Compressive Strength of Basic Magnesium Sulfate Cement Coral Aggregate Concrete(MCAC)on Non-Destructive Testing

Basic magnesium sulfate cement coral aggregate concrete(MCAC)is a new type of concrete consisting of basic magnesium sulfate cement,coarse coral aggregate,coral reef sand and seawater.The rebound hammer(RH),the ultrasonic pulse velocity(UPV)and the compressive strength(fcu)tests of 14 sets of cube specimens of the MCAC after 28 d of aging were conducted.The impact of the content and length of sisal fiber on the relationship between the fcu-RH and the fcu-UPV was determined.A mathematical model was established to predict the strength of the MCAC using the UPV,RH,and comprehensive UPV/RH methods and to obtain the curves of test strength.The applicability of the test strength curves of ordinary portland concrete(OPC),light-weight aggregate concrete(LAC),and coral aggregate concrete(CAC)to MCAC was assessed.The results showed that the test strength curves of OPC,LAC and CAC were inappropriate to determine the strength of MCAC using non-destructive method.The relative standard error of the curves of test strength of the RH method and the comprehensive method met the specifications,whereas that of the UPV method did not.

Using Magnesium Sulfate to Prevent Atrial Fibrillation after Coronary Artery Bypass Grafting Surgery: A Single Centre Experience in Bangladesh

Background: Atrial fibrillation commonly occurs following cardiac surgery, particularly after coronary artery bypass grafting. Magnesium, known for its stabilizing effect on cell membranes, has shown promise in preventing postoperative atrial fibrillation. This study aimed to assess the impact of intravenous magnesium infusion in preventing atrial fibrillation after off-pump coronary artery bypass grafting, where maintaining stable cell membranes is crucial in averting this complication. Methods: A cross-sectional study was conducted at the Department of Cardiac Surgery, Bangabandhu Sheikh Mujib Medical University, from March 2020 to February 2022. Sixty-six patients who underwent off-pump coronary artery bypass grafting were enrolled and divided into two groups. Group A (n = 33) received intravenous magnesium sulfate (10 mmol/2.47gm) for three days after surgery, while Group B (n = 33) did not receive magnesium sulfate. Postoperative atrial fibrillation occurrence in the Intensive Care Unit (ICU) within three days after surgery was evaluated using convenient sampling. Statistical analysis was performed with SPSS version 26.0, utilizing independent Student’s t-test for continuous data and Chi-square and Fisher’s exact test for categorical data. A p-value of ≤0.05 was considered statistically significant. Results: No significant differences in age or gender were observed between the two groups. Group B exhibited significantly lower magnesium levels than Group A on the 0th, 1st, 2nd, and 3rd days post-surgery. Additionally, Group B experienced a higher incidence of postoperative atrial fibrillation, longer ICU stays, and two mortalities. The study did not detect any adverse effects associated with magnesium infusion. Conclusion: It has been demonstrated that administering magnesium intravenously after off-pump coronary artery bypass grafting can lower the chances of developing atrial fibrillation. This demonstrates the potential advantages of using magnesium as a preventative measure for postoperative atrial fibrillation in such cases.

Leaching characteristics of ion-adsorption type rare earths ore with magnesium sulfate

Magnesium sulfate was proposed to be leaching agent to deal with the ion-adsorption type rare earths ore to reduce or even eliminate ammonia?nitrogen emissions. The effects of temperature, particle size and stirring speed on rare earth leaching process and the leaching behaviors of the single rare earth element were investigated in order to reveal the rare earth leaching characteristics. Besides, the comparison of leaching effects between magnesium sulfate and ammonium sulfate was also studied. The results showed that the rare earth leaching process could be well described with inner diffusion control model and the apparent activation energy was 9.48 kJ/mol. The leaching behaviors of the single rare earth element were brought into correspondence with rare earths. Moreover, when the concentration of leaching agent was 0.20 mol/L, the rare earth leaching efficiency could all reach above 95% and the leaching efficiency of aluminum impurities could be restrained by 10% using magnesium sulfate compared with ammonium sulfate.

