 4 ) 2 SO 4 by ultrasonically assisted leaching to deal with the ammonia-nitrogen pollution problem and enhance leaching process. At leaching conditions of 3wt% MgSO 4 concentration, 3:1L/S ratio and 30min, the total rare earth leaching efficiency reaches 75.5%. Ultrasound-assisted leaching experiments show that the leaching efficiency of rare earths is substantially increased by introducing ultrasound, and nearly completely leached out after two stage leaching process. Thus, ultrasonic-assisted leaching process with MgSO 4 is not only effective but also environmentally friendly, and beneficial to leach rare earths at laboratory scale. Copyright © 2017 Elsevier B.V. All rights reserved.

Antenatal magnesium sulfate and spontaneous intestinal perforation in infants less than 25 weeks gestation.

Science.gov (United States)

Rattray, B N; Kraus, D M; Drinker, L R; Goldberg, R N; Tanaka, D T; Cotten, C M

2014-11-01

Evaluate spontaneous intestinal perforation (SIP)/death among extremely low birthweight (ELBW) infants before, during and after initiation of an antenatal magnesium for neuroprotection protocol (MgPro). We tested associations between SIP/death and magnesium exposure, gestational age (GA) and interactions with GA and magnesium exposure in a cohort of inborn ELBW infants before, during and after MgPro. One hundred and fifty-five ELBW infants were included, 81 before, 23 during and 51 after MgPro. ELBW infants (78.3%) were exposed to Mg during MgPro compared with 50.6% and 60.8% before and after, respectively. Incidence of SIP on protocol was 30.4% vs 12.9% off protocol (P=0.03). GA was strongly associated with SIP (PSIP/death regardless of epoch (odds ratio 9.3 (1.04-104.6)), but increased SIP/death was limited to those SIP and death risk among infants with the lowest birthweights. Validation of this observation in larger populations is warranted.

Effect of magnesium sulfate and thyroxine on inflammatory markers in a rat model of hypothyroidism.

Science.gov (United States)

Abbas, Amr M; Sakr, Hussein F

2016-04-01

Inflammation is a major risk factor for cardiovascular complications. Magnesium sulfate (MgSO4) has anti-inflammatory actions. Therefore we investigated the effects of levothyroxine and MgSO4 on inflammatory markers as C-reactive protein (CRP), interleukin-6, tumor necrosis factor-α (TNF-α), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) in hypothyroid rats. Sixty male rats were divided into 6 groups; normal, normal + MgSO4, hypothyroidism, hypothyroidism + levothyroxine, hypothyroidism + MgSO4, and hypothyroidism + levothyroxine + MgSO4. Thyroxine, triiodothyronine, and thyroid-stimulating hormone (TSH), CRP, interleukin-6, TNF-α, ICAM-1, and VCAM-1 were measured in all rats. Hypothyroidism significantly increased TSH, CRP, interleukin-6, TNF-α, ICAM-1, and VCAM-1 and decreased triiodothronine and thyroxine. Treatment of hypothyroid rats with levothyroxine or MgSO4 significantly decreased CRP, interleukin-6, TNF-α, ICAM-1, and VCAM-1. Combined therapy of hypothyroid rats with levothyroxine and MgSO4 significantly decreased CRP, interleukin-6, TNF-α, ICAM-1, and VCAM-1 compared with hypothyroid rats either untreated or treated with levothyroxine or MgSO4. This study demonstrates that hypothyroid rats have chronic low grade inflammation, which may account for increased risk of cardiovascular diseases. Combined levothyroxine and MgSO4 is better than levothyroxine or MgSO4 alone in alleviating the chronic low grade inflammatory status and therefore reducing the risk of cardiovascular diseases in hypothyroid animals.

Effect of phospholipase A treatment of low density lipoproteins on the dextran sulfate--lipoprotein interaction.

Science.gov (United States)

Nishida, T

1968-09-01

The effect of phospholipase A on the interaction of low density lipoproteins of the S(f) 0-10 class with dextran sulfate was studied in phosphate buffer of pH 7.4, ionic strength 0.1, by chemical, spectrophotometric, and centrifugal methods. When low density lipoproteins that had been treated with phospholipase A were substituted for untreated lipoproteins, the amount of insoluble dextran sulfate-lipoprotein complex formed was greatly reduced. Hydrolysis of over 20% of the lecithin and phosphatidyl ethanolamine constituents of the lipoproteins prevented the formation of insoluble complex. However, even the lipoproteins in which almost all the phosphoglycerides were hydrolyzed produced soluble complex, which was converted to insoluble complex upon addition of magnesium sulfate. It is apparent that the lipoproteins altered extensively by treatment with phospholipase A retain many characteristic properties of native low density lipoproteins. Fatty acids, but not lysolecithin, released by the action of phospholipase A interfered with the formation of insoluble complex; this interference was due to association of the fatty acids with the lipoproteins. With increases in the concentration of the associated fatty acids, the amounts of magnesium ion required for the conversion of soluble complex to insoluble complex increased progressively. Charge interaction is evidently of paramount importance in the formation of sulfated polysaccharide-lipoprotein complexes.

Influence of magnesium sulfate on HCO3/Cl transmembrane exchange rate in human erythrocytes.

Science.gov (United States)

Chernyshova, Ekaterina S; Zaikina, Yulia S; Tsvetovskaya, Galina A; Strokotov, Dmitry I; Yurkin, Maxim A; Serebrennikova, Elena S; Volkov, Leonid; Maltsev, Valeri P; Chernyshev, Andrei V

2016-03-21

Magnesium sulfate (MgSO4) is widely used in medicine but molecular mechanisms of its protection through influence on erythrocytes are not fully understood and are considerably controversial. Using scanning flow cytometry, in this work for the first time we observed experimentally (both in situ and in vitro) a significant increase of HCO3(-)/Cl(-) transmembrane exchange rate of human erythrocytes in the presence of MgSO4 in blood. For a quantitative analysis of the obtained experimental data, we introduced and verified a molecular kinetic model, which describes activation of major anion exchanger Band 3 (or AE1) by its complexation with free intracellular Mg(2+) (taking into account Mg(2+) membrane transport and intracellular buffering). Fitting the model to our in vitro experimental data, we observed a good correspondence between theoretical and experimental kinetic curves that allowed us to evaluate the model parameters and to estimate for the first time the association constant of Mg(2+) with Band 3 as KB~0.07mM, which is in agreement with known values of the apparent Mg(2+) dissociation constant (from 0.01 to 0.1mM) that reflects experiments on enrichment of Mg(2+) at the inner erythrocyte membrane (Gunther, 2007). Results of this work partly clarify the molecular mechanisms of MgSO4 action in human erythrocytes. The method developed allows one to estimate quantitatively a perspective of MgSO4 treatment for a patient. It should be particularly helpful in prenatal medicine for early detection of pathologies associated with the risk of fetal hypoxia. Copyright © 2016 Elsevier Ltd. All rights reserved.

Calcium and magnesium silicate hydrates

International Nuclear Information System (INIS)

Lothenbach, B.; L'Hopital, E.; Nied, D.; Achiedo, G.; Dauzeres, A.

2015-01-01

Deep geological disposals are planed to discard long-lived intermediate-level and high-level radioactive wastes. Clay-based geological barriers are expected to limit the ingress of groundwater and to reduce the mobility of radioelements. In the interaction zone between the cement and the clay based material alteration can occur. Magnesium silicate hydrates (M-S-H) have been observed due to the reaction of magnesium sulfate containing groundwater with cements or in the interaction zone between low-pH type cement and clays. M-S-H samples synthesized in the laboratory showed that M-S-H has a variable composition within 0.7 ≤ Mg/Si ≤ 1.5. TEM/EDS analyses show an homogeneous gel with no defined structure. IR and 29 Si NMR data reveal a higher polymerization degree of the silica network in M-S-H compared to calcium silicate hydrates (C-S-H). The presence of mainly Q 3 silicate tetrahedrons in M-S-H indicates a sheet like or a triple-chain silica structure while C-S-H is characterised by single chain-structure. The clear difference in the silica structure and the larger ionic radius of Ca 2+ (1.1 Angstrom) compared to Mg 2+ (0.8 Angstrom) make the formation of an extended solid solution between M-S-H and C-S-H gel improbable. In fact, the analyses of synthetic samples containing both magnesium and calcium in various ratios indicate the formation of separate M-S-H and C-S-H gels with no or very little uptake of magnesium in CS-H or calcium in M-S-H

Magnesium, magnesium alloys, and magnesium composites

National Research Council Canada - National Science Library

Gupta, M; Sharon, Nai Mui Ling

2011-01-01

"Properties of Magnesium Composites for Material Scientists, Engineers and Selectors is the first book-length reference to provide an insight into current and future magnesium-based materials in terms...

Magnesium sulfate as an oral contrast medium in magnetic resonance imaging of the small intestine.

Science.gov (United States)

Shi, Hao; Liu, Cun; Ding, Hong Yu; Li, Chun Wei

2012-03-01

To explore the use of magnesium sulfate (MgSO4) as an oral contrast medium (CM) in MRI of the small intestine. By comparing MgSO4 SNRs at different concentrations, we determined that 2.5% MgSO4 is the ideal concentration for small bowel MRI. Twenty volunteers underwent MRI after drinking 2.5% MgSO4. Thirty-one patients with clinical suspicion of small intestinal pathology underwent both MRI and the air-barium contrast examination. The patient's tolerance, side effects and complications were noted. 2.5% MgSO4 can decrease the absorption of water and fully fill the enteric cavity, thereby increasing the contrast between the intestinal wall and lumen and facilitating radiographic examination of the small bowel. The mean diameter of the small intestine was 19.8±1.21 mm in the 20 volunteers consuming 2.5% MgSO4 and 12.7±0.84 mm in the 20 volunteers given water. There was a significant difference (P0.05) in side effects between MgSO4 and water groups. Small intestinal MRI was successfully performed in all 31 patients, who were also examined by the double contrast barium, which gave almost identical diagnoses to MRI in all cases except for 1 patient with small intestinal hemorrhage. MRI with 2.5% MgSO4 can demonstrate intestinal abnormalities. Therefore, 2.5% MgSO4 solution is an ideal oral CM for small bowel MRI. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Interactions between bicarbonate, potassium, and magnesium, and sulfur-dependent induction of luminescence in Vibrio fischeri.

Science.gov (United States)

Tabei, Yosuke; Era, Mariko; Ogawa, Akane; Morita, Hiroshi

2012-06-01

In spite of its central importance in research efforts, the relationship between seawater compounds and bacterial luminescence has not previously been investigated in detail. Thus, in this study, we investigated the effect of cations (Na(+) , K(+) , NH(4) (+) , Mg(2+) , and Ca(2+) ) and anions (Cl(-) , HCO(3) (-) , CO(3) (2-) , and NO(3) (-) ) on the induction of both inorganic (sulfate, sulfite, and thiosulfate) and organic (L-cysteine and L-cystine) sulfur-dependent luminescence in Vibrio fischeri. We found that HCO(3) (-) (bicarbonate) and CO(3) (2-) (carbonate), in the form of various compounds, had a stimulatory effect on sulfur-dependent luminescence. The luminescence induced by bicarbonate was further promoted by the addition of magnesium. Potassium also increased sulfur-dependent luminescence when sulfate or thiosulfate was supplied as the sole sulfur source, but not when sulfite, L-cysteine, or L-cystine was supplied. The positive effect of potassium was accelerated by the addition of magnesium and/or calcium. Furthermore, the additional supply of magnesium improved the induction of sulfite- or L-cysteine-dependent luminescence, but not the l-cystine-dependent type. These results suggest that sulfur-dependent luminescence of V. fischeri under nutrient-starved conditions is mainly controlled by bicarbonate, carbonate, and potassium. In addition, our results indicate that an additional supply of magnesium is effective for increasing V. fischeri luminescence. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The effect of magnesium sulfate concentration on the effective concentration of rocuronium, and sugammadex-mediated reversal, in isolated left phrenic nerve hemi-diaphragm preparations from the rat.

Science.gov (United States)

Cho, Choon-Kyu; Sung, Tae-Yun; Choi, Seok-Jun; Choi, Hey-Ran; Kim, Yong Beom; Lee, Jung-Un; Yang, Hong-Seuk

2018-05-30

Perioperative magnesium sulfate (MgSO4) is used for analgesic, anti-arrhythmic, and obstetric purposes. The effects of MgSO4 on the neuromuscular blockade (NMB) induced by rocuronium, and the sugammadex reversal thereof, have not been clearly quantified. We investigated the effect increase concentrations of MgSO4 on the NMB by rocuronium, and sugammadex reversal, in isolated left phrenic nerve hemi-diaphragm (PNHD) preparations from the rat. Rat PNHD preparations were randomly allocated to one of four groups varying in terms of MgSO4 concentration (1, 2, 3, and 4 mM, each n = 10, in Krebs solution). The train-of-four (TOF) and twitch height responses were recorded mechanomyographically. The preparations were treated with incrementally increasing doses of rocuronium and each group's effective concentration (EC)50, EC90, and EC95 of rocuronium were calculated via nonlinear regression. Then, sugammadex was administered in doses equimolar to rocuronium. The recovery index, time to T1 height >95% of control, and the time to a TOF ratio (TOFR) >0.9 after sugammadex administration were measured. The EC50, EC90, and EC95 of rocuronium fell significantly as the magnesium level increased. The EC50, EC90, and EC95 of rocuronium did not differ between the 3 and 4 mM groups. The recovery index, time to T1 height >95% of control, and time to a TOFR >0.9 after sugammadex administration did not differ among the four groups. Increases in the magnesium concentration in rat PNHD preparations proportionally enhanced the NMB induced by rocuronium but did not affect reversal by equimolar amounts of sugammadex.

Magnesium sulfate in femoral nerve block, does postoperative analgesia differ? A comparative study

Directory of Open Access Journals (Sweden)

Hossam A. ELShamaa

2014-04-01

Conclusion: The current study concluded that the admixture of magnesium to bupivacaine provides a profound prolongation of the femoral nerve block, in addition to a significant decrease in postoperative pain scores and total dose of rescue analgesia, with a longer bearable pain periods in the first postoperative day.

Oxide films on magnesium and magnesium alloys

International Nuclear Information System (INIS)

Shih, T.-S.; Liu, J.-B.; Wei, P.-S.

2007-01-01

Magnesium alloys are very active and readily ignite during heating and melting. In this study, we discuss the combustion of magnesium and magnesium alloys and propose prospective anti-ignition mechanisms for magnesium alloys during the heating process. When magnesium and magnesium alloys were heated in air, the sample surfaces produced layers of thermally formed oxides. These thermally formed oxides played an important role in affecting the combustion of the magnesium and magnesium alloys. When magnesium was heated in air, brucite that formed in the early stage was then transformed into periclase by dehydroxylation. By extending the heating time, more periclase formed and increased in thickness which was associated with microcracks formation. When magnesium was heated in a protective atmosphere (SF 6 ), a film of MgF 2 formed at the interface between the oxide layer and the Mg substrate. This film generated an anti-ignition behavior which protected the substrate from oxidation. When solution-treated AZ80 alloy was heated, spinel developed at the interface between the thermally formed oxide layer and the Mg substrate, improving the anti-ignition properties of the substrate. In addition, we also explain the effects of beryllium in an AZB91 alloy on the ignition-proofing behavior

Adding magnesium to lidocaine for intravenous regional anesthesia

Directory of Open Access Journals (Sweden)

Parviz Kashefi

2008-06-01

Full Text Available

• BACKGROUND: Magnesium (Mg has been used as an adjuvant medication in postoperative analgesia. We planed this study to assess the effects of Mg, when added to lidocaine in intravenous regional anesthesia (IVRA on the tourniquet pain.
• METHODS: Forty patients undertaking hand surgery were randomly allocated into 2 groups to be given IVRA. They received 20 ml lidocaine 1% diluted with 20 ml saline to a total of 40 ml in the group L (n = 20 or 7.5 ml magnesium sulfate 20% plus 20 ml lidocaine 1% diluted with 12.5 ml saline to a total of 40 ml in the group M (n = 20. Sensory and motor block onset and recovery times, anesthesia and operation qualities were recorded. Before and after the tourniquet use at 5, 10, 15, 20, 30, 40, and 50 minutes, hemodynamic variables, tourniquet pain, and analgesic use were noted. Subsequent to the tourniquet deflation, at 6, 12, and 24 hours, hemodynamic variables, pain, time to first analgesic requirement, analgesic use and side effects were recorded.
• RESULTS: Shortened sensory and motor block onset times were established in group M (P < 0.05. Visual analog scale (VAS scores were less in group M at 20, 30, 40, and 50 minutes after tourniquet inflation (P < 0.05. Intraoperative, analgesic requirement was less in group M (P < 0.05. Anesthesia excellence, as determined by the anesthesiologist and surgeon, was significantly better in group M (P < 0.05. Time to the first analgesic requirement in group M was 53.75 ± 6.94 minutes and in group L was 40.76 ± 14.55 minutes (P < 0.05. Postoperative VAS scores were higher at 6, 12, and 24 hours in group L (P < 0.05.
• CONCLUSIONS: Adding Mg to lidocaine for IVRA enhanced the quality of anesthesia and analgesia without causing side effects.
• KEYWORDS: Magnesium sulfate, intravenous regional anesthesia, postoperative pain.

Surface Corrosion and Microstructure Degradation of Calcium Sulfoaluminate Cement Subjected to Wet-Dry Cycles in Sulfate Solution

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Wuman Zhang

2017-01-01

Full Text Available The hydration products of calcium sulfoaluminate (CSA cement are different from those of Portland cement. The degradation of CSA cement subjected to wet-dry cycles in sulfate solution was studied in this paper. The surface corrosion was recorded and the microstructures were examined by scanning electron microscopy (SEM. The results show that SO42-, Na+, Mg2+, and Cl− have an effect on the stability of ettringite. In the initial period of sulfate attack, salt crystallization is the main factor leading to the degradation of CSA cement specimens. The decomposition and the carbonation of ettringite will cause long-term degradation of CSA cement specimens under wet-dry cycles in sulfate solution. The surface spalling and microstructure degradation increase significantly with the increase of wet-dry cycles, sulfate concentration, and water to cement ratio. Magnesium sulfate and sodium chloride reduce the degradation when the concentration of sulfate ions is a constant value.

Surface modification of magnesium hydroxide sulfate hydrate whiskers using a silane coupling agent by dry process

International Nuclear Information System (INIS)

Zhu, Donghai; Nai, Xueying; Lan, Shengjie; Bian, Shaoju; Liu, Xin; Li, Wu

2016-01-01

Highlights: • Dry process was adopted to modify the surface of MHSH whiskers using silane. • Si−O−Mg bonds were formed directly by the reaction between Si−OC 2 H 5 and −OH of MHSH. • Dispersibility and compatibility of modified whiskers greatly improved in organic phase. • Thermal stability of whiskers was enhanced after modified. - Abstract: In order to improve the compatibility of magnesium hydroxide sulfate hydrate (MHSH) whiskers with polymers, the surface of MHSH whiskers was modified using vinyltriethoxysilane (VTES) by dry process. The possible mechanism of the surface modification and the interfacial interactions between MHSH whiskers and VTES, as well as the effect of surface modification, were studied. Scanning electronic microscopy (SEM), transmission electron microscopy (TEM) and X-ray powder diffraction (XRD) analyses showed that the agglomerations were effectively separated and a thin layer was formed on the surface of the whiskers after modification. Fourier transform infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS) analyses showed that the VTES molecules were bound to the surface of MHSH whiskers after modification. Chemical bonds (Si−O−Mg) were formed by the reaction between Si−OC 2 H 5 or Si−OH and the hydroxyl group of MHSH whiskers. The effect of surface modification was evaluated by sedimentation tests, contact angle measurements and thermogravimetric analysis (TGA). The results showed that the surface of MHSH whiskers was transformed from hydrophilic to hydrophobic, and the dispersibility and the compatibility of MHSH whiskers were significantly improved in the organic phase. Additionally, the thermal stability of the VTES-modified MHSH whiskers was improved significantly.

Ketamine versus Ketamine / magnesium Sulfate for Procedural Sedation and Analgesia in the Emergency Department: A Randomized Clinical Trial.

Science.gov (United States)

Azizkhani, Reza; Bahadori, Azadeh; Shariati, Mohammadreza; Golshani, Keyhan; Ahmadi, Omid; Masoumi, Babak

2018-01-01

The present study was designed to evaluate the effectiveness of magnesium sulfate (MgSO 4 ) in procedural sedation and analgesia (PSA) when combined with ketamine in patients with fractures in emergency departments and required short and painful emergency procedures. In this study, 100 patients with fractures and dislocations who were presented to the emergency departments and required PSA for short and painful emergency procedures were randomly allocated to groups of ketamine plus MgSO 4 or ketamine alone. Train of four (TOF) stimulation pattern was assessed using nerve stimulator machine and compared between groups. The mean age of studied patients was 46.9 ± 9.3 years old. 48% were male and 52% were female. No significant differences were noted between groups in demographic variables. The status of TOF, 2 min after the injection of ketamine (1.5 mg/kg), in both groups was similar. After the injection of the second dose of ketamine (1 mg/kg) the status of TOF in four patients in ketamine plus MgSO 4 (0.45 mg/kg) group changed, it was three quarters but in ketamine group, the status of TOF in all patients was four quarters. The difference between groups was not statistically significant ( P = 0.12). The findings revealed that for muscle relaxation during medical procedures in the emergency department, ketamine in combination with MgSO 4 with this dose was not effective for muscle relaxation during procedures.

Magnesium Gluconate

Science.gov (United States)

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

Corrosion and hydrogen permeation of A216 Grade WCA steel in hydrothermal magnesium-containing brines

International Nuclear Information System (INIS)

Haberman, J.H.; Frydrych, D.J.; Westerman, R.E.

1988-03-01

Corrosion rates determined at 1 month in 150/degree/C brine increased with magnesium concentration. The structure of the corrosion product, as determined by x-ray diffraction, depended upon the magnesium concentration. In brines with less than 10,000 ppM magnesium, the primary corrosion product had a spinel structure characteristic of magnetite or magnesioferrite. In brines containing magnesium concentrations greater than 20,000 ppM, the primary corrosion product had the amakinite structure characteristic of a complex iron-magnesium hydroxide. The high corrosion rates observed in brines containing high magnesium concentrations suggest that the corrosion products having the amakinite structure is less protective than corrosion products having the spinel structure. Corrosion rates in high-magnesium (inclusion) brine determined over a 6-month test duration were essentially constant. Hydrogen permeation rates observed in exposing mild steel to high-Mg/sup 2/plus// brine at 150/degree/C could be potentially damaging to a mild steel waste package container. The rate of hydrogen permeation was proportional to the brine flow rate in the autoclave. Thiourea additions to the brine increased the hydrogen permeation rate; sulfate and bromide ion additions did not. The maximum gaseous hydrogen pressure attainable is not known (based on 3Fe /plus/ 4H 2 O /plus/ Fe(sub 3)O /plus/ 4H 2 , would be /approximately/900 atmospheres), and the dependence of permeation rate on temperature is not known. 8 refs., 13 figs., 3 tabs

Production of magnesium metal

Science.gov (United States)

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

2010-02-23

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

Decontamination of acid mine water from Ronneburg/Thueringen which is high in sulfates and metals using sulfate-reducing bacteria. Final report of the preliminary phase

International Nuclear Information System (INIS)

Hard, B.; Friedrich, S.

1995-01-01

The mining in Eastern Europe, particularly in East-Germany, is a major source of pollution to the surrounding areas of the mines. With the end of the cold war the demand for uranium has drastically declined. Many of the pits have therefore been closed down or are in the process of closure such as the uranium mine in Ronneburg in Thueringen. One major problem is the safe-making of the pits and dumps as they are highly radioactive through naturally occurring uranium and other radioactive elements. Because of the leaching process through bacteria, drainage water is very acidic, with pH-values between 1-2. The water is very rich in magnesium, iron and aluminium sulfate. Here the application of a microbial process to decontaminate acid mine drainage was investigated. Decontamination of the water includes: - Increase in pH - decrease in sulfate concentrations - minimization of the metal and radionuclide load. Sulfate-reducing bacteria seem suitable for this process. In order for such a microbial process to be economically viable a cheap and widely available electron donar has to be used eg. methanol. The work carried out reports on the isolation, characterization and physiology of sulfate-reducing methylotrophic bacteria and their suitability for a decontamination process of sulfuric acid uranium mine water. (orig.) [de

Isotopic Zonation Within Sulfate Evaporite Mineral Crystals Reveal Quantitative Paleoenvironment Details

Science.gov (United States)

Coleman, M.; Rhorssen, M.; Mielke, R. E.

2008-12-01

Isotopic variations measured within a single crystal of hydrated magnesium sulfate are greater than 30 permil for delta 2-H, almost 10 permil for δ18O in water of hydration; and greater than 3 permil in sulfate oxygen. These results are interpreted to indicate the relative humidity of the system during evaporation (15 to 20 percent in this test case) and constrain the volume of water involved. The theoretical basis of this system is the isotopic fractionation between the species in solution and those precipitated as evaporite salts. Precipitation preferentially accumulates more of the heavy isotopes of sulfur and oxygen in mineral sulfate, relative to sulfate in solution. During the course of mineral growth this leads to successive depletion of the respective heavier isotopes in the residual brine reflected in a parallel trend in successive precipitates or even in successive zones within a single crystal. The change in isotopic composition at any one time during the process, relative to the initial value, can be described by an isotopic version of the Rayleigh Fractionation equation, depending only on the extent of the completion of the process and the relevant fractionation factor. Evaporation preferentially removes isotopically lighter hydrogen and oxygen leading to successive extents of enrichment in the respective heavier isotopes in the residual water. However, the relative effects on hydrogen and oxygen isotopes differs as function of relative humidity [1]. ALL OF THESE CHANGES ARE PRESERVED IN THE MINERAL ISOTOPE COMPOSITIONS. We precipitated barium sulfate from epsomite or gypsum samples, which was reduced at 1450°C in the presence of graphite and glassy carbon in a Finnigan TC/EA to produce CO for O isotopic analysis in a Finnigan 253 mass spectrometer, while a separate subsample was oxidized to SO2 in a Costech Elemental Analyzer. However, to make progress with this approach we needed to make a large number of measurements of hydration water and so we

Recorrência da Crise Convulsiva após Terapia Anticonvulsivante com Sulfato de Magnésio em Pacientes com Eclâmpsia Recurrence of Seizures after Anticonvulsant Therapy with Magnesium Sulfate in Patients with Eclampsia

Directory of Open Access Journals (Sweden)

Melania Maria Ramos de Amorim

2000-04-01

Full Text Available Objetivos: determinar a freqüência de recorrência das crises convulsivas após tratamento com sulfato de magnésio, avaliando o tratamento adotado e o prognóstico materno. Casuística e Métodos: analisaram-se todos os casos de eclâmpsia atendidos no IMIP entre janeiro de 1995 e junho de 1998. Sulfato de magnésio e oxigenoterapia foram administrados para todas as pacientes, interrompendo-se a gravidez após estabilização do quadro clínico. Determinou-se a freqüência de complicações maternas de acordo com a presença ou não de recorrência da crise convulsiva, utilizando-se o teste chi² de associação, a um nível de significância de 5%. Resultados: doze pacientes apresentaram recorrência da eclâmpsia após sulfato de magnésio (10%, repetindo-se então metade da dose de ataque. Em 4 destas verificou-se nova recorrência, administrando-se então diazepam endovenoso. Depois do diazepam, uma paciente ainda teve crises repetidas, sendo então realizada infusão de fenitoína e, posteriormente, indução do coma barbitúrico (tionembutal. Essa paciente foi submetida a tomografia computadorizada, constatando-se hemorragia intracraniana. As complicações maternas foram significativamente mais freqüentes no grupo com recorrência: coma (16,7% versus 0,9%, acidose (50% versus 2,9%, edema agudo de pulmão (16,7% versus 2,9%, hemorragia cerebral (16,7% versus 0% e insuficiência renal aguda (16,7% versus 1,9%. Ocorreram 3 casos de morte materna no grupo com recorrência (25% e 2 no grupo sem recorrência (1,9%. Conclusões: a recorrência da crise convulsiva é pouco freqüente após uso do sulfato de magnésio (10%, porém associa-se a aumento da morbimortalidade materna, requerendo acompanhamento em UTI e realização de tomografia para exclusão de hemorragia cerebral.Purpose: to determine the frequency of recurrence of seizures after anticonvulsant therapy with magnesium sulfate and to evaluate treatment and maternal prognosis

Ferric sulfates on Mars: Surface Explorations and Laboratory Experiments

Science.gov (United States)

Wang, A.; Ling, Z.; Freeman, J. J.

2008-12-01

hydration state (epsomite, at mid-low temperature), which would dehydrate readily at low relative humidity, ferricopiapite remains unchanged over ten months under extremely dry conditions. On the other hand, amorphous ferric sulfate which forms easily from solutions at dry conditions, is similar to the amorphous magnesium sulfate in stability field, thus can potentially be a very important phase in the phase transition pathways of ferric sulfates on Mars.

The analgesic effect of Magnesium Sulfate in postoperative pain of inguinal hernia repair

Directory of Open Access Journals (Sweden)

Mehraein A

2007-08-01

Full Text Available Background: Magnesium Sulfate (MgSO4 has been used as a pharmacologic agent in different situations for many years in the treatment of tachyarrhythmias, myocardial ischemia, preeclampsia, and tocolysis among others. The analgesic effect of MgSO4 for postoperative pain has been used since the 1990s. Postoperative pain is one of the most common complications in the perioperative period and can result in serious consequences in different organs if left untreated. Inguinal herniorrhaphy is among the most common surgeries and is almost always accompanied by severe pain. The object of this study is to determine the effect of a pre-induction infusion of MgSO4 on the reduction of postsurgical pain after herniorrhaphy. Methods: This double-blind, randomized clinical trial included 105 ASA class I and class II herniorrhaphy patients at Shariati Hospital in years 2004 and 2005. For statistical analysis, the 2 and T tests were used. The patients were divided into three groups based on block randomization. Patients in the following groups received: Group A, 200 ml of normal saline infusion (placebo; Group B, 25 mg/kg MgSO4 in 200 ml of normal saline; Group C, 50 mg/kg MgSO4 in 200 ml of normal saline. All groups were infused twenty minutes before induction of anesthesia using identical methods and dosage in all three groups. Heart rate and mean arterial pressure (MAP at pre- and postintubation and so at skin incision time were charted. Visual analog scale (VAS pain score, nausea, vomiting and the amount of morphine used before recovery room discharge and in six, twelve and twenty-four hours after recovery discharge was recorded. Results: The average age for the different groups was as follows: Group A: 33.6, Group B: 37.37, Group C: 32.74. Nausea and vomiting between the case and control groups were not statistically different (60% vs. 71.4%, p=0.0499, nor was the amount of Morphine used. On recovery room discharge, the VAS scores were 8.1, 7.2, and 5

The effect of magnesium ion concentration on the fibrocartilage regeneration potential of goat costal chondrocytes.

Science.gov (United States)

Hagandora, Catherine K; Tudares, Mauro A; Almarza, Alejandro J

2012-03-01

Magnesium has recently been explored as a potential biomaterial for degradable orthopedic implants but its effect on fibrocartilage remains unknown. The objective of this study was to assess the effect of high concentrations of magnesium ions on the matrix production of goat costal fibrochondrocytes in vitro. Cells were cultured using a scaffoldless approach with media containing magnesium chloride (MgCl(2)) or magnesium sulfate (MgSO(4)) at concentrations of 20, 50, and 100 mM in addition to the baseline magnesium concentration of 0.8 mM MgSO(4). At 4 weeks, there were no significant differences in compressive tangent modulus and total matrix production between constructs cultured in 20 mM Mg(2+) and the 0.8 mM Mg(2+) control (435 ± 47 kPa). There was a significant decrease in compressive tangent modulus compared to the 0.8 mM Mg(2+) constructs in the 50 mM MgCl(2) and MgSO(4) groups, while the 100 mM groups were not mechanically testable (p < 0.05). The collagen and glycosaminoglycan (GAG) content of the 50 and 100 mM MgCl(2) and MgSO(4) constructs was significantly lower than the control (6.9 ± 0.5% and 16.5 ± 1.3% per dry weight, respectively) (p < 0.05). The results show that goat costal fibrochondrocytes exhibit a high degree of resiliency to magnesium ion concentrations up to 20 mM in vitro.

Magnesium and Osteoporosis

Directory of Open Access Journals (Sweden)

Ferda Özdemir

2004-03-01

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

Magnesium Borohydride: From Hydrogen Storage to Magnesium Battery**

OpenAIRE

Mohtadi, Rana; Matsui, Masaki; Arthur, Timothy S; Hwang, Son-Jong

2012-01-01

Beyond hydrogen storage: The first example of reversible magnesium deposition/stripping onto/from an inorganic salt was seen for a magnesium borohydride electrolyte. High coulombic efficiency of up to 94 % was achieved in dimethoxyethane solvent. This Mg(BH_4)_2 electrolyte was utilized in a rechargeable magnesium battery.

Building a Geochemical View of Microbial Salt Tolerance: Halophilic Adaptation of Marinococcus in a Natural Magnesium Sulfate Brine

Directory of Open Access Journals (Sweden)

Mark G. Fox-Powell

2018-04-01

Full Text Available Current knowledge of life in hypersaline habitats is mostly limited to sodium and chloride-dominated environments. This narrow compositional window does not reflect the diversity of brine environments that exist naturally on Earth and other planetary bodies. Understanding the limits of the microbial biosphere and predicting extraterrestrial habitability demands a systematic effort to characterize ionic specificities of organisms from a representative range of saline habitats. Here, we investigated a strain of Marinococcus isolated from the magnesium and sulfate-dominated Basque Lakes (British Columbia, Canada. This organism was the sole isolate obtained after exposure to exceptionally high levels of Mg2+ and SO42- ions (2.369 and 2.840 M, respectively, and grew at extremes of ionic strength not normally encountered in Na+/Cl- brines (12.141 mol liter-1. Its association at the 16S rDNA level with bacterial halophiles suggests that ancestral halophily has allowed it to adapt to a different saline habitat. Growth was demonstrated in media dominated by NaCl, Na2SO4, MgCl2, and MgSO4, yet despite this plasticity the strain was still restricted; requiring either Na+ or Cl- to maintain short doubling times. Water activity could not explain growth rate differences between media, demonstrating the importance of ionic composition for dictating microbial growth windows. A new framework for understanding growth in brines is required, that accounts for the geochemical history of brines as well as the various stresses that ions impose on microbes. Studies such as this are required to gain a truly universal understanding of the limits of biological ion tolerance.

Building a Geochemical View of Microbial Salt Tolerance: Halophilic Adaptation of Marinococcus in a Natural Magnesium Sulfate Brine.

Science.gov (United States)

Fox-Powell, Mark G; Cockell, Charles S

2018-01-01

Current knowledge of life in hypersaline habitats is mostly limited to sodium and chloride-dominated environments. This narrow compositional window does not reflect the diversity of brine environments that exist naturally on Earth and other planetary bodies. Understanding the limits of the microbial biosphere and predicting extraterrestrial habitability demands a systematic effort to characterize ionic specificities of organisms from a representative range of saline habitats. Here, we investigated a strain of Marinococcus isolated from the magnesium and sulfate-dominated Basque Lakes (British Columbia, Canada). This organism was the sole isolate obtained after exposure to exceptionally high levels of Mg 2+ and SO 4 2- ions (2.369 and 2.840 M, respectively), and grew at extremes of ionic strength not normally encountered in Na + /Cl - brines (12.141 mol liter -1 ). Its association at the 16S rDNA level with bacterial halophiles suggests that ancestral halophily has allowed it to adapt to a different saline habitat. Growth was demonstrated in media dominated by NaCl, Na 2 SO 4 , MgCl 2 , and MgSO 4 , yet despite this plasticity the strain was still restricted; requiring either Na + or Cl - to maintain short doubling times. Water activity could not explain growth rate differences between media, demonstrating the importance of ionic composition for dictating microbial growth windows. A new framework for understanding growth in brines is required, that accounts for the geochemical history of brines as well as the various stresses that ions impose on microbes. Studies such as this are required to gain a truly universal understanding of the limits of biological ion tolerance.

Magnesium borohydride: from hydrogen storage to magnesium battery.

Science.gov (United States)

Mohtadi, Rana; Matsui, Masaki; Arthur, Timothy S; Hwang, Son-Jong

2012-09-24

Beyond hydrogen storage: The first example of reversible magnesium deposition/stripping onto/from an inorganic salt was seen for a magnesium borohydride electrolyte. High coulombic efficiency of up to 94 % was achieved in dimethoxyethane solvent. This Mg(BH(4))(2) electrolyte was utilized in a rechargeable magnesium battery. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Magnesium in pregnancy.

Science.gov (United States)

Dalton, Lynne M; Ní Fhloinn, Deirdre M; Gaydadzhieva, Gergana T; Mazurkiewicz, Ola M; Leeson, Heather; Wright, Ciara P

2016-09-01

Magnesium deficiency is prevalent in women of childbearing age in both developing and developed countries. The need for magnesium increases during pregnancy, and the majority of pregnant women likely do not meet this increased need. Magnesium deficiency or insufficiency during pregnancy may pose a health risk for both the mother and the newborn, with implications that may extend into adulthood of the offspring. The measurement of serum magnesium is the most widely used method for determining magnesium levels, but it has significant limitations that have both hindered the assessment of deficiency and affected the reliability of studies in pregnant women. Thus far, limited studies have suggested links between magnesium inadequacy and certain conditions in pregnancy associated with high mortality and morbidity, such as gestational diabetes, preterm labor, preeclampsia, and small for gestational age or intrauterine growth restriction. This review provides recommendations for further study and improved testing using measurement of red cell magnesium. Pregnant women should be counseled to increase their intake of magnesium-rich foods such as nuts, seeds, beans, and leafy greens and/or to supplement with magnesium at a safe level. © The Author(s) 2016. Published by Oxford University Press on behalf of the International Life Sciences Institute. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Magnesium stannide as a high-capacity anode for magnesium-ion batteries

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Nguyen, Dan-Thien; Song, Seung-Wan

2017-11-01

Driven by the limited global resources of lithium, magnesium metal batteries are considered as potential energy storage systems. The battery chemistry of magnesium metal anode, however, limits the selection of electrolytes, cathode materials and working temperature, making the realization of magnesium metal batteries complicated. Herein, we report the development of a new magnesium-insertion anode, magnesium stannide (Mg2Sn), and demonstrate reversible electrochemical Mg2+-extraction and insertion of Mg2Sn anode at 0.2 V versus Mg, delivering discharge capacity of 270 mAhg-1 in a half-cell with the electrolyte of PhMgCl/THF and enabling of room temperature magnesium-ion batteries with Mg2Sn anode combined with Mg-free oxide cathode and conventional-type electrolyte of Mg(TFSI)2/diglyme. The combination of Mg2Sn anode with various cathodes and electrolytes holds great promise for enabling room temperature magnesium-ion batteries.

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

OpenAIRE

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

1980-01-01

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

Magnesium, magnesium alloys, and magnesium composites

National Research Council Canada - National Science Library

Gupta, M; Sharon, Nai Mui Ling

2011-01-01

.... With the popularity of magnesium-based materials in the automotive, aerospace, electronics, and sports equipment industries, and its unique role as a lightweight, energy-saving and high-performance...

Myth or Reality-Transdermal Magnesium?

Science.gov (United States)

Gröber, Uwe; Werner, Tanja; Vormann, Jürgen; Kisters, Klaus

2017-07-28

In the following review, we evaluated the current literature and evidence-based data on transdermal magnesium application and show that the propagation of transdermal magnesium is scientifically unsupported. The importance of magnesium and the positive effects of magnesium supplementation are extensively documented in magnesium deficiency, e.g., cardiovascular disease and diabetes mellitus. The effectiveness of oral magnesium supplementation for the treatment of magnesium deficiency has been studied in detail. However, the proven and well-documented oral magnesium supplementation has become questioned in the recent years through intensive marketing for its transdermal application (e.g., magnesium-containing sprays, magnesium flakes, and magnesium salt baths). In both, specialist and lay press as well as on the internet, there are increasing numbers of articles claiming the effectiveness and superiority of transdermal magnesium over an oral application. It is claimed that the transdermal absorption of magnesium in comparison to oral application is more effective due to better absorption and fewer side effects as it bypasses the gastrointestinal tract.

Magnesium stearine production via direct reaction of palm stearine and magnesium hydroxide

Science.gov (United States)

Pratiwi, M.; Ylitervo, P.; Pettersson, A.; Prakoso, T.; Soerawidjaja, T. H.

2017-06-01

The fossil oil production could not compensate with the increase of its consumption, because of this reason the renewable alternative energy source is needed to meet this requirement of this fuel. One of the methods to produce hydrocarbon is by decarboxylation of fatty acids. Vegetable oil and fats are the greatest source of fatty acids, so these can be used as raw material for biohydrocarbon production. From other researchers on their past researchs, by heating base soap from divalent metal, those metal salts will decarboxylate and produce hydrocarbon. This study investigate the process and characterization of magnesium soaps from palm stearine by Blachford method. The metal soaps are synthesized by direct reaction of palm stearine and magnesium hydroxide to produce magnesium stearine and magnesium stearine base soaps at 140-180°C and 6-10 bar for 3-6 hours. The operation process which succeed to gain metal soaps is 180°C, 10 bar, for 3-6 hours. These metal soaps are then compared with commercial magnesium stearate. Based on Thermogravimetry Analysis (TGA) results, the decomposition temperature of all the metal soaps were 250°C. Scanning Electron Microscope with Energy Dispersive X-ray (SEM-EDX) analysis have shown the traces of sodium sulphate for magnesium stearate commercial and magnesium hydroxide for both type of magnesium stearine soaps. The analysis results from Microwave Plasma-Atomic Emission Spectrometry (MP-AES) have shown that the magnesium content of magnesium stearine approximate with magnesium stearate commercial and lower compare with magnesium stearine base soaps. These experiments suggest that the presented saponification process method could produced metal soaps comparable with the commercial metal soaps.

Low magnesium level

Science.gov (United States)

Low magnesium level is a condition in which the amount of magnesium in the blood is lower than normal. The medical ... that convert or use energy ( metabolism ). When the level of magnesium in the body drops below normal, ...

System and process for production of magnesium metal and magnesium hydride from magnesium-containing salts and brines

Science.gov (United States)

McGrail, Peter B.; Nune, Satish K.; Motkuri, Radha K.; Glezakou, Vassiliki-Alexandra; Koech, Phillip K.; Adint, Tyler T.; Fifield, Leonard S.; Fernandez, Carlos A.; Liu, Jian

2016-11-22

A system and process are disclosed for production of consolidated magnesium metal products and alloys with selected densities from magnesium-containing salts and feedstocks. The system and process employ a dialkyl magnesium compound that decomposes to produce the Mg metal product. Energy requirements and production costs are lower than for conventional processing.

Anticorrosive magnesium hydroxide coating on AZ31 magnesium alloy by hydrothermal method

International Nuclear Information System (INIS)

Zhu Yanying; Wu Guangming; Xing Guangjian; Li Donglin; Zhao Qing; Zhang Yunhong

2009-01-01

Magnesium alloys are potential biodegradable biomaterials in orthopedic surgery. However, the rapid degradation rate has limited their application in biomedical field. A great deal of studies have been done to improve the resistance of magnesium alloys. In this article, An anticorrosive magnesium hydroxide coating with a thickness of approximately 100μm was formed on an AZ31 magnesium alloy by hydrothermal method. The morphology of the coatings were observed by an optical microscope and SEM. And the samples were soaked in hank's solution (37 deg. C) to investigate the corrosion resistance. Magnesium alloy AZ31 with magnesium hydroxide coatings present superior corrosion resistance than untreated samples.

Magnesium and Space Flight

Science.gov (United States)

Smith, Scott M.; Zwart, Sara R.

2015-01-01

Magnesium is an essential nutrient for muscle, cardiovascular, and bone health on Earth, and during space flight. We sought to evaluate magnesium status in 43 astronauts (34 male, 9 female; 47 ± 5 years old, mean ± SD) before, during, and after 4–6-month space missions. We also studied individuals participating in a ground analog of space flight (head-down-tilt bed rest; n = 27 (17 male, 10 female), 35 ± 7 years old). We evaluated serum concentration and 24-h urinary excretion of magnesium, along with estimates of tissue magnesium status from sublingual cells. Serum magnesium increased late in flight, while urinary magnesium excretion was higher over the course of 180-day space missions. Urinary magnesium increased during flight but decreased significantly at landing. Neither serum nor urinary magnesium changed during bed rest. For flight and bed rest, significant correlations existed between the area under the curve of serum and urinary magnesium and the change in total body bone mineral content. Tissue magnesium concentration was unchanged after flight and bed rest. Increased excretion of magnesium is likely partially from bone and partially from diet, but importantly, it does not come at the expense of muscle tissue stores. While further study is needed to better understand the implications of these findings for longer space exploration missions, magnesium homeostasis and tissue status seem well maintained during 4–6-month space missions. PMID:26670248

Magnesium and Space Flight

Directory of Open Access Journals (Sweden)

Scott M. Smith

2015-12-01

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

Sulfation of chondroitin. Specificity, degree of sulfation, and detergent effects with 4-sulfating and 6-sulfating microsomal systems

International Nuclear Information System (INIS)

Sugumaran, G.; Silbert, J.E.

1988-01-01

Microsomal preparations from chondroitin 6-sulfate-producing chick embryo epiphyseal cartilage, and from chondroitin 4-sulfate-producing mouse mastocytoma cells, were incubated with UDP-[14C]glucuronic acid and UDP-N-acetylgalactosamine to form non-sulfated proteo[14C]chondroitin. Aliquots of the incubations were then incubated with 3'-phosphoadenylylphosphosulfate (PAPS) in the presence or absence of various detergents. In the absence of detergents, there was good sulfation of this endogenous proteo[14C]chondroitin by the original microsomes from both sources. Detergents, with the exception of Triton X-100, markedly inhibited sulfation in the mast cell system but not in the chick cartilage system. These results indicate that sulfation and polymerization are closely linked on cell membranes and that in some cases this organization can be disrupted by detergents. When aliquots of the original incubation were heat inactivated, and then reincubated with new microsomes from chick cartilage and/or mouse mastocytoma cells plus PAPS, there was no significant sulfation of this exogenous proteo[14C] chondroitin with either system unless Triton X-100 was added. Sulfation of exogenous chondroitin and chondroitin hexasaccharide was compared with sulfation of endogenous and exogenous proteo[14C]chondroitin. Sulfate incorporation into hexasaccharide and chondroitin decreased as their concentrations (based on uronic acid) approached that of the proteo[14C]chondroitin. At the same time, the degree of sulfation in percent of substituted hexosamine increased. However, the degree of sulfation did not reach that of the endogenous proteo[14C]chondroitin. Hexasaccharide and chondroitin sulfation were stimulated by the presence of Triton X-100. However, in contrast to the exogenous proteo[14C]chondroitin, there was some sulfation of hexasaccharide and chondroitin in the absence of this detergent

In vitro studies on magnesium uptake by rumen epithelium using magnesium-28

International Nuclear Information System (INIS)

Martens, H.; Harmeyer, J.; Breves, G.

1976-01-01

Magnesium-28 transfer across the rumen epithelium has been studied using surviving epithelia in an in vitro system. Net absorption of magnesium in the direction from lumen to blood could be observed as the result of two opposite unidirectional fluxes of different magnitude. Net uptake of magnesium occurred against an electrical potential difference, and was associated with the presence of an unaltered transmural potential difference in the mucosal tissue. Both the net transfer of magnesium and the transmural potential difference decreased during two hours of incubation. Unidirectional fluxes of magnesium and net efflux from the lumen were markedly reduced although not completely inhibited by the addition of ouabain (10 -4 mol/l). The findings suggest that the mechanism of magnesium absorption by the rumen epithelium can be considered as an active transport process, and that the rumen is the main area of magnesium absorption in the living animal. (author)

Reactions Involving Calcium and Magnesium Sulfates as Potential Sources of Sulfur Dioxide During MSL SAM Evolved Gas Analyses

Science.gov (United States)

McAdam, A. C.; Knudson, C. A.; Sutter, B.; Franz, H. B.; Archer, P. D., Jr.; Eigenbrode, J. L.; Ming, D. W.; Morris, R. V.; Hurowitz, J. A.; Mahaffy, P. R.;

Magnesium, magnesium alloys, and magnesium composites

National Research Council Canada - National Science Library

Gupta, M; Sharon, Nai Mui Ling

2011-01-01

... of science, characteristics, and applications. It emphasizes the properties of magnesium-based composites and the effects of different types of reinforcements, from micron length to nanometer scale, on the properties of the resulting composites...

Magnesium Hydroxide

Science.gov (United States)

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

Research Progress in Plasma arc welding of Magnesium Alloys and Magnesium Matrix Composites

Science.gov (United States)

Hui, Li; Yang, Zou; Yongbo, Li; Lei, Jiao; Ruijun, Hou

2017-11-01

Magnesium alloys and magnesium matrix composites by means of its excellent performance have wide application prospect in electronics, automotive, biotechnology, aerospace field, and welding technology has become a key of restricting its application. This paper describes the welding characteristics of magnesium, the obvious advantages in the application and the domestic and foreign research advance technology of plasma arc welding of magnesium, and summarizes the existing problems and development trends of plasma arc welding technology of magnesium.

Sulfate metabolism. I. Sulfate uptake and redistribution of acid rain sulfate by edible plants

International Nuclear Information System (INIS)

Dallam, R.D.

1987-01-01

Sulfur is the major component of polluted air in industrialized societies. Atmospheric sulfur is converted to sulfuric acid through a series of chemical reactions which can eventually reenter many ecosystems. When edible plants are grown in soils containing varying amounts of sulfate, the roots take up and transport inorganic sulfate to the stems and leaves. The sulfate taken up by the roots and the amount transported to the stem and leaves was found to be a function of the concentration of sulfate in the soil. Inorganic sulfate taken up by a corn plant seedling can be rapidly converted to organic sulfate by the root system. Nine days after one of a pair of pea plants was inoculated with artificial acid rain sulfate (dilute H 2 35 SO 4 ) it was found that the sulfate was translocated not only in the inoculated plant, but also to the uninoculated pea plant in the same container. Also, when the leaves of a mature potato plant were inoculated with artificial acid rain sulfate it was found that the sulfate was translocated into the edible potatoes. Fractionation of the potatoes showed that most of the sulfate was water soluble of which 30% was inorganic sulfate and 70% was in the form of organic sulfur. One third of the non-water soluble translocated acid rain sulfate was equally divided between lipid and non-lipid organic sulfur of the potato. 9 references, 2 figures, 5 tables

Serum and tissue contents of copper, calcium, iron and magnesium elements in cases of acne vulgaris after zinc therapy

International Nuclear Information System (INIS)

El-Said, S.M.; El-Bedewi, A.F.

2002-01-01

The effect of zinc therapy on some trace elements contents in serum and skin was studied in normal group (forty) and patients group with acne vulgaris (26 males and 14 females) with age ranged between 14-30 year. They were under medical treatment with 330 mg oral zinc sulfate for 12 weeks. Highly significant decreases in both serum and tissue contents of copper and calcium were detected, as well as, highly significant decrease in the serum content of magnesium was recorded. The serum content of iron was highly significantly increased and that for tissue content was slightly significantly increased. It could be concluded that zinc therapy could be valuable through modulation of copper. calcium, iron and magnesium in acne patients

FOCUS ON MAGNESIUM BASED DRUGS

Directory of Open Access Journals (Sweden)

I. I. Esenova

2011-01-01

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

Magnesium Oxide

Science.gov (United States)

Magnesium is an element your body needs to function normally. Magnesium oxide may be used for different reasons. Some people use it as ... one to four times daily depending on which brand is used and what condition you have. Follow ...

To evaluate the efficacy of intrathecal magnesium sulphate for hysterectomy under subarachnoid block with bupivacaine and fentanyl: A prospective randomized double blind clinical trial

Directory of Open Access Journals (Sweden)

Mridu Paban Nath

2012-01-01

Full Text Available Background: Intrathecal magnesium has been found to prolong the duration of analgesia in various surgical procedures like lower limb surgeries and as adjuncts to general anesthesia for pain management. The present study was designed to examine whether addition of intrathecal magnesium sulfate would enhance the analgesic efficacy of intrathecal bupivacaine and fentanyl in patients undergoing total abdominal hysterectomy. Methods: After taking informed consent, 60 patients were randomised into two groups with 30 patients. Group "S" received 2.5 mL (12.5 mg of hyperbaric bupivacaine + 0.5 mL (25 mcg of fentanyl + 0.5 mL of normal saline and Group "M" received 2.5 mL (12.5 mg of hyperbaric bupivacaine + 0.5 mL (25 mcg of fentanyl + 0.5 mL (100 mg of magnesium sulfate. Onset of sensory, motor block and duration of analgesia was noted. Results: Demographic profile and duration of surgery were comparable (P>0.5. Time of onset of sensory and motor blockade was delayed in Group M compared with Group S, and this was statistically significant. A statistically significant longer duration of analgesia was observed in Group M compared with the control Group S. However, the recovery of motor blockade was found to be statistically insignificant in both the groups. The hemodynamic parameters were comparable in the perioperative period (P>0.05. The incidence of side-effects in both the groups were also comparable (P>0.05. Conclusion: The addition of 100 mg intrathecal magnesium led to prolonged duration of analgesia significantly without increasing the incidence of side-effects. Also, there was a significant delay in the onset of both sensory and motor blockade.

Magnesium motorcycle applications

International Nuclear Information System (INIS)

Jianyong Cao; Zonghe Zhang; Dongxia Xiang; Jun Wang

2005-01-01

Magnesium, the lightest engineering structural metal, has been comprehensively used in castings of aviation and aerospace, communication and transportation, and IT components. This paper introduced the history, advantages and difficulties of magnesium castings for motorcycle application as well as its application state in China. It also indicated the production situation of magnesium motorcycle components in CQMST and difficulties need to overcome for further development. (orig.)

Comparison of the effects of magnesium and ketamine on postoperative pain and morphine consumption. A double-blind randomized controlled clinical study.

Science.gov (United States)

Arıkan, Müge; Aslan, Bilge; Arıkan, Osman; Horasanlı, Eyüp; But, Abdulkadir

2016-01-01

To compare the effects of magnesium sulfate and ketamine on postoperative pain and total morphine consumption in a placebo-controlled design. One hundred and twenty women scheduled for total abdominal hysterectomy were included in this prospective, randomized, double-blind study. Postoperatively, when the Numeric Pain Rating Scale (NPRS) was four or more, IV-PCA morphine was applied to all patients. The patients were randomized into three groups: Group K ketamine, Group M magnesium, and Group C saline received as infusion. Total morphine consumption for 48h, pain scores, adverse effects, and patients' satisfaction were evaluated. Total morphine consumption was significantly lower in Group K (32.6±9.2 mg) than in Group M (58.9±6.5 mg) and in Group C (65.7±8.2 mg). The satisfaction level of patients in Group K was higher than the other two groups (petamine to IV-PCA morphine reduces the total consumption of morphine without psychotic effects; however, magnesium did not influence morphine consumption.

Function of magnesium aluminate hydrate and magnesium nitrate ...

Indian Academy of Sciences (India)

MgO was added both as spinel (MgAl2O4) forming precursor i.e. magnesium aluminate hydrate, and magnesium nitrate. Sintering investigations were conducted in the temperature range 1500–1600°C with 2 h soaking. Structural study of sintered pellets was carried out by extensive XRD analysis. Scanning electron mode ...

Effects of preoperative magnesium sulphate on post-cesarean pain, a placebo controlled double blind study.

Directory of Open Access Journals (Sweden)

Seyed Mohamad Mireskandari

2015-03-01

Full Text Available To study the role of preoperative intravenous magnesium sulphate in decreasing post-cesarean pain and opioid requirement during first 24hrs.In a double blind randomized clinical trial, prior to induction of general anesthesia, fifty elective cesarean candidates were randomly assigned to one of the two groups of placebo or magnesium sulfate. After surgery visual analogue scale (VAS and infused morphine by PCA during 24 hrs were recorded. The data were analyzed by mann-Whitney -test, analysis of variance, and student t- test.VAS was significantly lower among patients in the magnesium sulphate group at intervals of 1(st, 6(th & 12(th hours after cesarean section (C/S with the mean scales of (48.9 ± 19.6 VS 74.7 ± 18.4, (42.1 ± 0.9 VS 58.3 ± 16.5 and (25.2 ± 6.1VS 30 ± 8.1 respectively and p-value of <0.001, 0.002 and 0.05 respectively. However at 24 hrs there was no significant difference in VAS with mean VAS scales of 22.6 ± 4.5 VS 23.6 ± 4.9 and p-value of 0.49. The dose of infused Morphine during 24 hrs was significantly less in the magnesium sulphate group than the placebo group with the means of 4.36 ± 1.4 VS 7.02 ± 1.9 mg respectively (p < 0.001.Administration of bolus 50 mg/kg magnesium sulphate prior to induction of general anesthesia may significantly decreased the morphine requirement during immediate post operative period and can be recommended as one of the modalities of post-operative pain control in the pregnant patients.

Magnesium compounds

Science.gov (United States)

Kramer, D.A.

2007-01-01

Seawater and natural brines accounted for about 52 percent of U.S. magnesium compounds production in 2006. Dead-burned magnesia was produced by Martin Marietta Magnesia Specialties from well brines in Michigan. Caustic-calcined magnesia was recovered from sea-water by Premier Chemicals in Florida; from well brines in Michigan by Martin Marietta and Rohm and Haas; and from magnesite in Nevada by Premier Chemicals. Intrepid Potash-Wendover and Great Salt Lake Minerals recovered magnesium chloride brines from the Great Salt Lake in Utah. Magnesium hydroxide was produced from brucite by Applied Chemical Magnesias in Texas, from seawater by SPI Pharma in Delaware and Premier Chemicals in Florida, and by Martin Marietta and Rohm and Haas from their operations mentioned above. About 59 percent of the magnesium compounds consumed in the United States was used for refractories that are used mainly to line steelmaking furnaces. The remaining 41 percent was consumed in agricultural, chemical, construction, environmental and industrial applications.

Innovative Vacuum Distillation for Magnesium Recycling

Science.gov (United States)

Zhu, Tianbai; Li, Naiyi; Mei, Xiaoming; Yu, Alfred; Shang, Shixiang

Magnesium recycling now becomes a very important subject as magnesium consumption increases fast around the world. All commonly used magnesium die-casting alloys can be recycled and recovered to the primary metal quality. The recycled materials may be comprised of biscuits, sprues, runners, flash, overflows, dross, sludge, scrap parts, and old parts that are returned from service, An innovative magnesium recycle method, vacuum distillation, is developed and proved out to be able to recycle magnesium scraps, especially machining chips, oily magnesium, smelting sludge, dross or the mixture. With this process at a specific temperature and environment condition, magnesium in scraps can be gasified and then solidified to become crystal magnesium crown. This `recycled' magnesium crown is collected and used as the raw material of magnesium alloys. The experimental results show the vacuum distillation is a feasible and plausible method to recycle magnesium. Further, the cost analysis will be addressed in this paper.

Structure and thermal decomposition of sulfated β-cyclodextrin intercalated in a layered double hydroxide

International Nuclear Information System (INIS)

Wang Ji; Wei Min; Rao Guoying; Evans, D.G.; Duan Xue

2004-01-01

The sodium salt of hexasulfated β-cyclodextrin has been synthesized and intercalated into a magnesium-aluminum layered double hydroxide by ion exchange. The structure, composition and thermal decomposition behavior of the intercalated material have been studied by variable temperature X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), inductively coupled plasma emission spectroscopy (ICP), and thermal analysis (TG-DTA) and a model for the structure has been proposed. The thermal stability of the intercalated sulfated β-cyclodextrin is significantly enhanced compared with the pure form before intercalation

Structure and thermal decomposition of sulfated β-cyclodextrin intercalated in a layered double hydroxide

Science.gov (United States)

Wang, Ji; Wei, Min; Rao, Guoying; Evans, David G.; Duan, Xue

2004-01-01

The sodium salt of hexasulfated β-cyclodextrin has been synthesized and intercalated into a magnesium-aluminum layered double hydroxide by ion exchange. The structure, composition and thermal decomposition behavior of the intercalated material have been studied by variable temperature X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), inductively coupled plasma emission spectroscopy (ICP), and thermal analysis (TG-DTA) and a model for the structure has been proposed. The thermal stability of the intercalated sulfated β-cyclodextrin is significantly enhanced compared with the pure form before intercalation.

INVESTIGATION OF MAGNESIUM ALLOYS MACHINABILITY

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Berat Barıs BULDUM

2013-01-01

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

21 CFR 310.531 - Drug products containing active ingredients offered over-the-counter (OTC) for the treatment of...

Science.gov (United States)

2010-04-01

..., juniper tar (oil of cade), lanolin, magnesium sulfate, menthol, methyl salicylate, oxyguinoline sulfate..., hexachlorophene, isobutamben, juniper tar (oil of cade), lanolin, magnesium sulfate, menthol, methyl salicylate...

Magnesium-enriched hydroxyapatite compared to calcium sulfate in the healing of human extraction sockets: radiographic and histomorphometric evaluation at 3 months.

Science.gov (United States)

Crespi, Roberto; Capparè, Paolo; Gherlone, Enrico

2009-02-01

Reduction of alveolar height and width after tooth extraction may present problems for implant placement, especially in the anterior maxilla where bone volume is important for biologic and esthetic reasons. Different graft materials have been proposed to minimize the reduction in ridge volume. The aim of this study was to compare radiographic and histomorphometric results of magnesium-enriched hydroxyapatite (MHA) and calcium sulfate (CS) grafts in fresh sockets after tooth extractions. Forty-five fresh extraction sockets with three bone walls were selected in 15 patients. A split-mouth design was used: 15 sockets on the right side of the jaw received MHA, 15 sockets on the left side received CS, and 15 random unfilled sockets were considered the control (C) group. Intraoral digital radiographs were taken at baseline and at 3 months after graft material placement. At 3 months, cylinder bone samples were obtained for histology and histomorphometry analysis. The difference in mean radiographic vertical bone level from baseline to 3 months was -2.48 +/- 0.65 mm in the CS group, -0.48 +/- 0.21 mm in the MHA group, and -3.75 +/- 0.63 mm in the unfilled C group. Statistically significant differences (P sockets showed 13.9% +/- 3.4% residual implant material, whereas the MHA-treated sockets showed 20.2% +/- 3.2% residual material. The difference between the groups was statistically significant (P <0.05). Radiographs revealed a greater reduction of alveolar ridge in the CS group than in the MHA group. Histologic examination showed more bone formation and faster resorption in the CS group and more residual implant material in the MHA group.

Magnesium compounds

Science.gov (United States)

Kramer, D.A.

2012-01-01

Seawater and natural brines accounted for about 57 percent of magnesium compounds produced in the United States in 2011. Dead-burned magnesia was produced by Martin Marietta Magnesia Specialties LLC from well brines in Michigan. Caustic-calcined magnesia was recovered from seawater by Premier Magnesia LLC in Florida, from well brines in Michigan by Martin Marietta and from magnesite in Nevada by Premier Magnesia. Intrepid Potash Wendover LLC and Great Salt Lake Minerals Corp. recovered magnesium chloride brines from the Great Salt Lake in Utah. Magnesium hydroxide was produced from seawater by SPI Pharma Inc. in Delaware and Premier Magnesia in Florida, and by Martin Marietta from its brine operation in Michigan.

Magnesium-based implants: a mini-review.

Science.gov (United States)

Luthringer, Bérengère J C; Feyerabend, Frank; Willumeit-Römer, Regine

2014-01-01

The goal of this review is to bring to the attention of the readership of Magnesium Research another facet of the importance of magnesium, i.e. magnesium-based biomaterials. A concise history of biomaterials and magnesium are thus presented. In addition, historical and current, clinical magnesium-based applications are presented.

The Effect of Systemic and Regional Use of Magnesium Sulfate on Postoperative Tramadol Consumption in Lumbar Disc Surgery

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Melek Demiroglu

2016-01-01

Full Text Available Aim. To investigate the effect of magnesium administered to the operative region muscle and administered systemically on postoperative analgesia consumption after lumbar disc surgery. Material and Method. The study included a total of 75 ASA I-II patients aged 18–65 years. The patients were randomly allocated into 1 of 3 groups of 25: the Intravenous (IV Group, the Intramuscular (IM Group, and the Control (C Group. At the stage of suturing the surgical incision site, the IV Group received 50 mg/kg MgSO4 intravenously in 150 mL saline within 30 mins. In the IM Group, 50 mg/kg MgSO4 in 30 mL saline was injected intramuscularly into the paraspinal muscles. In Group C, 30 mL saline was injected intramuscularly into the paraspinal muscles. After operation patients in all 3 groups were given 100 mg tramadol and 10 mg metoclopramide and tramadol solution was started intravenously through a patient-controlled analgesia device. Hemodynamic changes, demographic data, duration of anesthesia and surgery, pain scores (NRS, the Ramsay sedation score (RSS, the amount of analgesia consumed, nausea- vomiting, and potential side effects were recorded. Results. No difference was observed between the groups. Nausea and vomiting side effects occurred at a rate of 36% in Group C, which was a significantly higher rate compared to the other groups (p<0.05. Tramadol consumption in the IM Group was found to be significantly lower than in the other groups (p<0.05. Conclusion. Magnesium applied to the operative region was found to be more effective on postoperative analgesia than systemically administered magnesium.

Ionized magnesium in plasma and erythrocytes for the assessment of low magnesium status in alcohol dependent patients.

Science.gov (United States)

Ordak, Michal; Maj-Zurawska, Magdalena; Matsumoto, Halina; Bujalska-Zadrozny, Magdalena; Kieres-Salomonski, Ilona; Nasierowski, Tadeusz; Muszynska, Elzbieta; Wojnar, Marcin

2017-09-01

Studies on the homeostasis of magnesium in alcohol-dependent patients have often been characterized by low hypomagnesemia detection rates. This may be due to the fact that the content of magnesium in blood serum constitutes only 1% of the average magnesium level within the human body. However, the concentration of ionized magnesium is more physiologically important and makes up 67% of the total magnesium within a human organism. There are no data concerning the determination of the ionized fraction of magnesium in patients addicted to alcohol and its influence on mental health status. This study included 100 alcohol-dependent patients and 50 healthy subjects. The free magnesium fraction was determined using the potentiometric method by means of using ion-selective electrodes. The total magnesium level was determined by using a biochemical Indiko Plus analyzer. In this study, different psychometric scales were applied. Our results confirm the usefulness of ionized magnesium concentrations in erythrocytes and plasma as a diagnostic parameter of low magnesium status in alcohol-dependent patients. The lower the concentration of ionized magnesium, the worse the quality of life an alcohol-dependent person might experience. In the case of total magnesium, no such correlation was determined. Copyright © 2017 Elsevier B.V. All rights reserved.

Magnesium sulfate treatment reverses seizure susceptibility and decreases neuroinflammation in a rat model of severe preeclampsia.

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Abbie Chapman Johnson

Full Text Available Eclampsia, defined as unexplained seizure in a woman with preeclampsia, is a life-threatening complication of pregnancy with unclear etiology. Magnesium sulfate (MgSO4 is the leading eclamptic seizure prophylactic, yet its mechanism of action remains unclear. Here, we hypothesized severe preeclampsia is a state of increased seizure susceptibility due to blood-brain barrier (BBB disruption and neuroinflammation that lowers seizure threshold. Further, MgSO4 decreases seizure susceptibility by protecting the BBB and preventing neuroinflammation. To model severe preeclampsia, placental ischemia (reduced uteroplacental perfusion pressure; RUPP was combined with a high cholesterol diet (HC to cause maternal endothelial dysfunction. RUPP+HC rats developed symptoms associated with severe preeclampsia, including hypertension, oxidative stress, endothelial dysfunction and fetal and placental growth restriction. Seizure threshold was determined by quantifying the amount of pentylenetetrazole (PTZ; mg/kg required to elicit seizure in RUPP + HC ± MgSO4 and compared to normal pregnant controls (n = 6/group; gestational day 20. RUPP+HC rats were more sensitive to PTZ with seizure threshold being ∼ 65% lower vs. control (12.4 ± 1.7 vs. 36.7 ± 3.9 mg/kg PTZ; p<0.05 that was reversed by MgSO4 (45.7 ± 8.7 mg/kg PTZ; p<0.05 vs. RUPP+HC. BBB permeability to sodium fluorescein, measured in-vivo (n = 5-7/group, was increased in RUPP+HC vs. control rats, with more tracer passing into the brain (15.9 ± 1.0 vs. 12.2 ± 0.3 counts/gram ×1000; p<0.05 and was unaffected by MgSO4 (15.6 ± 1.0 counts/gram ×1000; p<0.05 vs. controls. In addition, RUPP+HC rats were in a state of neuroinflammation, indicated by 35 ± 2% of microglia being active compared to 9 ± 2% in normal pregnancy (p<0.01; n = 3-8/group. MgSO4 treatment reversed neuroinflammation, reducing microglial activation to 6 ± 2% (p<0.01 vs. RUPP+HC. Overall, RUPP+HC rats were in a state of augmented

Choline Magnesium Trisalicylate

Science.gov (United States)

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

Sulfate Transporters in Dissimilatory Sulfate Reducing Microorganisms: A Comparative Genomics Analysis

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Angeliki Marietou

2018-03-01

Full Text Available The first step in the sulfate reduction pathway is the transport of sulfate across the cell membrane. This uptake has a major effect on sulfate reduction rates. Much of the information available on sulfate transport was obtained by studies on assimilatory sulfate reduction, where sulfate transporters were identified among several types of protein families. Despite our growing knowledge on the physiology of dissimilatory sulfate-reducing microorganisms (SRM there are no studies identifying the proteins involved in sulfate uptake in members of this ecologically important group of anaerobes. We surveyed the complete genomes of 44 sulfate-reducing bacteria and archaea across six phyla and identified putative sulfate transporter encoding genes from four out of the five surveyed protein families based on homology. We did not find evidence that ABC-type transporters (SulT are involved in the uptake of sulfate in SRM. We speculate that members of the CysP sulfate transporters could play a key role in the uptake of sulfate in thermophilic SRM. Putative CysZ-type sulfate transporters were present in all genomes examined suggesting that this overlooked group of sulfate transporters might play a role in sulfate transport in dissimilatory sulfate reducers alongside SulP. Our in silico analysis highlights several targets for further molecular studies in order to understand this key step in the metabolism of SRMs.

Enhanced sulfate reduction with acidogenic sulfate-reducing bacteria

International Nuclear Information System (INIS)

Wang Aijie; Ren Nanqi; Wang Xu; Lee Duujong

2008-01-01

Sulfate reduction in a continuous flow, acidogenic reactor using molasses wastewater as the carbon source was studied at varying chemical oxygen demand/sulfate (COD/SO 4 2- ) ratios. At a critical COD/SO 4 2- ratio of 2.7, neither COD nor sulfate were in excess for extra production of ethanol or acetate in the reactor. An acetic-type microbial metabolism was established with sulfate-reducing bacteria (SRB) significantly consuming hydrogen and volatile fatty acids produced by acidogenic bacteria and hydrogen producing acetogens in degrading COD, thereby yielding sulfate removal rate >94.6%. A low critical COD/SO 4 2- ratio of 1.6 was also observed with the enriched ASRB population in reactor which overcomes the barrier to the treatment capability of sulfate-laden wastewater treatment with limited COD supply

Reduced sulfation of chondroitin sulfate but not heparan sulfate in kidneys of diabetic db/db mice.

Science.gov (United States)

Reine, Trine M; Grøndahl, Frøy; Jenssen, Trond G; Hadler-Olsen, Elin; Prydz, Kristian; Kolset, Svein O

2013-08-01

Heparan sulfate proteoglycans are hypothesized to contribute to the filtration barrier in kidney glomeruli and the glycocalyx of endothelial cells. To investigate potential changes in proteoglycans in diabetic kidney, we isolated glycosaminoglycans from kidney cortex from healthy db/+ and diabetic db/db mice. Disaccharide analysis of chondroitin sulfate revealed a significant decrease in the 4-O-sulfated disaccharides (D0a4) from 65% to 40%, whereas 6-O-sulfated disaccharides (D0a6) were reduced from 11% to 6%, with a corresponding increase in unsulfated disaccharides. In contrast, no structural differences were observed in heparan sulfate. Furthermore, no difference was found in the molar amount of glycosaminoglycans, or in the ratio of hyaluronan/heparan sulfate/chondroitin sulfate. Immunohistochemical staining for the heparan sulfate proteoglycan perlecan was similar in both types of material but reduced staining of 4-O-sulfated chondroitin and dermatan was observed in kidney sections from diabetic mice. In support of this, using qRT-PCR, a 53.5% decrease in the expression level of Chst-11 (chondroitin 4-O sulfotransferase) was demonstrated in diabetic kidney. These results suggest that changes in the sulfation of chondroitin need to be addressed in future studies on proteoglycans and kidney function in diabetes.

Semi-synthesis of chondroitin sulfate-E from chondroitin sulfate-A

OpenAIRE

Cai, Chao; Solakyildirim, Kemal; Yang, Bo; Beaudet, Julie M.; Weyer, Amanda; Linhardt, Robert J.; Zhang, Fuming

2012-01-01

Chondroitin sulfate-E (chondroitin-4, 6-disulfate) was prepared from chondroitin sulfate-A (chondroitin-4 - sulfate) by regioselective sulfonation, performed using trimethylamine sulfur trioxide in formamide under argon. The structure of semi-synthetic chondroitin sulfate-E was analyzed by PAGE, 1H NMR, 13C NMR, 2D NMR and disaccharide analysis and compared with natural chondroitin sulfate-E. Both semi-synthetic and natural chondroitin sulfate-E were each biotinylated and immobilized on BIAco...

Combustion and extinction of magnesium fires

International Nuclear Information System (INIS)

Malet, J.C.; Duverger de Cuy, G.

1988-01-01

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

Magnesium deficiency: What is our status

Science.gov (United States)

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

Spider silk as a template for obtaining magnesium oxide and magnesium hydroxide fibers

Directory of Open Access Journals (Sweden)

Dmitrović Svetlana

2018-01-01

Full Text Available Spider silk fibers, collected from Pholcus Phalangioides spider were used as a template for obtaining magnesium oxide (MgO, periclase as well as magnesium hydroxide (Mg(OH2, brucite fibers. Magnesium oxide fibers were obtained in a simple manner by heat induced decomposition of magnesium salt (MgCl2 in the presence of the spider silk fibers, while magnesium hydroxide fibers were synthesized by hydration of MgO fibers at 50, 70 and 90 C, for 48 and 96 h. According to Scanning electron microscopy (SEM, dimensions of spider silk fibers determined the dimension of synthesized MgO fibers, while for Mg(OH2 fibers, the average diameter was increased with prolonging the hydration period. The surface of Mg(OH2 fibers was noticed to be covered with brucite in a form of plates. X-Ray diffraction (XRD analysis showed that MgO fibers were single-phased (the pure magnesium oxide fibers were obtained, while Mg(OH2 fibers were two- or single-phased brucite depending on incubation period, and/or incubation temperature. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 45012

Magnesium Technology : Preface

NARCIS (Netherlands)

Sillekens, W.H.; Agnew, S.R.; Neelameggham, N.R.; Mathaudhu, S.N.

2011-01-01

The Magnesium Technology Symposium, which takes place every year at the TMS Annual Meeting & Exhibition, is one of the largest yearly gatherings of magnesium specialists in the world. Papers are presented in all aspects of the field, ranging from primary production to applications to recycling.

The Corrosion of Magnesium and of the Magnesium Aluminum Alloys Containing Manganese

Science.gov (United States)

Boyer, J A

1927-01-01

The extensive use of magnesium and its alloys in aircraft has been seriously handicapped by the uncertainties surrounding their resistance to corrosion. This problem has been given intense study by the American Magnesium Corporation and at the request of the Subcommittee on Materials for Aircraft of the National Advisory Committee for Aeronautics this report was prepared on the corrosion of magnesium. The tentative conclusions drawn from the experimental facts of this investigation are as follows: the overvoltage of pure magnesium is quite high. On immersion in salt water the metal corrodes with the liberation of hydrogen until the film of corrosion product lowers the potential to a critical value. When the potential reaches this value it no longer exceeds the theoretical hydrogen potential plus the overvoltage of the metal. Rapid corrosion consequently ceases. When aluminum is added, especially when in large amounts, the overvoltage is decreased and hydrogen plates out at a much lower potential than with pure magnesium. The addition of small amount of manganese raises the overvoltage back to practically that of pure metal, and the film is again negative.

Propofol and magnesium attenuate isoflurane-induced caspase-3 activation via inhibiting mitochondrial permeability transition pore

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Zhang Yiying

2012-08-01

Full Text Available Abstract Background The inhalation anesthetic isoflurane has been shown to open the mitochondrial permeability transition pore (mPTP and induce caspase activation and apoptosis, which may lead to learning and memory impairment. Cyclosporine A, a blocker of mPTP opening might attenuate the isoflurane-induced mPTP opening, lessening its ripple effects. Magnesium and anesthetic propofol are also mPTP blockers. We therefore set out to determine whether propofol and magnesium can attenuate the isoflurane-induced caspase activation and mPTP opening. Methods We investigated the effects of magnesium sulfate (Mg2+, propofol, and isoflurane on the opening of mPTP and caspase activation in H4 human neuroglioma cells stably transfected to express full-length human amyloid precursor protein (APP (H4 APP cells and in six day-old wild-type mice, employing Western blot analysis and flowcytometry. Results Here we show that Mg2+ and propofol attenuated the isoflurane-induced caspase-3 activation in H4-APP cells and mouse brain tissue. Moreover, Mg2+ and propofol, the blockers of mPTP opening, mitigated the isoflurane-induced mPTP opening in the H4-APP cells. Conclusion These data illustrate that Mg2+ and propofol may ameliorate the isoflurane-induced neurotoxicity by inhibiting its mitochondrial dysfunction. Pending further studies, these findings may suggest the use of Mg2+ and propofol in preventing and treating anesthesia neurotoxicity.

Precipitation of calcium, magnesium, strontium and barium in tissues of four Acacia species (Leguminosae: Mimosoideae).

Science.gov (United States)

He, Honghua; Bleby, Timothy M; Veneklaas, Erik J; Lambers, Hans; Kuo, John

2012-01-01

Precipitation of calcium in plants is common. There are abundant studies on the uptake and content of magnesium, strontium and barium, which have similar chemical properties to calcium, in comparison with those of calcium in plants, but studies on co-precipitation of these elements with calcium in plants are rare. In this study, we compared morphologies, distributional patterns, and elemental compositions of crystals in tissues of four Acacia species grown in the field as well as in the glasshouse. A comparison was also made of field-grown plants and glasshouse-grown plants, and of phyllodes of different ages for each species. Crystals of various morphologies and distributional patterns were observed in the four Acacia species studied. Magnesium, strontium and barium were precipitated together with calcium, mainly in phyllodes of the four Acacia species, and sometimes in branchlets and primary roots. These elements were most likely precipitated in forms of oxalate and sulfate in various tissues, including epidermis, mesophyll, parenchyma, sclerenchyma (fibre cells), pith, pith ray and cortex. In most cases, precipitation of calcium, magnesium, strontium and barium was biologically induced, and elements precipitated differed between soil types, plant species, and tissues within an individual plant; the precipitation was also related to tissue age. Formation of crystals containing these elements might play a role in regulating and detoxifying these elements in plants, and protecting the plants against herbivory.

Photoluminescence of magnesium-associated color centers in LiF crystals implanted with magnesium ions

Science.gov (United States)

Nebogin, S. A.; Ivanov, N. A.; Bryukvina, L. I.; V. Shipitsin, N.; E. Rzhechitskii, A.; Papernyi, V. L.

2018-05-01

In the present paper, the effect of magnesium nanoparticles implanted in a LiF crystal on the optical properties of color centers is studied. The transmittance spectra and AFM images demonstrate effective formation of the color centers and magnesium nanoparticles in an implanted layer of ∼ 60-100 nm in thickness. Under thermal annealing, a periodical structure is formed on the surface of the crystal and in the implanted layer due to self-organization of the magnesium nanoparticles. Upon excitation by argon laser with a wavelength of 488 nm at 5 K, in a LiF crystal, implanted with magnesium ions as well as in heavily γ-irradiated LiF: Mg crystals, luminescence of the color centers at λmax = 640 nm with a zero-phonon line at 601.5 nm is observed. The interaction of magnesium nanoparticles and luminescing color centers in a layer implanted with magnesium ions has been revealed. It is shown that the luminescence intensity of the implanted layer at a wavelength of 640 nm is by more than two thousand times higher than that of a heavily γ-irradiated LiF: Mg crystal. The broadening of the zero-phonon line at 601.5 nm in the spectrum of the implanted layer indicates the interaction of the emitting quantum system with local field of the surface plasmons of magnesium nanoparticles. The focus of this work is to further optimize the processing parameters in a way to result in luminescence great enhancement of color centers by magnesium nanoparticles in LiF.

Magnesium oxychloride cement concrete

Indian Academy of Sciences (India)

TECS

exposure to water and salt attack by replacing 10% magnesium chloride solution by magnesium sulphate solution ... Having tremendous load bearing capacity, it can withstand .... retention coefficients for similar concrete compositions.

Mineral resource of the month: magnesium

Science.gov (United States)

Kramer, Deborah A.

2012-01-01

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

21 CFR 184.1431 - Magnesium oxide.

Science.gov (United States)

2010-04-01

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

21 CFR 184.1426 - Magnesium chloride.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Magnesium chloride. 184.1426 Section 184.1426 Food... Specific Substances Affirmed as GRAS § 184.1426 Magnesium chloride. (a) Magnesium chloride (MgC12·6H2O, CAS... hydrochloric acid solution and crystallizing out magnesium chloride hexahydrate. (b) The ingredient meets the...

Lightweight Heat Pipes Made from Magnesium

Science.gov (United States)

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

2010-01-01

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

21 CFR 862.1495 - Magnesium test system.

Science.gov (United States)

2010-04-01

... magnesium levels in serum and plasma. Magnesium measurements are used in the diagnosis and treatment of hypomagnesemia (abnormally low plasma levels of magnesium) and hypermagnesemia (abnormally high plasma levels of magnesium). (b) Classification. Class I. ...

Radioactive 210Po in magnesium supplements

International Nuclear Information System (INIS)

Struminska-Parulska, Dagmara Ida

2016-01-01

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

Alkoxide-based magnesium electrolyte compositions for magnesium batteries

Science.gov (United States)

Dai, Sheng; Sun, Xiao-Guang; Liao, Chen; Guo, Bingkun

2018-01-30

Alkoxide magnesium halide compounds having the formula: RO--Mg--X (1) wherein R is a saturated or unsaturated hydrocarbon group that is unsubstituted, or alternatively, substituted with one or more heteroatom linkers and/or one or more heteroatom-containing groups comprising at least one heteroatom selected from fluorine, nitrogen, oxygen, sulfur, and silicon; and X is a halide atom. Also described are electrolyte compositions containing a compound of Formula (1) in a suitable polar aprotic or ionic solvent, as well as magnesium batteries in which such electrolytes are incorporated.

Corrosion resistance of multilayered magnesium phosphate/magnesium hydroxide film formed on magnesium alloy using steam-curing assisted chemical conversion method

International Nuclear Information System (INIS)

Ishizaki, Takahiro; Kudo, Ruriko; Omi, Takeshi; Teshima, Katsuya; Sonoda, Tsutomu; Shigematsu, Ichinori; Sakamoto, Michiru

2012-01-01

Anticorrosive multilayered films were successfully prepared on magnesium alloy AZ31 by chemical conversion treatment, followed by steam curing treatment. The crystal structures, chemical composition, surface morphologies, chemical bonding states of the film was characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and field emission scanning electron microscope (FE-SEM) measurements. All the films had thicknesses of ranging from 24 to 32 μm. The film had two layers that were composed of crystalline NH 4 MgPO 4 ·H 2 O, Mg 2 PO 4 OH·3H 2 O, Mg(OH) 2 and amorphous MgO. The outer layers include magnesium, oxygen, and phosphorous, and the inner layers include magnesium and oxygen. The corrosion resistant performances of the multilayered films in 5 wt% NaCl aqueous solution were investigated by electrochemical and gravimetric measurements. The potentiodynamic polarization curves revealed that the corrosion current density (j corr ) of all the film coated magnesium alloys decreased by more than four orders of magnitude as compared to that of the bare magnesium alloy, indicating that all the films had an inhibiting effect of corrosion reaction. Gravimetric measurements showed that the average corrosion rates obtained from the weight loss rates were estimated to be in the ranges of ca. 0.085–0.129 mm/y. American Society for Testing and Materials (ASTM) standard D 3359-02 cross cut tape test revealed that the adhesion of our anticorrosive multilayered film to the magnesium alloy surface was very good.