Electrochemical behaviors of tantalum in anhydrous ethanol containing hydrogen sulfate ions

The electrochemical behaviors of Ta in tetrabutylammonium hydrogen sulfate（TBAHS） ethanol solutions were studied using potentiodynamic polarization,cyclic voltammetry,potentiostatic current time transient and impedance techniques.The results revealed that no active-passive transition is presented in the cyclic voltammogram,and the anodic current density increases with the increase of solution temperature,TBAHS concentration,potential scan rate and water content.The apparent activation energy is about 43.389 kJ/mol and the dissolution process is diffusion-controlled.Potentiostatic measurements showed that the current density gradually decays to a steady value when the potential is low;however,when the potential is higher than a certain value,the current density initially declines to a minimum value and then increases gradually.The resistance of passive film decreases with increasing potential,and inductive loops are presented when the potential is higher than 2.0 V.

Effects of Foliar Spraying of Magnesiumpotassium Sulfate Fertilizer on Absorption of Magnesium, Potassium and Calcium in Differentposition Tobacco Leaves

[Objective] ln the Mg-deficient （exchangeable Ca/Mg ratio ＆gt; 20） tobacco-growing areas in Qujing City of Yunnan Province, the ratio of Ca/Mg was adjusted by applying Mg fertilizer in soil and spraying Mg fertilizer on tobacco leaves. ln ad-dition, the effects of Mg fertilization on the absorption of K, Ca and Mg in flue-cured tobacco leaves were investigated, providing theoretical basis and production guidance for the balanced fertilization technology in the Mg-deficient flue-cured to-bacco-growing areas in Qujing City of Yunnan Province. [Method] The field plot test and randomized complete block design were adopted in this research. The group without Mg fertilization was treated as control. There were 3 treatment groups for foliar spraying of magnesium-potassium sulfate fertilizer and 2 treatment groups for soil application ＋ foliar spraying of magnesium-potassium sulfate fertilizer. The tobac-co roots, stems, lower leaves, middle leaves and upper leaves were dried and weighed. They were grinded for the determination of K, Ca and Mg content. The total K, Ca and Mg content in upper （B2F）, middle （C3F） and lower （X2F） flue-cured tobacco leaves in each plot was measured. [Result] The foliar spraying and soil application ＋ foliar spraying al increased the absorption of Mg and K in middle and lower tobacco leaves and the absorption of Ca in lower tobacco leaves, but de-creased the absorption of Mg, K and Ca in upper leaves and the absorption of Ca in middle leaves. Among the positions, the accumulated distribution of Mg, K and Ca ranked as middle leaves ＆gt; lower leaves ＆gt; upper leaves. With the application of Mg fertilizer, the Ca/Mg ratio and K/Mg ratio al decreased in middle and upper to-bacco leaves; while the Ca/Mg ratio increased in the lower tobacco leaves, and the K/Mg ratio showed no significant difference among treatment groups. [Conclusion] The foliar spraying and soil application ＋ foliar spraying of magnesium-potassium sulfate fertilizer affected the Ca/Mg ratio and K/Mg ratio in tobacco leaves mainly through affecting the absorption of Mg.

Influence of magnesium and aluminum salts on hydrolysis of titanyl sulfate solution

The influence of magnesium and aluminum salts as impurities on the hydrolysis of titanyl sulfate was investigated.The degree of TiOSO4 conversion to hydrated titanium dioxide（HTD） and the particle size of HTD were measured as functions of the concentrations of MgSO4 and Al2（SO4）3 in the TiOSO4 solution.The Boltzmann growth model,which focuses on two main parameters,namely the concentrations of Mg2＋ and Al3＋（ρ（Mg2＋） and ρ（Al3＋）,respectively）,fits the data from the hydrolysis process well with R20.988.The samples were characterized by ICP,SEM,XRD,and laser particle size analyzer.It is found that the addition of Mg SO4 simultaneously improves the hydrolysis ratio and the hydrolysis rate,especially when F（the mass ratio of H2SO4 to TiO2） is high,hydrolysis ratio increases from 42.8% to 83.0%,whereas the addition of Al2（SO4）3 has negligible effect on the chemical kinetics of HTD precipitation during the hydrolysis process,hydrolysis ratio increases from 42.8% to 51.9%.An investigation on the particle size of HTD reveals that the addition of Mg SO4 and Al2（SO4）3 clearly increases the size of the crystallites and decreases the size of the aggregates.