Nanostructured magnesium increases bone cell density.

Science.gov (United States)

Weng, Lucy; Webster, Thomas J

2012-12-07

Magnesium has attracted some attention in orthopedics due to its biodegradability and mechanical properties. Since magnesium is an essential natural mineral for bone growth, it can be expected that as a biomaterial, it would support bone formation. However, upon degradation in the body, magnesium releases OH(-) which results in an alkaline pH that can be detrimental to cell density (for example, osteoblasts or bone forming cells). For this reason, modification of magnesium may be necessary to compensate for such detrimental effects to cells. This study created biologically inspired nanoscale surface features on magnesium by soaking magnesium in various concentrations of NaOH (from 1 to 10 N) and for various periods of time (from 10 to 30 min). The results provided the first evidence of increased roughness, surface energy, and consequently greater osteoblast adhesion, after 4 h as well as density up to 7 days on magnesium treated with any concentration of NaOH for any length of time compared to untreated controls. For these reasons, this study suggests that soaking magnesium in NaOH could be an inexpensive, simple and effective manner to promote osteoblast functions for numerous orthopedic applications and, thus, should be further studied.

Calcium and magnesium determination

International Nuclear Information System (INIS)

Bhattacharya, S.K.

1982-01-01

The roles of calcium and magnesium in human health and disease have been extensively studied. Calcium and magnesium have been determined in biological specimens by atomic absorption spectroscopy using stiochiometric nitrous oxide-acetylene flame

A SEARCH FOR MAGNESIUM IN EUROPA'S ATMOSPHERE

International Nuclear Information System (INIS)

Hörst, S. M.; Brown, M. E.

2013-01-01

Europa's tenuous atmosphere results from sputtering of the surface. The trace element composition of its atmosphere is therefore related to the composition of Europa's surface. Magnesium salts are often invoked to explain Galileo Near Infrared Mapping Spectrometer spectra of Europa's surface, thus magnesium may be present in Europa's atmosphere. We have searched for magnesium emission in the Hubble Space Telescope Faint Object Spectrograph archival spectra of Europa's atmosphere. Magnesium was not detected and we calculate an upper limit on the magnesium column abundance. This upper limit indicates that either Europa's surface is depleted in magnesium relative to sodium and potassium, or magnesium is not sputtered as efficiently resulting in a relative depletion in its atmosphere.

Corrosion of magnesium and some magnesium alloys in gas cooled reactors

International Nuclear Information System (INIS)

Caillat, R.; Darras, R.

1958-01-01

The results of corrosion tests on magnesium and some magnesium alloys (Mg-Zr and Mg-Zr-Zn) in moist air (like G1 reactor) and in CO 2 : (like G2, G3, EDF1 reactors) are reported. The maximum temperature for exposure of magnesium to moist air without any risk of corrosion is 350 deg. C. Indeed, the oxidation rate follows a linear law above 350 deg. C although it reaches a constant level and keeps on very low under 350 deg. C. However, as far as corrosion is concerned this temperature limit can be raised up to 500 deg. C if moist air is very slightly charged with fluorinated compounds. Under pressure of CO 2 , these three materials oxidate much more slowly even if 500 deg. C is reached. The higher is the temperature, the higher is the constant level of the weight increase and the quicker is reached this one. However, Mg-Zr alloy behaves quite better than pure magnesium and especially than Mg-Zr-Zn alloy. (author) [fr

Nanostructured magnesium increases bone cell density

International Nuclear Information System (INIS)

Weng, Lucy; Webster, Thomas J

2012-01-01

Magnesium has attracted some attention in orthopedics due to its biodegradability and mechanical properties. Since magnesium is an essential natural mineral for bone growth, it can be expected that as a biomaterial, it would support bone formation. However, upon degradation in the body, magnesium releases OH − which results in an alkaline pH that can be detrimental to cell density (for example, osteoblasts or bone forming cells). For this reason, modification of magnesium may be necessary to compensate for such detrimental effects to cells. This study created biologically inspired nanoscale surface features on magnesium by soaking magnesium in various concentrations of NaOH (from 1 to 10 N) and for various periods of time (from 10 to 30 min). The results provided the first evidence of increased roughness, surface energy, and consequently greater osteoblast adhesion, after 4 h as well as density up to 7 days on magnesium treated with any concentration of NaOH for any length of time compared to untreated controls. For these reasons, this study suggests that soaking magnesium in NaOH could be an inexpensive, simple and effective manner to promote osteoblast functions for numerous orthopedic applications and, thus, should be further studied. (paper)

Nutrition and magnesium absorption

NARCIS (Netherlands)

Brink, E.J.

1992-01-01

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

Sulfate adsorption on goethite

Energy Technology Data Exchange (ETDEWEB)

Rietra, R P.J.J.; Hiemstra, T; Riemsdijk, W.H. van

1999-10-15

Recent spectroscopic work has suggested that only one surface species of sulfate is dominant on hematite. Sulfate is therefore a very suitable anion to test and develop adsorption models for variable charge minerals. The authors have studied sulfate adsorption on goethite covering a large range of sulfate concentrations, surface coverages, pH values, and electrolyte concentrations. Four different techniques were used to cover the entire range of conditions. For characterization at low sulfate concentrations, below the detection limit of sulfate with ICP-AES, the authors used proton-sulfate titrations at constant pH. Adsorption isotherms were studied for the intermediate sulfate concentration range. Acid-base titrations in sodium sulfate and electromobility were used for high sulfate concentrations. All the data can be modeled with one adsorbed species if it is assumed that the charge of adsorbed sulfate is spatially distributed in the interface. The charge distribution of sulfate follows directly from modeling the proton-sulfate adsorption stoichoimemtry sine this stoichiometry is independent of the intrinsic affinity constant of sulfate. The charge distribution can be related to the structure of the surface complex by use of the Pauling bond valence concept and is in accordance with the microscopic structure found by spectroscopy. The intrinsic affinity constant follows from the other measurements. Modeling of the proton-ion stoichoimetry with the commonly used 2-pK models, where adsorbed ions are treated as point charges, is possible only if at least two surface species for sulfate are used.

Influence of sulfate ion concentration and pH on the corrosion of Mg-Al-Zn-Mn (GA9 magnesium alloy

Directory of Open Access Journals (Sweden)

Sudarshana Shetty

2015-09-01

Full Text Available The corrosion behavior of Mg-Al-Zn-Mn (GA9 alloy in sodium sulfate solutions was studied over a range of concentrations and solution temperatures at different pH conditions by electrochemical techniques like Tafel extrapolation and electrochemical impedance spectroscopy (EIS. The studies were carried out in solutions with sodium sulfate concentrations 0.1M, 0.5M, 1M, 1.5M and 2M; and at five different temperatures of 30, 35, 40, 45 and 50 °C in a pH range of 3–12. As per the experimental data, the corrosion rate of the alloy increased with the increase in temperature, and also with the increase in concentration of sodium sulfate in the medium. It was observed that the rate of corrosion decreased with the increase in pH. The activation parameters like activation energy, enthalpy of activation and entropy of activation for the corrosion process were calculated. The surface morphology of the alloy was examined before and after corrosion using scanning electron microscopy (SEM.

Magnesium-DNA interactions and the possible relation of magnesium to carcinogenesis. Irradiation and free radicals.

Science.gov (United States)

Anastassopoulou, J; Theophanides, T

2002-04-01

Magnesium deficiency causes renal complications. The appearance of several diseases is related to its depletion in the human body. In radiotherapy, as well as in chemotherapy, especially in treatment of cancers with cis-platinum, hypomagnesaemia is observed. The site effects of chemotherapy that are due to hypomagnesaemia are decreased using Mg supplements. The role of magnesium in DNA stabilization is concentration dependent. At high concentrations there is an accumulation of Mg binding, which induces conformational changes leading to Z-DNA, while at low concentration there is deficiency and destabilization of DNA. The biological and clinical consequences of abnormal concentrations are DNA cleavage leading to diseases and cancer. Carcinogenesis and cell growth are also magnesium-ion concentration dependent. Several reports point out that the interaction of magnesium in the presence of other metal ions showed that there is synergism with Li and Mn, but there is magnesium antagonism in DNA binding with the essential metal ions in the order: Zn>Mg>Ca. In the case of toxic metals such as Cd, Ga and Ni there is also antagonism for DNA binding. It was found from radiolysis of deaerated aqueous solutions of the nucleoside 5'-guanosine monophosphate (5'-GMP) in the presence as well as in the absence of magnesium ions that, although the addition of hydroxyl radicals (*OH) has been increased by 2-fold, the opening of the imidazole ring of the guanine base was prevented. This effect was due to the binding of Mg2+ ions to N7 site of the molecule by stabilizing the five-member ring imitating cis-platinum. It was also observed using Fourier Transform Infrared spectroscopy, Raman spectroscopy and Fast Atom Bombardment mass spectrometry that *OH radicals subtract H atoms from the C1', C4' and C5' sites of the nucleotide. Irradiation of 5'-GMP in the presence of oxygen (2.5 x 10(-4) M) shows that magnesium is released from the complex. There is spectroscopic evidence that

Porous bioresorbable magnesium as bone substitute

Energy Technology Data Exchange (ETDEWEB)

Wen, C.E.; Yamada, Y.; Shimojima, K.; Chino, Y.; Hosokawa, H.; Mabuchi, M. [Inst. for Structural and Engineering Materials, National Inst. of Advanced Industrial Science and Technology, Nagoya (Japan)

2003-07-01

Recently magnesium has been recognized as a very promising biomaterial for bone substitutes because of its excellent properties of biocompatibility, biodegradability and bioresorbability. In the present study, magnesium foams were fabricated by using a powder metallurgical process. Scanning electron microscopy equipped with energy dispersive X-ray spectrometer (EDS) and compressive tester were used to characterize the porous magnesium. Results show that the Young's modulus and the peak stress of the porous magnesium increase with decreasing porosity and pore size. This study suggests that the mechanical properties of the porous magnesium with the low porosity of 35% and/or with the small pore size of about 70 {mu}m are close to those of human cancellous bones. (orig.)

Small for Gestational Age and Magnesium: Intrauterine magnesium deficiency may induce metabolic syndrome in later life

Directory of Open Access Journals (Sweden)

Junji Takaya

2015-12-01

Full Text Available Magnesium deficiency during pregnancy as a result of insufficient or low intake of magnesium is common in developing and developed countries. Previous reports have shown that intracellular magnesium of cord blood platelets is lower among small for gestational age (SGA groups than that of appropriate for gestational age (AGA groups, suggesting that intrauterine magnesium deficiency may result in SGA. Additionally, the risk of adult-onset diseases such as insulin resistance syndrome is greater among children whose mothers were malnourished during pregnancy, and who consequently had a low birth weight. In a number of animal models, poor nutrition during pregnancy leads to offspring that exhibit pathophysiological changes similar to human diseases. The offspring of pregnant rats fed a magensium restricted diet have developed hypermethylation in the hepatic 11β-hydroxysteroid dehydrogenase-2 promoter. These findings indicate that maternal magnesium deficiencies during pregnancy influence regulation of non-imprinted genes by altering the epigenetic regulation of gene expression, thereby inducing different metabolic phenotypes. Magnesium deficiency during pregnancy may be responsible for not only maternal and fetal nutritional problems, but also lifelong consequences that affect the offspring throughout their life. Epidemiological, clinical, and basic research on the effects of magnesium deficiency now indicates underlying mechanisms, especially epigenetic processes.

States and transport of hydrogen in the corrosion process of an AZ91 magnesium alloy in aqueous solution

International Nuclear Information System (INIS)

Chen Jian; Wang Jianqiu; Han Enhou; Dong Junhua; Ke Wei

2008-01-01

Mott-Schottky measurement and secondary ion mass spectroscopy (SIMS) were used to investigate the states and transport of hydrogen during the corrosion behavior of an AZ91 magnesium alloy in 0.1 M sodium sulfate solution. The results showed that when samples were immersed or charged in solution, hydrogen atoms diffused into the film and reacted with vacancy to cause the increases of the carrier concentration (excess electron or hole carrier) and diffusion rate of hydrogen. Some hydrogen atoms diffused to interior of matrix and enriched in β phase while others resorted in the corrosive film. With the increase of immersion or charging time, magnesium hydride would be brittle fractured when the inner stress caused by hydrogen pressure and expansion stress of formation of magnesium hydride was above the fracture strength, which provided the direct experimental evidence of the hydrogen embrittlement (HE) mechanism of magnesium and its alloys. After immersion in solution, the transfer of excess electrons to the interfaces of corrosion film and solution would destroy the charge equilibrium in the film and stimulate the adsorption of SO 4 2- , which resulted in the initiation of localized corrosion; after cathodic charging and then immersion, the enrichment of hydrogen atoms at interior of corrosion film would combine into hydrogen gas to form high pressure and result in the rupture of corrosion film, and localized corrosion initiated and developed at surface. Therefore, localized corrosion nucleated earlier on the charged samples than on the uncharged samples. Hydrogen invasion accelerated the corrosion of matrix

Magnesium in Prevention and Therapy

Science.gov (United States)

Gröber, Uwe; Schmidt, Joachim; Kisters, Klaus

2015-01-01

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

Corrosion of Magnesium in Multimaterial System

Energy Technology Data Exchange (ETDEWEB)

Joshi, Vineet V.; Agnew, Sean

2017-08-16

The TMS Magnesium Committee has been actively involved in presenting cutting-edge research and development and the latest trends related to magnesium and its alloys to industry and academia. Topics including magnesium alloy development, applications, mechanism of deformation and corrosion, thermomechanical processing, modelling, etc. have been captured year after year through the Magnesium Technology symposium and conference proceedings at TMS and through special topics in JOM. Every year, based on the unanimous endorsement from the industry and academia, a topic is selected to address the latest developments within this subject in JOM. In continuation with last year’s coverage of Advances and Achievements in In-Situ Analysis of Corrosions and Structure–Property Relationship in Mg Alloys,[1] this year’s topic focuses on the Corrosion of Magnesium in Multimaterial Systems. Magnesium, the lightest of all the structural materials, has garnered much interest in the transportation, electronics packaging, defense equipments and industries alike and are more commonly being incorporated in multimaterial design concepts.[2-4] However, the application of the same is limited due to its highly corrosive nature, and understanding and mitigating the corrosion of magnesium has been a major research challenge.

The reference range of serum, plasma and erythrocyte magnesium

Directory of Open Access Journals (Sweden)

Suzanna Immanuel

2006-12-01

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

Magnesium Tube Hydroforming

International Nuclear Information System (INIS)

Liewald, M.; Pop, R.; Wagner, S.

2007-01-01

Magnesium alloys can be considered as alternative materials towards achieving light weight structures with high material stiffness. The formability of two magnesium alloys, viz. AZ31 and ZM21 has been experimentally tested using the IHP forming process. A new die set up for hot IHP forming has been designed and the process experimentally investigated for temperatures up to 400 deg. C. Both alloys exhibit an increase in formability with increasing forming temperature. The effect of annealing time on materials forming properties shows a fine grained structure for sufficient annealing times as well as deterioration with a large increase at the same time. The IHP process has also been used to demonstrate practicability and feasibility for real parts from manufacture a technology demonstrator part using the magnesium alloy ZM21

Periodate Oxidation for Sulfated Glycosaminoglycans, with Special Reference to the Position of Extra Sulfate Groups in Chondroitin Polysulfates, Chondroitin Sulfate D and Chondroitin Sulfate K

OpenAIRE

Seno, Nobuko; Murakami, Keiko; Shibusawa, Haru

1981-01-01

The optimum conditions for periodate oxidation of sulfated disaccharides were investigated to determine the position of extra sulfate groups on the saturated disulfated disaccharides obtained from chondroitin polysulfates, chondroitin sulfates D and K. Under the conditions: 2mM saturated disulfated disaccharide with 20mM sodium periodate at 37°in the dark, the uronic acid residue in the disulfated disaccharide from chondroitin sulfate D was rapidly and completely destroyed, whereas that in th...

Health system barriers to access and use of magnesium sulfate for women with severe pre-eclampsia and eclampsia in Pakistan: evidence for policy and practice.

Directory of Open Access Journals (Sweden)

Maryam Bigdeli

Full Text Available Severe pre-eclampsia and eclampsia are rare but serious complications of pregnancy that threaten the lives of mothers during childbirth. Evidence supports the use of magnesium sulfate (MgSO4 as the first line treatment option for severe pre-eclampsia and eclampsia. Eclampsia is the third major cause of maternal mortality in Pakistan. As in many other Low- and Middle-Income Countries (LMIC, it is suspected that MgSO4 is critically under-utilized in the country. There is however a lack of information on context-specific health system barriers that prevent optimal use of this life-saving medicine in Pakistan. Combining quantitative and qualitative methods, namely policy document review, key informant interviews, focus group discussions and direct observation at health facility, we explored context-specific health system barriers and enablers that affect access and use of MgSO4 for severe pre-eclampsia and eclampsia in Pakistan. Our study finds that while international recommendations on MgSO4 have been adequately translated in national policies in Pakistan, the gap remains in implementation of national policies into practice. Barriers to access to and effective use of MgSO4 occur at health facility level where the medicine was not available and health staff was reluctant to use it. Low price of the medicine and the small market related to its narrow indications acted as disincentives for effective marketing. Results of our survey were further discussed in a multi-stakeholder round-table meeting and an action plan for increasing access to this life-saving medicine was identified.

Health system barriers to access and use of magnesium sulfate for women with severe pre-eclampsia and eclampsia in Pakistan: evidence for policy and practice.

Science.gov (United States)

Bigdeli, Maryam; Zafar, Shamsa; Assad, Hafeez; Ghaffar, Adbul

2013-01-01

Severe pre-eclampsia and eclampsia are rare but serious complications of pregnancy that threaten the lives of mothers during childbirth. Evidence supports the use of magnesium sulfate (MgSO4) as the first line treatment option for severe pre-eclampsia and eclampsia. Eclampsia is the third major cause of maternal mortality in Pakistan. As in many other Low- and Middle-Income Countries (LMIC), it is suspected that MgSO4 is critically under-utilized in the country. There is however a lack of information on context-specific health system barriers that prevent optimal use of this life-saving medicine in Pakistan. Combining quantitative and qualitative methods, namely policy document review, key informant interviews, focus group discussions and direct observation at health facility, we explored context-specific health system barriers and enablers that affect access and use of MgSO4 for severe pre-eclampsia and eclampsia in Pakistan. Our study finds that while international recommendations on MgSO4 have been adequately translated in national policies in Pakistan, the gap remains in implementation of national policies into practice. Barriers to access to and effective use of MgSO4 occur at health facility level where the medicine was not available and health staff was reluctant to use it. Low price of the medicine and the small market related to its narrow indications acted as disincentives for effective marketing. Results of our survey were further discussed in a multi-stakeholder round-table meeting and an action plan for increasing access to this life-saving medicine was identified.

Magnesium-phosphate-glass cements with ceramic-type properties

Science.gov (United States)

Sugama, T.; Kukacka, L.E.

1982-09-23

Rapid setting magnesium phosphate (Mg glass) cementitious materials consisting of magnesium phosphate cement paste, polyborax and water-saturated aggregate, exhibits rapid setting and high early strength characteristics. The magnesium glass cement is prepared from a cation-leachable powder and a bivalent metallic ion-accepting liquid such as an aqueous solution of diammonium phosphate and ammonium polyphosphate. The cation-leachable powder includes a mixture of two different magnesium oxide powders processed and sized differently which when mixed with the bivalent metallic ion-accepting liquid provides the magnesium glass cement consisting primarily of magnesium ortho phosphate tetrahydrate, with magnesium hydroxide and magnesium ammonium phosphate hexahydrate also present. The polyborax serves as a set-retarder. The resulting magnesium mono- and polyphosphate cements are particularly suitable for use as a cementing matrix in rapid repair systems for deteriorated concrete structures as well as construction materials and surface coatings for fireproof structures.

Magnesium phosphate glass cements with ceramic-type properties

Science.gov (United States)

Sugama, Toshifumi; Kukacka, Lawrence E.

1984-03-13

Rapid setting magnesium phosphate (Mg glass) cementitious materials consisting of magnesium phosphate cement paste, polyborax and water-saturated aggregate exhibiting rapid setting and high early strength characteristics. The magnesium glass cement is prepared from a cation-leachable powder and a bivalent metallic ion-accepting liquid such as an aqueous solution of diammonium phosphate and ammonium polyphosphate. The cation-leachable powder includes a mixture of two different magnesium oxide powders processed and sized differently which when mixed with the bivalent metallic ion-accepting liquid provides the magnesium glass cement consisting primarily of magnesium ortho phosphate tetrahydrate, with magnesium hydroxide and magnesium ammonium phosphate hexahydrate also present. The polyborax serves as a set-retarder. The resulting magnesium mono- and polyphosphate cements are particularly suitable for use as a cementing matrix in rapid repair systems for deteriorated concrete structures as well as construction materials and surface coatings for fireproof structures.

Magnesium deficiency and increased inflammation: current perspectives

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Nielsen FH

2018-01-01

Full Text Available Forrest H Nielsen Research Nutritionist Consultant, Grand Forks, ND, USA Abstract: Animal studies have shown that magnesium deficiency induces an inflammatory response that results in leukocyte and macrophage activation, release of inflammatory cytokines and acute-phase proteins, and excessive production of free radicals. Animal and in vitro studies indicate that the primary mechanism through which magnesium deficiency has this effect is through increasing cellular Ca2+, which is the signal that results in the priming of cells to give the inflammatory response. Primary pro-inflammatory cytokines such as tumor necrosis factor-α and interleukin (IL-1; the messenger cytokine IL-6; cytokine responders E-selectin, intracellular adhesion molecule-1 and vascular cell adhesion molecule-1; and acute-phase reactants C-reactive protein and fibrinogen have been determined to associate magnesium deficiency with chronic low-grade inflammation (inflammatory stress. When magnesium dietary intake, supplementation, and/or serum concentration suggest/s the presence of magnesium deficiency, it often is associated with low-grade inflammation and/or with pathological conditions for which inflammatory stress is considered a risk factor. When magnesium intake, supplementation, and/or serum concentration suggest/s an adequate status, magnesium generally has not been found to significantly affect markers of chronic low-grade inflammation or chronic disease. The consistency of these findings can be modified by other nutritional and metabolic factors that affect inflammatory and oxidative stress. In spite of this, findings to date provide convincing evidence that magnesium deficiency is a significant contributor to chronic low-grade inflammation that is a risk factor for a variety of pathological conditions such as cardiovascular disease, hypertension, and diabetes. Because magnesium deficiency commonly occurs in countries where foods rich in magnesium are not consumed in

Effect of Magnesium Hydride on the Corrosion Behavior of Pure Magnesium in 0.1 M NaCl Solution

OpenAIRE

Xu, Shanna; Dong, Junhua; Ke, Wei

2010-01-01

The effect of magnesium hydride on the corrosion behavior of pure magnesium in 0.1 M NaCl solution was investigated using the gas collection method, potentiostatic current decay test, and in situ Raman spectrum. The formation of magnesium hydride (MgH2, Mg2H4) was observed at the cathodic region. Applying anodic potential leads to decomposition of magnesium hydride. Magnesium hydride plays an important role on the negative difference effect (NDE) in both the cathodic and anodic regions.

Corrosion and protection of magnesium alloys

Energy Technology Data Exchange (ETDEWEB)

Ghali, E. [Laval Univ., Quebec City, PQ (Canada). Dept. of Mining and Metallurgy

2000-07-01

The oxide film on magnesium offers considerable surface protection in rural and some industrial environments and the corrosion rate lies between that of aluminum and low carbon steels. Galvanic coupling of magnesium alloys, high impurity content such as Ni, Fe, Cu and surface contamination are detrimental for corrosion resistance of magnesium alloys. Alloying elements can form secondary particles which are noble to the Mg matrix, thereby facilitating corrosion, or enrich the corrosion product thereby possibly inhibiting the corrosion rate. Bimetallic corrosion resistance can be increased by fluxless melt protection, choice of compatible alloys, insulating materials, and new high-purity alloys. Magnesium is relatively insensible to oxygen concentration. Pitting, corrosion in the crevices, filiform corrosion are observed. Granular corrosion of magnesium alloys is possible due to the cathodic grain-boundary constituent. More homogeneous microstructures tend to improve corrosion resistance. Under fatigue loading conditions, microcrack initiation in Mg alloys is related to slip in preferentially oriented grains. Coating that exclude the corrosive environments can provide the primary defense against corrosion fatigue. Magnesium alloys that contain neither aluminum nor zinc are the most SCC resistant. Compressive surface residual stresses as that created by short peening increase SCC resistance. Cathodic polarization or cladding with a SCC resistant sheet alloy are good alternatives. Effective corrosion prevention for magnesium alloy components and assemblies should start at the design stage. Selective surface preparation, chemical treatment and coatings are recommended. Oil application, wax coating, anodizing, electroplating, and painting are possible alternatives. Recently, it is found that a magnesium hydride layer, created on the magnesium surface by cathodic charging in aqueous solution is a good base for painting. (orig.)

Mineral Carbonation of Phosphogypsum Waste for Production of Useful Carbonate and Sulfate Salts

Energy Technology Data Exchange (ETDEWEB)

Mattila, Hannu-Petteri, E-mail: hmattila@abo.fi; Zevenhoven, Ron [Thermal and Flow Engineering Laboratory, Åbo Akademi University, Turku (Finland)

2015-11-16

Phosphogypsum (CaSO{sub 4}·2H{sub 2}O, PG) waste is produced in large amounts during phosphoric acid (H{sub 3}PO{sub 4}) production. Minor quantities are utilized in construction or agriculture, while most of the material is stockpiled, creating an environmental challenge to prevent pollution of natural waters. In principle, the gypsum waste could be used to capture several hundred megatonnes of carbon dioxide (CO{sub 2}). For example, when gypsum is converted to ammonium sulfate [(NH{sub 4}){sub 2}SO{sub 4}] with ammonia (NH{sub 3}) and CO{sub 2}, also solid calcium carbonate (CaCO{sub 3}) is generated. The ammonium sulfate can be utilized as a fertilizer or in other mineral carbonation processes that use magnesium silicate-based rock as feedstock, while calcium carbonate has various uses as, e.g., filler material. The reaction extent of the described process was studied by thermodynamic modeling and experimentally as a function of reactant concentrations and temperature. Other essential properties such as purity and quality of the solid products are also followed. Conversion efficiencies of >95% calcium from PG to calcium carbonate are obtained. Scalenohedral, rhombohedral, and prismatic calcite particles can be produced, although the precipitates contain certain contaminants such as rare earth metals and sulfur from the gypsum. A reverse osmosis membrane cartridge is also tested as an alternative and energy-efficient method of concentrating the ammonium sulfate salt solution instead of the traditional evaporation of the process solution.

Mineral carbonation of phosphogypsum waste for production of useful carbonate and sulfate salts

Directory of Open Access Journals (Sweden)

Hannu-Petteri eMattila

2015-11-01

Full Text Available Phosphogypsum (CaSO4·2H2O waste is produced in large amounts during phosphoric acid (H3PO4 production. Minor quantities are utilized in construction or agriculture, while most of the material is stockpiled, creating an environmental challenge to prevent pollution of natural waters. In principle, the gypsum waste could be used to capture several hundred Mt of carbon dioxide (CO2. For example, when gypsum is converted to ammonium sulfate ((NH42SO4 with ammonia (NH3 and CO2, also solid calcium carbonate (CaCO3 is generated. The ammonium sulfate can be utilized as a fertilizer or in other mineral carbonation processes that use magnesium silicate-based rock as feedstock, while calcium carbonate has various uses as e.g. filler material. The reaction extent of the described process was studied by thermodynamic modeling and experimentally as a function of reactant concentrations and temperature. Other essential properties such as purity and quality of the solid products are also followed. Conversion efficiencies of >95% calcium from phosphogypsum to calcium carbonate are obtained. Scalenohedral, rhombohedral and prismatic calcite particles can be produced, though the precipitates contain certain contaminants such as rare earth metals and sulfur from the gypsum. A reverse osmosis membrane cartridge is also tested as an alternative and energy-efficient method of concentrating the ammonium sulfate salt solution instead of the traditional evaporation of the process solution.

Effect of Magnesium Hydride on the Corrosion Behavior of Pure Magnesium in 0.1 M NaCl Solution

Directory of Open Access Journals (Sweden)

Shanna Xu

2010-01-01

Full Text Available The effect of magnesium hydride on the corrosion behavior of pure magnesium in 0.1 M NaCl solution was investigated using the gas collection method, potentiostatic current decay test, and in situ Raman spectrum. The formation of magnesium hydride (MgH2, Mg2H4 was observed at the cathodic region. Applying anodic potential leads to decomposition of magnesium hydride. Magnesium hydride plays an important role on the negative difference effect (NDE in both the cathodic and anodic regions.

21 CFR 582.5431 - Magnesium oxide.

Science.gov (United States)

2010-04-01

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

21 CFR 582.1431 - Magnesium oxide.

Science.gov (United States)

2010-04-01

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

Imparting passivity to vapor deposited magnesium alloys

Science.gov (United States)

Wolfe, Ryan C.

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

Separation of magnesium from magnesium chloride and zirconium and/or hafnium subchlorides in the production of zirconium and/or hafnium sponge metal

International Nuclear Information System (INIS)

Abodishish, H.A.M.; Adams, R.J.; Kearl, S.R.

1992-01-01

This patent describes the producing of a refractory metal wherein a sponge refractory metal is produced as an intermediate product by the use of magnesium with the incidental production of magnesium chloride, and wherein residual magnesium is separated from the magnesium chloride and from refractory metal to a vacuum distillation step which fractionally distills the magnesium, the magnesium chloride, and the metal sub-chlorides; the steps of: recovering fractionally distilled vapors of magnesium chloride and metal sub-chlorides from a sponge refractory metal; separately condensing the vapors as separately recovered; and recycling the separately recovered magnesium at a purity of at least about 96%

Participation of peripheral TRPV1, TRPV4, TRPA1 and ASIC in a magnesium sulfate-induced local pain model in rat.

Science.gov (United States)

Srebro, Dragana; Vučković, Sonja; Prostran, Milica

2016-12-17

We previously showed that magnesium sulfate (MS) has systemic antinociceptive and local peripheral pronociceptive effects. The role of transient receptor potential (TRP) channels and acid-sensing ion channels (ASICs) in the mechanism of action of MS has not been investigated in detail. The aim of this study was to explore the participation of TRP channels in the pronociceptive action of MS in rats after its intraplantar injection. The paw withdrawal threshold (PWT) to mechanical stimuli was measured by the electronic von Frey test. Drugs that were tested were either co-administered with an isotonic pH-unadjusted or pH-adjusted solution of MS intraplantarily, or to the contralateral paw to exclude systemic effects. We found that the subcutaneous administration of both pH-adjusted (7.4) and pH-unadjusted (about 6.0) isotonic (6.2% w/v in water) solutions of MS induce the pain at the injection site. The pH-unadjusted MS solution-induced mechanical hyperalgesia decreased in a dose-dependent manner as a consequence of co-injection of capsazepine, a selective TRPV1 antagonist (20, 100 and 500pmol/paw), RN-1734, a selective TRPV4 antagonist (1.55, 3.1 and 6.2μmol/paw), HC-030031, a selective TRPA1 antagonist (5.6, 28.1 and 140nmol/paw), and amiloride hydrochloride, a non-selective ASIC inhibitor (0.83, 2.5 and 7.55μmol/paw). In pH-adjusted MS-induced hyperalgesia, the highest doses of TRPV1, TRPV4 and TRPA1 antagonists displayed effects that were, respectively, either similar, less pronounced or delayed in comparison to the effect induced by administration of the pH-unadjusted MS solution; the ASIC antagonist did not have any effect. These results suggest that the MS-induced local peripheral mechanical hyperalgesia is mediated via modulation of the activity of peripheral TRPV1, TRPV4, TRPA1 and ASICs. Specific local inhibition of TRP channels represents a novel approach to treating local injection-related pain. Copyright © 2016 IBRO. Published by Elsevier Ltd. All

Improved cytotoxicity testing of magnesium materials

Energy Technology Data Exchange (ETDEWEB)

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

2011-06-25

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

Improved cytotoxicity testing of magnesium materials

International Nuclear Information System (INIS)

Fischer, Janine; Proefrock, Daniel; Hort, Norbert; Willumeit, Regine; Feyerabend, Frank

2011-01-01

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

On the ionization of interstellar magnesium

International Nuclear Information System (INIS)

Gurzadyan, G.A.

1977-01-01

It has been shown that two concentric ionization zones of interstellar magnesium must exist around each star: internal, with a radius coinciding with that of the zone of hydrogen ionization Ssub(H); and external, with a radius greater than Ssub(H), by one order. Unlike interstellar hydrogen, interstellar magnesium is ionized throughout the Galaxy. It also transpires that the ionizing radiation of ordinary hot stars cannot provide for the observed high degree of ionization of interstellar magnesium. The discrepance can be eliminated by assuming the existence of circumstellar clouds or additional ionization sources of interstellar magnesium (X-ray background radiation, high-energy particles, etc.). Stars of the B5 and BO class play the main role in the formation of ionization zones of interstellar magnesium; the contribution of O class stars is negligible (<1%). (Auth.)

Improving the hardness of dry granulated tablets containing sodium lauryl sulfate.

Science.gov (United States)

Moore, Francis; Okelo, Geoffrey; Colón, Ivelisse; Kushner, Joseph

2010-11-15

The impact of the addition of a wetting agent, the surfactant sodium lauryl sulfate (SLS), on the tablet hardness of a dry granulated, solid oral dosage form was investigated. In three batches, SLS was added concurrently with: (1) a poorly soluble, highly hydrophobic active pharmaceutical ingredient (API) and the other excipients prior to the initial blending step, (2) magnesium stearate prior to roller compaction, or (3) magnesium stearate prior to tableting. A fourth batch, which did not contain SLS, served as a control. The maximum hardness of 100 mg, 1/4″-SRC tablets for the four batches--SLS added initially, prior to roller compaction, prior to tableting, and no SLS--were 61±3, 71±3, 89±5, and 86±3N, respectively, suggesting reduced processing of SLS improves tablet hardness by ∼50%. Dissolution of the tablets in 900 ml of simulated gastric fluid with paddles at 75 rpm showed that: (1) there was no impact on the insertion point of SLS into the process on API dissolution, and (2) that the presence of SLS improved dissolution by 5% compared to the control tablets. Adding SLS just prior to tableting can improve tablet hardness and yield similar dissolution performance relative to SLS addition prior to the initial blending step. Copyright © 2010 Elsevier B.V. All rights reserved.

Significant role of organic sulfur in supporting sedimentary sulfate reduction in low-sulfate environments

Science.gov (United States)

Fakhraee, Mojtaba; Li, Jiying; Katsev, Sergei

2017-09-01

Dissimilatory sulfate reduction (DSR) is a major carbon mineralization pathway in aquatic sediments, soils, and groundwater, which regulates the production of hydrogen sulfide and the mobilization rates of biologically important elements such as phosphorus and mercury. It has been widely assumed that water-column sulfate is the main sulfur source to fuel this reaction in sediments. While this assumption may be justified in high-sulfate environments such as modern seawater, we argue that in low-sulfate environments mineralization of organic sulfur compounds can be an important source of sulfate. Using a reaction-transport model, we investigate the production of sulfate from sulfur-containing organic matter for a range of environments. The results show that in low sulfate environments (50%) of sulfate reduction. In well-oxygenated systems, porewater sulfate profiles often exhibit sub-interface peaks so that sulfate fluxes are directed out of the sediment. Our measurements in Lake Superior, the world's largest lake, corroborate this conclusion: offshore sediments act as sources rather than sinks of sulfate for the water column, and sediment DSR is supported entirely by the in-sediment production of sulfate. Sulfate reduction rates are correlated to the depth of oxygen penetration and strongly regulated by the supply of reactive organic matter; rate co-regulation by sulfate availability becomes appreciable below 500 μM level. The results indicate the need to consider the mineralization of organic sulfur in the biogeochemical cycling in low-sulfate environments, including several of the world's largest freshwater bodies, deep subsurface, and possibly the sulfate-poor oceans of the Early Earth.

Magnesium balances and 28Mg studies in man

International Nuclear Information System (INIS)

Spencer, H.; Schwartz, R.; Osis, D.

1988-01-01

The intestinal absorption of magnesium was determined under strictly controlled dietary conditions in patients with normal renal function and also in patients with chronic renal failure. The average net absorption of magnesium of patients with normal renal function, expressed as percent of the magnesium intake, was 48.5%, while that of patients with chronic renal failure was significantly lower, 17%. Increasing the calcium intake from a low calcium intake of 200 mg/day to different higher intake levels up to 2000 mg/day did not change the magnesium balance nor the net absorption of magnesium of both types of patients. The lack of effect of the higher calcium intake on the absorption of magnesium was confirmed in 28 Mg studies in which an oral dose of 28 Mg, as the chloride, was given. The excretion of the absorbed magnesium into the intestine, the endogenous fecal magnesium, was low. Also, increasing the phosphorus intake up to 2000 mg/day in subjects with normal renal function did not affect the magnesium balance, regardless of the calcium intake

Aluminum Hydroxide and Magnesium Hydroxide

Science.gov (United States)

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

Serum magnesium levels in patients with pre-eclampsia and eclampsia with different regimens of magnesium sulphate

Directory of Open Access Journals (Sweden)

Arpita Singh

2013-01-01

Full Text Available Background Pre-eclampsia and the subsequent eclampsia account for a common cause of maternal mortality worldwide and efforts aimed at reducing its menace are vital. Objective To estimate the serum magnesium levels in pre-eclampsia and eclampsia and to study the effect of using different regimens of magnesium sulphate. Methods 70 cases of pre-eclampsia and eclampsia and 35 normal pregnant women as controls were studied. Serum magnesium levels were estimated using Atomic Absorption Spectrophotometer (Model AAS-4139 at baseline and at frequent intervals during gestation and the overall parameters were meticulously observed. Results Majority(60%ofstudiedcaseswasnulliparawithgestationageof36-40 weeks. Statistically significant reduction of mean diastolic blood pressure and protein-urea was observed after using both intramuscular and intravenous regimens of magnesium sulphate. Mean initial serum magnesium level (mg/dl±SD was 1.81±0.58 in group A,1.55±0.41 in group B and 1.49±0.41 in group C. Mean serum magnesium levels during first 4 hours after therapy were statistically significant between intramuscular and intravenous regimen groups while same were statistically insignificant at 8,12,16,24 and 32 hours. Besides, few minor side effects including headache, vomiting, reduced tendon reflexes and thrombocytopenia, no severe side effects and no maternal mortality were seen. Conclusion Hypomagnesemia occurs during states of preeclampsia and eclampsia, and, administration of magnesium sulphate is effective and safe in preventing maternal mortality.

Serum magnesium levels in patients with pre-eclampsia and eclampsia with different regimens of magnesium sulphate

Directory of Open Access Journals (Sweden)

Arpita Singh

2013-03-01

Full Text Available Background Pre-eclampsia and the subsequent eclampsia account for a common cause of maternal mortality worldwide and efforts aimed at reducing its menace are vital. Objective To estimate the serum magnesium levels in pre-eclampsia and eclampsia and to study the effect of using different regimens of magnesium sulphate. Methods 70 cases of pre-eclampsia and eclampsia and 35 normal pregnant women as controls were studied. Serum magnesium levels were estimated using Atomic Absorption Spectrophotometer (Model AAS-4139 at baseline and at frequent intervals during gestation and the overall parameters were meticulously observed. Results Majority (60% of studied cases was nullipara with gestation age of 36-40 weeks. Statistically significant reduction of mean diastolic blood pressure and protein-urea was observed after using both intramuscular and intravenous regimens of magnesium sulphate. Mean initial serum magnesium level (mg/dl±SD was 1.81±0.58 in group A,1.55±0.41 in group B and 1.49±0.41 in group C. Mean serum magnesium levels during first 4 hours after therapy were statistically significant between intramuscular and intravenous regimen groups while same were statistically insignificant at 8,12,16,24 and 32 hours. Besides, few minor side effects including headache, vomiting, reduced tendon reflexes and thrombocytopenia, no severe side effects and no maternal mortality were seen. Conclusion Hypomagnesemia occurs during states of preeclampsia and eclampsia, and, administration of magnesium sulphate is effective and safe in preventing maternal mortality.

Computational micromechanics of bioabsorbable magnesium stents.

Science.gov (United States)

Grogan, J A; Leen, S B; McHugh, P E

2014-06-01

Magnesium alloys are a promising candidate material for an emerging generation of absorbable metal stents. Due to its hexagonal-close-packed lattice structure and tendency to undergo twinning, the deformation behaviour of magnesium is quite different to that of conventional stent materials, such as stainless steel 316L and cobalt chromium L605. In particular, magnesium exhibits asymmetric plastic behaviour (i.e. different yield behaviours in tension and compression) and has lower ductility than these conventional alloys. In the on-going development of absorbable metal stents it is important to assess how the unique behaviour of magnesium affects device performance. The mechanical behaviour of magnesium stent struts is investigated in this study using computational micromechanics, based on finite element analysis and crystal plasticity theory. The plastic deformation in tension and bending of textured and non-textured magnesium stent struts with different numbers of grains through the strut dimension is investigated. It is predicted that, unlike 316L and L605, the failure risk and load bearing capacity of magnesium stent struts during expansion is not strongly affected by the number of grains across the strut dimensions; however texturing, which may be introduced and controlled in the manufacturing process, is predicted to have a significant influence on these measures of strut performance. Copyright © 2014 Elsevier Ltd. All rights reserved.

Magnesium fluoride recovery method

International Nuclear Information System (INIS)

Gay, R.L.; McKenzie, D.E.