Effect of Limestone Powder and Fly Ash on Magnesium Sulfate Resistance of Mortar

The effect of limestone powder and fly ash on magnesium sulfate resistance of mortar was studied by testing on the strength, expansion and hydration products of the specimens stored in MgSO4 solution at certain periods. The experimental results show that the strength of mortar stored in MgSO4 solution increases a little before 28 d, but decreases fast subsequently. The more the contents of limestone powder and fly ash, the less the strength losses. Mortar swells in the MgSO4 solution with the soaking time. And the more the contents of limestone powder and fly ash, the less the expansion rate is. The expansion or strength loss of mortars results from the expansion of gypsum, as well as the loss of Ca（OH）2 and other hydration products of cement. The magnesium sulfate resistance of the mortars containing limestone powder and fly ash is high.

Magnesium sulfate and fetal neuroprotection: overview of clinical evidence

Antenatal administration of magnesium sulfate is an important part of the neuroprotective strategy for preterm infants. Strong evidence from five randomized controlled trials and five meta-analyses has demonstrated that magnesium sulfate, when administered before preterm delivery, significantly reduces the risk of cerebral palsy at two years. Through secondary analyses of randomized controlled trials and other original clinical studies, this state-of-the-art review highlights the absence of serious adverse effects in both pregnant women and neonates, as well as the impact of maternal body mass index and preeclamptic status on the maternal and neonatal magnesium levels, which could influence the magnitude of the neuroprotective effect. Although antenatal magnesium sulfate is a cost-effective strategy, some practice surveys have demonstrated that the use of magnesium sulfate is not sufficient and that its use is heterogeneous, differing among different maternity wards. Since 2010, an increasing number of obstetrical societies have recommended its use to improve the neurological outcomes of preterm infants, especially the International Federation of Gynecology and Obstetrics and World Health Organization in 2015, and France in 2017. Considering the neuroprotective impact of magnesium sulfate when administered before delivery, postnatal administration should be considered, and its effects should be assessed using randomized controlled trials.

Leaching behaviors of calcium and magnesium in ion-adsorption rare earth tailings with magnesium sulfate

The leaching behaviors of calcium and magnesium in the rare earth tailings leached with magnesium sulfate using deionized water,CaCl2 solution and lime water were investigated.Experimental data indicated that magnesium in the tailings was easy to be leached out since most of the magnesium was in the form of water-soluble phase.Most of calcium in the lime water was electrostatically adsorbed on the clay mineral of the tailings,and the water-soluble magnesium was also gradually converted into exchangeable phase because of back-adsorption of Mg2+on the clay mineral with increasing the pH values.When the liquid-to-solid ratio was 0.80,the contents of readily-available magnesium and calcium were 104.4−207.6 and 201.7−1426.3 mg/kg,respectively,which could meet the requirements for plants.These results suggest a promising route for the environmental remediation of ion-adsorption rare earth ore after in-situ leaching.

Interventional effect of magnesium sulfate on nitric oxide synthase activity after acute craniocerebral injury