1989-01-01

A method of obtaining magnesium fluoride substantially free from radioactive uranium from a slag formed in the production of metallic uranium by the reduction of depleted uranium tetrafluoride with metallic magnesium in a retort wherein the slag contains the free metals magnesium and uranium and also oxides and fluorides of the metals. The slag having a radioactivity level of at least about 7,000 rhoCi/gm. The method comprises the steps of: grinding the slag to a median particle size of about 200 microns; contacting the ground slag in a reaction zone with an acid having a strength of from about 0.5 to 1.5 N for a time of from about 4 to about 20 hours in the presence of a catalytic amount of iron; removing the liquid product; treating the particulate solid product; repeating the last two steps at least one more time to produce a solid residue consisting essentially of magnesium fluoride substantially free of uranium and having a residual radioactivity level of less than about 1000 rhoCi/gm

Radioactive {sup 210}Po in magnesium supplements

Energy Technology Data Exchange (ETDEWEB)

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

2016-08-01

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

Distinction between magnesium diboride and tetraboride by kelvin probe force microscopy

International Nuclear Information System (INIS)

Kim, Du-Na; Caron, Arnaud; Park, Hai Woong

2016-01-01

We analyze mixtures of magnesium diboride and tetraboride synthesized with magnesium powders of different shapes. To distinguish between magnesium diboride and tetraboride we use the contrast of kelvin probe force microscopy. The microstructural morphology strongly depends on the shape of the magnesium powders used in the reaction between magnesium and magnesium tetraboride to form magnesium diboride. With spherical magnesium powder an equiaxed microstructure of magnesium diboride is formed with residual magnesium tetraboride at the grain boundaries. With plate-like magnesium powders elongated magnesium diboride grains are formed. In this case, residual magnesium tetraboride is found to agglomerate.

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

DEFF Research Database (Denmark)

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

2014-01-01

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

Solvation of magnesium dication: molecular dynamics simulation and vibrational spectroscopic study of magnesium chloride in aqueous solutions.

Science.gov (United States)

Callahan, Karen M; Casillas-Ituarte, Nadia N; Roeselová, Martina; Allen, Heather C; Tobias, Douglas J

2010-04-22

Magnesium dication plays many significant roles in biochemistry. While it is available to the environment from both ocean waters and mineral salts on land, its roles in environmental and atmospheric chemistry are still relatively unknown. Several pieces of experimental evidence suggest that contact ion pairing may not exist at ambient conditions in solutions of magnesium chloride up to saturation concentrations. This is not typical of most ions. There has been disagreement in the molecular dynamics literature concerning the existence of ion pairing in magnesium chloride solutions. Using a force field developed during this study, we show that contact ion pairing is not energetically favorable. Additionally, we present a concentration-dependent Raman spectroscopic study of the Mg-O(water) hexaaquo stretch that clearly supports the absence of ion pairing in MgCl(2) solutions, although a transition occurring in the spectrum between 0.06x and 0.09x suggests a change in solution structure. Finally, we compare experimental and calculated observables to validate our force field as well as two other commonly used magnesium force fields, and in the process show that ion pairing of magnesium clearly is not observed at higher concentrations in aqueous solutions of magnesium chloride, independent of the choice of magnesium force field, although some force fields give better agreement to experimental results than others.

Intradermal administration of magnesium sulphate and magnesium chloride produces hypesthesia to mechanical but hyperalgesia to heat stimuli in humans

Directory of Open Access Journals (Sweden)

Ikemoto Tatsunori

2009-08-01

Full Text Available Abstract Background Although magnesium ions (Mg2+ are known to display many similar features to other 2+ charged cations, they seem to have quite an important and unique role in biological settings, such as NMDA blocking effect. However, the role of Mg2+ in the neural transmission system has not been studied as sufficiently as calcium ions (Ca2+. To clarify the sensory effects of Mg2+ in peripheral nervous systems, sensory changes after intradermal injection of Mg2+ were studied in humans. Methods Magnesium sulphate, magnesium chloride and saline were injected into the skin of the anterior region of forearms in healthy volunteers and injection-induced irritating pain ("irritating pain", for short, tactile sensation, tactile pressure thresholds, pinch-pain changes and intolerable heat pain thresholds of the lesion were monitored. Results Flare formation was observed immediately after magnesium sulphate or magnesium chloride injection. We found that intradermal injections of magnesium sulphate and magnesium chloride transiently caused irritating pain, hypesthesia to noxious and innocuous mechanical stimulations, whereas secondary hyperalgesia due to mechanical stimuli was not observed. In contrast to mechanical stimuli, intolerable heat pain-evoking temperature was significantly decreased at the injection site. In addition to these results, spontaneous pain was immediately attenuated by local cooling. Conclusion Membrane-stabilizing effect and peripheral NMDA-blocking effect possibly produced magnesium-induced mechanical hypesthesia, and extracellular cation-induced sensitization of TRPV1 channels was thought to be the primary mechanism of magnesium-induced heat hyperalgesia.

Effect of magnesium hydride on the corrosion behavior of an AZ91 magnesium alloy in sodium chloride solution

International Nuclear Information System (INIS)

Chen Jian; Dong Junhua; Wang Jianqiu; Han Enhou; Ke Wei

2008-01-01

The effect of magnesium hydride on the corrosion behavior of an as-cast AZ91 alloy in 3.5 wt.% NaCl solution was investigated using gas collection method and potentiostatic test. The Pourbaix diagram of Mg-H 2 O system was built using thermodynamic calculation. It was possible that magnesium hydride could form in the whole pH range in theory. The experimental results showed that at cathodic region, magnesium hydride formed on surface, which was the controlling process for the corrosion behavior of AZ91 alloy; at anodic region and free corrosion potential, magnesium hydride model and partially protective film model, monovalent magnesium ion model and particle undermining model were responsible for the corrosion process of AZ91 alloy

Higher dietary magnesium intake and higher magnesium status are associated with lower prevalence of coronary heart disease in patients with type 2 diabetes

NARCIS (Netherlands)

Gant, C.M.; Soedamah-Muthu, S.S.; Binnenmars, S.H.; Bakker, S.J.L.; Navis, G.; Laverman, G.D.

2018-01-01

In type 2 diabetes mellitus (T2D), the handling of magnesium is disturbed. Magnesium deficiency may be associated with a higher risk of coronary heart disease (CHD). We investigated the associations between (1) dietary magnesium intake; (2) 24 h urinary magnesium excretion; and (3) plasma magnesium

Serum magnesium concentration in drug-addicted patients.

Science.gov (United States)

Karakiewicz, Beata; Kozielec, Tadeusz; Brodowski, Jacek; Chlubek, Dariusz; Noceń, Iwona; Starczewski, Andrzej; Brodowska, Agnieszka; Laszczyńska, Maria

2007-03-01

Drug addiction is a complex problem which leads to many somatic, psychic and social diseases. It is accompanied by the disturbed metabolism of various macro and micronutrients. The aim of this study was to assess serum magnesium concentration in drug-addicted patients and analyze whether Human Immunodeficiency Virus (HIV) infection and methadone treatment affect the level of serum magnesium in these patients. The examination was conducted in a group of 83 people - patients of Szczecin-Zdroje Psychiatric Hospital (Poland). They were 21 to 49 years old, and the mean age was 32 +/- 7 years. The control group consisted of 81 healthy individuals. Flame atomic-absorption spectrometry method was used to determine the magnesium concentration. The total serum magnesium concentration was calculated for the whole patient group, subgroups of women and men, a subgroup of people infected with HIV, and a subgroup receiving methadone substitution treatment. How magnesium behaves depending on age and addiction period, was checked. The mean concentration of magnesium in blood serum of the patients examined was 0.57 mmol/L, which was significantly lower than in the control group. In the subgroup of men it was 0.57 mmol/L, and in the subgroup of women - 0.55 mmol/L; the differences were not statistically significant. In the patient group nobody had the appropriate magnesium concentration in blood serum. No significant correlation was found between the magnesium concentration, age of the patients and addiction period. In the subgroup of seropositive people the mean concentration of magnesium was 0.55 mmol/L, and in the subgroup of non-infected patients - 0.58 mmol/L; the difference was not statistically significant. The mean concentration of magnesium in the subgroup treated with methadone was 0.59 mmol/L, and in the subgroup not involved in this type of therapy - 0.55 mmol/L; it was not a statistically significant difference.

The Role of Magnesium in Neurological Disorders

Directory of Open Access Journals (Sweden)

Anna E. Kirkland

2018-06-01

Full Text Available Magnesium is well known for its diverse actions within the human body. From a neurological standpoint, magnesium plays an essential role in nerve transmission and neuromuscular conduction. It also functions in a protective role against excessive excitation that can lead to neuronal cell death (excitotoxicity, and has been implicated in multiple neurological disorders. Due to these important functions within the nervous system, magnesium is a mineral of intense interest for the potential prevention and treatment of neurological disorders. Current literature is reviewed for migraine, chronic pain, epilepsy, Alzheimer’s, Parkinson’s, and stroke, as well as the commonly comorbid conditions of anxiety and depression. Previous reviews and meta-analyses are used to set the scene for magnesium research across neurological conditions, while current research is reviewed in greater detail to update the literature and demonstrate the progress (or lack thereof in the field. There is strong data to suggest a role for magnesium in migraine and depression, and emerging data to suggest a protective effect of magnesium for chronic pain, anxiety, and stroke. More research is needed on magnesium as an adjunct treatment in epilepsy, and to further clarify its role in Alzheimer’s and Parkinson’s. Overall, the mechanistic attributes of magnesium in neurological diseases connote the macromineral as a potential target for neurological disease prevention and treatment.

Brittlestars contain highly sulfated chondroitin sulfates/dermatan sulfates that promote fibroblast growth factor 2-induced cell signaling.

Science.gov (United States)

Ramachandra, Rashmi; Namburi, Ramesh B; Ortega-Martinez, Olga; Shi, Xiaofeng; Zaia, Joseph; Dupont, Sam T; Thorndyke, Michael C; Lindahl, Ulf; Spillmann, Dorothe

2014-02-01

Glycosaminoglycans (GAGs) isolated from brittlestars, Echinodermata class Ophiuroidea, were characterized, as part of attempts to understand the evolutionary development of these polysaccharides. A population of chondroitin sulfate/dermatan sulfate (CS/DS) chains with a high overall degree of sulfation and hexuronate epimerization was the major GAG found, whereas heparan sulfate (HS) was below detection level. Enzymatic digestion with different chondroitin lyases revealed exceptionally high proportions of di- and trisulfated CS/DS disaccharides. The latter unit appears much more abundant in one of four individual species of brittlestars, Amphiura filiformis, than reported earlier in other marine invertebrates. The brittlestar CS/DS was further shown to bind to growth factors such as fibroblast growth factor 2 and to promote FGF-stimulated cell signaling in GAG-deficient cell lines in a manner similar to that of heparin. These findings point to a potential biological role for the highly sulfated invertebrate GAGs, similar to those ascribed to HS in vertebrates.

Influence of process variables on biooxidation of ferrous sulfate by an indigenous Acidithiobacillus ferrooxidans. Part I: Flask experiments

Energy Technology Data Exchange (ETDEWEB)

S.M. Mousavi; S. Yaghmaei; F. Salimi; A. Jafari [Sharif University of Technology, Tehran (Iran). Department of Chemical and Petroleum Engineering

2006-12-15

Biological oxidation of ferrous sulfate by Acidithiobacillus ferrooxidans has proved to be a significant step in the bioleaching of sulfide minerals and the treatment of acid mine drainage. The same bioreaction also has beneficial applications in the desulphurization of coal and removal of hydrogen sulfide from gaseous effluents. In this research, the effects of some process variables such as pH, temperature, elemental sulfur, amount of initial ferrous and magnesium ions on oxidation of ferrous sulfate by a native A. ferrooxidans, which was isolated from a chalcopyrite concentrate, were investigated. All experiments carried out in shake flasks at 33{sup o}C that was obtained as optimum temperature for the specific bacterial growth rate. The optimum range of pH for the maximum growth of the cells and effective biooxidation of ferrous sulfate varied from 2 to 2.3. The maximum biooxidation rate was achieved 1.2 g/L h in a culture initially containing 20.2 g/L Fe{sup 2+}. Mg{sup 2+} from 20 mg/L to 120 mg/L did not have any effect on the efficiency of the process, while the presence of elemental sulfur had negative effect on the biooxidation. 16 refs., 8 figs.

Discovery of a Heparan sulfate 3- o -sulfation specific peeling reaction

NARCIS (Netherlands)

Huang, Yu; Mao, Yang; Zong, Chengli; Lin, Cheng; Boons, Geert Jan|info:eu-repo/dai/nl/088245489; Zaia, Joseph

2015-01-01

Heparan sulfate (HS) 3-O-sulfation determines the binding specificity of HS/heparin for antithrombin III and plays a key role in herpes simplex virus (HSV) infection. However, the low natural abundance of HS 3-O-sulfation poses a serious challenge for functional studies other than the two cases

p-Cresyl sulfate and indoxyl sulfate in pediatric patients on chronic dialysis

Directory of Open Access Journals (Sweden)

Hye Sun Hyun

2013-04-01

Full Text Available &lt;b&gt;Purpose:&lt;/b&gt; Indoxyl sulfate and p- cresyl sulfate are important protein-bound uremic retention solutes whose levels can be partially reduced by renal replacement therapy. These solutes originate from intestinal bacterial protein fermentation and are associated with cardiovascular outcomes and chronic kidney disease progression. The aims of this study were to investigate the levels of indoxyl sulfate and p- cresyl sulfate as well as the effect of probiotics on reducing the levels of uremic toxins in pediatric patients on dialysis. &lt;b&gt;Methods:&lt;/b&gt; We enrolled 20 pediatric patients undergoing chronic dialysis; 16 patients completed the study. The patients underwent a 12-week regimen of VSL#3, a high-concentration probiotic preparation, and the serum levels of indoxyl sulfate and p- cresyl sulfate were measured before treatment and at 4, 8, and 12 weeks after the regimen by using fluorescence liquid chromatography. To assess the normal range of indoxyl sulfate and p- cresyl sulfate we enrolled the 16 children with normal glomerular filtration rate who had visited an outpatient clinic for asymptomatic microscopic hematuria that had been detected by a school screening in August 2011. &lt;b&gt;Results:&lt;/b&gt; The baseline serum levels of indoxyl sulfate and p- cresyl sulfate in the patients on chronic dialysis were significantly higher than those in the children with microscopic hematuria. The baseline serum levels of p- cresyl sulfate in the peritoneal dialysis group were significantly higher than those in the hemodialysis group. There were no significant changes in the levels of these uremic solutes after 12-week VSL#3 treatment in the patients on chronic dialysis. &lt;b&gt;Conclusion:&lt;/b&gt; The levels of the uremic toxins p- cresyl sulfate and indoxyl sulfate are highly elevated in pediatric patients on dialysis, but there was no significant effect by

Nanostructured magnesium has fewer detrimental effects on osteoblast function

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Weng L

2013-05-01

Full Text Available Lucy Weng, Thomas J Webster School of Engineering and Department of Orthopedics, Brown University, Providence, RI, USA Abstract: Efforts have been made recently to implement nanoscale surface features on magnesium, a biodegradable metal, to increase bone formation. Compared with normal magnesium, nanostructured magnesium has unique characteristics, including increased grain boundary properties, surface to volume ratio, surface roughness, and surface energy, which may influence the initial adsorption of proteins known to promote the function of osteoblasts (bone-forming cells. Previous studies have shown that one way to increase nanosurface roughness on magnesium is to soak the metal in NaOH. However, it has not been determined if degradation of magnesium is altered by creating nanoscale features on its surface to influence osteoblast density. The aim of the present in vitro study was to determine the influence of degradation of nanostructured magnesium, created by soaking in NaOH, on osteoblast density. Our results showed a less detrimental effect of magnesium degradation on osteoblast density when magnesium was treated with NaOH to create nanoscale surface features. The detrimental degradation products of magnesium are of significant concern when considering use of magnesium as an orthopedic implant material, and this study identified a surface treatment, ie, soaking in NaOH to create nanoscale features for magnesium that can improve its use in numerous orthopedic applications. Keywords: nanostructured magnesium, degradation, detrimental effects, osteoblasts

Corrosion Screening of EV31A Magnesium and Other Magnesium Alloys using Laboratory-Based Accelerated Corrosion and Electro-Chemical Methods

Science.gov (United States)

2014-07-01

Spray. Journal of Failure Analysis and Prevention 2008, 8 (2), 164–175. 34. Aluminium Alloy 5083, Plate and Sheet; SAE-AMS-QQ-A-250/6S; SAE...Corrosion Screening of EV31A Magnesium and Other Magnesium Alloys Using Laboratory-Based Accelerated Corrosion and Electro-chemical Methods...Magnesium and Other Magnesium Alloys Using Laboratory-Based Accelerated Corrosion and Electro-chemical Methods Brian E. Placzankis, Joseph P

Hydrostatic extrusion of magnesium alloys

NARCIS (Netherlands)

Sillekens, W.H.; Bohlen, J.

2012-01-01

This chapter deals with the capabilities and limitations of the hydrostatic extrusion process for the manufacturing of magnesium alloy sections. Firstly, the process basics for the hydrostatic extrusion of materials in general and of magnesium in particular are introduced. Next, some recent research

Magnesium bicarbonate as an in situ uranium lixiviant

International Nuclear Information System (INIS)

Sibert, J.W.

1984-01-01

In the subsurface solution mining of mineral values, especially uranium, in situ, magnesium bicarbonate leaching solution is used instead of sodium, potassium and ammonium carbonate and bicarbonates. The magnesium bicarbonate solution is formed by combining carbon dioxide with magnesium oxide and water. The magnesium bicarbonate lixivant has four major advantages over prior art sodium, potassium and ammonium bicarbonates

Magnesium supplement in pregnancy-induced hypertension. A clinicopathological study

DEFF Research Database (Denmark)

Rudnicki, M; Junge, Jette; Frølich, A

1990-01-01

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

Preparation and corrosion resistance of magnesium phytic acid/hydroxyapatite composite coatings on biodegradable AZ31 magnesium alloy.

Science.gov (United States)

Zhang, Min; Cai, Shu; Zhang, Feiyang; Xu, Guohua; Wang, Fengwu; Yu, Nian; Wu, Xiaodong

2017-06-01

In this work, a magnesium phytic acid/hydroxyapatite composite coating was successfully prepared on AZ31 magnesium alloy substrate by chemical conversion deposition technology with the aim of improving its corrosion resistance and bioactivity. The influence of hydroxyapatite (HA) content on the microstructure and corrosion resistance of the coatings was investigated. The results showed that with the increase of HA content in phytic acid solution, the cracks on the surface of the coatings gradually reduced, which subsequently improved the corrosion resistance of these coated magnesium alloy. Electrochemical measurements in simulated body fluid (SBF) revealed that the composite coating with 45 wt.% HA addition exhibited superior surface integrity and significantly improved corrosion resistance compared with the single phytic acid conversion coating. The results of the immersion test in SBF showed that the composite coating could provide more effective protection for magnesium alloy substrate than that of the single phytic acid coating and showed good bioactivity. Magnesium phytic acid/hydroxyapatite composite, with the desired bioactivity, can be synthesized through chemical conversion deposition technology as protective coatings for surface modification of the biodegradable magnesium alloy implants. The design idea of the new type of biomaterial is belong to the concept of "third generation biomaterial". Corrosion behavior and bioactivity of coated magnesium alloy are the key issues during implantation. In this study, preparation and corrosion behavior of magnesium phytic acid/hydroxyapatite composite coatings on magnesium alloy were studied. The basic findings and significance of this paper are as follows: 1. A novel environmentally friendly, homogenous and crack-free magnesium phytic acid/hydroxyapatite composite coating was fabricated on AZ31 magnesium alloy via chemical conversion deposition technology with the aim of enhancing its corrosion resistance and

Co-existence of Methanogenesis and Sulfate Reduction with Common Substrates in Sulfate-Rich Estuarine Sediments

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Michal Sela-Adler

2017-05-01

Full Text Available The competition between sulfate reducing bacteria and methanogens over common substrates has been proposed as a critical control for methane production. In this study, we examined the co-existence of methanogenesis and sulfate reduction with shared substrates over a large range of sulfate concentrations and rates of sulfate reduction in estuarine systems, where these processes are the key terminal sink for organic carbon. Incubation experiments were carried out with sediment samples from the sulfate-methane transition zone of the Yarqon (Israel estuary with different substrates and inhibitors along a sulfate concentrations gradient from 1 to 10 mM. The results show that methanogenesis and sulfate reduction can co-exist while the microbes share substrates over the tested range of sulfate concentrations and at sulfate reduction rates up to 680 μmol L-1 day-1. Rates of methanogenesis were two orders of magnitude lower than rates of sulfate reduction in incubations with acetate and lactate, suggesting a higher affinity of sulfate reducing bacteria for the available substrates. The co-existence of both processes was also confirmed by the isotopic signatures of δ34S in the residual sulfate and that of δ13C of methane and dissolved inorganic carbon. Copy numbers of dsrA and mcrA genes supported the dominance of sulfate reduction over methanogenesis, while showing also the ability of methanogens to grow under high sulfate concentration and in the presence of active sulfate reduction.

Nanostructured magnesium has fewer detrimental effects on osteoblast function

Science.gov (United States)

Weng, Lucy; Webster, Thomas J

2013-01-01

Efforts have been made recently to implement nanoscale surface features on magnesium, a biodegradable metal, to increase bone formation. Compared with normal magnesium, nanostructured magnesium has unique characteristics, including increased grain boundary properties, surface to volume ratio, surface roughness, and surface energy, which may influence the initial adsorption of proteins known to promote the function of osteoblasts (bone-forming cells). Previous studies have shown that one way to increase nanosurface roughness on magnesium is to soak the metal in NaOH. However, it has not been determined if degradation of magnesium is altered by creating nanoscale features on its surface to influence osteoblast density. The aim of the present in vitro study was to determine the influence of degradation of nanostructured magnesium, created by soaking in NaOH, on osteoblast density. Our results showed a less detrimental effect of magnesium degradation on osteoblast density when magnesium was treated with NaOH to create nanoscale surface features. The detrimental degradation products of magnesium are of significant concern when considering use of magnesium as an orthopedic implant material, and this study identified a surface treatment, ie, soaking in NaOH to create nanoscale features for magnesium that can improve its use in numerous orthopedic applications. PMID:23674891

Nanostructured magnesium has fewer detrimental effects on osteoblast function.

Science.gov (United States)

Weng, Lucy; Webster, Thomas J

2013-01-01

Efforts have been made recently to implement nanoscale surface features on magnesium, a biodegradable metal, to increase bone formation. Compared with normal magnesium, nanostructured magnesium has unique characteristics, including increased grain boundary properties, surface to volume ratio, surface roughness, and surface energy, which may influence the initial adsorption of proteins known to promote the function of osteoblasts (bone-forming cells). Previous studies have shown that one way to increase nanosurface roughness on magnesium is to soak the metal in NaOH. However, it has not been determined if degradation of magnesium is altered by creating nanoscale features on its surface to influence osteoblast density. The aim of the present in vitro study was to determine the influence of degradation of nanostructured magnesium, created by soaking in NaOH, on osteoblast density. Our results showed a less detrimental effect of magnesium degradation on osteoblast density when magnesium was treated with NaOH to create nanoscale surface features. The detrimental degradation products of magnesium are of significant concern when considering use of magnesium as an orthopedic implant material, and this study identified a surface treatment, ie, soaking in NaOH to create nanoscale features for magnesium that can improve its use in numerous orthopedic applications.

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

NARCIS (Netherlands)

Flores Ramirez, J.R.

2006-01-01

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

Rare earth sulfates

International Nuclear Information System (INIS)

Komissarova, L.N.; Shatskij, V.M.; Pokrovskij, A.N.; Chizhov, S.M.; Bal'kina, T.I.; Suponitskij, Yu.L.

1986-01-01

Results of experimental works on the study of synthesis conditions, structure and physico-chemical properties of rare earth, scandium and yttrium sulfates, have been generalized. Phase diagrams of solubility and fusibility, thermodynamic and crystallochemical characteristics, thermal stability of hydrates and anhydrous sulfates of rare earths, including normal, double (with cations of alkali and alkaline-earth metals), ternary and anion-mixed sulfates of rare earths, as well as their adducts, are considered. The state of ions of rare earths, scandium and yttrium in aqueous sulfuric acid solutions is discussed. Data on the use of rare earth sulfates are given

Solubilities of magnesium-L-ascorbate, calcium-L-ascorbate, magnesium-L-glutamate, magnesium-D-gluconate, calcium-D-gluconate, calcium-D-heptagluconate, L-aspartic acid, and 3-nitrobenzoic acid in water

Energy Technology Data Exchange (ETDEWEB)

Mishelevich, Alexander [Department of Chemical Engineering, Ben Gurion University of the Negev, Beer Sheva 84105 (Israel); Apelblat, Alexander [Department of Chemical Engineering, Ben Gurion University of the Negev, Beer Sheva 84105 (Israel)], E-mail: apelblat@bgu.ac.il

2008-05-15

The solubility in water of magnesium-L-ascorbate, calcium-L-ascorbate, magnesium-L-glutamate, magnesium-D-gluconate, calcium-D-gluconate, calcium-D-heptagluconate, L-aspartic acid, and 3-nitrobenzoic acid was determined in the 278.15 K to 343.15 K temperature range. The solubility of these compounds served to permit the evaluation of the apparent molar enthalpies of solution.

Solubilities of magnesium-L-ascorbate, calcium-L-ascorbate, magnesium-L-glutamate, magnesium-D-gluconate, calcium-D-gluconate, calcium-D-heptagluconate, L-aspartic acid, and 3-nitrobenzoic acid in water

International Nuclear Information System (INIS)

Mishelevich, Alexander; Apelblat, Alexander

2008-01-01

The solubility in water of magnesium-L-ascorbate, calcium-L-ascorbate, magnesium-L-glutamate, magnesium-D-gluconate, calcium-D-gluconate, calcium-D-heptagluconate, L-aspartic acid, and 3-nitrobenzoic acid was determined in the 278.15 K to 343.15 K temperature range. The solubility of these compounds served to permit the evaluation of the apparent molar enthalpies of solution

Proton Pump Inhibitors and Serum Magnesium Levels in Patients With Torsades de Pointes

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Pietro E. Lazzerini

2018-04-01

Full Text Available Background: Torsades de pointes (TdP is a life-threatening ventricular tachycardia occurring in long QT-syndrome patients. It usually develops when multiple QT-prolonging factors are concomitantly present, more frequently drugs and electrolyte imbalances. Since proton–pump inhibitors (PPIs-associated hypomagnesemia is an increasingly recognized adverse event, PPIs were recently included in the list of drugs with conditional risk of TdP, despite only few cases of TdP in PPI users have been reported so far.Objectives: Aim of the present study is to evaluate whether PPI-induced hypomagnesemia actually has a significant clinical impact on the risk of TdP in the general population.Methods: Forty-eight unselected patients who experienced TdP were consecutively enrolled (2008-2017. Shortly after the first TdP episode, in those patients who did not receive magnesium sulfate and/or potassium or calcium replacement therapy, serum electrolytes were measured and their relationship with PPI usage analyzed.Results: Many patients (28/48, 58% were under current PPI treatment when TdP occurred. Among TdP patients in whom serum electrolyte determinations were obtained before replacement therapy (27/48, those taking PPIs had significantly lower serum magnesium levels than those who did not. Hypomagnesemia occurred in ~40% of patients receiving PPIs (6/14, in all cases after an extended treatment (>2 weeks. In patients taking PPIs the mean QT-prolonging risk factor number was significantly higher than in those who did not, a difference which was mainly driven by lower magnesium levels.Conclusions: In unselected TdP patients, PPI-induced hypomagnesemia was common and significantly contributed to their cumulative arrhythmic risk. By providing clinical support to current recommendations, our data confirm that more awareness is needed when a PPI is prescribed, specifically as regards the risk of life-threatening arrhythmias.

Heparan sulfate biosynthesis

DEFF Research Database (Denmark)

Multhaupt, Hinke A B; Couchman, John R

2012-01-01

Heparan sulfate is perhaps the most complex polysaccharide known from animals. The basic repeating disaccharide is extensively modified by sulfation and uronic acid epimerization. Despite this, the fine structure of heparan sulfate is remarkably consistent with a particular cell type. This suggests...... that the synthesis of heparan sulfate is tightly controlled. Although genomics has identified the enzymes involved in glycosaminoglycan synthesis in a number of vertebrates and invertebrates, the regulation of the process is not understood. Moreover, the localization of the various enzymes in the Golgi apparatus has......-quality resolution of the distribution of enzymes. The EXT2 protein, which when combined as heterodimers with EXT1 comprises the major polymerase in heparan sulfate synthesis, has been studied in depth. All the data are consistent with a cis-Golgi distribution and provide a starting point to establish whether all...

Study of Serum Magnesium in Surgical Stress

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Sandip D. Lambe

2016-10-01

Full Text Available Background: A deficiency of magnesium is of clinical importance in hospitalized patients. The prevalence of hypomagnesaemia is high in critically ill patients. Knowing the important role of magnesium in surgical cases, it is necessary to anticipate and diagnose magnesium deficiency prior to surgery and in the immediate postoperative period to correct it. Aims and Objectives: The aim of this study was to analyse serum magnesium levels in patients undergoing emergency surgical procedures, planned surgical procedures and normal healthy matched controls and to compare the serum magnesium levels in all the three groups. Materials and Methods: The study participants were divided into three groups: i Group I: patients undergoing emergency major surgery ii Group II: patients undergoing planned major surgery iii Group III: normal healthy controls. Serum Magnesium investigation was done by Xylidyl Blue Method using UV-1800/Shimadzu UV-Spectrophotometer. Results: The mean serum Magnesium in control group was found to be 2.16 ± 0.30 mg/dl. In patients undergoing planned surgery, pre-operative serum magnesium was normal (2.16 ± 0.22 mg/dl but decreased significantly on postoperative day 3 (1.63 ± 0.27 mg/dl and day 6 (1.97 ± 0.12 mg/dl and returned to normal level by post-operative day 9 (2.14 ± 0.14 mg/dl compared to controls. In patients undergoing emergency surgery, serum magnesium was decreased pre-operatively (1.90 ± 0.48 mg/dl.Further significant reduction was found at post-operative day 3 (1.38 ± 0.28 mg/dl, day 6 (1.59 ± 0.30 mg/dl and day 9 (1.88 ± 0.46 mg/dl compared to controls. Mean serum Magnesium overall in emergency surgery patients was reduced significantly compared to planned surgery patients. Conclusion: A transient fall in the serum Magnesium as compared to its pre-operative level was seen in every patient undergoing surgical procedure due to surgical stress. In patients undergoing emergency surgical procedure, the decrease was

Low Temperature Synthesis of Magnesium Aluminate Spinel

International Nuclear Information System (INIS)

Lebedovskaya, E.G.; Gabelkov, S.V.; Litvinenko, L.M.; Logvinkov, D.S.; Mironova, A.G.; Odejchuk, M.A.; Poltavtsev, N.S.; Tarasov, R.V.

2006-01-01

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

Wide Strip Casting Technology of Magnesium Alloys

Science.gov (United States)

Park, W.-J.; Kim, J. J.; Kim, I. J.; Choo, D.

Extensive investigations relating to the production of high performance and low cost magnesium sheet by strip casting have been performed for the application to automotive parts and electronic devices. Research on magnesium sheet production technology started in 2004 by Research Institute of Industrial Science and Technology (RIST) with support of Pohang Iron and Steel Company (POSCO). POSCO has completed the world's first plant to manufacture magnesium coil. Another big project in order to develop wide strip casting technology for the automotive applications of magnesium sheets was started in succession.

Effect of oxygen on the hydrogenation properties of magnesium films

DEFF Research Database (Denmark)

Ostenfeld, Christopher Worsøe; Chorkendorff, Ib

2006-01-01

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

The potential for ionic liquid electrolytes to stabilise the magnesium interface for magnesium/air batteries

International Nuclear Information System (INIS)

Khoo, Timothy; Howlett, Patrick C.; Tsagouria, Maureen; MacFarlane, Douglas R.; Forsyth, Maria

2011-01-01

Magnesium/air batteries are a possible high-energy density power source that, to date, have not received strong commercial interest due to issues with the corrosion of the magnesium and evaporation of the electrolyte. In this work we report on the use of ionic liquid based electrolytes to stabilise the metal/electrolyte interface and their impact on the electrochemical performance. Galvanostatic measurements indicate that the water content of the ionic liquid electrolyte plays an important role in the cell discharge characteristics. Surface characterisation using EIS, ATR-FTIR and powder diffraction examined the unique properties of the surface film formed on the magnesium anode.

Integrated approach for investigating the durability of self-consolidating concrete to sulfate attack

Science.gov (United States)

Bassuoni, Mohamed Tamer F.

The growing use of self-consolidating concrete (SCC) in various infrastructure applications exposed to sulfate-rich environments necessitates conducting comprehensive research to evaluate its durability to external sulfate attack. Since the reliability and adequacy of standard sulfate immersion tests have been questioned, the current thesis introduced an integrated testing approach for assessing the durability of a wide scope of SCC mixtures to external sulfate attack. This testing approach involved progressive levels of complexity from single to multiple damage processes. A new series of sulfate attack tests involving multiple field-like parameters and combined damage mechanisms (various cations, controlled pH, wetting-drying, partial immersion, freezing-thawing, and cyclic cold-hot conditions with or without sustained flexural loading) were designed to evaluate the performance (suitability) of the SCC mixtures under various sulfate attack exposure scenarios. The main mixture design variables of SCC included the type of binder (single, binary, ternary and quaternary), air-entrainment, sand-to-aggregate mass ratio and hybrid fibre reinforcement. The comprehensive database and knowledge obtained from this research were used to develop smart models (fuzzy and neuro-fuzzy inference systems) based on artificial-intelligence to evaluate and predict the performance of the SCC mixtures under various sulfate attack exposure regimes implemented in this study. In full immersion tests involving high concentration sodium and magnesium sulfate solutions with controlled pH, the low penetrability of SCC was responsible for the high durability of specimens. Ternary and quaternary cementitious systems with or without limestone materials provided a passivating layer, with or without acid neutralization capacity, which protected SCC from severe damage in the aggressive sulfuric acid and ammonium sulfate solutions. In contrast to conclusions drawn from the sodium sulfate immersion

Irradiation effects in magnesium and aluminium alloys

International Nuclear Information System (INIS)

Sturcken, E.F.

1979-01-01

Effects of neutron irradiation on microstructure, mechanical properties and swelling of several magnesium and aluminium alloys were studied. The neutron fluences of 2-3 X 10 22 n/cm 2 , >0.2 MeV produced displacement doses of 20 to 45 displacements per atom (dpa). Ductility of the magnesium alloys was severely reduced by irradiation induced recrystallization and precipitation of various forms. Precipitation of transmuted silicon occurred in the aluminium alloys. However, the effect on ductility was much less than for the magnesium alloys. The magnesium and aluminium alloys had excellent resistance to swelling: The best magnesium alloy was Mg/3.0 wt% Al/0.19 wt% Ca; its density decreased by only 0.13%. The best aluminium alloy was 6063, with a density decrease of 0.22%. (Auth.)

Surface modification of magnesium aluminum hydroxide nanoparticles with poly(methyl methacrylate) via one-pot in situ polymerization

Energy Technology Data Exchange (ETDEWEB)

Guo Xiaojun, E-mail: guoxj6906@163.com [College of Chemistry and Chemical Engineering, Northwest Normal University, 967 Anning East Road, Lanzhou 730070 (China); Zhao Leihua; Zhang Li; Li Jing [College of Chemistry and Chemical Engineering, Northwest Normal University, 967 Anning East Road, Lanzhou 730070 (China)

2012-01-15

Hydrophobic magnesium aluminum hydroxide composite particles (PMMA-MAH) were obtained by means of grafting poly(methyl methacrylate) (PMMA) onto the surface of magnesium aluminum hydroxide(MAH) nanoparticles after a novel type of phosphate coupling agent (DN-27) modification. The introduction of functional double bonds was firstly conducted on the surface of nanoparticles by DN-27 modification, followed by one-pot in situ polymerization on the particles surface using methyl methacrylate (MMA) as monomer, azoisobutyronitrile (AIBN) as initiator and sodium dodecyl sulfate (SDS) as stabilizer to graft PMMA on the surface of DN-27-modified MAH particles. The obtained composite particles were characterized by field-emission scanning electron microscope (FESEM), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), X-ray powder diffraction (XRD). The results show that the organic macromolecule PMMA could be successfully grafted on the surface of DN-27-modified MAH nanoparticles and the thermal stability of the PMMA-MAH composite particles had been improved. Compared with unmodified blank MAH sample, the product obtained with this method possesses better hydrophobic properties such as a higher water contact angle of 108 Degree-Sign and a well dispersion.

Modeling of ferric sulfate decomposition and sulfation of potassium chloride during grate‐firing of biomass

DEFF Research Database (Denmark)

Wu, Hao; Jespersen, Jacob Boll; Jappe Frandsen, Flemming

2013-01-01

Ferric sulfate is used as an additive in biomass combustion to convert the released potassium chloride to the less harmful potassium sulfate. The decomposition of ferric sulfate is studied in a fast heating rate thermogravimetric analyzer and a volumetric reaction model is proposed to describe...... the process. The yields of sulfur oxides from ferric sulfate decomposition under boiler conditions are investigated experimentally, revealing a distribution of approximately 40% SO3 and 60% SO2. The ferric sulfate decomposition model is combined with a detailed kinetic model of gas‐phase KCl sulfation...... and a model of K2SO4 condensation to simulate the sulfation of KCl by ferric sulfate addition. The simulation results show good agreements with experiments conducted in a biomass grate‐firing reactor. The results indicate that the SO3 released from ferric sulfate decomposition is the main contributor to KCl...

Electrolytes for magnesium electrochemical cells

Science.gov (United States)

Burrell, Anthony K.; Sa, Niya; Proffit, Danielle Lee; Lipson, Albert; Liao, Chen; Vaughey, John T.; Ingram, Brian J.

2017-07-04

An electrochemical cell includes a high voltage cathode configured to operate at 1.5 volts or greater; an anode including Mg.sup.0; and an electrolyte including an ether solvent and a magnesium salt; wherein: a concentration of the magnesium salt in the ether is 1 M or greater.

Correction: Dermatan sulfate in tunicate phylogeny: Order-specific sulfation pattern and the effect of [→4IdoA(2-Sulfateβ-1→3GalNAc(4-Sulfateβ-1→] motifs in dermatan sulfate on heparin cofactor II activity

Directory of Open Access Journals (Sweden)

Sugahara Kazuyuki

2011-07-01

Full Text Available Abstract After the publication of the work entitled "Dermatan sulfate in tunicate phylogeny: Order-specific sulfation pattern and the effect of [→4IdoA(2-Sulfateβ-1→3GalNAc(4-Sulfateβ-1→] motifs in dermatan sulfate on heparin cofactor II activity", by Kozlowski et al., BMC Biochemistry 2011, 12:29, we found that the legends to Figures 2 to 5 contain serious mistakes that compromise the comprehension of the work. This correction article contains the correct text of the legends to Figures 2 to 5.

Efek Pemberian Magnesium Sulfat Intravena Perioperatif terhadap Nilai Visual Analog Scale (VAS dan Kebutuhan Analgetik Pascabedah pada Pasien yang Menjalani Pembedahan Abdominal Ginekologi dengan Anestesi Umum

Directory of Open Access Journals (Sweden)

Dhany Budipratama

2013-08-01

Full Text Available Magnesium sulphate is N-methyl-D-aspartate (NMDA receptor antagonist and calcium channel blocker with antinociceptive and antihyperalgesia effects. A randomized, double blind, controlled study was conducted to evaluate the effect of perioperative magnesium sulphate infusion on visual analog scale (VAS scores and cumulative rescue analgesic petidin consumption in 30 ASA physical status I–II female patients, aged 18– 60 years, scheduled for gynaecological surgery under general anaesthesia in central operating theatre Dr. Hasan Sadikin Hospital-Bandung within June–September 2011. Subjects were divided into two groups that received either intravenous bolus and maintenance of MgSO4 (M group or 0.9% normal saline (S group. The results showed that postoperative VAS score during movement and the number of analgesic pethidin were significantly lower in M group compared to S group (p<0.05. In conclusions, intravenous bolus of magnesium sulphate perioperative are able to demonstrate the lower value of VAS during mobilization and reducing the amount of analgesic rescue petidin postoperative abdominal gynaecological surgery.

Immunological Response to Biodegradable Magnesium Implants

Science.gov (United States)

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

2014-04-01

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

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

International Nuclear Information System (INIS)

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 7 days. Gene expression level of osteoblastic markers ALP, COL I, OCN, OPN, RUNX2 were monitored and they were normalized to GAPDH housekeeping gene. Beta actin expression level was monitored as the second housekeeping gene to confirm the accuracy of results. In general, AMPs and CMPs showed higher expression level of osteoblastic genes after 7 days which can further confirm the stimulating role of Mg + 2 and Ca +2 ions in increasing the proliferation rate, differentiation, and mineralization of MC3T3-E1 preosteoblasts. - Highlights: • Role of Mg 2+ and Ca 2+ ions in proliferation, and differentiation

Investigation of magnesium oxychloride cement at the initial hardening stage

Directory of Open Access Journals (Sweden)

Averina Galina

2018-01-01

Full Text Available The paper investigates the process of variation of magnesium oxychloride cement deformations at the initial hardening stage depending on the activity of magnesium oxide powder which is determined by the parameters of the source material burning. Investigation is focused on magnesium cements obtained from pure magnesium hydroxide. Source materials were burnt at various temperatures with the purpose to obtain magnesium oxide powder with different activity. Regular content of hydrated phases was determined in hardened magnesium cement prepared on the basis of binders with different activity. The study reveals the influence of magnesium oxide powder activity on the process of deformation occurrence in hardened magnesium cement and its tendency to crack formation.

Recrystallization of magnesium deformed at low temperatures

International Nuclear Information System (INIS)

Fromageau, R.; Pastol, J.L.; Revel, G.

1978-01-01

The recrystallization of magnesium was studied after rolling at temperatures ranging between 248 and 373 K. For zone refined magnesium the annealing behaviour as observed by electrical resistivity measurements showed two stages at about 250 K and 400 K due respectively to recrystallization and grain growth. The activation energy associated with the recrystallization stage was 0.75 +- 0.01 eV. In less pure magnesium, with nominal purity 99.99 and 99.9%, the recrystallization stage was decomposed into two substages. Activation energies were determined in relation with deformation temperature and purity. The magnesium of intermediate purity (99.99%) behaved similarly to the lowest purity metal when it was deformed at high temperature and to the purest magnesium when the deformation was made at low temperature. This behaviour was discussed in connection with the theories of Luecke and Cahn. (Auth.)

Benefits of magnesium wheels for consumer cars

Science.gov (United States)

Frishfelds, Vilnis; Timuhins, Andrejs; Bethers, Uldis

2018-05-01

Advantages and disadvantages of magnesium wheels are considered based on a mechanical model of a car. Magnesium wheels are usually applied to racing cars as they provide slightly better strength/weight ratio than aluminum alloys. Do they provide notable benefits also for the everyday user when the car speeds do not exceed allowed speed limit? Distinct properties of magnesium rims are discussed. Apart from lighter weight of magnesium alloys, they are also good in dissipating the energy of vibrations. The role of energy dissipation in the rim of a wheel is estimated by a quarter car model. Improvements to safety by using the magnesium wheels are considered. Braking distance and responsiveness of the car is studied both with and without using an Anti Blocking System (ABS). Influence of rim weight on various handling parameters of the car is quantitatively tested.

A review on hot tearing of magnesium alloys

Directory of Open Access Journals (Sweden)

Jiangfeng Song

2016-09-01

Full Text Available Hot tearing is often a major casting defect in magnesium alloys and has a significant impact on the quality of their casting products. Hot tearing of magnesium alloys is a complex solidification phenomenon which is still not fully understood, it is of great importance to investigate the hot tearing behaviour of magnesium alloys. This review attempts to summarize the investigations on hot tearing of magnesium alloys over the past decades. The hot tearing criteria including recently developed Kou's criterion are summarized and compared. The numeric simulation and assessing methods of hot tearing, factors influencing hot tearing, and hot tearing susceptibility (HTS of magnesium alloys are discussed.

Manufacturing and characterization of magnesium alloy foils for use as anode materials in rechargeable magnesium ion batteries

Science.gov (United States)

Schloffer, Daniel; Bozorgi, Salar; Sherstnev, Pavel; Lenardt, Christian; Gollas, Bernhard

2017-11-01

The fabrication of thin foils of magnesium for use as anode material in rechargeable magnesium ion batteries is described. In order to improve its workability, the magnesium was alloyed by melting metallurgy with zinc and/or gadolinium, producing saturated solid solutions. The material was extruded to thin foils and rolled to a thickness of approximately 100 μm. The electrochemical behavior of Mg-1.63 wt% Zn, Mg-1.55 wt% Gd and Mg-1.02 wt% Zn-1.01 wt% Gd was studied in (PhMgCl)2-AlCl3/THF electrolyte by cyclic voltammetry and galvanostatic cycling in symmetrical cells. Analysis of the current-potential curves in the Tafel region and the linear region close to the equilibrium potential show almost no effect of the alloying elements on the exchange current densities (5-45 μA/cm2) and the transfer coefficients. Chemical analyses of the alloy surfaces and the electrolyte demonstrate that the alloying elements not only dissolve with the magnesium during the anodic half-cycles, but also re-deposit during the cathodic half-cycles together with the magnesium and aluminum from the electrolyte. Given the negligible corrosion rate in aprotic electrolytes under such conditions, no adverse effects of alloying elements are expected for the performance of magnesium anodes in secondary batteries.

Transport of Magnesium by a Bacterial Nramp-Related Gene

Science.gov (United States)

Rodionov, Dmitry A.; Freedman, Benjamin G.; Senger, Ryan S.; Winkler, Wade C.

2014-01-01

Magnesium is an essential divalent metal that serves many cellular functions. While most divalent cations are maintained at relatively low intracellular concentrations, magnesium is maintained at a higher level (∼0.5–2.0 mM). Three families of transport proteins were previously identified for magnesium import: CorA, MgtE, and MgtA/MgtB P-type ATPases. In the current study, we find that expression of a bacterial protein unrelated to these transporters can fully restore growth to a bacterial mutant that lacks known magnesium transporters, suggesting it is a new importer for magnesium. We demonstrate that this transport activity is likely to be specific rather than resulting from substrate promiscuity because the proteins are incapable of manganese import. This magnesium transport protein is distantly related to the Nramp family of proteins, which have been shown to transport divalent cations but have never been shown to recognize magnesium. We also find gene expression of the new magnesium transporter to be controlled by a magnesium-sensing riboswitch. Importantly, we find additional examples of riboswitch-regulated homologues, suggesting that they are a frequent occurrence in bacteria. Therefore, our aggregate data discover a new and perhaps broadly important path for magnesium import and highlight how identification of riboswitch RNAs can help shed light on new, and sometimes unexpected, functions of their downstream genes. PMID:24968120

Fracture healing using degradable magnesium fixation plates and screws.

Science.gov (United States)

Chaya, Amy; Yoshizawa, Sayuri; Verdelis, Kostas; Noorani, Sabrina; Costello, Bernard J; Sfeir, Charles

2015-02-01

Internal bone fixation devices made with permanent metals are associated with numerous long-term complications and may require removal. We hypothesized that fixation devices made with degradable magnesium alloys could provide an ideal combination of strength and degradation, facilitating fracture fixation and healing while eliminating the need for implant removal surgery. Fixation plates and screws were machined from 99.9% pure magnesium and compared with titanium devices in a rabbit ulnar fracture model. Magnesium device degradation and the effect on fracture healing and bone formation were assessed after 4 weeks. Fracture healing with magnesium device fixation was compared with that of titanium devices using qualitative histologic analysis and quantitative histomorphometry. Micro-computed tomography showed device degradation after 4 weeks in vivo. In addition, 2-dimensional micro-computed tomography slices and histologic staining showed that magnesium degradation did not inhibit fracture healing or bone formation. Histomorphology showed no difference in bone-bridging fractures fixed with magnesium and titanium devices. Interestingly, abundant new bone was formed around magnesium devices, suggesting a connection between magnesium degradation and bone formation. Our results show potential for magnesium fixation devices in a loaded fracture environment. Furthermore, these results suggest that magnesium fixation devices may enhance fracture healing by encouraging localized new bone formation. Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Behaviour of magnesium and two magnesium alloys heated in a carbon dioxide flow

International Nuclear Information System (INIS)

Boussion, M.-L.; Darras, R.; Leclercq, D.

1959-01-01

Magnesium is a particularly attractive material for sheathing uranium fuel elements in nuclear reactors in order to avoid uranium hot temperature oxidation by the cooling fluid. As this cooling fluid will be carbon dioxide at the (future) Marcoule plants, a thorough study of magnesium and magnesium alloys behaviour when heated by carbon dioxide at a 400 C temperature, have been completed. Tests on three materials (Mg, Mg-Zr and Mg-Zr-Zn) have been performed with CO 2 up to a temperature of 550 C, at atmospheric pressure in the presence of a certain amount of oxygen and nitrogen (in order to study the influence of these impurities), and at a pressure of 15 kg / cm 2 . Oxidation results are detailed. Reprint of a paper published in 'Revue de Metallurgie', LVI, n. 1, 1959, p. 61-67

Magnesium and related low alloys

Energy Technology Data Exchange (ETDEWEB)

Bernard, J; Caillat, R; Darras, R [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1959-07-01

In the first part the authors examine the comparative corrosion of commercial magnesium, of a magnesium-zirconium alloy (0,4 per cent {<=} Zr {<=} 0,7 per cent) of a ternary magnesium-zinc-zirconium alloy (0,8 per cent {<=} Zn {<=} 1,2 per cent) and of english 'Magnox type' alloys, in dry carbon dioxide-free air, in damp carbon dioxide-free air, and in dry and damp carbon dioxide, at temperatures from 300 to 600 deg. C. In the second part the structural stability of these materials is studied after annealings, of 10 to 1000 hours at 300 to 450 deg. C. Variations in grain after these heat treatments and mechanical stretching properties at room temperature are presented. Finally various creep rate and life time diagrams are given for these materials, for temperatures ranging from 300 to 450 deg. C. (author) [French] Dans une premiere partie les auteurs etudient la corrosion comparee du magnesium commercial, d'un alliage magnesium-zirconium (0,4 pour cent {<=} Zr {<=} 0,7 pour cent), d'un alliage ternaire magnesium-zinc-zirconium (0,8 pour cent {<=} Zn {<=} 1,2 pour cent), et d'alliages anglais 'type Magnox', dans l'air sec decarbonate, l'air humide decarbonate, le gaz carbonique sec et humide a des temperatures de 300 a 600 deg. C. Dans une seconde partie, est etudiee la stabilite structurale de ces materiaux apres des recuits de 300 a 450 deg. C, et de 10 a 1000 heures. Sont presentees les variations, apres ces traitements thermiques, de la grosseur du grain, et des caracteristiques mecaniques de traction a la temperature ambiante. Enfin, quelques diagrammes de vitesse de fluage et de durees de vie sont presentes sur ces materiaux pour des temperatures variant entre 300 et 450 deg. C. (auteur)

Multi-functional magnesium alloys containing interstitial oxygen atoms.

Science.gov (United States)

Kang, H; Choi, H J; Kang, S W; Shin, S E; Choi, G S; Bae, D H

2016-03-15

A new class of magnesium alloys has been developed by dissolving large amounts of oxygen atoms into a magnesium lattice (Mg-O alloys). The oxygen atoms are supplied by decomposing titanium dioxide nanoparticles in a magnesium melt at 720 °C; the titanium is then completely separated out from the magnesium melt after solidification. The dissolved oxygen atoms are located at the octahedral sites of magnesium, which expand the magnesium lattice. These alloys possess ionic and metallic bonding characteristics, providing outstanding mechanical and functional properties. A Mg-O-Al casting alloy made in this fashion shows superior mechanical performance, chemical resistance to corrosion, and thermal conductivity. Furthermore, a similar Mg-O-Zn wrought alloy shows high elongation to failure (>50%) at room temperature, because the alloy plastically deforms with only multiple slips in the sub-micrometer grains (alloys are expected to open a new paradigm in commercial alloy design.

Dose-response relationship between dietary magnesium intake, serum magnesium concentration and risk of hypertension: a systematic review and meta-analysis of prospective cohort studies.

Science.gov (United States)

Han, Hedong; Fang, Xin; Wei, Xin; Liu, Yuzhou; Jin, Zhicao; Chen, Qi; Fan, Zhongjie; Aaseth, Jan; Hiyoshi, Ayako; He, Jia; Cao, Yang

2017-05-05

The findings of prospective cohort studies are inconsistent regarding the association between dietary magnesium intake and serum magnesium concentration and the risk of hypertension. We aimed to review the evidence from prospective cohort studies and perform a dose-response meta-analysis to investigate the relationship between dietary magnesium intake and serum magnesium concentrations and the risk of hypertension. We searched systematically PubMed, EMBASE and the Cochrane Library databases from October 1951 through June 2016. Prospective cohort studies reporting effect estimates with 95% confidence intervals (CIs) for hypertension in more than two categories of dietary magnesium intake and/or serum magnesium concentrations were included. Random-effects models were used to combine the estimated effects. Nine articles (six on dietary magnesium intake, two on serum magnesium concentration and one on both) of ten cohort studies, including 20,119 cases of hypertension and 180,566 participates, were eligible for inclusion in the meta-analysis. We found an inverse association between dietary magnesium intake and the risk of hypertension [relative risk (RR) = 0.92; 95% CI: 0.86, 0.98] comparing the highest intake group with the lowest. A 100 mg/day increment in magnesium intake was associated with a 5% reduction in the risk of hypertension (RR = 0.95; 95% CI: 0.90, 1.00). The association of serum magnesium concentration with the risk of hypertension was marginally significant (RR = 0.91; 95% CI: 0.80, 1.02). Current evidence supports the inverse dose-response relationship between dietary magnesium intake and the risk of hypertension. However, the evidence about the relationship between serum magnesium concentration and hypertension is limited.

Magnesium isotope fractionation in cation-exchange chromatography

International Nuclear Information System (INIS)

Oi, T.; Yanase, S.; Kakihana, H.

1987-01-01

Band displacement chromatography of magnesium has been carried out successfully for the purpose of magnesium isotope separation by using a strongly acidic cation-exchange resin and the strontium ion as the replacement ion. A small but definite accumulation of the heavier isotopes ( 25 Mg, 26 Mg) has been observed at the front parts of the magnesium chromatograms. The heavier isotopes have been fractionated preferentially into the solution phase. The single-stage separation factors have been calculated for the 25 Mg/ 24 Mg and 26 Mg/ 24 isotopic pairs at 25 0 C. The reduced partition function ratios of magnesium species involved in the present study have been estimated

Exoelectron emission from magnesium borate glass ceramics

International Nuclear Information System (INIS)

Kawamoto, Takamichi; Yanagisawa, Hideo; Nakamichi, Hiroshi; Kikuchi, Riichi; Kawanishi, Masaharu.

1986-01-01

Thermally stimulated exoelectron emission (TSEE) of a magnesium borate glass ceramics was investigated for its application to dosemetric use. It has been found that the TSEE glow patterns of the magnesium borate glass ceramics as well as a Li 2 B 4 O 7 glass ceramics depend on the kind of the radiation used and that the heat resistance of the magnesium borate glass ceramics is higher than that of the Li 2 B 4 O 7 glass ceramics. Therefore, the TSEE glow patterns of the magnesium borate glass ceramics indicate a possibility to be used as the dose measurement for each kind of radiation in the mixed radiation field. (author)

Cerebral Magnesium Levels in Preeclampsia; A Phosphorus Magnetic Resonance Spectroscopy Study.

Science.gov (United States)

Nelander, Maria; Weis, Jan; Bergman, Lina; Larsson, Anders; Wikström, Anna-Karin; Wikström, Johan

2017-07-01

Magnesium sulfate (MgSO4) is used as a prophylaxis for eclamptic seizures. The exact mechanism of action is not fully established. We used phosphorus magnetic resonance spectroscopy (31P-MRS) to investigate if cerebral magnesium (Mg2+) levels differ between women with preeclampsia, normal pregnant, and nonpregnant women. This cross-sectional study comprised 28 women with preeclampsia, 30 women with normal pregnancies in corresponding gestational week (range: 23-41 weeks) and 11 nonpregnant healthy controls. All women underwent 31P-MRS from the parieto-occipital region of the brain and were interviewed about cerebral symptoms. Differences between groups were assessed by analysis of variance and Tukey's post-hoc test. Correlations between Mg2+ levels and specific neurological symptoms were estimated with Spearman's rank test. Mean maternal cerebral Mg2+ levels were lower in women with preeclampsia (0.12 mM ± 0.02) compared to normal pregnant controls (0.14 mM ± 0.03) (P = 0.04). Nonpregnant and normal pregnant women did not differ in Mg2+ levels. Among women with preeclampsia, lower Mg2+ levels correlated with presence of visual disturbances (P = 0.04). Plasma levels of Mg2+ did not differ between preeclampsia and normal pregnancy. Women with preeclampsia have reduced cerebral Mg2+ levels, which could explain the potent antiseizure prophylactic properties of MgSO4. Within the preeclampsia group, women with visual disturbances have lower levels of Mg2+ than those without such symptoms. © American Journal of Hypertension, Ltd 2017. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Magnesium doping of boron nitride nanotubes

Science.gov (United States)

Legg, Robert; Jordan, Kevin

2015-06-16

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

Special metallurgy - the electrical butt-welding by flashing of sintered magnesium-magnesium oxide composites (1963)

International Nuclear Information System (INIS)

Charleux, J.

1963-01-01

Electrical resistance welding has become quite important since World War II because of the need of a high yield in aeronautical production. Progress has been due in particular to the improvements made in electronically controlled apparatus making possible the automatic control of welding. For the butt-welding of sections requiring either a high production rate or a high quality weld, the flash butt-welding system has been very much developed these last few years. The use of this welding method is of great importance in the field of the bonding of oxidisable metals such as magnesium or aluminium and its alloys, because the welded joint is free from oxides. This study consists of general considerations on the flash-welding process with regard to temperature distribution in the parts during welding, and to electrical phenomena connected with flashing. Besides this general or theoretical section, we have applied the welding process to the bonding of sintered magnesium, a magnesium-magnesium oxide composite, whose use as a structural element in nuclear reactors is considered. (author) [fr

Direct Sulfation of Limestone

DEFF Research Database (Denmark)

Hu, Guilin; Dam-Johansen, Kim; Wedel, Stig

2007-01-01

The direct sulfation of limestone was studied in a laboratory fixed-bed reactor. It is found that the direct sulfation of limestone involves nucleation and crystal grain growth of the solid product (anhydrite). At 823 K and at low-conversions (less than about 0.5 %), the influences of SO2, O-2...... and CO2 on the direct sulfation of limestone corresponds to apparent reaction orders of about 0.2, 0.2 and -0.5, respectively. Water is observed to promote the sulfation reaction and increase the apparent reaction orders of SO2 and O-2. The influence of O-2 at high O-2 concentrations (> about 15...... %) becomes negligible. In the temperature interval from 723 K to 973 K, an apparent activation energy of about 104 kJ/mol is observed for the direct sulfation of limestone. At low temperatures and low conversions, the sulfation process is most likely under mixed control by chemical reaction and solid...

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

DEFF Research Database (Denmark)

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

1991-01-01

The objective of this study was to evaluate the effect of low dose magnesium supplement upon maternal and fetal serum levels of mineral status in pregnancies complicated with hypertension (PIH). Twenty-five patients with PIH agreed to participate and were randomly allocated, in a double-blind man......The objective of this study was to evaluate the effect of low dose magnesium supplement upon maternal and fetal serum levels of mineral status in pregnancies complicated with hypertension (PIH). Twenty-five patients with PIH agreed to participate and were randomly allocated, in a double...... period despite a significant increased loss of calcium during the first 24 h of inclusion. Low dose maternal magnesium treatment did not cause neonatal hypocalcemia....

Measurement of chemical leaching potential of sulfate from landfill disposed sulfate containing wastes.

Science.gov (United States)

Sun, Wenjie; Barlaz, Morton A

2015-02-01

A number of sulfate-containing wastes are disposed in municipal solid wastes (MSW) landfills including residues from coal, wood, and MSW combustion, and construction and demolition (C&D) waste. Under anaerobic conditions that dominate landfills, the sulfate can be reduced to hydrogen sulfide which is problematic for several reasons including its low odor threshold, toxicity, and corrosive nature. The overall objective of this study was to evaluate existing protocols for the quantification of total leachable sulfate from solid samples and to compare their effectiveness and efficiency with a new protocol described in this study. Methods compared include two existing acid extraction protocols commonly used in the U.S., a pH neutral protocol that requires multiple changes of the leaching solution, and a new acid extraction method. The new acid extraction method was shown to be simple and effective to measure the leaching potential of sulfate from a range of landfill disposed sulfate-containing wastes. However, the acid extraction methods do not distinguish between sulfate and other forms of sulfur and are thus most useful when sulfate is the only form of sulfur present. Copyright © 2014 Elsevier Ltd. All rights reserved.

Magnesium sulphate for fetal neuroprotection

DEFF Research Database (Denmark)

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

2013-01-01

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

A survey of the signal stability and radiation dose response of sulfates in the context of adapting optical dating for Mars

International Nuclear Information System (INIS)

O'Connor, V.A.; Lepper, K.; Morken, T.O.; Thorstad, D.J.; Podoll, A.; Giles, M.J.

2011-01-01

The Martian landscape is currently dominated by eolian processes, and eolian dunes are a direct geomorphic expression of the dynamic interaction between the atmosphere and the lithosphere of planets. The timing, frequency, and spatial extent of dune mobility directly reflects changing climatic conditions, therefore, sedimentary depositional ages are important for understanding the paleoclimatic and geomorphologic history of features and processes present on the surface of the Earth or Mars. Optical dating is an established terrestrial dosimetric dating technique that is being developed for this task on Mars. Gypsum and anhydrite are two of the most stable and abundant sulfate species found on the Earth, and they have been discovered in Martian sediments along with various magnesium sulfates and jarosite. In this study, the optical dating properties of various Ca-, Mg-, and Fe-bearing sulfates were documented to help evaluate the influence they may have on in-situ optical dating in eolian environments on Mars. Single-aliquot regenerative-dose (SAR) experimental procedures have been adapted to characterize the radiation dose response and signal stability of the Martian sulfate analogs. Jarosite was dosimetrically inert in our experiments. The radiation dose response of the Ca- and Mg-sulfates was monotonically increasing in all cases with characteristic doses ranging from ∼100 to ∼1000 Gy. Short-term signal fading also varied considerably in the Ca- and Mg-sulfates ranging from ∼0% to ∼40% per decade for these materials. These results suggest that the OSL properties of Ca- and Mg-sulfates will need to be considered when developing protocols for in-situ optical dating on Mars, but more enticingly, our results foreshadow the potential for gypsum to be developed as a geochronometer for Mars or the Earth. - Highlights: → The radiation dose response and OSL signal stability of Ca- and Mg-sulfates was highly variable. → OSL properties of Ca- and Mg-sulfates

Improved biological performance of magnesium by micro-arc oxidation

Directory of Open Access Journals (Sweden)

W.H. Ma

2015-03-01

Full Text Available Magnesium and its alloys have recently been used in the development of lightweight, biodegradable implant materials. However, the corrosion properties of magnesium limit its clinical application. The purpose of this study was to comprehensively evaluate the degradation behavior and biomechanical properties of magnesium materials treated with micro-arc oxidation (MAO, which is a new promising surface treatment for developing corrosion resistance in magnesium, and to provide a theoretical basis for its further optimization and clinical application. The degradation behavior of MAO-treated magnesium was studied systematically by immersion and electrochemical tests, and its biomechanical performance when exposed to simulated body fluids was evaluated by tensile tests. In addition, the cell toxicity of MAO-treated magnesium samples during the corrosion process was evaluated, and its biocompatibility was investigated under in vivo conditions. The results of this study showed that the oxide coating layers could elevate the corrosion potential of magnesium and reduce its degradation rate. In addition, the MAO-coated sample showed no cytotoxicity and more new bone was formed around it during in vivo degradation. MAO treatment could effectively enhance the corrosion resistance of the magnesium specimen and help to keep its original mechanical properties. The MAO-coated magnesium material had good cytocompatibility and biocompatibility. This technique has an advantage for developing novel implant materials and may potentially be used for future clinical applications.

The Effects of High Level Magnesium Dialysis/Substitution Fluid on Magnesium Homeostasis under Regional Citrate Anticoagulation in Critically Ill.

Directory of Open Access Journals (Sweden)

Mychajlo Zakharchenko

Full Text Available The requirements for magnesium (Mg supplementation increase under regional citrate anticoagulation (RCA because citrate acts by chelation of bivalent cations within the blood circuit. The level of magnesium in commercially available fluids for continuous renal replacement therapy (CRRT may not be sufficient to prevent hypomagnesemia.Patients (n = 45 on CRRT (2,000 ml/h, blood flow (Qb 100 ml/min with RCA modality (4% trisodium citrate using calcium free fluid with 0.75 mmol/l of Mg with additional magnesium substitution were observed after switch to the calcium-free fluid with magnesium concentration of 1.50 mmol/l (n = 42 and no extra magnesium replenishment. All patients had renal indications for CRRT, were treated with the same devices, filters and the same postfilter ionized calcium endpoint (<0.4 mmol/l of prefilter citrate dosage. Under the high level Mg fluid the Qb, dosages of citrate and CRRT were consequently escalated in 9h steps to test various settings.Median balance of Mg was -0.91 (-1.18 to -0.53 mmol/h with Mg 0.75 mmol/l and 0.2 (0.06-0.35 mmol/h when fluid with Mg 1.50 mmol/l was used. It was close to zero (0.02 (-0.12-0.18 mmol/h with higher blood flow and dosage of citrate, increased again to 0.15 (-0.11-0.25 mmol/h with 3,000 ml/h of high magnesium containing fluid (p<0.001. The arterial levels of Mg were mildly increased after the change for high level magnesium containing fluid (p<0.01.Compared to ordinary dialysis fluid the mildly hypermagnesemic fluid provided even balances and adequate levels within ordinary configurations of CRRT with RCA and without a need for extra magnesium replenishment.ClinicalTrials.gov Identifier: NCT01361581.

Urinary and plasma magnesium and risk of ischemic heart disease

NARCIS (Netherlands)

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

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

Inhibition of synthesis of heparan sulfate by selenate: Possible dependence on sulfation for chain polymerization

International Nuclear Information System (INIS)

Dietrich, C.P.; Nader, H.B.; Buonassisi, V.; Colburn, P.

1988-01-01

Selenate, a sulfation inhibitor, blocks the synthesis of heparan sulfate and chondroitin sulfate by cultured endothelial cells. In contrast, selenate does not affect the production of hyaluronic acid, a nonsulfated glycosaminoglycan. No differences in molecular weight, [ 3 H]glucosamine/[ 35 S]sulfuric acid ratios, or disaccharide composition were observed when the heparan sulfate synthesized by selenate-treated cells was compared with that of control cells. The absence of undersulfated chains in preparations from cultures exposed to selenate supports the concept that, in the intact cell, the polymerization of heparan sulfate might be dependent on the sulfation of the saccharide units added to the growing glycosaminoglycan chain

Growth and sedimentation of fine particles produced in aqueous solutions of palladium sulfate and palladium sulfate-silver sulfate induced by gamma-ray irradiation

International Nuclear Information System (INIS)

Hatada, Motoyoshi; Jonah, C.D.

1994-10-01

It is known that palladium and palladium-silver fine particles were formed from deaerated aqueous solutions of palladium sulfate and palladium sulfate-silver sulfate induced by gamma-ray irradiation. Changes in particle size and with amount of particles in the solution with time during and after irradiation were studied using dynamic light scattering technique and UV spectrophotometer. The particles formed from palladium sulfate solution are found to be water-filled bulky particles of diameter of 200 nm, which grow by mutual coagulation even after irradiation was terminated. Average density depends on concentration of palladium ion in the solution and dose, and the lowest density was about 2 g/cm 3 for particles of 200 nm obtained from 0.06 mM solution by 2.4 kGy irradiation. The average density of the particles obtained from palladium sulfate-silver sulfate solutions was smaller than those obtained for the corresponding palladium sulfate solutions. Supersonic agitation destroyed coagulated precipitates to form fine particles, but did not form clusters of a few atoms. (author)

A review on magnesium alloys as biodegradable materials

Science.gov (United States)

Gu, Xue-Nan; Zheng, Yu-Feng

2010-06-01

Magnesium alloys attracted great attention as a new kind of degradable biomaterials. One research direction of biomedical magnesium alloys is based on the industrial magnesium alloys system, and another is the self-designed biomedical magnesium alloys from the viewpoint of biomaterials. The mechanical, biocorrosion properties and biocompatibilities of currently reported Mg alloys were summarized in the present paper, with the mechanical properties of bone tissue, the healing period postsurgery, the pathophysiology and toxicology of the alloying elements being discussed. The strategy in the future development of biomedical Mg alloys was proposed.

High rates of sulfate reduction in a low-sulfate hot spring microbial mat are driven by a low level of diversity of sulfate-respiring microorganisms

DEFF Research Database (Denmark)

Dillon, Jesse G; Fishbain, Susan; Miller, Scott R

2007-01-01

The importance of sulfate respiration in the microbial mat found in the low-sulfate thermal outflow of Mushroom Spring in Yellowstone National Park was evaluated using a combination of molecular, microelectrode, and radiotracer studies. Despite very low sulfate concentrations, this mat community...... was shown to sustain a highly active sulfur cycle. The highest rates of sulfate respiration were measured close to the surface of the mat late in the day when photosynthetic oxygen production ceased and were associated with a Thermodesulfovibrio-like population. Reduced activity at greater depths...... was correlated with novel populations of sulfate-reducing microorganisms, unrelated to characterized species, and most likely due to both sulfate and carbon limitation....

Paramedic Initiation of Neuroprotective Agent Infusions: Successful Achievement of Target Blood Levels and Attained Level Effect on Clinical Outcomes in the FAST-MAG Pivotal Trial (Field Administration of Stroke Therapy - Magnesium).

Science.gov (United States)

Shkirkova, Kristina; Starkman, Sidney; Sanossian, Nerses; Eckstein, Marc; Stratton, Samuel; Pratt, Frank; Conwit, Robin; Hamilton, Scott; Sharma, Latisha; Liebeskind, David; Restrepo, Lucas; Valdes-Sueiras, Miguel; Saver, Jeffrey L

2017-07-01

Paramedic use of fixed-size lumen, gravity-controlled tubing to initiate intravenous infusions in the field may allow rapid start of neuroprotective therapy for acute stroke. In a large, multicenter trial, we evaluated its efficacy in attaining target serum levels of candidate neuroprotective agent magnesium sulfate and the relation of achieved magnesium levels to outcome. The FAST-MAG phase 3 trial (Field Administration of Stroke Therapy - Magnesium) randomized 1700 patients within 2 hours of onset to paramedic-initiated, a 15-minute loading intravenous infusion of magnesium or placebo followed by a 24-hour maintenance dose. The drug delivery strategy included fixed-size lumen, gravity-controlled tubing for field drug administration, and a shrink-wrapped ambulance kit containing both the randomized field loading and hospital maintenance doses for seamless continuation. Among patient randomized to active treatment, magnesium levels in the first 72 hours were assessed 987 times in 572 patients. Mean patient age was 70 years (SD±14 years), and 45% were women. During the 24-hour period of active infusion, mean achieved serum level was 3.91 (±0.8), consistent with trial target. Mg levels were increased by older age, female sex, lower weight, height, body mass index, and estimated glomerular filtration rate, and higher blood urea nitrogen, hemoglobin, and higher hematocrit. Adjusted odds for clinical outcomes did not differ by achieved Mg level, including disability at 90 days, symptomatic hemorrhage, or death. Paramedic infusion initiation using gravity-controlled tubing permits rapid achievement of target serum levels of potential neuroprotective agents. The absence of association of clinical outcomes with achieved magnesium levels provides further evidence that magnesium is not biologically neuroprotective in acute stroke. © 2017 American Heart Association, Inc.

Synthesis of Nano-Light Magnesium Hydride for Hydrogen Storage ...

African Journals Online (AJOL)

Abstract. Nano-light magnesium hydride that has the capability for hydrogen storage was synthesized from treatment of magnesium ribbon with hydrogen peroxide. The optimum time for complete hydrogenation of the magnesium hydride was 5 hours.

Hydrogenations of alloys and intermetallic compounds of magnesium

International Nuclear Information System (INIS)

Gavra, Z.

1981-08-01

A kinetic and thermodynamic study of the hydrogenation of alloys and intermetallic compounds of magnesium is presented. It was established that the addition of elements of the IIIA group (Al, Ga, In) to magnesium catalyses its hydrogenation. This is explained by the mechanism of diffusion of magnesium cation vacancies. The hydride Mg 2 NiH 4 was characterized by thermal analysis, x-ray diffraction and NMR measurements. The possibility of forming pseudo-binary compounds of Mg 2 Ni by the substitution of nickel or magnesium was examined. The hydrogenation of the inter-metallic compounds of the Mg-Al system was investigated. It was found that the addition of indium and nickel affected the hydrogenation kinetics. A preliminary study of the hydrogenation of various binary and ternary alloys of magnesium was carried out. (Author)

Reprint of: Improved cytotoxicity testing of magnesium materials

International Nuclear Information System (INIS)

Fischer, Janine; Pröfrock, Daniel; Hort, Norbert; Willumeit, Regine; Feyerabend, Frank

2011-01-01

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

Reprint of: Improved cytotoxicity testing of magnesium materials

Energy Technology Data Exchange (ETDEWEB)

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

2011-12-15

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

Process for selectively concentrating the radioactivity of thorium containing magnesium slag

International Nuclear Information System (INIS)

Wilson, D.A.; Christiansen, S.H.; Simon, J.; Morin, D.W.

1993-01-01

In a process for separating magnesium from a magnesium slag using water and carbon dioxide, the improvement described comprises: (a) forming an aqueous magnesium slurry from the magnesium slag, which slag contains radioactive thorium and its daughters, and water; (b) solubilizing magnesium from the magnesium slurry by reacting the aqueous magnesium slurry with carbon dioxide wherein the carbon dioxide is at a pressure from greater than ambient to about 1,000 psig (about 7,000 kPa); (c) selectively concentrating by filtering the radioactive thorium and its daughters such that the radioactive thorium and its daughters are separated from the solubilized magnesium filtrate; and (d) reducing volume and/or weight of radioactive solids for disposal as radioactive waste

Sulfation of corrosive alkali chlorides by ammonium sulfate in a biomass fired CFB boiler

Energy Technology Data Exchange (ETDEWEB)

Brostroem, Markus; Backman, Rainer; Nordin, Anders [Energy Technology and Thermal Process Chemistry, Umeaa University, SE-901 87 Umeaa (Sweden); Kassman, Haakan [Vattenfall Power Consultant AB, Box 1046, SE-611 29 Nykoeping (Sweden); Helgesson, Anna; Berg, Magnus; Andersson, Christer [Vattenfall Research and Development AB, SE-814 26 Aelvkarleby (Sweden)

2007-12-15

Biomass and waste derived fuels contain relatively high amounts of alkali and chlorine, but contain very little sulfur. Combustion of such fuels can result in increased deposit formation and superheater corrosion. These problems can be reduced by using a sulfur containing additive, such as ammonium sulfate, which reacts with the alkali chlorides and forms less corrosive sulfates. Ammonium sulfate injection together with a so-called in situ alkali chloride monitor (IACM) is patented and known as ''ChlorOut''. IACM measures the concentrations of alkali chlorides (mainly KCl in biomass combustion) at superheater temperatures. Tests with and without spraying ammonium sulfate into the flue gases have been performed in a 96MW{sub th}/25MW{sub e} circulating fluidized bed (CFB) boiler. The boiler was fired mainly with bark and a chlorine containing waste. KCl concentration was reduced from more than 15 ppm to approximately 2 ppm during injection of ammonium sulfate. Corrosion probe measurements indicated that both deposit formation and material loss due to corrosion were decreased using the additive. Analysis of the deposits showed significantly higher concentration of sulfur and almost no chlorine in the case with ammonium sulfate. Results from impactor measurements supported that KCl was sulfated to potassium sulfate by the additive. (author)

Magnesium Cermets and Magnesium-Beryllium Alloys; Cermets au magnesium et au magnesium-beryllium; Metallokeramicheskie magnievye i magnievo-berillievye splavy; Cermets de magnesio y aleaciones de magnesio y berillio

Energy Technology Data Exchange (ETDEWEB)

Ivanov, V. E.; Zelenskij, V. F.; Fajfer, S. I.; Zhdanov, S. M.; Maksimenko, V. I.; Savchenko, V. I. [Fiziko-Tekhnicheskij Institut an USSR, Khar' kov, SSSR (Russian Federation)

1963-11-15

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

Magnesium in Disease Prevention and Overall Health12

Science.gov (United States)

Volpe, Stella Lucia

2013-01-01

Magnesium is the fourth most abundant mineral and the second most abundant intracellular divalent cation and has been recognized as a cofactor for >300 metabolic reactions in the body. Some of the processes in which magnesium is a cofactor include, but are not limited to, protein synthesis, cellular energy production and storage, reproduction, DNA and RNA synthesis, and stabilizing mitochondrial membranes. Magnesium also plays a critical role in nerve transmission, cardiac excitability, neuromuscular conduction, muscular contraction, vasomotor tone, blood pressure, and glucose and insulin metabolism. Because of magnesium’s many functions within the body, it plays a major role in disease prevention and overall health. Low levels of magnesium have been associated with a number of chronic diseases including migraine headaches, Alzheimer’s disease, cerebrovascular accident (stroke), hypertension, cardiovascular disease, and type 2 diabetes mellitus. Good food sources of magnesium include unrefined (whole) grains, spinach, nuts, legumes, and white potatoes (tubers). This review presents recent research in the areas of magnesium and chronic disease, with the goal of emphasizing magnesium’s role in disease prevention and overall health. PMID:23674807

There is chronic latent magnesium deficiency in apparently healthy university students

OpenAIRE

Hermes Sales, Cristiane; Azevedo Nascimento, Débora; Queiroz Medeiros, Anna Cecília; Costa Lima, Kênio; Campos Pedrosa, Lucia Fátima; Colli, Célia

2014-01-01

Introduction: Magnesium is an essential micronutrient for human body, and its deficiency has been associated with risk of non-communicable diseases. Objective: Assessment of magnesium status, and evaluation of the frequency of magnesium deficiency in a group of healthy adults. Methods: Plasma and erythrocyte magnesium levels, and magnesium intake were determined in 115 students (55 women and 60 men), from a public university in Brazil. Results: The medians of magnesium concentration in plasma...

Direct-reading spectrochemical analysis of magnesium alloys

International Nuclear Information System (INIS)

Roca Adell, M.

1964-01-01

A Quantometer has been applied to the determination of aluminum, berylium, calcium, iron, silicon and zinc in magnesium alloys Magnox, after the conversion of the samples to the oxide. For the aluminum, whose concentration is relatively high, the conducting briquets technique with an interrupted discharge is employed, using the magnesium as the internal standard. For the other elements a total burning method with direct current arc is employed, using also the magnesium as the internal standard. (Author) 7 refs

Chondroitin sulfate/dermatan sulfate sulfatases from mammals and bacteria.

Science.gov (United States)

Wang, Shumin; Sugahara, Kazuyuki; Li, Fuchuan

2016-12-01

Sulfatases that specifically catalyze the hydrolysis of the sulfate groups on chondroitin sulfate (CS)/dermatan sulfate (DS) poly- and oligosaccharides belong to the formylglycine-dependent family of sulfatases and have been widely found in various mammalian and bacterial organisms. However, only a few types of CS/DS sulfatase have been identified so far. Recently, several novel CS/DS sulfatases have been cloned and characterized. Advanced studies have provided significant insight into the biological function and mechanism of action of CS/DS sulfatases. Moreover, further studies will provide powerful tools for structural and functional studies of CS/DS as well as related applications. This article reviews the recent progress in CS/DS sulfatase research and is expected to initiate further research in this field.

Novel processes for anaerobic sulfate production from elemental sulfur by sulfate-reducing bacteria

Science.gov (United States)

Lovley, D.R.; Phillips, E.J.P.

1994-01-01

Sulfate reducers and related organisms which had previously been found to reduce Fe(III) with H2 or organic electron donors oxidized S0 to sulfate when Mn(IV) was provided as an electron acceptor. Organisms catalyzing this reaction in washed cell suspensions included Desulfovibrio desulfuricans, Desulfomicrobium baculatum. Desulfobacterium autotrophicum, Desulfuromonas acetoxidans, and Geobacter metallireducens. These organisms produced little or no sulfate from S0 with Fe(III) as a potential electron acceptor or in the absence of an electron acceptor. In detailed studies with Desulfovibrio desulfuricans, the stoichiometry of sulfate and Mn(II) production was consistent with the reaction S0 + 3 MnO2 + 4H+ ???SO42- + 3Mn(II) + 2H2O. None of the organisms evaluated could be grown with S0 as the sole electron donor and Mn(IV) as the electron acceptor. In contrast to the other sulfate reducers evaluated, Desulfobulbus propionicus produced sulfate from S0 in the absence of an electron acceptor and Fe(III) oxide stimulated sulfate production. Sulfide also accumulated in the absence of Mn(IV) or Fe(III). The stoichiometry of sulfate and sulfide production indicated that Desulfobulbus propionicus disproportionates S0 as follows: 4S0 + 4H2O???SO42- + 3HS- + 5 H+. Growth of Desulfobulbus propionicus with S0 as the electron donor and Fe(III) as a sulfide sink and/or electron acceptor was very slow. The S0 oxidation coupled to Mn(IV) reduction described here provides a potential explanation for the Mn(IV)-dependent sulfate production that previous studies have observed in anoxic marine sediments. Desulfobulbus propionicus is the first example of a pure culture known to disproportionate S0.

Heparan sulfate-chondroitin sulfate hybrid proteoglycan of the cell surface and basement membrane of mouse mammary epithelial cells

International Nuclear Information System (INIS)

David, G.; Van den Berghe, H.

1985-01-01

Chondroitin sulfate represents approximately 15% of the 35 SO 4 -labeled glycosaminoglycans carried by the proteoglycans of the cell surface and of the basolateral secretions of normal mouse mammary epithelial cells in culture. Evidence is provided that these chondroitin sulfate-carrying proteoglycans are hybrid proteoglycans, carrying both chondroitin sulfate and heparan sulfate chains. Complete N-desulfation but limited O-desulfation, by treatment with dimethyl sulfoxide, of the proteoglycans decreased the anionic charge of the chondroitin sulfate-carrying proteoglycans to a greater extent than it decreased the charge of their constituent chondroitin sulfate chains. Partial depolymerization of the heparan sulfate residues of the proteoglycans with nitrous acid or with heparin lyase also reduced the effective molecular radius of the chondroitin sulfate-carrying proteoglycans. The effect of heparin lyase on the chondroitin sulfate-carrying proteoglycans was prevented by treating the proteoglycan fractions with dimethyl sulfoxide, while the effect of nitrous acid on the dimethyl sulfoxide-treated proteoglycans was prevented by acetylation. This occurrence of heparan sulfate-chondroitin sulfate hybrid proteoglycans suggests that the substitution of core proteins by heparan sulfate or chondroitin sulfate chains may not solely be determined by the specific routing of these proteins through distinct chondroitin sulfate and heparan sulfate synthesizing mechanisms. Moreover, regional and temporal changes in pericellular glycosaminoglycan compositions might be due to variable postsynthetic modification of a single gene product

Constraints on Weathering from Riverine Magnesium Isotope Ratios

DEFF Research Database (Denmark)

Wiechert, Uwe; Ullmann, Clemens Vinzenz; Meixner, Anette

and industrialized regions, the d26Mg values mirror the lithologies of the catchment areas: the Danubian catchment is dominated by carbonatic lithologies and in the Danube dissolved magnesium exhibits the most negative d26Mg values between -1.85 and -1.70 ‰. The mainly siliceous catchment of the river Elbe causes....... Simple mass balance calculations on the basis of the magnesium isotopes obtained for the investigated rivers imply 26 to 59 % magnesium derived from carbonatic lithologies and 41 to 74 % magnesium from siliceous lithologies. This is in contrast to estimates using conventional methods for the tribute...

Magnesium analysis. Spectrophotometric determination of chromium

International Nuclear Information System (INIS)

Anon.

Chromium determination in magnesium used in uranium fabrication by magnesiothermics, applicable for chromium content between 2 to 10 ppm. Magnesium is dissolved in sulfuric acid, oxidized by potassium permanganate, the excess of permanganate is eliminated by sodium nitride. Spectrophotometry at 540 nm of the chromium (VI)-diphenylcarbazide complex [fr

Semi-solid twin-roll casting process of magnesium alloy sheets

International Nuclear Information System (INIS)

Watari, H.; Davey, K.; Rasgado, M.T. Alonso; Haga, T.; Koga, N.