BACKGROUND： Abnormal changes in magnesium ion are closely related to cerebral injury. At present, some evidence indicates that magnesium reagent can improve nerve function and prognosis of patients with cerebral injury. OBJECTIVE： To observe the effect of magnesium sulfate on changes in nitric oxide synthase （NOS） activity in brain tissue of rats with acute craniocerebral injury. DESIGN： Completely randomized grouping design and randomly controlled study. SETTING： Laboratory of Neurosurgery, the Third Hospital of Chinese PLA. MATERIALS： Fifty-four male SD rats of clean grade and weighing 220 - 250 g were randomly divided into normal control group （n =6）, cerebral injury group （n =24） and magnesium sulfate group （n =24）. Especially, rats in cerebral injury group and magnesium sulfate group were equally divided into four subgroups and observed at 0.5, 2, 6 and 24 hours after model establishment. A solution of 125 g/L of magnesium sulfate was provided by the Seventh Pharmaceutical Factory of Wuxi and the NOS assay kit by Nanjing Jiancheng Bioengineering Institute. METHODS： The experiment was carried out in the Institute of Neurosurgery, the Third Hospital of Chinese PLA from August 2000 to August 2002. ① Rats in the cerebral injury group and magnesium sulfate group were anesthetized to establish cerebral injury models based on modified Feeney technique; magnesium sulfate group were intraperitoneally injected 600 mg/kg magnesium sulfate （125 g/L）, but rats in the normal control group remained untreated. ② At 0.5, 2, 6 and 24 hours after cerebral injury, rats in cerebral injury group and magnesium sulfate group were decapitated and brains were dissected. Cerebral cortex of rats in cerebral injury group was selected for NOS assay; in addition, at 0.5 hour after cerebral injury, a portion of the parietal lobe was selected from the brains of rats in the normal control group. Brain samples were homogenized, the homogenated centrifuged and the supernatants were used to measure NOS activity with NOS kit. ③ Differences among the three groups were compared with t test. MAIN OUTCOME MEASURES： NOS activity in cerebral cortex of rats in each group. RESULTS： A total of 54 SD rats were involved in the final analysis. At 0.5 hour after cerebral injury, NOS activity in cerebral cortex was （42.45 ± 13.46） nmol/L in cerebral injury group and （41.17 ± 12.53） nmol/L in magnesium sulfate group, respectively, which was higher than that in normal control group [（39.45 ± 11.84） nmol/L, P 〈 0.05]. At 2 hours after cerebral injury, NOS activities were （66.48 ±21.43） and （63.24 ± 19.18） umol/L, respectively, while at 6 hours after cerebral injury, NOS activities were （62.45 ± 24.18） and （51.97 ±20.46） nmol/L, respectively, which were higher than those in normal control group （P 〈 0.0 1）. At 24 hours after cerebral injury, NOS activity returned to basal level. Moreover, NOS activity was significantly lower in the magnesium sulfate group than that in the cerebral injury group at 2 and 6 hours after cerebral injury （P 〈 0.05, 0.01）.CONCLUSION： NOS activity is increased in injured brain tissue of rats with craniocerebral injury, and treatment with magnesium sulfate provides some degrees of protection possibly through inhibition of NOS activity after cerebral injury.

Research on the Evaporating Crystalization Behavior of the Magnesium Sulfate Subtypes Brine at High Temperature

Research the evaporating crystalization process of the magnesium sulfate subtypes brine at high temperature from Dalangtan salt lake in Qinghai province.It was revealed that the salt lake is a typical subtype magnesium

Does magnesium sulfate increase the incidence of postpartum hemorrhage? A systematic review

The incidence of Postpartum Hemorrhage (PPH) is increasing in the western world. We hypothesize that magnesium sulfate (MgSO4) could be a contributing factor. MgSO4 might increase the incidence of PPH by induction of vasodilation, tocolytic effects, and effects on the blood like red cell deformity, platelet activity inhibition and a prolonged bleeding time. Based on these effects of MgSO4 a correlation with PPH is suspected. MgSO4 is widely used in the prevention of eclampsia. However, the working mechanism of this effective drug is largely unknown. We performed a systematic search to find all Randomized Controlled trials (RCTs) containing MgSO4 in preeclamsia as well as all MgSO4 studies with information on PPH. Titles, abstracts and references of publications were evaluated for appropriateness and whether they met the inclusion criteria. RCTs about MgSO4 with original data on PPH prevalence were included in our systematic review. We calculated the relative risk of PPH in every study as well as an overall relative risk. Four relevant and valid RCTs were found, totalling 11,621 relevant patients. The relative risk of PPH in women treated with MgSO4 is 0.964 (95% CI 0.886 - 1.050) In this systematic review we found no significant increase in PPH in women treated with MgSO4. However, there is still room for discussion due to the heterogeneity in methods (dosage and duration of treatment), results, and tertiary outcomes, as well as the small number of studies found with respect to this important issue.

Comparative effect of intrathecal meperidine,tramadol,magnesium sulfate,and dexmedetomidine on preventing post-spinal anesthesia shivering and adverse events in hip fracture repair patients:A randomized clinical trial