2004-01-01

An experimental approach has been performed to ascertain the effectiveness of semi-solid strip casting using a horizontal twin roll caster. The demand for light-weight products with high strength has grown recently due to the rapid development of automobile and aircraft technology. One key to such development has been utilization of magnesium alloys, which can potentially reduce the total product weight. However, the problems of utilizing magnesium alloys are still mainly related to high manufacturing cost. One of the solutions to this problem is to develop magnesium casting-rolling technology in order to produce magnesium sheet products at competitive cost for commercial applications. In this experiment, magnesium alloy AZ31B was used to ascertain the effectiveness of semi-solid roll strip casting for producing magnesium alloy sheets. The temperature of the molten magnesium, and the roll speeds of the upper and lower rolls, (which could be changed independently), were varied to find an appropriate manufacturing condition. Rolling and heat treatment conditions were changed to examine which condition would be appropriate for producing wrought magnesium alloys with good formability. Microscopic observation of the crystals of the manufactured wrought magnesium alloys was performed. It has been found that a limiting drawing ratio of 2.7 was possible in a warm deep drawing test of the cast magnesium alloy sheets after being hot rolled

Features of solid solutions composition in magnesium with yttrium alloys

International Nuclear Information System (INIS)

Drits, M.E.; Rokhlin, L.L.; Tarytina, I.E.

1983-01-01

Additional data on features of yttrium solid solutions composition in magnesium in the course of their decomposition investigation in the case of aging are obtianed. The investigation has been carried out on the base of a binary magnesium-yttrium alloy the composition of which has been close to maximum solubility (at eutectic temperature) and magnesium-yttrium alloys additionally doped with zinc. It is shown that higher yttrium solubility in solid magnesium than it has been expected, issueing from the difference in atomic radii of these metals indicates electron yttrium-magnesium atoms interaction. In oversaturated magnesium-yttrium solid solutions at earlier decomposition stages Mg 3 Cd type ordering is observed. At aging temperatures up to 250 deg C and long exposures corresponding to highest strengthening in oversaturated magnesium yttrium solid solutions a rhombic crystal lattice phase with three symmetric orientations is formed

A Case of a Magnesium Oxide Bezoar.

Science.gov (United States)

Iwamuro, Masaya; Saito, Shunsuke; Yoshioka, Masao; Urata, Haruo; Ueda, Kumiko; Yamamoto, Kazuhide; Okada, Hiroyuki

2018-06-06

A 75-year-old Japanese woman presented with nausea and appetite loss. Computed tomography showed a radiopaque substance in the stomach. Esophagogastroduodenoscopy revealed bezoars in the stomach, which were endoscopically retrieved. The bezoars were mainly composed of magnesium and oxide. Although bezoar formation associated with magnesium oxide consumption is infrequently encountered, the present case indicates that pharmacobezoar should be considered among the differential diagnoses in patients who demonstrate a radiopaque mass in the digestive tract and have a history of magnesium oxide use.

Analysis of tyrosine-O-sulfation

DEFF Research Database (Denmark)

Bundgaard, J.R.; Sen, J.W.; Johnsen, A.H.

2008-01-01

Tyrosine O-sulfation was first described about 50 years ago as a post-translational modification of fibrinogen. In the following 30 years it was considered to be a rare modification affecting only a few proteins and peptides. However, in the beginning of the 1980s tyrosine (Tyr) sulfation was shown...... to be a common modification and since then an increasing number of proteins have been identified as sulfated. The target proteins belong to the classes of secretory, plasma membrane, and lysosomal proteins, which reflects the intracellular localization of the enzymes catalyzing Tyr sulfation, the tyrosylprotein...... sulfotransferases (TPSTs).Traditionally, Tyr sulfation has been analyzed by incorporation of radiolabeled sulfate into target cells followed by purification of the target protein. Subsequently, the protein is degraded enzymatically or by alkaline hydrolysis followed by thin-layer electrophoresis to demonstrate...

Immunohistochemical localization of chondroitin sulfate, chondroitin sulfate proteoglycan, heparan sulfate proteoglycan, entactin, and laminin in basement membranes of postnatal developing and adult rat lungs

DEFF Research Database (Denmark)

Sannes, P L; Burch, K K; Khosla, J

1993-01-01

Histologic preparations of lungs from 1-, 5-, 10-, 18-, and 25-day-old postnatal and adult rats were examined immunohistochemically with antibodies specific against chondroitin sulfate (CS), basement membrane chondroitin sulfate proteoglycan (BM-CSPG), heparan sulfate proteoglycan (HSPG), entactin...

Role of magnesium on the biomimetic deposition of calcium phosphate

Science.gov (United States)

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.

Magnesium and diltiazem relaxes phenylephrine-precontracted rat aortic rings

Science.gov (United States)

Dogan, Mustafa; Peker, Recep O.; Donmez, Soner; Gokalp, Osman

2012-01-01

Perioperative vasospasm during cardiovascular surgery is a challenging problem. Several vasodilator agents are frequently utilized for its prevention in surgical practice. Magnesium and diltiazem both have known potential vasorelaxant effects. We planned to compare the efficacy of diltiazem and magnesium in relieving phenylephrine-precontracted rat aortic rings. Ten young adult female Wistar albino rats weighing 230–260 g were used in this study. The aortic rings in the organ bath equilibrated and reached their baseline tension. Precontraction was induced by 0.001 mmol/l phenylephrine and cumulative concentration–relaxation curves were obtained by consecutively increasing the addition of either diltiazem (10−6-0.1 mmol/l) or magnesium (0.1–10 mmol/l). The mean maximal relaxation responses observed by diltiazem and magnesium on separate aortic rings were 90 ± 3 and 53 ± 2%, respectively. The calculated EC50 of diltiazem was 0.01035 mmol/l, whereas the EC50 of magnesium was 4.064 mmol/l (P < 0.05). Both magnesium and diltiazem produced vasorelaxation on phenylephrine-precontracted rat aortic rings in this study, but the potency of diltiazem regarding the EC50 value was significantly higher than that of magnesium. Magnesium could be a candidate together with diltiazem to inhibit vasospasm on arterial grafts during coronary bypass surgery. PMID:22523136

Telomere Homeostasis: Interplay with Magnesium

Directory of Open Access Journals (Sweden)

Donogh Maguire

2018-01-01

Full Text Available Telomere biology, a key component of the hallmarks of ageing, offers insight into dysregulation of normative ageing processes that accompany age-related diseases such as cancer. Telomere homeostasis is tightly linked to cellular metabolism, and in particular with mitochondrial physiology, which is also diminished during cellular senescence and normative physiological ageing. Inherent in the biochemistry of these processes is the role of magnesium, one of the main cellular ions and an essential cofactor in all reactions that use ATP. Magnesium plays an important role in many of the processes involved in regulating telomere structure, integrity and function. This review explores the mechanisms that maintain telomere structure and function, their influence on circadian rhythms and their impact on health and age-related disease. The pervasive role of magnesium in telomere homeostasis is also highlighted.

Yttrium ion implantation on the surface properties of magnesium

International Nuclear Information System (INIS)

Wang, X.M.; Zeng, X.Q.; Wu, G.S.; Yao, S.S.

2006-01-01

Owing to their excellent physical and mechanical properties, magnesium and its alloys are receiving more attention. However, their application has been limited to the high reactivity and the poor corrosion resistance. The aim of the study was to investigate the beneficial effects of ion-implanted yttrium using a MEVVA ion implanter on the surface properties of pure magnesium. Isothermal oxidation tests in pure O 2 at 673 and 773 K up to 90 min indicated that the oxidation resistance of magnesium had been significantly improved. Surface morphology of the oxide scale was analyzed using scanning electron microscope (SEM). Auger electron spectroscopy (AES) and X-ray diffraction (XRD) analyses indicated that the implanted layer was mainly composed of MgO and Y 2 O 3 , and the implanted layer with a duplex structure could decrease the inward diffusion of oxygen and reduce the outward diffusion of Mg 2+ , which led to improving the oxidation resistance of magnesium. Potentiodynamic polarization curves were used to evaluate the corrosion resistance of the implanted magnesium. The results show yttrium implantation could enhance the corrosion resistance of implanted magnesium compared with that of pure magnesium

Alloying principles for magnesium base heat resisting alloys

International Nuclear Information System (INIS)

Drits, M.E.; Rokhlin, L.L.; Oreshkina, A.A.; Nikitina, N.I.

1982-01-01

Some binary systems of magnesium-base alloys in which solid solutions are formed, are considered for prospecting heat resistant alloys. It is shown that elements having essential solubility in solid magnesium strongly decreasing with temperature should be used for alloying maqnesium base alloys with high strength properties at increased temperatures. The strengthening phases in these alloys should comprise essential quantity of magnesium and be rather refractory

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

Science.gov (United States)

2010-07-01

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

Effect of magnesium treatment and glucose levels on delayed cerebral ischemia in patients with subarachnoid hemorrhage: a substudy of the Magnesium in Aneurysmal Subarachnoid Haemorrhage trial (MASH-II).

Science.gov (United States)

Leijenaar, Jolien F; Dorhout Mees, Sanne M; Algra, Ale; van den Bergh, Walter M; Rinkel, Gabriel J E

2015-10-01

Magnesium treatment did not improve outcome in patients with aneurysmal subarachnoid haemorrhage in the Magnesium in Aneurysmal Subarachnoid Haemorrhage II trial. We hypothesized that high glucose levels may have offset a potential beneficial effect to prevent delayed cerebral ischemia. We investigated if magnesium treatment led to less delayed cerebral ischemia and if glucose levels interacted with magnesium treatment in the Magnesium in Aneurysmal Subarachnoid Haemorrhage II trial. To investigate the effect of magnesium treatment on occurrence of delayed cerebral ischemia and the interaction between glucose levels and magnesium treatment in subarachnoid hemorrhage patients. The Magnesium in Aneurysmal Subarachnoid Haemorrhage was a phase III randomized placebo-controlled trial assessing the effect of magnesium sulphate on clinical outcome in aneurysmal subarachnoid hemorrhage patients. For the current study, we included only the patients admitted to the University Medical Centre-Utrecht. We calculated hazard ratios for occurrence of delayed cerebral ischemia in patients treated with magnesium vs. placebo for the entire study population, and separately in the subgroups of patients with high and low mean fasting and mean daily glucose levels until onset of delayed cerebral ischemia. We used the cross-product of magnesium and glucose in the regression analysis to evaluate whether an interaction between magnesium and glucose existed. We included 616 patients: 307 received magnesium and 309 placebo; 156 patients had delayed cerebral ischemia. Hazard ratio for magnesium on occurrence of delayed cerebral ischemia was 1·0 (95% confidence interval: 0·7-1·4). Results were similar in patients with low or high fasting or daily glucose levels. We found no interactions between magnesium treatment and high fasting (P = 0·54) and daily glucose (P = 0·60). Magnesium treatment did not reduce the risk of delayed cerebral ischemia in patients with aneurysmal

Blood compatibility of magnesium and its alloys.

Science.gov (United States)

Feyerabend, Frank; Wendel, Hans-Peter; Mihailova, Boriana; Heidrich, Stefanie; Agha, Nezha Ahmad; Bismayer, Ulrich; Willumeit-Römer, Regine

2015-10-01

Blood compatibility analysis in the field of biomaterials is a highly controversial topic. Especially for degradable materials like magnesium and its alloys no established test methods are available. The purpose of this study was to apply advanced test methodology for the analysis of degrading materials to get a mechanistic insight into the corrosion process in contact with human blood and plasma. Pure magnesium and two magnesium alloys were analysed in a modified Chandler-Loop setup. Standard clinical parameters were determined, and a thorough analysis of the resulting implant surface chemistry was performed. The contact of the materials to blood evoked an accelerated inflammatory and cell-induced osteoconductive reaction. Corrosion products formed indicate a more realistic, in vivo like situation. The active regulation of corrosion mechanisms of magnesium alloys by different cell types should be more in the focus of research to bridge the gap between in vitro and in vivo observations and to understand the mechanism of action. This in turn could lead to a better acceptance of these materials for implant applications. The presented study deals with the first mechanistic insights during whole human blood contact and its influence on a degrading magnesium-based biomaterial. The combination of clinical parameters and corrosion layer analysis has been performed for the first time. It could be of interest due to the intended use of magnesium-based stents and for orthopaedic applications for clinical applications. An interest for the readers of Acta Biomaterialia may be given, as one of the first clinically approved magnesium-based devices is a wound-closure device, which is in direct contact with blood. Moreover, for orthopaedic applications also blood contact is of high interest. Although this is not the focus of the manuscript, it could help to rise awareness for potential future applications. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All

Enzymatic, urease-mediated mineralization of gellan gum hydrogel with calcium carbonate, magnesium-enriched calcium carbonate and magnesium carbonate for bone regeneration applications.

Science.gov (United States)

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.

The Magnesium Industry Today…The Global Perspective

Science.gov (United States)

Patzer, Greg

World demand for magnesium will show a decline in 2009. The outlook for 2010, which is guardedly optimistic, will be for a resumption of slow growth. The industry has seen marked changes in the sources of supply for primary and alloyed magnesium in recent years. Technological advances in magnesium continue at a strong pace as does interest in the material as a substitute for other light metals. The automotive segment remains the end-use area with the largest growth potential, if for no other reason than the size and quantity of the potential materials substitution applications. However, the shrinkage of that market, particularly in North America will have a definite impact on expectations for magnesium. The 3C market (computers, communications & consumer electronics) will continue to show above average growth. Other niche markets related to medical and construction industries also offer potential.

QUALITY OF YOGHURTS FROM GOAT'S MILK ENRICHED WITH MAGNESIUM CHLORIDE

Directory of Open Access Journals (Sweden)

Agata Znamirowska

2015-02-01

Full Text Available Goat’s milk can be enriched with magnesium in the form of chloride before pasteurization with a save dose, i.e. 20 mg of magnesium for 100 g of milk. Higher doses of magnesium can lead to coagulation of proteins since together with the increase of the dose of fortification there increases general acidity while pH of milk decreases. Together with the increase of the dose of fortification of yoghurts with magnesium there was shown an essential proportional increase of acidity and hardness of curds persisting for 21 days of storage. Enriching goat’s milk yoghurts with magnesium decreased the intensity of „goat” smell and aftertaste and did not cause a change in colour. The most favourable solution is the production of goat’s milk yoghurts enriched with 10-20 mg of magnesium in the form of magnesium chloride. Such doses of enrichment caused successive lowering of perceptibility of „goat” aftertaste and smell together with extension of storage time.

Serum Magnesium Levels in Non-Pregnant, Pregnant And Pre ...

African Journals Online (AJOL)

The objective of this study was to compare the serum magnesium levels in normal pregnancy and pregnancy complicated by pre-eclampsia since magnesium has been implicated in the pathogenesis of vascular dysfunction. We measured serum magnesium levels in patients with pre-eclampsia (n=36), patients with normal ...

Magnesium for Hydrogen Storage

DEFF Research Database (Denmark)

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

1980-01-01

The reaction of hydrogen with commercially pure magnesium powder (above 99.7%) was investigated in the temperature range 250–400 °C. Hydrogen is readily sorbed above the dissociation pressure. During the initial exposure the magnesium powder sorbs hydrogen slowly below 400 °C but during the second...... that the particles do not disintegrate is explained by a sintering process at the working temperatures. Exposure to air does not impair the sorption ability; on the contrary, it appears that surface oxidation plays an important role in the reaction. Some handling problems, e.g. the reaction of the hydride with water...

Macrokinetics of magnesium sulfite oxidation inhibited by ascorbic acid

International Nuclear Information System (INIS)

Lidong, Wang; Yongliang, Ma; Wendi, Zhang; Qiangwei, Li; Yi, Zhao; Zhanchao, Zhang

2013-01-01

Graphical abstract: Ascorbic acid is used as an inhibitor to retard the oxidation rate of magnesium sulfite. It shows that the oxidation rate would decrease greatly with the rise of initial ascorbic acid concentration, which provides a useful reference for sulfite recovery in magnesia desulfurization. -- Highlights: • We studied the kinetics of magnesium sulfite oxidation inhibited by ascorbic acid. • The oxidation process was simulated by a three-phase model and proved by HPLC–MS. • We calculated the kinetic parameters of intrinsic oxidation of magnesium sulfite. -- Abstract: Magnesia flue gas desulfurization is a promising process for small to medium scale industrial coal-fired boilers in order to reduce sulfur dioxide emissions, in which oxidation control of magnesium sulfite is of great importance for the recycling of products. Effects of four inhibitors were compared by kinetic experiments indicating that ascorbic acid is the best additive, which retards the oxidation process of magnesium sulfite in trace presence. The macrokinetics of magnesium sulfite oxidation inhibited by ascorbic acid were studied. Effects of the factors, including ascorbic acid concentration, magnesium sulfite concentration, oxygen partial pressure, pH, and temperature, were investigated in a stirred reactor with bubbling. The results show that the reaction rate is −0.55 order in ascorbic acid, 0.77 in oxygen partial pressure, and zero in magnesium sulfite concentration, respectively. The apparent activation energy is 88.0 kJ mol −1 . Integrated with the kinetic model, it is concluded that the oxidation rate of magnesium sulfite inhibited by ascorbic acid is controlled by the intrinsic chemical reaction. The result provides a useful reference for sulfite recovery in magnesia desulfurization

Corrosion of magnesium and some magnesium alloys in gas cooled reactors; Corrosion du magnesium et de certains de ses alliages dans les piles refroidies par gaz

Energy Technology Data Exchange (ETDEWEB)

Caillat, R; Darras, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

The results of corrosion tests on magnesium and some magnesium alloys (Mg-Zr and Mg-Zr-Zn) in moist air (like G1 reactor) and in CO{sub 2}: (like G2, G3, EDF1 reactors) are reported. The maximum temperature for exposure of magnesium to moist air without any risk of corrosion is 350 deg. C. Indeed, the oxidation rate follows a linear law above 350 deg. C although it reaches a constant level and keeps on very low under 350 deg. C. However, as far as corrosion is concerned this temperature limit can be raised up to 500 deg. C if moist air is very slightly charged with fluorinated compounds. Under pressure of CO{sub 2}, these three materials oxidate much more slowly even if 500 deg. C is reached. The higher is the temperature, the higher is the constant level of the weight increase and the quicker is reached this one. However, Mg-Zr alloy behaves quite better than pure magnesium and especially than Mg-Zr-Zn alloy. (author)Fren. [French] On expose essentiellement les resultats d'etudes sur la corrosion du magnesium et de certains de ses alliages (Mg-Zr et Mg-Zr-Zn) dans l'air humide (cas de la pile G1) et dans le gaz carbonique (cas des piles G2, G3, EDF1, etc...). La temperature limite d'exposition du magnesium dans l'air humide sans risque de corrosion se situe a 350 deg. C; en effet l'oxydation a un caractere lineaire au-dessus de cette temperature, alors qu'elle atteint un palier et reste tres limitee au-dessous de 350 deg. C. Du point de vue de la corrosion, cette temperature limite d'emploi peut cependant etre elevee jusqu'a 500 deg. C si l'on introduit dans l'air humide de tres faibles teneurs de composes fluores. Dans le gaz carbonique sous pression, l'oxydation est beaucoup plus faible, meme jusqu'a 50g. C pour les trois materiaux: l'augmentation de poids atteint un palier d'autant plus eleve et ceci d'autant plus rapidement que la temperature est elle-meme plus elevee. Cependant, l'alliage Mg-Zr se comporte nettement mieux que le magnesium pur et surtout que l

Corrosion of magnesium and some magnesium alloys in gas cooled reactors; Corrosion du magnesium et de certains de ses alliages dans les piles refroidies par gaz

Energy Technology Data Exchange (ETDEWEB)

Caillat, R.; Darras, R. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

The results of corrosion tests on magnesium and some magnesium alloys (Mg-Zr and Mg-Zr-Zn) in moist air (like G1 reactor) and in CO{sub 2}: (like G2, G3, EDF1 reactors) are reported. The maximum temperature for exposure of magnesium to moist air without any risk of corrosion is 350 deg. C. Indeed, the oxidation rate follows a linear law above 350 deg. C although it reaches a constant level and keeps on very low under 350 deg. C. However, as far as corrosion is concerned this temperature limit can be raised up to 500 deg. C if moist air is very slightly charged with fluorinated compounds. Under pressure of CO{sub 2}, these three materials oxidate much more slowly even if 500 deg. C is reached. The higher is the temperature, the higher is the constant level of the weight increase and the quicker is reached this one. However, Mg-Zr alloy behaves quite better than pure magnesium and especially than Mg-Zr-Zn alloy. (author)Fren. [French] On expose essentiellement les resultats d'etudes sur la corrosion du magnesium et de certains de ses alliages (Mg-Zr et Mg-Zr-Zn) dans l'air humide (cas de la pile G1) et dans le gaz carbonique (cas des piles G2, G3, EDF1, etc...). La temperature limite d'exposition du magnesium dans l'air humide sans risque de corrosion se situe a 350 deg. C; en effet l'oxydation a un caractere lineaire au-dessus de cette temperature, alors qu'elle atteint un palier et reste tres limitee au-dessous de 350 deg. C. Du point de vue de la corrosion, cette temperature limite d'emploi peut cependant etre elevee jusqu'a 500 deg. C si l'on introduit dans l'air humide de tres faibles teneurs de composes fluores. Dans le gaz carbonique sous pression, l'oxydation est beaucoup plus faible, meme jusqu'a 50g. C pour les trois materiaux: l'augmentation de poids atteint un palier d'autant plus eleve et ceci d'autant plus rapidement que la temperature est elle-meme plus elevee. Cependant, l

Acute Exacerbations of COPD Are Associated With Increased Expression of Heparan Sulfate and Chondroitin Sulfate in BAL.

Science.gov (United States)

Papakonstantinou, Eleni; Klagas, Ioannis; Roth, Michael; Tamm, Michael; Stolz, Daiana

2016-03-01

Acute exacerbations of COPD (AECOPDs) are associated with accelerated aggravation of clinical symptoms and deterioration of pulmonary function. The mechanisms by which exacerbations may contribute to airway remodeling and declined lung function are poorly understood. We investigated whether AECOPDs are associated with differential expression of glycosaminoglycans in BAL in a cohort of 97 patients with COPD. Patients with COPD with either stable disease (n = 53) or AECOPD (n = 44) and undergoing diagnostic bronchoscopy were matched for demographics and lung function parameters. Levels of heparan sulfate, chondroitin sulfate, dermatan sulfate, and matrix metalloproteinases (MMPs) in BAL were measured by enzyme-linked immunosorbent assay. Heparan sulfate and chondroitin sulfate were significantly increased in BAL of patients during exacerbations. Levels of heparan sulfate were higher in the BAL of patients with microbial infections. Chondroitin sulfate was negatively correlated with FEV1 % predicted but not with diffusing capacity of lung for carbon monoxide % predicted, indicating that chondroitin sulfate is associated with airway remodeling, leading to obstruction rather than to emphysema. Furthermore, heparan sulfate and chondroitin sulfate were significantly correlated with MMP-9, MMP-2, and MMP-12 in BAL, indicating that they were cleaved from their respective proteoglycans by MMPs and subsequently washed out in BAL. During AECOPD, there is increased expression of heparan sulfate and chondroitin sulfate in BAL. These molecules are significantly correlated with MMPs in BAL, indicating that they may be associated with airway remodeling and may lead to lung function decline during exacerbations of COPD. Copyright © 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

Chondroitin Sulfate Perlecan Enhances Collagen Fibril Formation

DEFF Research Database (Denmark)

Kvist, A. J.; Johnson, A. E.; Mörgelin, M.

2006-01-01

in collagen type II fibril assembly by perlecan-null chondrocytes. Cartilage perlecan is a heparin sulfate or a mixed heparan sulfate/chondroitin sulfate proteoglycan. The latter form binds collagen and accelerates fibril formation in vitro, with more defined fibril morphology and increased fibril diameters...... produced in the presence of perlecan. Interestingly, the enhancement of collagen fibril formation is independent on the core protein and is mimicked by chondroitin sulfate E but neither by chondroitin sulfate D nor dextran sulfate. Furthermore, perlecan chondroitin sulfate contains the 4,6-disulfated...... disaccharides typical for chondroitin sulfate E. Indeed, purified glycosaminoglycans from perlecan-enriched fractions of cartilage extracts contain elevated levels of 4,6-disulfated chondroitin sulfate disaccharides and enhance collagen fibril formation. The effect on collagen assembly is proportional...

Activation and transfer of sulfate in biological systems (1960); Activation biologique du sulfate et son transfert (1960)

Energy Technology Data Exchange (ETDEWEB)

Chapeville, F [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

It examines in this review the successive stages of active sulfate formation and its role in biological synthesis of sulfuric esters. The possible role of active sulfate as intermediary in sulfate reduction is also discussed. (author) [French] On examine dans cette etude les stades successifs de la mise en evidence du sulfate actif, son role dans la formation des esters sulfuriques de natures diverses, ainsi que sa participation eventuelle comme intermediaire au cours de la reduction du sulfate. On decrit aussi un procede de preparation du systeme biologique, generateur du sulfate actif et une methode de synthese chimique. (auteur)

Solid state cathode materials for secondary magnesium-ion batteries that are compatible with magnesium metal anodes in water-free electrolyte

International Nuclear Information System (INIS)

Crowe, Adam J.; Bartlett, Bart M.

2016-01-01

With high elemental abundance, large volumetric capacity, and dendrite-free metal deposition, magnesium metal anodes offer promise in beyond-lithium-ion batteries. However, the increased charge density associated with the divalent magnesium-ion (Mg 2+ ), relative to lithium-ion (Li + ) hinders the ion-insertion and extraction processes within many materials and structures known for lithium-ion cathodes. As a result, many recent investigations incorporate known amounts of water within the electrolyte to provide temporary solvation of the Mg 2+ , improving diffusion kinetics. Unfortunately with the addition of water, compatibility with magnesium metal anodes disappears due to forming an ion-insulating passivating layer. In this short review, recent advances in solid state cathode materials for rechargeable magnesium-ion batteries are highlighted, with a focus on cathode materials that do not require water contaminated electrolyte solutions for ion insertion and extraction processes. - Graphical abstract: In this short review, we present candidate materials for reversible Mg-battery cathodes that are compatible with magnesium metal in water-free electrolytes. The data suggest that soft, polarizable anions are required for reversible cycling.

Quantitative analysis of glycosaminoglycans, chondroitin/dermatan sulfate, hyaluronic acid, heparan sulfate, and keratan sulfate by liquid chromatography-electrospray ionization-tandem mass spectrometry.

Science.gov (United States)

Osago, Harumi; Shibata, Tomoko; Hara, Nobumasa; Kuwata, Suguru; Kono, Michihaya; Uchio, Yuji; Tsuchiya, Mikako

2014-12-15

We developed a method using liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) with a selected reaction monitoring (SRM) mode for simultaneous quantitative analysis of glycosaminoglycans (GAGs). Using one-shot analysis with our MS/MS method, we demonstrated the simultaneous quantification of a total of 23 variously sulfated disaccharides of four GAG classes (8 chondroitin/dermatan sulfates, 1 hyaluronic acid, 12 heparan sulfates, and 2 keratan sulfates) with a sensitivity of less than 0.5 pmol within 20 min. We showed the differences in the composition of GAG classes and the sulfation patterns between porcine articular cartilage and yellow ligament. In addition to the internal disaccharides described above, some saccharides derived from the nonreducing terminal were detected simultaneously. The simultaneous quantification of both internal and nonreducing terminal saccharides could be useful to estimate the chain length of GAGs. This method would help to establish comprehensive "GAGomic" analysis of biological tissues. Copyright © 2014 Elsevier Inc. All rights reserved.

Investigation of samarium solubility in the magnesium based solid solution

International Nuclear Information System (INIS)

Rokhlin, L.L.; Padezhnova, E.M.; Guzej, L.S.

1976-01-01

Electric resistance measurements and microscopic analysis were used to investigate the solubility of samarium in a magnesium-based solid solution. The constitutional diagram Mg-Sm on the magnesium side is of an eutectic type with the temperature of the eutectic transformation of 542 deg C. Samarium is partly soluble in solid magnesium, the less so, the lower is the temperature. The maximum solubility of samarium in magnesium (at the eutectic transformation point) is 5.8 % by mass (0.99 at. %). At 200 deg C, the solubility of samarium in magnesium is 0.4 % by mass (0.063 at. %)

Magnesium and related low alloys

International Nuclear Information System (INIS)

Bernard, J.; Caillat, R.; Darras, R.

1959-01-01

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

Magnesium enhances exercise performance via increasing glucose availability in the blood, muscle, and brain during exercise.

Directory of Open Access Journals (Sweden)

Hsuan-Ying Chen

Full Text Available Glucose mobilization and utilization in the periphery and central nervous system are important during exercise and are responsible for exercise efficacy. Magnesium (Mg is involved in energy production and plays a role in exercise performance. This study aimed to explore the effects of Mg on the dynamic changes in glucose and lactate levels in the muscle, blood and brain of exercising rats using a combination of auto-blood sampling and microdialysis. Sprague-Dawley rats were pretreated with saline or magnesium sulfate (MgSO4, 90 mg/kg, i.p. 30 min before treadmill exercise (20 m/min for 60 min. Our results indicated that the muscle, blood, and brain glucose levels immediately increased during exercise, and then gradually decreased to near basal levels in the recovery periods of both groups. These glucose levels were significantly enhanced to approximately two-fold (P<0.05 in the Mg group. Lactate levels in the muscle, blood, and brain rapidly and significantly increased in both groups during exercise, and brain lactate levels in the Mg group further elevated (P<0.05 than those in the control group during exercise. Lactate levels significantly decreased after exercise in both groups. In conclusion, Mg enhanced glucose availability in the peripheral and central systems, and increased lactate clearance in the muscle during exercise.

Comparison of Serum Calcium and Magnesium Between ...

African Journals Online (AJOL)

Background: Evidence suggests the involvement of calcium and magnesium metabolism in the pathophysiology of preeclampsia. However, findings from studies are heterogenous and inconsistent. Aim: The study aimed to compare the total serum calcium and magnesium levels in preeclamptic women with that of ...

Constraining Δ33S signatures of Archean seawater sulfate with carbonate-associated sulfate

Science.gov (United States)

Peng, Y.; Bao, H.; Bekker, A.; Hofmann, A.

2017-12-01

Non-mass dependent sulfur isotope deviation of S-bearing phases in Archean sedimentary strata, and expressed as Δ33S, has a consistent pattern, i.e., sulfide (pyrite) predominantly bear positive Δ33S values, while Paleoarchean sulfate (barite) has negative Δ33S values. This pattern was later corroborated by observations of negative Δ33S values in Archean volcanogenic massive sulfide deposits and negative Δ33S values in early diagenetic nodular pyrite with a wide range of δ34S values, which is thought to be due to microbial sulfate reduction. These signatures have provided a set of initial conditions for a mechanistic interpretation at physical chemistry level. Unlike the younger geological times when large bodies of seawater evaporite deposits are common, to expand seawater sulfate records, carbonate-associated sulfate (CAS) was utilized as a proxy for ancient seawater sulfate. CAS extracted from the Archean carbonates carries positive Δ33S values. However, CAS could be derived from pyrite oxidation following exposure to modern oxidizing conditions and/or during laboratory extraction procedures. It is, therefore, important for us understanding context of the overall early earth atmospheric condition to empirically confirm whether Archean seawater sulfate was generally characterized by negative Δ33S signatures. Combined δ18O, Δ17O, δ34S, and Δ33S analyses of sequentially extracted water-leachable sulfate (WLS) and acid-leachable sulfate (ALS = CAS) and δ34S and Δ33S analyses of pyrite can help to identify the source of extracted sulfate. We studied drill-core samples of Archean carbonates from the 2.55 Ga Malmani and Campell Rand supgroups, South Africa. Our preliminary results show that 1) neither WLS nor ALS were extracted from samples with extremely low pyrite contents (less than 0.05 wt.%); 2) extractable WLS and ALS is present in samples with relatively high pyrite contents (more than 1 wt.%), and that δ34S and Δ33S values of WLS, ALS, and

Justification for intravenous magnesium therapy in acute myocardial infarction

DEFF Research Database (Denmark)

Rasmussen, H S

1988-01-01

Recent studies have shown that patients with acute myocardial infarction (AMI) are magnesium-deficient and develop an additional transient decrease in serum magnesium concentrations (S-Mg c) during the acute phase of the infarct. Animal experiments, as well as studies on humans, have indicated.......v. magnesium therapy on mortality and incidence of arrhythmias in patients with AMI has been evaluated. Magnesium treatment more than halved the acute mortality and incidence of arrhythmias requiring treatment in three of the four intervention studies. The mechanisms behind the beneficial effect of magnesium...... therapy are probably multifactorial; a direct depressive effect on the cardiac conducting system; a peripheral dilatory effect on the arteries, reducing the afterload on the myocardium; a reduced infarct size; an ion-stabilizing effect, maintaining stable intra and extracellular concentrations...

Magnesium Borate Synthesis by Microwave Energy: A New Method

Directory of Open Access Journals (Sweden)

Azmi Seyhun Kipcak

2013-01-01

Full Text Available Magnesium borates are one of the major groups of boron minerals that have important properties such as high heat and corrosion resistances and high coefficients of elasticity. In this study, magnesium borate minerals are synthesized using boric acid and magnesium oxide with a new method of microwave, and the synthesized minerals are characterized by various analysis techniques. The results show that pure, “magnesium borate hydrate” minerals are obtained at the end of various steps. The characterization of the products is determined with the techniques of X-Ray Diffraction (XRD, Fourier Transform Infrared Spectroscopy (FT-IR, Raman Spectroscopy, and Scanning Electron Microscopy (SEM. Additionally, overall “magnesium borate hydrate” yields are calculated and found about 67% at 270 W, 8 minutes and 360 W, 3 minutes of reaction times, respectively.

Magnesium in diet

Science.gov (United States)

... sources of magnesium: Fruits or vegetables (such as bananas, dried apricots, and avocados) Nuts (such as almonds ... deficiency: Low blood calcium level (hypocalcemia) Low blood potassium level (hypokalemia) Recommendations These are the recommended daily ...

Effects of sulfate deprivation on the production of chondroitin/dermatan sulfate by cultures of skin fibroblasts from normal and diabetic individuals

International Nuclear Information System (INIS)

Silbert, C.K.; Humphries, D.E.; Palmer, M.E.; Silbert, J.E.

1991-01-01

Human skin fibroblast monolayer cultures from two normal men, three Type I diabetic men, and one Type I diabetic woman were incubated with [3H]glucosamine in the presence of diminished concentrations of sulfate. Although total synthesis of [3H]chondroitin/dermatan glycosaminoglycans varied somewhat between cell lines, glycosaminoglycan production was not affected within any line when sulfate levels were decreased from 0.3 mM to 0.06 mM to 0.01 mM to 0 added sulfate. Lowering of sulfate concentrations resulted in diminished sulfation of chondroitin/dermatan in a progressive manner, so that overall sulfation dropped to as low as 19% for one of the lines. Sulfation of chondroitin to form chondroitin 4-sulfate and chondroitin 6-sulfate was progressively and equally affected by decreasing the sulfate concentration in the culture medium. However, sulfation to form dermatan sulfate was preserved to a greater degree, so that the relative proportion of dermatan sulfate to chondroitin sulfate increased. Essentially all the nonsulfated residues were susceptible to chondroitin AC lyase, indicating that little epimerization of glucuronic acid residues to iduronic acid had occurred in the absence of sulfation. These results confirm the previously described dependency of glucuronic/iduronic epimerization on sulfation, and indicate that sulfation of the iduronic acid-containing disaccharide residues of dermatan can take place with sulfate concentrations lower than those needed for 6-sulfation and 4-sulfation of the glucuronic acid-containing disaccharide residues of chondroitin. There were considerable differences among the six fibroblast lines in susceptibility to low sulfate medium and in the proportion of chondroitin 6-sulfate, chondroitin 4-sulfate, and dermatan sulfate. However, there was no pattern of differences between normals and diabetics

INTRACELLULAR SYNTHESIS OF CHONDROITIN SULFATE

Science.gov (United States)

Dziewiatkowski, Dominic D.

1962-01-01

In autoradiograms of slices of costal cartilage, incubated for 4 hours in a salt solution containing S35-sulfate and then washed extensively and dehydrated, about 85 per cent of the radioactivity was assignable to the chondrocytes. From alkaline extracts of similarly prepared slices of cartilage, 64 to 83 per cent of the total sulfur-35 in the slices was isolated as chondroitin sulfate by chromatography on an anion-exchange resin. In view of the estimate that only about 15 per cent of the radioactivity was in the matrix, the isolation of 64 to 83 per cent of the total sulfur-35 as chondroitin sulfate is a strong argument that the chondrocytes are the loci in which chondroitin sulfate(s) is synthesized. PMID:13888910

Is serum magnesium estimate necessary in patients with Eclampsia ...

African Journals Online (AJOL)

The therapeutic index of magnesium is said to be low, hence, there are fears of toxicity when used as anticonvulsant in eclamptic patients. The objective of this study was to determine the serum levels of magnesium in eclamptic patients treated with magnesium sulphate and relate the levels with clinical indicators. It was a ...

Synthesis of N-oleyl O-sulfate chitosan from methyl oleate with O-sulfate chitosan as edible film material

Science.gov (United States)

Daniel; Sihaloho, O.; Saleh, C.; Magdaleni, A. R.

2018-04-01

The research on the synthesis of N-oleyl O-sulfate chitosan through sulfonation reaction on chitosan with ammonium sulfate and followed by amidation reaction using methyl oleate has been done. In this study, chitosan was chemically modified into N-oleyl O-sulfatechitosan as an edible film making material. N-oleyl O-sulfate chitosan was synthesized by reaction between methyl oleate and O-sulfate chitosan. Wherein the depleted chitosan of O-sulfate chitosan into O-sulfate chitosan was obtained by reaction of sulfonation between ammonium sulfate and chitosan aldimine. While chitosan aldimine was obtained through reaction between chitosan with acetaldehyde. The structure of N-oleyl O-sulfate chitosan was characterized by FT-IR analysis which showed vibration uptake of C-H sp3 group, S=O group, and carbonyl group C=O of the ester. The resulting of N-oleyl O-sulfate chitosan yielded a percentage of 93.52%. Hydrophilic-Lipophilic Balance (HLB) test results gave a value of 6.68. In the toxicity test results of N-oleyl O-sulfate chitosan obtained LC50 value of 3738.4732 ppm. In WVTR (Water Vapor Transmission Rate) test results for chitosan film was 407.625 gram/m2/24 hours and N-oleylO-sulfate chitosan film was 201.125 gram/m2/24 hours.

Magnesium removal in the electrolytic zinc industry

NARCIS (Netherlands)

Booster, J.L.

2003-01-01

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

Machinability of magnesium and aluminium alloys. Part I: cutting resistance

International Nuclear Information System (INIS)

Balout, B.; Songmene, V.; Masounave, J.

2002-01-01

Aluminium (2.7 g/cm 3 ) and magnesium (1.7 g/cm 3 ) are two competing light metals with similar mechanical properties and excellent possibilities for recycling. The forming of magnesium is often seen as an impediment to its use. New forming techniques using magnesium shavings are being developed, particularly in Japan. The machining of magnesium alloys by removal of metal raises safety concerns (risk of fire), which limits many potential applications of magnesium. The purpose of this work is to clarify and compare the machining properties of these two types of metal and better understand the mechanisms that may explain the differences in behaviour. Such a comparison could eventually provide an estimate of the cost of producing shavings for the manufacture of aluminium and magnesium parts through forging and extrusion, which would limit environmental pollution. Based on an analysis of cutting resistance during machining, it was demonstrated that magnesium alloys are easier to machine than similar aluminium alloys. Magnesium shavings are shorter than those of 6061-T6, but are especially more regular than those of A356, and their size is independent of cutting speed. It was also demonstrated that the fragility of materials can be characterized based on the results of cutting resistance produced during drilling

Magnesium and manganese content of halophilic bacteria

International Nuclear Information System (INIS)

de Medicis, E.; Paquette, J.; Gauthier, J.J.; Shapcott, D.

1986-01-01

Magnesium and manganese contents were measured by atomic absorption spectrophotometry in bacteria of several halophilic levels, in Vibrio costicola, a moderately halophilic eubacterium growing in 1 M NaCl, Halobacterium volcanii, a halophilic archaebacterium growing in 2.5 NaCl, Halobacterium cutirubrum, an extremely halophilic archaebacterium growing in 4 M NaCl, and Escherichia coli, a nonhalophilic eubacterium growing in 0.17 M NaCl. Magnesium and manganese contents varied with the growth phase, being maximal at the early log phase. Magnesium and manganese molalities in cell water were shown to increase with the halophilic character of the logarithmically growing bacteria, from 30 mmol of Mg per kg of cell water and 0.37 mmol of Mn per kg of cell water for E. coli to 102 mmol of Mg per kg of cell water and 1.6 mmol of Mn per kg of cell water for H cutirubrum. The intracellular concentrations of manganese were determined independently by a radioactive tracer technique in V. costicola and H. volcanii. The values obtained by 54 Mn loading represented about 70% of the values obtained by atomic absorption. The increase of magnesium and manganese contents associated with the halophilic character of the bacteria suggests that manganese and magnesium play a role in haloadaptation

Effects of extracellular magnesium on the differentiation and function of human osteoclasts.

Science.gov (United States)

Wu, Lili; Luthringer, Bérengère J C; Feyerabend, Frank; Schilling, Arndt F; Willumeit, Regine

2014-06-01

Magnesium-based implants have been shown to influence the surrounding bone structure. In an attempt to partially reveal the cellular mechanisms involved in the remodelling of magnesium-based implants, the influence of increased extracellular magnesium content on human osteoclasts was studied. Peripheral blood mononuclear cells were driven towards an osteoclastogenesis pathway via stimulation with receptor activator of nuclear factor kappa-B ligand and macrophage colony-stimulating factor for 28 days. Concomitantly, the cultures were exposed to variable magnesium concentrations (from either magnesium chloride or magnesium extracts). Osteoclast proliferation and differentiation were evaluated based on cell metabolic activity, total protein content, tartrate-resistant acid phosphatase activity, cathepsin K and calcitonin receptor immunocytochemistry, and cellular ability to form resorption pits. While magnesium chloride first enhanced and then opposed cell proliferation and differentiation in a concentration-dependent manner (peaking between 10 and 15mM magnesium chloride), magnesium extracts (with lower magnesium contents) appeared to decrease cell metabolic activity (≈50% decrease at day 28) while increasing osteoclast activity at a lower concentration (twofold higher). Together, the results indicated that (i) variations in the in vitro extracellular magnesium concentration affect osteoclast metabolism and (ii) magnesium extracts should be used preferentially in vitro to more closely mimic the in vivo environment. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Magnesium borate radiothermoluminescent detectors

International Nuclear Information System (INIS)

Kazanskaya, V.A.; Kuzmin, V.V.; Minaeva, E.E.; Sokolov, A.D.

1974-01-01

In the report the technology of obtaining polycrystalline magnesium borate activated by dysprosium is described briefly and the method of preparing the tabletted detectors from it is presented. The dependence of the light sum of the samples on the proportion of the components and on the sintering regime has shown that the most sensitive material is obtained at the proportion of boric anhydride and magnesium oxide 2.2-2.4 and at the dysprosium concentration about 1 milligram-atom per gram molecule of the base. The glow curve of such a material has a simple form with one peak the maximum of which is located at 190-200 0 C. The measurement of the main dosimetric characteristics of the magnesium borate tabletted detectors and the comparison with similar parmaeters of the lithium fluoride tabletted detectors have shown that at practically identical effective number the former detectors have the following substantial advantages: the sensitivity is ten-twenty times as large, they are substantially more technological on synthesis of the radiothermoluminophor and during the production of the tabletted detectors, they have a simple glow curve, they do not require the utilization of the thermocycling during the use. (author)

Fatigue Analysis of Magnesium Alloys Components for Car Industry

Science.gov (United States)

Marsavina, Liviu; Rusu, Lucian; Șerban, Dan Andrei; Negru, Radu Marcel; Cernescu, Anghel

2017-12-01

The use of magnesium alloys in the automotive industry increased in the last decade because of their low weight and relative good mechanical properties. However, the variable loading conditions require a good fatigue behavior. This paper summaries the fatigue properties of magnesium alloys and presents new fatigue curve results for die cast AM50 magnesium alloy.

Magnesium supplementation in children with attention deficit ...

African Journals Online (AJOL)

Background: Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder with associated mineral deficiency. Aim: To assess magnesium level in ADHD children and compare it to the normal levels in children. Then, to detect the effect of magnesium supplementation as an add on therapy, ...

Design Considerations for Developing Biodegradable Magnesium Implants

Science.gov (United States)

Brar, Harpreet S.; Keselowsky, Benjamin G.; Sarntinoranont, Malisa; Manuel, Michele V.

The integration of biodegradable and bioabsorbable magnesium implants into the human body is a complex undertaking that faces major challenges. The complexity arises from the fact that biomaterials must meet both engineering and physiological requirements to ensure the desired properties. Historically, efforts have been focused on the behavior of commercial magnesium alloys in biological environments and their resultant effect on cell-mediated processes. Developing causal relationships between alloy chemistry and micro structure, and its effect on cellular behavior can be a difficult and time intensive process. A systems design approach driven by thermodynamics has the power to provide significant contributions in developing the next generation of magnesium alloy implants with controlled degradability, biocompatibility, and optimized mechanical properties, at reduced time and cost. This approach couples experimental research with theory and mechanistic modeling for the accelerated development of materials. The aim of this article is to enumerate this strategy, design considerations and hurdles for developing new magnesium alloys for use as biodegradable implant materials [1].

Selectivity coefficients of ion-selective magnesium electrodes used for simultaneous determination of magnesium and calcium ions.

Science.gov (United States)

Maj-Zurawska, Magdalena; Lewenstam, Andrzej

2011-12-15

Membrane ion-selective magnesium electrodes are commonly used to determine ionized magnesium concentration in blood serum and intracellular fluid by potentiometric clinical analyzers. The selectivity of these electrodes against calcium ion is typically insufficient to avoid calcium interference in blood serum analysis. For this reason the selectivity coefficient for calcium ion has to be studied to make possible any mathematical corrections for calcium ion influence. Existing methods relate to the thermodynamic concept of ISE response which suggest a single constant value of the selectivity coefficient and slope that are stable over the concentration ranges of calcium and magnesium ions in the samples. Unfortunately, this rarely happens, and we rather observe dependences on solution and membrane composition, readout time, matrices (anticoagulant, vial coats) that justify usage of apparent selectivities and slopes. To get the practical insight into the response of magnesium ion-selective electrodes a novel method for estimating the selectivity coefficients and the slope of the electrode characteristics is proposed. This method is an effective starting point for selecting electrodes and designing transient signal software in a potentiometric clinical analyzer. The method allows obtaining the ionized magnesium concentration in blood serum with minimal possible error by addressing the assessed targets, i.e. apparent selectivity and slope. The method is based on computer simulation and on the Nicolsky-Eisenman equation. Usually only a few iterations are needed to obtain stable congruent results. The method presented is particularly useful in conditions where is not possible to obtain calibration curve, which is typical for clinical analyzer where at most three point calibration is performed. Copyright © 2011 Elsevier B.V. All rights reserved.

Biodegradable magnesium nanoparticle-enhanced laser hyperthermia therapy

Directory of Open Access Journals (Sweden)

Wang Q

2012-08-01

Full Text Available Qian Wang,1 Liping Xie,1 Zhizhu He,2 Derui Di,2 Jing Liu1,21Department of Biomedical Engineering, School of Medicine, Tsinghua University, 2Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, People's Republic of ChinaBackground: Recently, nanoparticles have been demonstrated to have tremendous merit in terms of improving the treatment specificity and thermal ablation effect on tumors. However, the potential toxicity and long-term side effects caused by the introduced nanoparticles and by expelling them out of the body following surgery remain a significant challenge. Here, we propose for the first time to directly adopt magnesium nanoparticles as the heating enhancer in laser thermal ablation to avoid these problems by making full use of the perfect biodegradable properties of this specific material.Methods: To better understand the new nano “green” hyperthermia modality, we evaluated the effects of magnesium nanoparticles on the temperature transients inside the human body subject to laser interstitial heating. Further, we experimentally investigated the heating enhancement effects of magnesium nanoparticles on a group of biological samples: oil, egg white, egg yolk, in vitro pig tissues, and the in vivo hind leg of rabbit when subjected to laser irradiation.Results: Both the theoretical simulations and experimental measurements demonstrated that the target tissues injected with magnesium nanoparticles reached much higher temperatures than tissues without magnesium nanoparticles. This revealed the enhancing behavior of the new nanohyperthermia method.Conclusion: Given the unique features of magnesium nanoparticles – their complete biological safety and ability to enhance heating – which most other advanced metal nanoparticles do not possess, the use of magnesium nanoparticles in hyperthermia therapy offers an important “green” nanomedicine modality for treating tumors

Magnesium Counteracts Vascular Calcification: Passive Interference or Active Modulation?

Science.gov (United States)

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.

21 CFR 184.1261 - Copper sulfate.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Copper sulfate. 184.1261 Section 184.1261 Food and... Substances Affirmed as GRAS § 184.1261 Copper sulfate. (a) Copper sulfate (cupric sulfate, CuSO4·5H2O, CAS... the reaction of sulfuric acid with cupric oxide or with copper metal. (b) The ingredient must be of a...

Heritability and clinical determinants of serum indoxyl sulfate and p-cresyl sulfate, candidate biomarkers of the human microbiome enterotype.

Directory of Open Access Journals (Sweden)

Liesbeth Viaene

Full Text Available BACKGROUND: Indoxyl sulfate and p-cresyl sulfate are unique microbial co-metabolites. Both co-metabolites have been involved in the pathogenesis of accelerated cardiovascular disease and renal disease progression. Available evidence suggests that indoxyl sulfate and p-cresyl sulfate may be considered candidate biomarkers of the human enterotype and may help to explain the link between diet and cardiovascular disease burden. OBJECTIVE AND DESIGN: Information on clinical determinants and heritability of indoxyl sulfate and p-cresyl sulfate serum is non-existing. To clarify this issue, the authors determined serum levels of indoxyl sulfate and p-cresyl sulfate in 773 individuals, recruited in the frame of the Flemish Study on Environment, Genes and Health Outcomes (FLEMENGHO study. RESULTS: Serum levels of indoxyl sulfate and p-cresyl sulfate amounted to 3.1 (2.4-4.3 and 13.0 (7.4-21.5 μM, respectively. Regression analysis identified renal function, age and sex as independent determinants of both co-metabolites. Both serum indoxyl sulfate (h2 = 0.17 and p-cresyl sulfate (h2 = 0.18 concentrations showed moderate but significant heritability after adjustment for covariables, with significant genetic and environmental correlations for both co-metabolites. LIMITATIONS: Family studies cannot provide conclusive evidence for a genetic contribution, as confounding by shared environmental effects can never be excluded. CONCLUSIONS: The heritability of indoxyl sulfate and p-cresyl sulfate is moderate. Besides genetic host factors and environmental factors, also renal function, sex and age influence the serum levels of these co-metabolites.

X-linked immunodeficiency with magnesium defect, Epstein-Barr virus infection, and neoplasia disease: a combined immune deficiency with magnesium defect.

Science.gov (United States)

Ravell, Juan; Chaigne-Delalande, Benjamin; Lenardo, Michael

2014-12-01

To describe the role of the magnesium transporter 1 (MAGT1) in the pathogenesis of 'X-linked immunodeficiency with magnesium defect, Epstein-Barr virus (EBV) infection, and neoplasia' (XMEN) disease and its clinical implications. The magnesium transporter protein MAGT1 participates in the intracellular magnesium ion (Mg) homeostasis and facilitates a transient Mg influx induced by the activation of the T-cell receptor. Loss-of-function mutations in MAGT1 cause an immunodeficiency named 'XMEN syndrome', characterized by CD4 lymphopenia, chronic EBV infection, and EBV-related lymphoproliferative disorders. Patients with XMEN disease have impaired T-cell activation and decreased cytolytic function of natural killer (NK) and CD8 T cells because of decreased expression of the NK stimulatory receptor 'natural-killer group 2, member D' (NKG2D). Patients may have defective specific antibody responses secondary to T cell dysfunction, but B cells have not been shown to be directly affected by mutations in MAGT1. XMEN disease has revealed a novel role for free intracellular magnesium in the immune system. Further understanding of the MAGT1 signaling pathway may lead to new diagnostic and therapeutic approaches.

Serum magnesium and the risk of prediabetes: a population-based cohort study.

Science.gov (United States)

Kieboom, Brenda C T; Ligthart, Symen; Dehghan, Abbas; Kurstjens, Steef; de Baaij, Jeroen H F; Franco, Oscar H; Hofman, Albert; Zietse, Robert; Stricker, Bruno H; Hoorn, Ewout J

2017-05-01

Previous studies have found an association between serum magnesium and incident diabetes; however, this association may be due to reverse causation, whereby diabetes may induce urinary magnesium loss. In contrast, in prediabetes (defined as impaired fasting glucose), serum glucose levels are below the threshold for urinary magnesium wasting and, hence, unlikely to influence serum magnesium levels. Thus, to study the directionality of the association between serum magnesium levels and diabetes, we investigated its association with prediabetes. We also investigated whether magnesium-regulating genes influence diabetes risk through serum magnesium levels. Additionally, we quantified the effect of insulin resistance in the association between serum magnesium levels and diabetes risk. Within the population-based Rotterdam Study, we used Cox models, adjusted for age, sex, lifestyle factors, comorbidities, kidney function, serum levels of electrolytes and diuretic use, to study the association between serum magnesium and prediabetes/diabetes. In addition, we performed two mediation analyses: (1) to study if common genetic variation in eight magnesium-regulating genes influence diabetes risk through serum magnesium levels; and (2) to quantify the proportion of the effect of serum magnesium levels on diabetes that is mediated through insulin resistance (quantified by HOMA-IR). A total of 8555 participants (mean age, 64.7 years; median follow-up, 5.7 years) with normal glucose levels (mean ± SD: 5.46 ± 0.58 mmol/l) at baseline were included. A 0.1 mmol/l decrease in serum magnesium level was associated with an increase in diabetes risk (HR 1.18 [95% CI 1.04, 1.33]), confirming findings from previous studies. Of interest, a similar association was found between serum magnesium levels and prediabetes risk (HR 1.12 [95% CI 1.01, 1.25]). Genetic variation in CLDN19, CNNM2, FXYD2, SLC41A2, and TRPM6 significantly influenced diabetes risk (p prediabetes 13.4% was

The electrical and thermal properties of sodium sulfate mixed with lithium sulfate, yttrium sulfate, and silicon dioxide

International Nuclear Information System (INIS)

Imanaka, N.; Yamaguchi, Y.; Adachi, G.; Shiokawa, J.

1986-01-01

Sodium sulfate mixed with lithium sulfate, yttrium sulfate, and silicon dioxide was prepared. The thermal and electrical properties of its phases were investigated. The Na 2 SO 4 -Li 2 SO 4 -Y 2 (SO 4 ) 3 SiO 2 samples are similar to the Na 2 SO 4 -I phase (a high temperature phase), which is appreciably effective for Na + ionic conduction. Phase transformation was considerably suppressed by mixing. Electromotive force (EMF) was measured, using Na 2 SO 4 -Li 2 SO 4 -Y 2 (SO 4 ) 3 -SiO 2 as a solid electrolyte, by constructing an SO 2 gas concentration cell. The measured EMF's at 823 and 773 K were in fairly good accordance with the calculated EMF's for inlet SO 2 gas concentration between 30 ppm and 1%, and 500 ppm and 0.5% respectively

21 CFR 172.822 - Sodium lauryl sulfate.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium lauryl sulfate. 172.822 Section 172.822 Food... Multipurpose Additives § 172.822 Sodium lauryl sulfate. The food additive sodium lauryl sulfate may be safely... specifications: (1) It is a mixture of sodium alkyl sulfates consisting chiefly of sodium lauryl sulfate [CH2(CH2...

Casting Porosity-Free Grain Refined Magnesium Alloys

Energy Technology Data Exchange (ETDEWEB)

Schwam, David [Case Western Reserve University

2013-08-12

The objective of this project was to identify the root causes for micro-porosity in magnesium alloy castings and recommend remedies that can be implemented in production. The findings confirm the key role played by utilizing optimal gating and risering practices in minimizing porosity in magnesium castings. 

Biodegradable magnesium-alloy stent:current situation in research

International Nuclear Information System (INIS)

Chen Hua; Zhao Xianxian

2011-01-01

In recent years, permanent metal stents are employed in the majority of interventional therapies; nevertheless, such kind of stents carries the problems of thrombosis and restenosis. Therefore, the biodegradable magnesium alloy stent has become the focus of attention. Theoretically, it has overcome the problems caused by permanent metal stents, so it is the development direction to use the biodegradable magnesium alloy in future. The authors believe that biodegradable magnesium alloy stents will be widely used in interventional procedures for many diseases. (authors)

Lithium/magnesium oxide catalyst and method of making

Energy Technology Data Exchange (ETDEWEB)

Lunsford, J.H.; Hinson, P.G.

1991-07-16

This patent describes a method for preparing a catalyst which is effective for converting methane to ethane and ethylene. It comprises mixing a solution of a magnesium alkoxide in an alcohol with a solution containing a source of lithium in an alcohol, to obtain a ratio of magnesium metal to lithium metal; hydrolyzing the magnesium alkoxide in the solution to form a gel; and calcining the gel to form a catalyst which is effective for converting methane to ethane and ethylene.

Cytotoxic effect of galvanically coupled magnesium-titanium particles.

Science.gov (United States)

Kim, Jua; Gilbert, Jeremy L

2016-01-01

Recent work has shown that reduction reactions at metallic biomaterial surfaces can induce significant killing of cells in proximity to the surface. To exploit this phenomenon for therapeutic purposes, for example, for cancer tumor killing or antibacterial effects (amongst other applications), magnesium metal particles, galvanically coupled to titanium by sputtering, have been evaluated for their cell-killing capability (i.e. cytotoxicity). Magnesium (Mg) particles large enough to prevent particle phagocytosis were investigated, so that only electrochemical reactions, and not particle toxicity per se, caused cytotoxic effects. Titanium (Ti) coated magnesium particles, as well as magnesium-only particles were introduced into MC3T3-E1 mouse pre-osteoblast cell cultures over a range of particle concentrations, and cells were observed to die in a dosage-dependent manner. Ti-coated magnesium particles killed more cells at lower particle concentration than magnesium alone (Pmagnesium and magnesium-titanium had no significant difference at similar particle concentrations. Complete cell killing occurred at 750μg/ml and 1500μg/ml for Mg-Ti and Mg, respectively. Thus, this work demonstrates that galvanically coupled Mg-Ti particles have a significant cell killing capability greater than Mg alone. In addition, when the pH associated with complete killing with particles was created using NaOH only (no particles), then the percentage of cells killed was significantly less (Pmagnesium-titanium microparticles kill cells more effectively than magnesium particles alone. The killing effect was shown to not be due to pH shifts since no differences were seen for different particle types and pH adjusted medium without particles did not exhibit the same level of killing. The significance of this work is the recognition of this killing effect with Mg particles and the potential therapeutic applications in infection control and cancer treatment that this process may provide. Copyright �

Impurity characterization of magnesium diuranate using simultaneous TG–DTA–FTIR measurements

Energy Technology Data Exchange (ETDEWEB)

Raje, Naina, E-mail: nraje@barc.gov.in [Analytical Chemistry Division, B.A.R.C., Mumbai 400 085 (India); Ghonge, Darshana K. [Analytical Chemistry Division, B.A.R.C., Mumbai 400 085 (India); Hemantha Rao, G.V.S. [NFC, ECIL Post, Hyderabad (India); Reddy, A.V.R. [Analytical Chemistry Division, B.A.R.C., Mumbai 400 085 (India)

2013-05-15

Current studies describe the application of simultaneous thermogravimetry–differential thermal analysis – evolved gas analysis techniques for the compositional characterization of magnesium diuranate (MDU) with respect to the impurities present in the matrix. The stoichiometric composition of MDU was identified as MgU{sub 2}O{sub 7}⋅3H{sub 2}O. Presence of carbonate and sulphate as impurities in the matrix was confirmed through the evolved gas analysis using Fourier Transformation Infrared Spectrometry detection. Carbon and magnesium hydroxide content present as impurities in magnesium diuranate have been determined quantitatively using TG and FTIR techniques and the results are in good agreement. Powder X-ray diffraction analysis of magnesium diuranate suggests the presence of magnesium hydroxide as impurity in the matrix. Also these studies confirm the formation of magnesium uranate, uranium sesquioxide and uranium dioxide above 1000 °C, due to the decomposition of magnesium diuranate.

Multivariate regression models for the simultaneous quantitative analysis of calcium and magnesium carbonates and magnesium oxide through drifts data

Directory of Open Access Journals (Sweden)

Marder Luciano

2006-01-01

Full Text Available In the present work multivariate regression models were developed for the quantitative analysis of ternary systems using Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS to determine the concentration in weight of calcium carbonate, magnesium carbonate and magnesium oxide. Nineteen spectra of standard samples previously defined in ternary diagram by mixture design were prepared and mid-infrared diffuse reflectance spectra were recorded. The partial least squares (PLS regression method was applied to the model. The spectra set was preprocessed by either mean-centered and variance-scaled (model 2 or mean-centered only (model 1. The results based on the prediction performance of the external validation set expressed by RMSEP (root mean square error of prediction demonstrated that it is possible to develop good models to simultaneously determine calcium carbonate, magnesium carbonate and magnesium oxide content in powdered samples that can be used in the study of the thermal decomposition of dolomite rocks.

Purification and sequence characterization of chondroitin sulfate and dermatan sulfate from fishes.

Science.gov (United States)

Lin, Na; Mo, Xiaoli; Yang, Yang; Zhang, Hong

2017-04-01

Chondroitin sulfate (CS) and dermatan sulfate (DS) were extracted and purified from skins or bones of salmon (Salmo salar), snakehead (Channa argus), monkfish (Lophius litulon) and skipjack tuna (Katsuwonus pelamis). Size, structural sequences and sulfate groups of oligosaccharides in the purified CS and DS could be characterized and identified using high performance liquid chromatography (HPLC) combined with Orbitrap mass spectrometry. CS and DS chain structure varies depending on origin, but motif structure appears consistent. Structures of CS and DS oligosaccharides with different size and sulfate groups were compared between fishes and other animals, and results showed that some minor differences of special structures could be identified by hydrophilic interaction chromatography-liquid chromatography-fourier transform-mass/mass spectrometry (HILIC-LC-FT-MS/MS). For example, data showed that salmon and skipjack CS had a higher percentage content of high-level sulfated oligosaccharides than that porcine CS. In addition, structural information of different origins of CS and DS was analyzed by principal component analysis (PCA) and results showed that CS and DS samples could be differentiated according to their molecular conformation and oligosaccharide fragments information. Understanding CS and DS structure derived from different origins may lead to the production of CS or DS with unique disaccharides or oligosaccharides sequence composition and biological functions.

Preparation of plate-shape nano-magnesium hydroxide from asbestos tailings

International Nuclear Information System (INIS)

Du Gaoxiang; Zheng Shuilin

2009-01-01

To prepare magnesium hydroxide is one of the effective methods to the comprehensive utilization of asbestos tailings. Nano-scale magnesium hydroxide was prepared and mechanisms of in-situ surface modification were characterized in the paper. Process conditions of preparation of magnesium hydroxide from purified hydrochloric acid leachate of asbestos tailings were optimized and in-situ surface modification of the product was carried out. Results showed that optimum process conditions for preparing nano-scale magnesium hydroxide were as follows: initial concentration of Mg 2+ in the leachate was 22.75g/L, precipitant was NaOH solution (mass concentration 20%), reaction temperature was 50 deg. C, and reaction time was 5min. The diameter and thickness of the plate nano-scale magnesium hydroxide powder prepared under optimal conditions were about 100 nm and 10 nm, respectively. However, particle agglomeration was obvious, the particle size increased to micron-grade. Dispersity of the magnesium hydroxide powder could be elevated by in-situ modification by silane FR-693, titanate YB-502 and polyethylene glycol and optimum dosages were 1.5%, 1.5% and 0.75% of the mass of magnesium hydroxide, respectively. All of the modifiers adsorbed chemically on surfaces of magnesium hydroxide particles, among which Si-O-Mg bonds formed among silane FR-693 and the particle surfaces and Ti-O-Mg among titanate YB-502 and the surfaces.

Treatment and electricity harvesting from sulfate/sulfide-containing wastewaters using microbial fuel cell with enriched sulfate-reducing mixed culture

International Nuclear Information System (INIS)

Lee, Duu-Jong; Lee, Chin-Yu; Chang, Jo-Shu

2012-01-01

Highlights: ► We started up microbial fuel cell (MFC) using enriched sulfate-reducing mixed culture. ► Sulfate-reducing bacteria and anode-respiring bacteria were enriched in anodic biofilms. ► The MFC effectively remove sulfate to elementary sulfur in the presence of lactate. ► The present device can treat sulfate laden wastewaters with electricity harvesting. - Abstract: Anaerobic treatment of sulfate-laden wastewaters can produce excess sulfide, which is corrosive to pipelines and is toxic to incorporated microorganisms. This work started up microbial fuel cell (MFC) using enriched sulfate-reducing mixed culture as anodic biofilms and applied the so yielded MFC for treating sulfate or sulfide-laden wastewaters. The sulfate-reducing bacteria in anodic biofilm effectively reduced sulfate to sulfide, which was then used by neighboring anode respiring bacteria (ARB) as electron donor for electricity production. The presence of organic carbons enhanced MFC performance since the biofilm ARB were mixotrophs that need organic carbon to grow. The present device introduces a route for treating sulfate laden wastewaters with electricity harvesting.

Treatment and electricity harvesting from sulfate/sulfide-containing wastewaters using microbial fuel cell with enriched sulfate-reducing mixed culture

Energy Technology Data Exchange (ETDEWEB)

Lee, Duu-Jong, E-mail: cedean@mail.ntust.edu.tw [Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan (China); Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan (China); Lee, Chin-Yu [Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan (China); Chang, Jo-Shu [Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan (China); Center for Bioscience and Biotechnology, National Cheng Kung University, Tainan, Taiwan (China); Research Center for Energy Technology and Strategy, National Cheng Kung University, Tainan, Taiwan (China)

2012-12-15

Highlights: Black-Right-Pointing-Pointer We started up microbial fuel cell (MFC) using enriched sulfate-reducing mixed culture. Black-Right-Pointing-Pointer Sulfate-reducing bacteria and anode-respiring bacteria were enriched in anodic biofilms. Black-Right-Pointing-Pointer The MFC effectively remove sulfate to elementary sulfur in the presence of lactate. Black-Right-Pointing-Pointer The present device can treat sulfate laden wastewaters with electricity harvesting. - Abstract: Anaerobic treatment of sulfate-laden wastewaters can produce excess sulfide, which is corrosive to pipelines and is toxic to incorporated microorganisms. This work started up microbial fuel cell (MFC) using enriched sulfate-reducing mixed culture as anodic biofilms and applied the so yielded MFC for treating sulfate or sulfide-laden wastewaters. The sulfate-reducing bacteria in anodic biofilm effectively reduced sulfate to sulfide, which was then used by neighboring anode respiring bacteria (ARB) as electron donor for electricity production. The presence of organic carbons enhanced MFC performance since the biofilm ARB were mixotrophs that need organic carbon to grow. The present device introduces a route for treating sulfate laden wastewaters with electricity harvesting.

Separation of radionuclides from water by magnesium oxide adsorption

International Nuclear Information System (INIS)

Tseng, Chia-Lian; Lo, Jem-Mau; Yeh, Si-Jung

1987-01-01

Adsorption by magnesium oxide of more than forty radionuclides in respective ionic species in water was observed. Generally, the radionuclides in di-valent and/or multi-valent cations are favorably adsorbed by magnesium oxide; but not for the those in mono-valent cations. In addition, the adsorption by magnesium oxide was not effective to most of the radionuclides in negative ionic species. From the observations, the adsorption mechanism is more prominently by the ion exchange of the di- or multi-valent cation species with the hydrous magnesium oxide. Separation of the radionuclides related to the corrosion products possibly produced in a nuclear power plant from natural seawater was attempted by the magnesium oxide adsorption method. It should be emphasized that the adsorption method was found to be practical for separating radionuclides from a large quantity of natural seawater with high recovery and high reproducibility. (author)

[SIGNIFICANCE OF MAGNESIUM IN PHISIOLOGY AND PATHOLOGY OF THE DIGESTIVE SYSTEM].

Science.gov (United States)

Grigus, Ya I; Mikhaylova, O D; Gorbunov A Yu; Vakhrushev, Ya M

2015-01-01

The article describes the physiological role of magnesium in the human body and its importance for metabolic processes. The reasons for the development of magnesium deficiency and hypermagnesaemia and its clinical symptoms are shown. The specialties of magnesium metabolism disturbances in gastroenterological pathology are described. Particular attention paid to the correction of magnesium levels with deviations of its content in the organism.

The prospects of biodegradable magnesium-based alloys in osteosynthesis

Directory of Open Access Journals (Sweden)

V. N. Chorny

2013-12-01

Full Text Available In the analytical review of the literature the main stages of development of biodegradable magnesium alloys in surgery and traumatology were discussed. The analysis revealed the main problems: there is no way to control the speed of the biological resorption alloys, the effects of products of magnesium degradation on the tissues and the organism in general are not studied, there is no information on the characteristics of the regeneration of bone tissue when implanted magnesium implanted magnesium alloys Materials for osteosynthesis with metal clamps made of steel X18H9T are used in 25,0-52,2% of cases, the corrosion of fasteners reaches 18-21%. Corrosion of the metal clips leads to the increase of the concentration of iron, chromium, nickel and titanium in the surrounding tissue. Electrochemical processes in metallic implants occurs due to their structural and chemical inhomogeneous. The microstructure of stainless steel is presented by differently oriented grains. Therefore, the question remains relevant to finding biodegradable materials suitable for implants for osteosynthesis, which could be completely metabolized by the organism, without causing of the pathological effects on the surrounding tissue and the body. The property of magnesium metal dissolved in the tissues of a living organism is known since the 19th century. Payr suggested the use of magnesium metal needles for the treatment of angiomas, in order to achieve thrombosis surrounding the tumor. In 1937 Lambotte made a post in the French Surgical Academy on the application of the osteosynthesis of the shin bone clamps with alloy Dow-metal (magnesium - 92% Aluminum - 8% + traces of manganese, made in the form of loops and screws. In 1938, Earl D. Mc.Braid and published their positive experience with plates and screws made of material similar in composition to the Dow-metal for osteosynthesis of fractures of the arm and forearm bones. Magnesium alloys may be used as a material for

Relationship of serum magnesium level and supplemental magnesium dosage with post coronary artery bypass graft surgery arrhythmias

Directory of Open Access Journals (Sweden)

Najafi M

2007-06-01

Full Text Available Background: Atrial and ventricular arrhythmias are among the most common complications after coronary artery bypass graft (CABG surgery. Previous studies demonstrated that cardiopulmonary bypass itself results in reduced serum magnesium levels. In this study, we evaluated the effect of total blood magnesium level (TMG on the prevention of perioperative arrhythmias with routine regimens of 2-4 grams supplemental magnesium (SMG. Methods: TMG was measured in patients who were scheduled for CABG on three occasions: just before anesthesia, just after entering the intensive care unit (ICU after completion of the sugery, and on the first morning after the operation. Patients were evaluated for primary cardiac rhythm and other variables that could have an influence on the magnesium level, including serum creatinine, urine output in the operating room and diuretic therapy. The SMG dosage was also recorded in the operating room and ICU. Patients were then evaluated for the rate and type of arrhythmia for the next three days. Results: The mean TMG levels in 174 cases were 2.2 (0.5, 2.6 (0.6 and 2.4 (0.6 mg/dl for the three occasions, respectively. The mean SMG was 2.5 (1.2 grams. Of 164 patients, 51 (31% developed the following post-operative arrhythmias: AF (7.3%, non-AF SVA (15.2% and ventricular (16.5%. The mean serum creatinine level and urine output were 1.2 mg/dl and 1800 ml, respectively. Although there was a significant difference between the TMG levels on the three different occasions (P<0.001, all values were within normal range. When we stratified the TMG levels of the patients based on administered SMG, the Mentel-Haenszel test revealed no significant difference between the first and third TMG (P=0.6. Although the TMG levels were higher in arrhythmic patients compared to those without arrhythmia (2.25 vs. 2.14 mg/dl, both values were within the normal range and there was no significant difference between the two groups. Serum creatinine levels

Thermionic vacuum arc (TVA) technique for magnesium thin film deposition

Energy Technology Data Exchange (ETDEWEB)

Balbag, M.Z., E-mail: zbalbag@ogu.edu.t [Eskisehir Osmangazi University, Education Faculty, Primary Education, Meselik Campus, Eskisehir 26480 (Turkey); Pat, S.; Ozkan, M.; Ekem, N. [Eskisehir Osmangazi University, Art and Science Faculty, Physics Department, Eskisehir 26480 (Turkey); Musa, G. [Ovidius University, Physics Department, Constanta (Romania)

2010-08-15

In this study, magnesium thin films were deposited on glass substrate by the Thermionic Vacuum Arc (TVA) technique for the first time. We present a different technique for deposition of high-quality magnesium thin films. By means of this technique, the production of films is achieved by condensing the plasma of anode material generated using Thermionic Vacuum Arc (TVA) under high vacuum conditions onto the surface to be coated. The crystal orientation and morphology of the deposited films were investigated by using XRD, EDX, SEM and AFM. The aim of this study is to search the use of TVA technique to coat magnesium thin films and to determine some of the physical properties of the films generated. Furthermore, this study will contribute to the scientific studies which search the thin films of magnesium or the compounds containing magnesium. In future, this study will be preliminary work to entirely produce magnesium diboride (MgB{sub 2}) superconductor thin film with the TVA technique.

Corrosion mechanism of model zinc-magnesium alloys in atmospheric conditions

International Nuclear Information System (INIS)

Prosek, T.; Nazarov, A.; Bexell, U.; Thierry, D.; Serak, J.

2008-01-01

Recently, superior corrosion properties of zinc coatings alloyed with magnesium have been reported. Corrosion behaviour of model zinc-magnesium alloys was studied to understand better the protective mechanism of magnesium in zinc. Alloys containing from 1 to 32 wt.% magnesium, pure zinc, and pure magnesium were contaminated with sodium chloride and exposed to humid air for 28 days. Composition of corrosion products was analyzed using infrared spectroscopy (FTIR), ion chromatography (IC), and Auger electron spectroscopy (AES). The exposure tests were completed with scanning Kelvin probe (SKP) and electrochemical measurements. Weight loss of ZnMg alloys with 1-16 wt.% magnesium was lower than that of pure zinc. Up to 10-fold drop in weight loss was found for materials with 4-8 wt.% Mg in the structure. The improved corrosion stability of ZnMg alloys was connected to the presence of an Mg-based film adjacent to the metal surface. It ensured stable passivity in chloride environment and limited the efficiency of oxygen reduction

Nuclear reactor shield including magnesium oxide

International Nuclear Information System (INIS)

Rouse, C.A.; Simnad, M.T.

1981-01-01

An improvement is described for nuclear reactor shielding of a type used in reactor applications involving significant amounts of fast neutron flux. The reactor shielding includes means providing structural support, neutron moderator material, neutron absorber material and other components, wherein at least a portion of the neutron moderator material is magnesium in the form of magnesium oxide either alone or in combination with other moderator materials such as graphite and iron

Isolation of a sulfate reducing bacterium and its application in sulfate ...

African Journals Online (AJOL)

The results show that the effect of C. freundii in removing sulfate was best when the temperature was 32°C, pH was 7.0, COD/SO42- was 5.0 and the initial SO42- concentration was 1500 mg/L. Also, the SRB was inoculated onto an up-flow anaerobic sludge bed (UASB) to remove sulfate in actual tannery wastewater.

On the effect of interaction of molybdenum trioxide and magnesium oxide in water

International Nuclear Information System (INIS)

Bunin, V.M.; Karelin, A.I.; Solov'eva, L.N.

1992-01-01

Interaction of molybdenum trioxide and magnesium oxide in water was studied. It is shown that molybdenum trioxide forms consecutively magnesium molybdate, dimolybdate and magnesium polymolybdates with magnesium oxide

Divergent Synthesis of Chondroitin Sulfate Disaccharides and Identification of Sulfate Motifs that Inhibit Triple Negative Breast Cancer

Science.gov (United States)

Wei Poh, Zhong; Heng Gan, Chin; Lee, Eric J.; Guo, Suxian; Yip, George W.; Lam, Yulin

2015-09-01

Glycosaminoglycans (GAGs) regulate many important physiological processes. A pertinent issue to address is whether GAGs encode important functional information via introduction of position specific sulfate groups in the GAG structure. However, procurement of pure, homogenous GAG motifs to probe the “sulfation code” is a challenging task due to isolation difficulty and structural complexity. To this end, we devised a versatile synthetic strategy to obtain all the 16 theoretically possible sulfation patterns in the chondroitin sulfate (CS) repeating unit; these include rare but potentially important sulfated motifs which have not been isolated earlier. Biological evaluation indicated that CS sulfation patterns had differing effects for different breast cancer cell types, and the greatest inhibitory effect was observed for the most aggressive, triple negative breast cancer cell line MDA-MB-231.

Metabolic Flexibility of Sulfate Reducing Bacteria

Directory of Open Access Journals (Sweden)

Caroline M. Plugge

2011-05-01

Full Text Available Dissimilatory sulfate-reducing prokaryotes (SRB are a very diverse group of anaerobic bacteria that are omnipresent in nature and play an imperative role in the global cycling of carbon and sulfur. In anoxic marine sediments sulfate reduction accounts for up to 50% of the entire organic mineralization in coastal and shelf ecosystems where sulfate diffuses several meters deep into the sediment. As a consequence, SRB would be expected in the sulfate-containing upper sediment layers, whereas methanogenic Archaea would be expected to succeed in the deeper sulfate-depleted layers of the sediment. Where sediments are high in organic matter, sulfate is depleted at shallow sediment depths, and biogenic methane production will occur. In the absence of sulfate, many SRB ferment organic acids and alcohols, producing hydrogen, acetate, and carbon dioxide, and may even rely on hydrogen- and acetate-scavenging methanogens to convert organic compounds to methane. SRB can establish two different life styles, and these can be termed as sulfidogenic and acetogenic, hydrogenogenic metabolism. The advantage of having different metabolic capabilities is that it raises the chance of survival in environments when electron acceptors become depleted. In marine sediments, SRB and methanogens do not compete but rather complement each other in the degradation of organic matter.Also in freshwater ecosystems with sulfate concentrations of only 10-200 μM, sulfate is consumed efficiently within the top several cm of the sediments. Here, many of the δ-Proteobacteria present have the genetic machinery to perform dissimilatory sulfate reduction, yet they have an acetogenic, hydrogenogenic way of life.In this review we evaluate the physiology and metabolic mode of SRB in relation with their environment.

2-Amino-4-hydroxyethylaminoanisole sulfate

DEFF Research Database (Denmark)

Madsen, Jakob T; Andersen, Klaus E

2016-01-01

positive patch test reactions to the coupler 2-amino-4-hydroxyethylaminoanisole sulfate 2% pet. from 2005 to 2014. METHODS: Patch test results from the Allergen Bank database for eczema patients patch tested with 2-amino-4-hydroxyethylaminoanisole sulfate 2% pet. from 2005 to 2014 were reviewed. RESULTS......: A total of 902 dermatitis patients (154 from the dermatology department and 748 from 65 practices) were patch tested with amino-4-hydroxyethylaminoanisole sulfate 2% pet. from 2005 to 2014. Thirteen (1.4%) patients had a positive patch test reaction. Our results do not indicate irritant reactions....... CONCLUSIONS: 2-Amino-4-hydroxyethylaminoanisole sulfate is a new but rare contact allergen....

Magnesium and Osteoporosis: Current State of Knowledge and Future Research Directions

Directory of Open Access Journals (Sweden)

Jeanette A. M. Maier

2013-07-01

Full Text Available A tight control of magnesium homeostasis seems to be crucial for bone health. On the basis of experimental and epidemiological studies, both low and high magnesium have harmful effects on the bones. Magnesium deficiency contributes to osteoporosis directly by acting on crystal formation and on bone cells and indirectly by impacting on the secretion and the activity of parathyroid hormone and by promoting low grade inflammation. Less is known about the mechanisms responsible for the mineralization defects observed when magnesium is elevated. Overall, controlling and maintaining magnesium homeostasis represents a helpful intervention to maintain bone integrity.

Special metallurgy - the electrical butt-welding by flashing of sintered magnesium-magnesium oxide composites (1963); Metallurgie speciale - le soudage electrique en bout par etincelage du composite fritte magnesium-magnesie (1963)

Energy Technology Data Exchange (ETDEWEB)

Charleux, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1963-07-01

Electrical resistance welding has become quite important since World War II because of the need of a high yield in aeronautical production. Progress has been due in particular to the improvements made in electronically controlled apparatus making possible the automatic control of welding. For the butt-welding of sections requiring either a high production rate or a high quality weld, the flash butt-welding system has been very much developed these last few years. The use of this welding method is of great importance in the field of the bonding of oxidisable metals such as magnesium or aluminium and its alloys, because the welded joint is free from oxides. This study consists of general considerations on the flash-welding process with regard to temperature distribution in the parts during welding, and to electrical phenomena connected with flashing. Besides this general or theoretical section, we have applied the welding process to the bonding of sintered magnesium, a magnesium-magnesium oxide composite, whose use as a structural element in nuclear reactors is considered. (author) [French] Le soudage electrique par resistance a pris un essor important depuis la derniere guerre mondiale a cause du besoin de haut rendement pour la production aeronautique. Les progres ont ete possibles surtout par l'amelioration des appareils de commande electronique qui permettent un controle automatique de la soudure. Pour le soudage bout a bout de profiles, demandant soit un haut debit de fabrication, soit une haute qualite du joint soude, le procede de soudage en bout par etincelage a ete tres developpe ces dernieres annees. Ce mode de soudage a un domaine d'utilisation important dans la liaison des metaux oxydables tels le magnesium ou l'aluminium et ses alliages, du fait de la proprete du joint soude exempt d'oxydes. Cette etude comporte une consideration generale du processus de l'etincelage, quant a la repartition de la temperature dans les pieces pendant le soudage et aux

Special metallurgy - the electrical butt-welding by flashing of sintered magnesium-magnesium oxide composites (1963); Metallurgie speciale - le soudage electrique en bout par etincelage du composite fritte magnesium-magnesie (1963)

Energy Technology Data Exchange (ETDEWEB)

Charleux, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1963-07-01

Electrical resistance welding has become quite important since World War II because of the need of a high yield in aeronautical production. Progress has been due in particular to the improvements made in electronically controlled apparatus making possible the automatic control of welding. For the butt-welding of sections requiring either a high production rate or a high quality weld, the flash butt-welding system has been very much developed these last few years. The use of this welding method is of great importance in the field of the bonding of oxidisable metals such as magnesium or aluminium and its alloys, because the welded joint is free from oxides. This study consists of general considerations on the flash-welding process with regard to temperature distribution in the parts during welding, and to electrical phenomena connected with flashing. Besides this general or theoretical section, we have applied the welding process to the bonding of sintered magnesium, a magnesium-magnesium oxide composite, whose use as a structural element in nuclear reactors is considered. (author) [French] Le soudage electrique par resistance a pris un essor important depuis la derniere guerre mondiale a cause du besoin de haut rendement pour la production aeronautique. Les progres ont ete possibles surtout par l'amelioration des appareils de commande electronique qui permettent un controle automatique de la soudure. Pour le soudage bout a bout de profiles, demandant soit un haut debit de fabrication, soit une haute qualite du joint soude, le procede de soudage en bout par etincelage a ete tres developpe ces dernieres annees. Ce mode de soudage a un domaine d'utilisation important dans la liaison des metaux oxydables tels le magnesium ou l'aluminium et ses alliages, du fait de la proprete du joint soude exempt d'oxydes. Cette etude comporte une consideration generale du processus de l'etincelage, quant a la repartition de la temperature dans les pieces

Treatment with magnesium sulphate in pre-term birth

DEFF Research Database (Denmark)

Wolf, Hans; Hegaard, H K; Greisen, G

2012-01-01

Premature birth increases a child's risk of cerebral palsy and death. The aim of this work is to investigate the association between treatment with magnesium sulphate during premature deliveries and infants' cerebral palsy and mortality through a meta-analysis of observational studies....... A comprehensive search of the Cochrane Library, EMBASE and the PubMed database from their inceptions to 1 October, 2010 using the keywords 'magnesium sulphate, children/infant/pre-term/premature and cerebral palsy/mortality/morbidity/adverse effects/outcome' identified 11 reports of observational studies. Two...... authors working independently extracted the data. A meta-analysis of the data found an association between magnesium sulphate treatment and a significantly reduced risk of mortality (RR 0.73; 95% CI 0.61-0.89) and cerebral palsy (OR 0.64; 95% CI 0.47-0.89). Antenatal treatment with magnesium sulphate...