Objective:To compare effect of intrathecal meperidine,tramadol,magnesium sulfate,and dexmedetomidine on the prevention of post-spinal anesthesia shivering and adverse events in hip fracture repair patients.Methods:In a randomized,double-blind trial,132 patients with American Society of Anesthesiology(ASA)ⅠandⅡspinal anesthesia who needed hip fracture surgery were enrolled.Patients were stratified into 4 intervention groups based on a randomized block pattern:meperidine,tramadol,magnesium sulfate,and dexmedetomidine.Hemodynamic parameters including blood pressure,heart rate,and oxygen saturation,as well as the severity of shivering,core body temperature,Ramsay sedation score,adverse events,meperidine consumption were recorded and compared.Results:There was no statistically significant difference in the normal hemodynamic parameters,temperature,duration of surgery,meperidine consumption,and adverse events such as dizziness,hypotension,nausea,and bradycardia among groups(P>0.05).Compared to other groups,severity of shivering was the lower in the dexmedetomidine group 6 and 8 h after surgery.The Ramsay sedation scores were higher in the dexmedetomidine and meperidine groups 4 h after surgery(P=0.020).Conclusion:Dexmedetomidine acts better than the other three adjuvants in reducing complications such as shivering.Overall,these four adjuvants are helpful to prevent postoperative shivering and could be put forward as promising local anesthetics in spinal anesthesia,based on anesthesiologists’discretion and patients’general conditions.Clinical registration:The study was approved by the Research and Ethics Committee at the Valiasr Hospital(Arak,Iran)with the clinical trial code of IRCT20141209020258N153.

Effect of nifedipine combined with Magnesium Sulfate on oxidative stress,hemorheology,platelet active substances and renal function in patients with pregnancy-induced hypertension

Objective: To investigate effect of nifedipine combined with Magnesium Sulfate on levels of oxidative stress, blood rheology, platelet active substance and renal function in patients with pregnancy-induced hypertension. Methods: A total of 99 cases of patients with pregnancy-induced hypertension were selected as the study object, according to random data table, they were divided into control group (n=50) and observation group (n=49), patients in control group were treated with Magnesium Sulfate, while patients in the observation group received Magnesium Sulfate combined with nifedipine treatment, levels of blood pressure and oxidative stress, blood rheology, platelet activity and renal function index before and after treatment of both groups were compared. Results: There were no significant difference of the level of DBP, SBP, Tac, MDA, SOD, high/low shear blood viscosity, PV, HCT, CD62P, CD63, GPⅡb/Ⅲa, SCr and BUN before treatment between control group and the observation group. Compared with intragroup before treatment, the levels of DBP, SBP, MDA, high/low shear blood viscosity, PV, HCT, CD62P, CD63, GPⅡb/Ⅲa, SCr and BUN after treatment of the two groups were significantly decreased, and the levels of the observation group after treatment was significantly lower than those in the control group, the difference was statistically significant;Compared with level of SOD and Tac, after treatment, the levels of SOD and Tac of the two groups were significantly higher than those in the same group before treatment, and levels of the observation group was significantly higher than in the control group, the difference was statistically significant. Conclusion: Nifedipine combined with magnesium sulfate treatment of pregnancy-induced hypertension, which can effectively reduce the blood pressure level of patients, improve the levels of oxidative stress, blood rheology and platelet active substance, protect renal function, with an important clinical value.

Effect of nifedipine in combined with magnesium sulfate on the hemorheology and coagulation indicators in patients with gestational hypertension

Objective:To explore the effect of nifedipine in combined with magnesium sulfate on the hemorheology and coagulation indicators in patients with gestational hypertension.Methods:A total of 90 patients with gestational hypertension were included in the study and randomized into the observation group and the control group with 45 cases in each group. The patients in the observation group were given magnesium sulfate in combined with nifedipine, while the patients in the control group were only given magnesium sulfate. The patients in the two groups were continuously treated for 2 weeks. The blood pressure, hemorheology indicators, and coagulation indicators before and after treatment in the two groups were detected and compared.Results: SBP, DBP, whole blood high, moderate, and low shear viscosity, plasma viscosity, and HCT after treatment in the two groups were significantly reduced when compared with before treatment (P<0.05). The levels of the above indicators after treatment in the observation group were significantly lower than those in the control group (P<0.05). PT, APTT, and TT after treatment in the two groups were significantly elevated when compared with before treatment (P<0.05), while Fib was significantly reduced (P<0.05). PT, APTT, and TT after treatment in the observation group were significantly higher than those in the control group (P<0.05), while Fib was significantly lower than that in the control group (P<0.05). Conclusions:Nifedipine in combined with magnesium sulfate can significantly stabilize the blood pressure level in patients with gestational hypertension, and improve the hemodynamic and coagulation indicators, with a significant efficacy.