Characterization of the whiskerlike products formed by hydriding magnesium metal powders

DEFF Research Database (Denmark)

Herley, P. J.; Jones, W.; Vigeholm, Bjørn

1985-01-01

The structure of filamentary crystals produced during the hydriding of magnesium powder has been studies in detail. The needles of small dimensions (typically 0.5 μm in diameter) have been identified by electron analytical techniques to be oriented microcrystals of metallic magnesium. Their forma......The structure of filamentary crystals produced during the hydriding of magnesium powder has been studies in detail. The needles of small dimensions (typically 0.5 μm in diameter) have been identified by electron analytical techniques to be oriented microcrystals of metallic magnesium....... Their formation has been ascribed to the melting of localized aluminum impurities within the bulk magnesium to form a liquid eutectic. In the presence of sublimed magnesium vapor and hydrogen (as a carrier gas) a vapor-liquid-solid mechanism operates to produce a rapid unidirectional extension followed...

Holothurian Fucosylated Chondroitin Sulfate

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Vitor H. Pomin

2014-01-01

Full Text Available Fucosylated chondroitin sulfate (FucCS is a structurally distinct glycosaminoglycan found in sea cucumber species. It has the same backbone composition of alternating 4-linked glucuronic acid and 3-linked N-acetyl galactosamine residues within disaccharide repeating units as regularly found in mammalian chondroitin sulfates. However, FucCS has also sulfated fucosyl branching units 3-O-linked to the acid residues. The sulfation patterns of these branches vary accordingly with holothurian species and account for different biological actions and responses. FucCSs may exhibit anticoagulant, antithrombotic, anti-inflammatory, anticancer, antiviral, and pro-angiogenic activities, besides its beneficial effects in hemodialysis, cellular growth modulation, fibrosis and hyperglycemia. Through an historical overview, this document covers most of the science regarding the holothurian FucCS. Both structural and medical properties of this unique GAG, investigated during the last 25 years, are systematically discussed herein.

Magnesium - distribution and basic metabolism | Olhaberry | South ...

African Journals Online (AJOL)

Magnesium is extensively distributed in soil, water and plants. It is essential for ehzymatic reactions requiring adenosine triphosphate, and the recommended dietary allowance in man is 5 - 10 mg/kg/d. About 50% of magnesium in man is stored in bone, where it is regulated by parathyroid hormone'and 1,25(OH)2-D3.

A Shortened versus Standard Matched Postpartum Magnesium ...

African Journals Online (AJOL)

Magnesium sulphate is currently the most ideal drug for the treatment of eclampsia but its use in Nigeria is still limited due its cost and clinicians inexperience with the drug. The purpose of this study was to determine whether a shortened postpartum course of magnesium sulphate is as effective as the standard Pritchard ...

Magnesium Hydride for Load Levelling Energy Storage

DEFF Research Database (Denmark)

Vigeholm, B.

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

Corrosion Monitoring of PEO-Pretreated Magnesium Alloys

Energy Technology Data Exchange (ETDEWEB)

Gnedenkov, A. S.; Sinebryukhov, S. L.; Mashtalyar, D. V.; Gnedenkov, S. V.; Sergienko, V. I. [Institute of Chemistry, Vladivostok (Russian Federation)

2017-06-15

The MA8 alloy (formula Mg-Mn-Ce) has been shown to have greater corrosion stability than the VMD10 magnesium alloy (formula Mg-Zn-Zr-Y) in chloride-containing solutions by Scanning Vibrating Electrode Technique (SVET) and by optical microscopy, gravimetry, and volumetry. It has been established that the crucial factor for the corrosion activity of these samples is the occurrence of microgalvanic coupling at the sample surface. The peculiarities of the kinetics and mechanism of the corrosion in the local heterogeneous regions of the magnesium alloy surface were investigated by localized electrochemical techniques. The stages of the corrosion process in artificial defects in the coating obtained by plasma electrolytic oxidation (PEO) at the surface of the MA8 magnesium alloy were also studied. The analysis of the experimental data enabled us to determine that the corrosion process in the defect zone develops predominantly at the magnesium/coating interface. Based on the measurements of the corrosion rate of the samples with PEO and composite polymer-containing coatings, the best anticorrosion properties were displayed by the composite polymer-containing coatings.

Effects of oral magnesium supplementation on inflammatory markers in middle-aged overweight women

Directory of Open Access Journals (Sweden)

Nazanin Moslehi

2012-01-01

Full Text Available Background: This study aimed to investigate whether magnesium supplementation might affect serum magnesium, high sensitive C-reactive protein (hs-CRP, plasma fibrinogen, and interleukin 6 (IL-6 levels in healthy middle-aged overweight women. The relationships, if any, between serum magnesium and the inflammatory markers were also examined cross-sectionally in the entire participants at the beginning of the study. Materials and Methods: This double-blinded, placebo-controlled, randomized trial included 74 middle-aged overweight women. Participants were randomly assigned to receive either 250 mg magnesium as magnesium oxide or placebo daily for 8 weeks. Serum magnesium, hs-CRP, fibrinogen and IL-6 concentrations were measured before and after the intervention. Results: Serum magnesium was found to be inversely correlated with hs-CRP (r s =−0.22, P=0.05 in the entire participants at baseline. Serum hs-CRP declined significantly in both groups as compared with baseline values (median change=0.8 mg/L; P Magnesium= 0.03, P Placebo 0.001. Plasma fibrinogen decreased significantly, by 9%, in the magnesium group at the end of week 8 compared to baseline (P=0.001. Mean concentration of IL-6 was significantly increased in the magnesium group comparing the baseline value(P=0.001. However hs-CRP, fibrinogen and IL-6 levels at week 8 or any changes during the study were not statistically different between the two groups. Serum magnesium showed no significant changes in any groups. Conclusions: Serum magnesium had a significant inverse correlation with hs-CRP. In the present study, magnesium as magnesium oxide, 250 mg/day, for 8 weeks did not significantly attenuate inflammatory markers in the magnesium group as compared to the placebo.

Magnesium silicide production and silane synthesis on its basis

International Nuclear Information System (INIS)

Taurbaev, T.I.; Mukashev, F.A.; Manakov, S.M.; Francev, U.V.; Kalblanbekov, B.M.; Akhter, P.; Abbas, M.; Hussain, A.

2003-01-01

We had developed an alternative method of production of magnesium silicide with use of ferroalloys of silicon. Magnesium silicide is raw material for silane synthesis. The essence of the method consist of sintering FS -75 (ferrosilicium with 75 % of silicon and 25 % of iron, made by ferroalloy factories) with metal magnesium at temperature of 650 deg. C. The X-ray analysis has shown formation of magnesium silicide. That is further used for synthesis of silane. The output of silane is 60 % in respect of the contents of silicon. After removing the water vapors the mass-spectrometer analysis has estimated the purity of silane as 99.95 % with no detection of phosphine and diborane. (author)

Polyanthraquinone-Based Organic Cathode for High-Performance Rechargeable Magnesium-Ion Batteries

Energy Technology Data Exchange (ETDEWEB)

Pan, Baofei [Joint Center for Energy Storage Research, Chemical Science and Engineering Division, Argonne National Laboratory, Lemont IL 60439 USA; Huang, Jinhua [Joint Center for Energy Storage Research, Chemical Science and Engineering Division, Argonne National Laboratory, Lemont IL 60439 USA; Feng, Zhenxing [Joint Center for Energy Storage Research, Chemical Science and Engineering Division, Argonne National Laboratory, Lemont IL 60439 USA; Zeng, Li [Applied Physics Program, Department of Materials Science and Engineering and Department of Physics and Astronomy, Northwestern University, Evanston IL 60208 USA; He, Meinan [Joint Center for Energy Storage Research, Chemical Science and Engineering Division, Argonne National Laboratory, Lemont IL 60439 USA; Zhang, Lu [Joint Center for Energy Storage Research, Chemical Science and Engineering Division, Argonne National Laboratory, Lemont IL 60439 USA; Vaughey, John T. [Joint Center for Energy Storage Research, Chemical Science and Engineering Division, Argonne National Laboratory, Lemont IL 60439 USA; Bedzyk, Michael J. [Applied Physics Program, Department of Materials Science and Engineering and Department of Physics and Astronomy, Northwestern University, Evanston IL 60208 USA; Fenter, Paul [Joint Center for Energy Storage Research, Chemical Science and Engineering Division, Argonne National Laboratory, Lemont IL 60439 USA; Zhang, Zhengcheng [Joint Center for Energy Storage Research, Chemical Science and Engineering Division, Argonne National Laboratory, Lemont IL 60439 USA; Burrell, Anthony K. [Joint Center for Energy Storage Research, Chemical Science and Engineering Division, Argonne National Laboratory, Lemont IL 60439 USA; Liao, Chen [Joint Center for Energy Storage Research, Chemical Science and Engineering Division, Argonne National Laboratory, Lemont IL 60439 USA

2016-05-09

Two anthraquinone-based polymers aiming at improving the capacity and voltage of magnesium ion batteries, were synthesized and characterized. The excellent battery cycling performance was demonstrated with the electrolyte consisting of magnesium bis(hexamethyldisilazide) and magnesium chloride.

A multi-analytical approach to better assess the keratan sulfate contamination in animal origin chondroitin sulfate

Energy Technology Data Exchange (ETDEWEB)

Restaino, Odile Francesca, E-mail: odilefrancesca.restaino@unina2.it [Department of Experimental Medicine, Section of Biotechnology and Molecular Biology, University of Campania-L.Vanvitelli, ex Second University of Naples, Via De Crecchio 7, 80138, Naples (Italy); Finamore, Rosario, E-mail: rosario.finamore@unina2.it [Department of Experimental Medicine, Section of Biotechnology and Molecular Biology, University of Campania-L.Vanvitelli, ex Second University of Naples, Via De Crecchio 7, 80138, Naples (Italy); Diana, Paola, E-mail: paola.diana@unina2.it [Department of Experimental Medicine, Section of Biotechnology and Molecular Biology, University of Campania-L.Vanvitelli, ex Second University of Naples, Via De Crecchio 7, 80138, Naples (Italy); Marseglia, Mariacarmela, E-mail: marimars84@hotmail.it [Department of Experimental Medicine, Section of Biotechnology and Molecular Biology, University of Campania-L.Vanvitelli, ex Second University of Naples, Via De Crecchio 7, 80138, Naples (Italy); Vitiello, Mario, E-mail: mariovitiello.ita@gmail.com [Department of Experimental Medicine, Section of Biotechnology and Molecular Biology, University of Campania-L.Vanvitelli, ex Second University of Naples, Via De Crecchio 7, 80138, Naples (Italy); Casillo, Angela, E-mail: angela.casillo@unina.it [Department of Chemical Sciences, University of Naples Federico II, Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126, Naples (Italy); Bedini, Emiliano, E-mail: emiliano.bedini@unina.it [Department of Chemical Sciences, University of Naples Federico II, Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126, Naples (Italy); Parrilli, Michelangelo, E-mail: michelangelo.parrilli@unina.it [Department of Biology, University of Naples Federico II, Complesso Universitario Monte S. Angelo, Via Cintia 4, 80126, Naples (Italy); and others

2017-03-15

Chondroitin sulfate is a glycosaminoglycan widely used as active principle of anti-osteoarthritis drugs and nutraceuticals, manufactured by extraction from animal cartilaginous tissues. During the manufacturing procedures, another glycosaminoglycan, the keratan sulfate, might be contemporarily withdrawn, thus eventually constituting a contaminant difficult to be determined because of its structural similarity. Considering the strict regulatory rules on the pureness of pharmaceutical grade chondrotin sulfate there is an urgent need and interest to determine the residual keratan sulfate with specific, sensitive and reliable methods. To pursue this aim, in this paper, for the first time, we set up a multi-analytical and preparative approach based on: i) a newly developed method by high performance anion-exchange chromatography with pulsed amperometric detection, ii) gas chromatography-mass spectrometry analyses, iii) size exclusion chromatography analyses coupled with triple detector array module and on iv) strong anion exchange chromatography separation. Varied KS percentages, in the range from 0.1 to 19.0% (w/w), were determined in seven pharmacopeia and commercial standards and nine commercial samples of different animal origin and manufacturers. Strong anion exchange chromatography profiles of the samples showed three or four different peaks. These peaks analyzed by high performance anion-exchange with pulsed amperometric detection and size exclusion chromatography with triple detector array, ion chromatography and by mono- or two-dimensional nuclear magnetic resonance revealed a heterogeneous composition of both glycosaminoglycans in terms of sulfation grade and molecular weight. High molecular weight species (>100 KDa) were also present in the samples that counted for chains still partially linked to a proteoglycan core. - Highlights: • A multi-analytical approach was set up, for the first time, for the determination of the residual keratan sulfate

A multi-analytical approach to better assess the keratan sulfate contamination in animal origin chondroitin sulfate

International Nuclear Information System (INIS)

Restaino, Odile Francesca; Finamore, Rosario; Diana, Paola; Marseglia, Mariacarmela; Vitiello, Mario; Casillo, Angela; Bedini, Emiliano; Parrilli, Michelangelo

2017-01-01

Chondroitin sulfate is a glycosaminoglycan widely used as active principle of anti-osteoarthritis drugs and nutraceuticals, manufactured by extraction from animal cartilaginous tissues. During the manufacturing procedures, another glycosaminoglycan, the keratan sulfate, might be contemporarily withdrawn, thus eventually constituting a contaminant difficult to be determined because of its structural similarity. Considering the strict regulatory rules on the pureness of pharmaceutical grade chondrotin sulfate there is an urgent need and interest to determine the residual keratan sulfate with specific, sensitive and reliable methods. To pursue this aim, in this paper, for the first time, we set up a multi-analytical and preparative approach based on: i) a newly developed method by high performance anion-exchange chromatography with pulsed amperometric detection, ii) gas chromatography-mass spectrometry analyses, iii) size exclusion chromatography analyses coupled with triple detector array module and on iv) strong anion exchange chromatography separation. Varied KS percentages, in the range from 0.1 to 19.0% (w/w), were determined in seven pharmacopeia and commercial standards and nine commercial samples of different animal origin and manufacturers. Strong anion exchange chromatography profiles of the samples showed three or four different peaks. These peaks analyzed by high performance anion-exchange with pulsed amperometric detection and size exclusion chromatography with triple detector array, ion chromatography and by mono- or two-dimensional nuclear magnetic resonance revealed a heterogeneous composition of both glycosaminoglycans in terms of sulfation grade and molecular weight. High molecular weight species (>100 KDa) were also present in the samples that counted for chains still partially linked to a proteoglycan core. - Highlights: • A multi-analytical approach was set up, for the first time, for the determination of the residual keratan sulfate

Magnesium and uranium ignition in different gaseous atmospheres; Inflammabilite du magnesium et de l'uranium dans l'air et le gaz carbonique

Energy Technology Data Exchange (ETDEWEB)

Darras, R; Baque, P; Leclercq, D [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

Magnesium, uranium and some of their alloys burning temperatures have been systematically determined in an air or carbon dioxide atmosphere, either dry or wet. Two different ways of heating have been used: either continuously rising up the temperature, or heating to and then maintaining a constant temperature. The results are clearly different in the two cases. Besides, if moisture has little effect on the magnesium burning temperatures in air, it does lower them by about 130-140 deg. C in CO{sub 2}. The differences of sight between the burning of magnesium and uranium have been noticed; this leads to distinguish between an 'ignition' and an 'inflammation'. (author) [French] Les temperatures auxquelles apparait la combustion vive du magnesium, de l'uranium et certains de leurs alliages ont ete determinees systematiquement dans l'air et le gaz carbonique, soit secs, soit humidifies. On a mis en evidence l'influence du mode de chauffage sur les resultats: soit montee en temperature continue, soit stabilisation a partir d'une certaine temperature. En outre, si la presence d'humidite affecte peu les temperatures de combustion vive du magnesium dans l'air, elle les abaisse de 130 a 140 deg. C dans le gaz carbonique. Les differences d'aspect entre la combustion vive du magnesium et de l'uranium ont egalement ete remarquees, ce qui amene notamment a distinguer une 'ignition' d'une 'inflammation'. (auteur)

Magnesium Hall Thruster

Science.gov (United States)

Szabo, James J.

2015-01-01

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

Extraction of magnesium from calcined dolomite ore using hydrochloric acid leaching

Science.gov (United States)

Royani, Ahmad; Sulistiyono, Eko; Prasetiyo, Agus Budi; Subagja, Rudi

2018-05-01

Magnesium is widely used in varieties industrial sector. Dolomite is one source of magnesium besides seawater. The extraction of magnesium from dolomite ores can be done by leaching process. In this work, the dolomite leaching to extract magnesium by hydrochloric acid was investigated. The leaching experiments were performed in a spherical glass batch reactor having a capacity of 1000 ml. The effects of the stirring speed, acid concentration, reaction temperature and liquid-solid ratio for each reaction time of 1; 2; and 3 h on the Mg leaching have been evaluated. 5 ml of solution sample were collected from the leached solutions, then it was filtered prior to analysis by ICP OES. The experimental results show that the magnesium extraction increases along with the increase of acid concentration, liquid-solid ratio and temperature. The optimum conditions for magnesium extraction were achieved at temperature 75 °C, extraction time 3 h, the HCl concentration of 2 M, the liquid-solid ratio 20 ml/g and stirring speed of 400 rpm. At this condition 98, 82 % of magnesium were extracted from dolomite. The conclusion obtained from this leaching process is that the magnesium can be extracted from dolomite by using hydrochloric acid solutions.

Evaluation of magnesium ions release, biocorrosion, and hemocompatibility of MAO/PLLA-modified magnesium alloy WE42.

Science.gov (United States)

Lu, Ping; Cao, Lu; Liu, Yin; Xu, Xinhua; Wu, Xiangfeng

2011-01-01

Magnesium alloys may potentially be applied as biodegradable metallic materials in cardiovascular stent. However, the high corrosion rate hinders its clinical application. In this study, a new approach was adopted to control the corrosion rate by fabricating a biocompatible micro-arc oxidation/poly-L-lactic acid (MAO/PLLA) composite coating on the magnesium alloy WE42 substrate and the biocompatibility of the modified samples was investigated. The scanning electronic microscope (SEM) images were used to demonstrate the morphology of the samples before and after being submerged in hanks solution for 4 weeks. The degradation was evaluated through the magnesium ions release rate and electrochemical impedance spectroscopy (EIS) test. The biocompatibility of the samples was demonstrated by coagulation time and hemolysis behavior. The result shows that the poly-L-lactic acid (PLLA) effectively improved the corrosion resistance by sealing the microcracks and microholes on the surface of the MAO coating. The modified samples had good compatibility. © 2010 Wiley Periodicals, Inc.

The High Strain Rate Deformation Behavior of High Purity Magnesium and AZ31B Magnesium Alloy

Science.gov (United States)

Livescu, Veronica; Cady, Carl M.; Cerreta, Ellen K.; Henrie, Benjamin L.; Gray, George T.

The deformation in compression of pure magnesium and AZ31B magnesium alloy, both with a strong basal pole texture, has been investigated as a function of temperature, strain rate, and specimen orientation. The mechanical response of both metals is highly dependent upon the orientation of loading direction with respect to the basal pole. Specimens compressed along the basal pole direction have a high sensitivity to strain rate and temperature and display a concave down work hardening behavior. Specimens loaded perpendicularly to the basal pole have a yield stress that is relatively insensitive to strain rate and temperature and a work hardening behavior that is parabolic and then linearly upwards. Both specimen orientations display a mechanical response that is sensitive to temperature and strain rate. Post mortem characterization of the pure magnesium was conducted on a subset of specimens to determine the microstructural and textural evolution during deformation and these results are correlated with the observed work hardening behavior and strain rate sensitivities were calculated.

Sol – Gel synthesis and characterization of magnesium peroxide nanoparticles

International Nuclear Information System (INIS)

Jaison, J; Chan, Y S; Ashok raja, C; Balakumar, S

2015-01-01

Magnesium peroxide is an excellent source of oxygen in agriculture applications, for instance it is used in waste management as a material for soil bioremediation to remove contaminants from polluted underground water, biological wastes treatment to break down hydrocarbon, etc. In the present study, sol-gel synthesis of magnesium peroxide (MgO 2 ) nanoparticles is reported. Magnesium peroxide is odourless; fine peroxide which releases oxygen when reacts with water. During the sol-gel synthesis, the magnesium malonate intermediate is formed which was then calcinated to obtain MgO 2 nanoparticles. The synthesized nanoparticles were characterized using Thermo gravimetric -Differential Thermal Analysis (TG- DTA), X-Ray Diffraction studies (XRD) and High Resolution Transmission Electron Microscope (HRTEM). Our study provides a clear insight that the formation of magnesium malonate during the synthesis was due to the reaction between magnesium acetate, oxalic acid and ethanol. In our study, we can conclude that the calcination temperature has a strong influence on particle size, morphology, monodispersity and the chemistry of the particles. (paper)

Effective and Environmentally Friendly Nickel Coating on the Magnesium Alloy

Directory of Open Access Journals (Sweden)

Ivana Škugor Rončević

2016-12-01

Full Text Available The low density and good mechanical properties make magnesium and its alloys attractive construction materials in the electronics, automotive, and aerospace industry, together with application in medicine due to their biocompatibility. Magnesium AZ91D alloy is an alloy with a high content of aluminum, whose mechanical properties overshadow the low corrosion resistance caused by the composition of the alloy and the existence of two phases: α magnesium matrix and β magnesium aluminum intermetallic compound. To improve the corrosion resistance, it is necessary to find an effective protection method for the alloy surface. Knowing and predicting electrochemical processes is an essential for the design and optimization of protective coatings on magnesium and its alloys. In this work, the formations of nickel protective coatings on the magnesium AZ91D alloy surface by electrodeposition and chemical deposition, are presented. For this purpose, environmentally friendly electrolytes were used. The corrosion resistance of the protected alloy was determined in chloride medium using appropriate electrochemical techniques. Characterization of the surface was performed with highly sophisticated surface-analytical methods.

Magnesium, hemostasis, and outcomes in patients with intracerebral hemorrhage.

Science.gov (United States)

Liotta, Eric M; Prabhakaran, Shyam; Sangha, Rajbeer S; Bush, Robin A; Long, Alan E; Trevick, Stephen A; Potts, Matthew B; Jahromi, Babak S; Kim, Minjee; Manno, Edward M; Sorond, Farzaneh A; Naidech, Andrew M; Maas, Matthew B

2017-08-22

We tested the hypothesis that admission serum magnesium levels are associated with hematoma volume, hematoma growth, and functional outcomes in patients with intracerebral hemorrhage (ICH). Patients presenting with spontaneous ICH were enrolled in an observational cohort study that prospectively collected demographic, clinical, laboratory, radiographic, and outcome data. We performed univariate and adjusted multivariate analyses to assess for associations between serum magnesium levels and initial hematoma volume, final hematoma volume, and in-hospital hematoma growth as radiographic measures of hemostasis, and functional outcome measured by the modified Rankin Scale (mRS) at 3 months. We included 290 patients for analysis. Admission serum magnesium was 2.0 ± 0.3 mg/dL. Lower admission magnesium levels were associated with larger initial hematoma volumes on univariate ( p = 0.02), parsimoniously adjusted ( p = 0.002), and fully adjusted models ( p = 0.006), as well as greater hematoma growth ( p = 0.004, p = 0.005, and p = 0.008, respectively) and larger final hematoma volumes ( p = 0.02, p = 0.001, and p = 0.002, respectively). Lower admission magnesium level was associated with worse functional outcomes at 3 months (i.e., higher mRS; odds ratio 0.14, 95% confidence interval 0.03-0.64, p = 0.011) after adjustment for age, admission Glasgow Coma Scale score, initial hematoma volume, time from symptom onset to initial CT, and hematoma growth, with evidence that the effect of magnesium is mediated through hematoma growth. These data support the hypothesis that magnesium exerts a clinically meaningful influence on hemostasis in patients with ICH. © 2017 American Academy of Neurology.

Dielectric behaviour of sodium and potassium doped magnesium ...

Indian Academy of Sciences (India)

Dielectric behaviour of sodium and potassium doped magnesium titanate. VISHNU SHANKER. ∗. , SANTOSH KUMAR and T SURENDAR. Department of Chemistry, National Institute of Technology, Warangal 506 004, India. MS received 10 November 2011; revised 27 February 2012. Abstract. Pure phase of magnesium ...

Post traumatic tetanus and role magnesium sulphate

International Nuclear Information System (INIS)

Sikendr, R.I.; Samad, B.U.; Memon, M.I.

2009-01-01

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

Modeling of sulfation of potassium chloride by ferric sulfate addition during grate-firing of biomass

DEFF Research Database (Denmark)

Wu, Hao; Jespersen, Jacob Boll; Aho, Martti

2013-01-01

Potassium chloride, KCl, formed from critical ash-forming elements released during combustion may lead to severe ash deposition and corrosion problems in biomass-fired boilers. Ferric sulfate, Fe2(SO4)3 is an effective additive, which produces sulfur oxides (SO2 and SO3) to convert KCl to the less...... harmful K2SO4. In the present study the decomposition of ferric sulfate is studied in a fast-heating rate thermogravimetric analyzer (TGA), and a kinetic model is proposed to describe the decomposition process. The yields of SO2 and SO3 from ferric sulfate decomposition are investigated in a laboratory......-scale tube reactor. It is revealed that approximately 40% of the sulfur is released as SO3, the remaining fraction being released as SO2. The proposed decomposition model of ferric sulfate is combined with a detailed gas phase kinetic model of KCl sulfation, and a simplified model of K2SO4 condensation...

Comparison of Selective Laser Melted Titanium and Magnesium Implants Coated with PCL

Science.gov (United States)

Matena, Julia; Petersen, Svea; Gieseke, Matthias; Teske, Michael; Beyerbach, Martin; Kampmann, Andreas; Escobar, Hugo Murua; Gellrich, Nils-Claudius; Haferkamp, Heinz; Nolte, Ingo

2015-01-01

Degradable implant material for bone remodeling that corresponds to the physiological stability of bone has still not been developed. Promising degradable materials with good mechanical properties are magnesium and magnesium alloys. However, excessive gas production due to corrosion can lower the biocompatibility. In the present study we used the polymer coating polycaprolactone (PCL), intended to lower the corrosion rate of magnesium. Additionally, improvement of implant geometry can increase bone remodeling. Porous structures are known to support vessel ingrowth and thus increase osseointegration. With the selective laser melting (SLM) process, defined open porous structures can be created. Recently, highly reactive magnesium has also been processed by SLM. We performed studies with a flat magnesium layer and with porous magnesium implants coated with polymers. The SLM produced magnesium was compared with the titanium alloy TiAl6V4, as titanium is already established for the SLM-process. For testing the biocompatibility, we used primary murine osteoblasts. Results showed a reduced corrosion rate and good biocompatibility of the SLM produced magnesium with PCL coating. PMID:26068455

Study of near-critical states of liquid-vapor phase transition of magnesium

International Nuclear Information System (INIS)

Emelyanov, A N; Shakhray, D V; Golyshev, A A

2015-01-01

Study of thermodynamic parameters of magnesium in the near-critical point region of the liquid-vapor phase transition and in the region of metal-nonmetal transition was carried out. Measurements of the electrical resistance of magnesium after shock compression and expansion into gas (helium) environment in the process of isobaric heating was carried out. Heating of the magnesium surface by heat transfer with hot helium was performed. The registered electrical resistance of expanded magnesium was about 10 4 -10 5 times lower than the electrical resistance of the magnesium under normal condition at the density less than the density of the critical point. Thus, metal-nonmetal transition was found in magnesium. (paper)

Increases in Intravenous Magnesium Use among Hospitalized Patients: An Institution Cross-Sectional Experience

Directory of Open Access Journals (Sweden)

Bryce A. Kiberd

2015-06-01

Full Text Available Background: Among hospitalized patients, indications for the measurement of magnesium levels and treatment of hypomagnesemia with intravenous magnesium are not well defined. Recently, there have been reports of worldwide shortages of intravenous magnesium sulphate. Objective: To examine secular trends in the administration of intravenous magnesium on hospital wards at a tertiary care institution. The secondary objective is to identify factors associated with magnesium use among admitted patients. Methods: Retrospective cross-section review of hospitalized patients at a single Canadian tertiary care center. Utilization of non-parental nutrition intravenous magnesium from 2003 to 2013 stratified by hospital ward was examined. In addition, patient level data from select wards (including medical and surgical services was examined at early and more recent time period (4/2006 versus 4/2013. Results: Among the 248,329 hospitalized patients, intravenous magnesium use increased by 2.86 fold from 2003 to 2013. Not all wards had an increase whereas some had nearly a 10 fold increase in use. In the sample ( n = 769, (adjusting for admission magnesium level, presence of an indication for intravenous magnesium, ward location, comorbidity and demographics intravenous magnesium administration was higher (25.8 % versus 5.5 % in 2013 versus 2006 (OR 13.91 (95 % CI, 6.21–31.17, p < 0.001. Despite this increase in intravenous magnesium administration, <3 % of patients were admitted on oral magnesium in 2006 and 2013. For patients receiving intravenous magnesium only a minority were discharged on oral therapy despite low levels. Conclusions: This center has witnessed a considerable increase in the use of in-hospital intravenous magnesium over the last 6 years that cannot be explained for by medical indications. The risks and benefits of this therapy deserve further study. If this change in practice is representative of other North American hospitals, it may be

Bactericide for sulfate-reducing bacteria

Energy Technology Data Exchange (ETDEWEB)

Shklyar, T F; Anoshina, G M; Blokhin, V Ye; Kisarrev, Ye L; Novikovsa, G M

1981-01-01

The aim of the invention is to find a bactericide for sulfate-reducing bacteria of oil fields in Western Siberia in order to suppress the biocorrosive activity on oil industry equipment. This goal is achieved by using M-nitroacetanylide as the bactericide of sulfate-reducing bacteria. This agent suppresses the activity of a stored culture of sulfate-reducing bacteria that comes from industrial waste waters injection wells of the Smotlor oil field.

Corrosion of pure magnesium under thin electrolyte layers

International Nuclear Information System (INIS)

Zhang Tao; Chen Chongmu; Shao Yawei; Meng Guozhe; Wang Fuhui; Li Xiaogang; Dong Chaofang

2008-01-01

The corrosion behavior of pure magnesium was investigated by means of cathodic polarization curve, electrochemical impedance spectroscopy (EIS) and electrochemical noise (EN) under aerated and deaerated thin electrolyte layers (TEL) with various thicknesses. Based on shot noise theory and stochastic theory, the EN results were quantitatively analyzed by using the Weibull and Gumbel distribution function, respectively. The results show that the cathodic process of pure magnesium under thin electrolyte layer was dominated by hydrogen reduction. With the decreasing of thin electrolyte layer thickness, cathodic process was retarded slightly while the anodic process was inhibited significantly, which indicated that both the cathodic and anodic process were inhibited in the presence of oxygen. The absence of oxygen decreased the corrosion resistance of pure magnesium in case of thin electrolyte layer. The corrosion was more localized under thin electrolyte layer than that in bulk solution. The results also demonstrate that there exist two kinds of effects for thin electrolyte layer on the corrosion behavior of pure magnesium: (1) the rate of pit initiation was evidently retarded compared to that in bulk solution; (2) the probability of pit growth oppositely increased. The corrosion model of pure magnesium under thin electrolyte layer was suggested in the paper

Contribution of stable isotopes to the study of pharmacokinetics of magnesium salts; Apport des isotopes stables a l'etude de la pharmacocinetique de sels de magnesium

Energy Technology Data Exchange (ETDEWEB)

Benech, H

1999-05-28

The use of stable isotopes as labels is becoming an attractive tool for the study of magnesium behavior in humans. It has been used two stable isotopes of magnesium, {sup 25}Mg and {sup 26}Mg, to measure the absolute bioavailability of a pharmaceutical form of magnesium. (N.C.)

Inter vs. intraglycosidic acetal linkages control sulfation pattern in semi-synthetic chondroitin sulfate.

Science.gov (United States)

Laezza, Antonio; De Castro, Cristina; Parrilli, Michelangelo; Bedini, Emiliano

2014-11-04

Microbial-sourced unsulfated chondroitin could be converted into chondroitin sulfate (CS) polysaccharide by a multi-step strategy relying upon benzylidenation and acetylation reactions as key-steps for its regioselective protection. By conducting the two reactions one- or two-pots, CSs with different sulfation patterns could be obtained at the end of the semi-synthesis. In particular, a CS polysaccharide possessing sulfate groups randomly distributed between positions 4 and 6 of N-acetyl-galactosamine (GalNAc) units could be obtained through the two-pots route, whereas the one-pot pathway allowed an additional sulfation at position 3 of some glucuronic acid (GlcA) units. This difference was ascribed to the stabilization of a labile interglycosidic benzylidene acetal involving positions O-3 and O-6 of some GlcA and GalNAc, respectively, when the benzylidene-acetylation reactions were conducted in a one-pot fashion. Isolation and characterization of a polysaccharide intermediate showing interglycosidic acetal moieties was accomplished. Copyright © 2014 Elsevier Ltd. All rights reserved.

Friction welding of AZ31 magnesium alloy

Energy Technology Data Exchange (ETDEWEB)

Tsujino, R.; Ochi, H. [Osaka Inst. of Tech., Osaka (Japan); Kawai, G. [Osaka Sangyo Univ., Osaka (Japan); Yamaguchi, H.; Ogawa, K. [Osaka Prefecture Univ., Osaka (Japan); Suga, Y. [Keio Univ., Kanagawa (Japan)

2003-07-01

In this paper, for an acceleration of utilization of magnesium alloy which is being interested in recent years, friction welding of AZ31 magnesium alloy was carried out, and the joint performance was discussed in relation to the deformation heat input in the upset stage and upset loss as a evaluation factor. Where, the deformation heat input in the upset stage is mechanical work represented by the product of upset speed and axial pressure. As a result, it was made clear that the friction welding of AZ31 magnesium alloy was easy in the atmosphere, and good welded joints without a non- adhesion area at the weld interface could de obtained. Moreover, the evaluation factors discussed were possible to evaluate to joint performance. (orig.)

Corrosion of magnesium and aluminum in palm biodiesel: A comparative evaluation

International Nuclear Information System (INIS)

Chew, K.V.; Haseeb, A.S.M.A.; Masjuki, H.H.; Fazal, M.A.; Gupta, M.

2013-01-01

The present study aims to investigate the comparative corrosion of light-weight metals such as aluminum and magnesium in palm biodiesel. Immersion test at room temperature was carried out for each metal for 1440 h. Sample characterization techniques employed include weight loss measurement, SEM (scanning electron microscope), XRD (X-ray diffraction), TAN (total acid number) and FTIR (Fourier transform infrared spectroscopy). Results showed that the corrosion rate of magnesium was much higher compared to that of aluminum. The surface morphology revealed a significant difference between the biodiesel exposed aluminum and magnesium specimens. Upon exposure to biodiesel, the magnesium surface was found to be fully covered by gel-like sticky mass while the aluminum surface remained clean. - Highlights: • Biodiesel is highly corrosive for magnesium. • Biodiesel exposed magnesium surface showed yellowish gel-like sticky mass. • Biodiesel undergoes significant degradation upon exposure to metals

Precipitation and Hardening in Magnesium Alloys

Science.gov (United States)

Nie, Jian-Feng

2012-11-01

Magnesium alloys have received an increasing interest in the past 12 years for potential applications in the automotive, aircraft, aerospace, and electronic industries. Many of these alloys are strong because of solid-state precipitates that are produced by an age-hardening process. Although some strength improvements of existing magnesium alloys have been made and some novel alloys with improved strength have been developed, the strength level that has been achieved so far is still substantially lower than that obtained in counterpart aluminum alloys. Further improvements in the alloy strength require a better understanding of the structure, morphology, orientation of precipitates, effects of precipitate morphology, and orientation on the strengthening and microstructural factors that are important in controlling the nucleation and growth of these precipitates. In this review, precipitation in most precipitation-hardenable magnesium alloys is reviewed, and its relationship with strengthening is examined. It is demonstrated that the precipitation phenomena in these alloys, especially in the very early stage of the precipitation process, are still far from being well understood, and many fundamental issues remain unsolved even after some extensive and concerted efforts made in the past 12 years. The challenges associated with precipitation hardening and age hardening are identified and discussed, and guidelines are outlined for the rational design and development of higher strength, and ultimately ultrahigh strength, magnesium alloys via precipitation hardening.

Some Structural Properties of the Mixed Lead-Magnesium Hydroxyapatites

Science.gov (United States)

Kaaroud, K.; Ben Moussa, S.; Brigui, N.; Badraoui, B.

2018-02-01

Lead-magnesium hydroxyapatite solid solutions Pb(10- x)Mg x (PO4)6(OH)2 have been prepared via a hydrothermal process. They were characterized by X-ray powder diffraction, Transmission Electron Microscopy (TEM), chemical and IR spectroscopic analyses. The results of the structural refinement indicated that the limits of lead-magnesium solid solutions ( x ≤ 1.5), a regular decrease of the lattice constant a and a preferential magnesium distribution in site S(I). Through the progressive replacement of Pb2+ ( r = 0.133 nm) by the smaller cation Mg2+ ( r = 0.072 nm), all interatomic distances decrease in accordance with the decrease of the cell parameters. According to what could be expected from the coordinance of the metallic sites S(I) (hexacoordination) and S(II) (heptacoordination), the small magnesium cation preferentially occupies the four sites S(I). The results of the TEM analysis confirm the presence of magnesium in the starting solution and reveals the decrease in the average size of crystals. The IR spectra show the presence of the absorption bands characteristic for the apatite structure.

Extracellular Calcium and Magnesium in Preeclampsia and Eclampsia

African Journals Online (AJOL)

The cause of preeclampsia remains unknown and calcium and magnesium supplement are being suggested as means of prevention. The objective of this study was to assess magnesium and calcium in the plasma and cerebrospinal fluid of Nigerian women with preeclampsia and eclampsia. Setting was University of ...

Serum magnesium is associated with the risk of dementia.

Science.gov (United States)

Kieboom, Brenda C T; Licher, Silvan; Wolters, Frank J; Ikram, M Kamran; Hoorn, Ewout J; Zietse, Robert; Stricker, Bruno H; Ikram, M Arfan

2017-10-17

To determine if serum magnesium levels are associated with the risk of all-cause dementia and Alzheimer disease. Within the prospective population-based Rotterdam Study, we measured serum magnesium levels in 9,569 participants, free from dementia at baseline (1997-2008). Participants were subsequently followed up for incident dementia, determined according to the DSM-III-R criteria, until January 1, 2015. We used Cox proportional hazard regression models to associate quintiles of serum magnesium with incident all-cause dementia. We used the third quintile as a reference group and adjusted for age, sex, Rotterdam Study cohort, educational level, cardiovascular risk factors, kidney function, comorbidities, other electrolytes, and diuretic use. Our study population had a mean age of 64.9 years and 56.6% were women. During a median follow-up of 7.8 years, 823 participants were diagnosed with all-cause dementia. Both low serum magnesium levels (≤0.79 mmol/L) and high serum magnesium levels (≥0.90 mmol/L) were associated with an increased risk of dementia (hazard ratio [HR] 1.32, 95% confidence interval [CI] 1.02-1.69, and HR 1.30, 95% CI 1.02-1.67, respectively). Both low and high serum magnesium levels are associated with an increased risk of all-cause dementia. Our results warrant replication in other population-based studies. © 2017 American Academy of Neurology.

21 CFR 582.5230 - Calcium sulfate.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium sulfate. 582.5230 Section 582.5230 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5230 Calcium sulfate. (a) Product. Calcium sulfate. (b) Conditions of use. This substance...

21 CFR 582.1125 - Aluminum sulfate.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Aluminum sulfate. 582.1125 Section 582.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This substance...

21 CFR 182.1125 - Aluminum sulfate.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Aluminum sulfate. 182.1125 Section 182.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Substances § 182.1125 Aluminum sulfate. (a) Product. Aluminum sulfate. (b) Conditions of use. This substance...

Sulfation pattern of fucose branches affects the anti-hyperlipidemic activities of fucosylated chondroitin sulfate.

Science.gov (United States)

Wu, Nian; Zhang, Yu; Ye, Xingqian; Hu, Yaqin; Ding, Tian; Chen, Shiguo

2016-08-20

Fucosylated chondroitin sulfates (fCSs) are glycosaminoglycans extracted from sea cucumbers, consisting of chondroitin sulfate E (CSE) backbones and sulfated fucose branches. The biological properties of fCSs could be affected by the sulfation pattern of their fucose branches. In the present study, two fCSs were isolated from sea cucumbers Isostichopus badionotus (fCS-Ib) and Pearsonothuria graeffei (fCS-Pg). Their monosaccharide compositions of glucuronic acid (GlcA), N-acetylgalactosamine (GalNAc), fucose (Fuc) and sulfate were at similar molar ratio with 1.0/0.7/0.9/3.1 for fCS-Ib and 1.0/0.8/1.5/2.6 for fCS-Pg. The two fCSs have different sulfation patterns on their fucose branches, fCS-Pg with 3,4-O-disulfation while fCS-Ib with 2,4-O-disulfation. Their antihyperlipidemic effects were compared using a high-fat high-fructose diet (HFFD)-fed C57BL/6J mice model. Both fCS-Ib and fCS-Pg had significant effects on lipid profile improvement, liver protection, blood glucose diminution and hepatic glycogen synthesis. Specifically, fCS-Pg with 3,4-O-disulfation fucose branches was more effective in reduction of blood cholesterol (TC), low density lipoprotein (LDL) and atherogenic index (AI). Our results indicate that both fCSs, especially fCS-Pg, could be used as a potential anti-hyperlipidemic drug. Copyright © 2016. Published by Elsevier Ltd.

Preparation of magnesium metal matrix composites by powder metallurgy process

Science.gov (United States)

Satish, J.; Satish, K. G., Dr.

2018-02-01

Magnesium is the lightest metal used as the source for constructional alloys. Today Magnesium based metal matrix composites are widely used in aerospace, structural, oceanic and automobile applications for its light weight, low density(two thirds that of aluminium), good high temperature mechanical properties and good to excellent corrosion resistance. The reason of designing metal matrix composite is to put in the attractive attributes of metals and ceramics to the base metal. In this study magnesium metal matrix hybrid composite are developed by reinforcing pure magnesium with silicon carbide (SiC) and aluminium oxide by method of powder metallurgy. This method is less expensive and very efficient. The Hardness test was performed on the specimens prepared by powder metallurgy method. The results revealed that the micro hardness of composites was increased with the addition of silicon carbide and alumina particles in magnesium metal matrix composites.