Attack of Limestone Cement-based Material Exposed to Magnesium Sulfate Solution at Low Temperature

Limestone in cement could be a source of CO3^2- needed for thaumasite formation which will result in thanmasite form of sulfate attack （TSA） probably. TSA has more deterioration than ettringite or gypsum form of sulfate attack because it targets the calcium silicate hydrates （C-S-H） which is the main binder phase in all Portland cement-based materials. By means of physical and mechanical property testing as well as erosion phases analysis, magnesium sulfate attack of cement-based material containing 35% limestone powder by mass at 5 ± 2 ℃ is investigated. The compressive strength and flexural strength of mortar specimen immersed in MgSO4 solution increase firstly, then decrease rapidly with the immersing age. Relative dynamic elastic modulus of mortar specimen changes in a phased process. After immersing in MgSO4 solution for 15 weeks, the main erosion phases in paste specimen change from four phases compounds, three phases compounds to two phases compounds from surface to inside. Deterioration course of limestone cement-based material exposed to magnesium sulfate aggressive environment appears progressive damage layer by layer, and every layer probably suffers four stages, which are property strengthening stage, initial degradation stage, thaumasite formation stage and cementation loss stage, respectively.

Ab Initio and DFT Study of Magnesium Sulfate Contact Ion Pairs

The stuctures of contact ion pairs of magnesium sulfate were studied. The geometries of contact ion pairs of MgSO 4(H 2O) n (n =1-6) were optimized by using Hartree Fock (HF/6 31+G *, HF/6 311+G ** ) and density functional theory (DFT) (B3LYP/6 31+G *, B3LYP/6 311+G ** ) methods. The stable structures of monodentate, bidentate and tridentate contact ion pairs were obtained. The bidentate structure of contact ion pairs are the most stable compaired with the monodentate and tridentate ones for the same composition. The hydration enthalpies of contact ion pairs of MgSO 4 (H 2O) n (n =1-4) increase with their hydration numbers.

The Effects of Magnesium Sulfate on Fetal Rats of FGR and the Expression of Caspase-3 in the Placenta of Maternal Rat

To investigate the effect of magnesium sulfate on the fetal rats of FGR and the expression of caspase-3 in the placenta of maternal rat ; To explore the mechanism of using magnesium sulfate to cure the FGR. Establish model of FGR by a way of passive smoking： giving the maternal rats different agent of magnesium sulfate by subcutaneous injection： low agent group （300 mg/kg）, high agent group （600 mg/kg）. Concentration of magnesium sulfate was monitored. The expression of caspase-3 was measured by RT-PCR and immunohistochemistry technology. Both of the concentrations of magnesium sulfate in high and low agents group are higher than the FGR group （P〈0.01）;the weight of the placenta and fetal rat in high agent group are higher than the FGR group （P〈0.05 and P〈0. 01） ; the expression of mRNA and protein of caspase-3 in the two agent group is higher than the FGR group （P〈0.05 respectively） ; concentration of magnesium sulfate in the maternal rat blood correlate to the weight of fetal rat （r=0. 899, P=0. 038） and the expression of caspase-3 in the placenta of maternal rat （r=-0. 747, P=0. 033; r=-0. 915, P=0. 001）. The research suggests that the weight of fetal rat could be increased by treatment of magnesium sulfate. Because it would imfrmove the placental function by depressing the expression of caspase-3.

Preparation of Adsorbent with Magnesium Sulfate and Straw Pulp Black Liquor and Its Phenol Adsorption Properties

A magnesia adsorbent was prepared from straw pulp black liquor and magnesium sulfate for the first time, and its adsorption of phenol from aqueous solution was examined. The characteristics of the adsorbent were tested through chemical analysis, surface analysis, X-ray diffraction and FT-IR spectroscopy. The effects of various factors, such as dose, adsorption time and adsorption temperature, on phenol adsorption behavior were studied. The results show that the adsorption processes can be fitted to the isotherm Langmuir model very well. It was found that the adsorption process was strongly influenced by temperature and the optimal temperature for phenol removal was 40 ℃. The optimum adsorption time was 10 min, and desorption would happen afterwards. Between the models of Langmuir and Freundlich, the adsorption process of phenol onto magnesia fitted the Langmuir equation better.