22,049 results match your criteria ca2+ concentrations


Approved drugs ezetimibe and disulfiram enhance mitochondrial Ca uptake and suppress cardiac arrhythmogenesis.

Br J Pharmacol 2021 Jul 21. Epub 2021 Jul 21.

Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, LMU Munich, Munich, Germany.

Treatment of cardiac arrhythmia remains challenging due to severe side effects of common anti-arrhythmic drugs. We previously demonstrated that mitochondrial Ca uptake in cardiomyocytes represents a promising new candidate structure for safer drug therapy. However, druggable agonists of mitochondrial Ca uptake suitable for preclinical and clinical studies are still missing. Read More

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NAADP-induced intracellular calcium ion is mediated by the TPCs (two-pore channels) in hypoxia-induced pulmonary arterial hypertension.

J Cell Mol Med 2021 Jul 15. Epub 2021 Jul 15.

Respiratory Medicine, Hunan Provincial People's Hospital, Changsha, China.

Pulmonary arterial hypertension (PAH) is a form of obstructive vascular disease. Chronic hypoxic exposure leads to excessive proliferation of pulmonary arterial smooth muscle cells and pulmonary arterial endothelial cells. This condition can potentially be aggravated by [Ca ] mobilization. Read More

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Trapped interfacial redox introduces reversibility in the oxygen reduction reaction in a non-aqueous Ca electrolyte.

Chem Sci 2021 Jul 28;12(25):8909-8919. Epub 2021 May 28.

Stephenson Institute for Renewable Energy, Department of Chemistry, University of Liverpool Liverpool L69 7ZD UK

Electrochemical investigations of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) have been conducted in a Ca-containing dimethyl sulfoxide electrolyte. While the ORR appears irreversible, the introduction of a tetrabutylammonium perchlorate (TBAClO) co-salt in excess concentrations results in the gradual appearance of a quasi-reversible OER process. Combining the results of systematic cyclic voltammetry investigations, the degree of reversibility depends on the ion pair competition between Ca and TBA cations to interact with generated superoxide (O ). Read More

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Molecular Mechanisms of Mast Cell Activation by Cholesterol-Dependent Cytolysins.

Front Immunol 2021 23;12:670205. Epub 2021 Jun 23.

Department of Signal Transduction, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia.

Mast cells are potent immune sensors of the tissue microenvironment. Within seconds of activation, they release various preformed biologically active products and initiate the process of synthesis of cytokines, chemokines, and other inflammatory mediators. This process is regulated at multiple levels. Read More

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Effects of Tl on the inner membrane thiol groups, respiration, and swelling in succinate-energized rat liver mitochondria were modified by thiol reagents.

Biometals 2021 Jul 8. Epub 2021 Jul 8.

Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, Thorez pr. 44, St. Petersburg, Russian Federation, 194223.

The effects of both Tl and thiol reagents were studied on the content of the inner membrane free SH-groups, detected with Ellman reagent, and the inner membrane potential as well as swelling and respiration of succinate-energized rat liver mitochondria in medium containing TlNO and KNO. These effects resulted in a rise in swelling and a decrease in the content, the potential, and mitochondrial respiration in 3 and 2,4-dinitrophenol-uncoupled states. A maximal effect was seen when phenylarsine oxide reacting with thiol groups recessed into the hydrophobic regions of the membrane. Read More

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Mibefradil reduces hepatic glucose output in HepG2 cells via Ca/calmodulin-dependent protein kinase II-dependent Akt/forkhead box O1signaling.

Eur J Pharmacol 2021 Jul 3;907:174296. Epub 2021 Jul 3.

Department of Integrative Medicine, Xinqiao Hospital, Army Medical University, Chongqing, 400037, China. Electronic address:

The effects and underlying mechanisms of mibefradil on gluconeogenesis and glycogenesis were investigated using insulin-resistant HepG2 human hepatocellular carcinoma cells and a mouse model of type 2 diabetes mellitus (T2DM). HepG2 cells were divided into one of four groups: control, palmitate (PA)-induced insulin-resistance (0.25 mM), low-concentration mibefradil (0. Read More

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Cellular Mechanisms Underlying the Low Cardiotoxicity of Istaroxime.

J Am Heart Assoc 2021 Jul 3;10(14):e018833. Epub 2021 Jul 3.

Centro de Investigaciones Cardiovasculares Horacio Cingolani CONICET La Plata Facultad de Ciencias Médicas Universidad Nacional de La Plata Argentina.

Background Istaroxime is an inhibitor of Na/K ATPase with proven efficacy to increase cardiac contractility and to accelerate relaxation attributable to a relief in phospholamban-dependent inhibition of the sarcoplasmic reticulum Ca ATPase. We have previously shown that pharmacologic Na/K ATPase inhibition promotes calcium/calmodulin-dependent kinase II activation, which mediates both cardiomyocyte death and arrhythmias. Here, we aim to compare the cardiotoxic effects promoted by classic pharmacologic Na/K ATPase inhibition versus istaroxime. Read More

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Uroguanylin increases Ca2+ concentration in astrocytes via guanylate cyclase C-independent signaling pathway.

Croat Med J 2021 Jun;62(3):250-263

Aleksandra Dugandžić (née Sinđić), Department of Physiology, Croatian Institute for Brain Research, Zagreb University School of Medicine, Šalata 3, 10000 Zagreb, Croatia,

Aim: To investigate the cyclic guanosine monophosphate (cGMP)/guanylate cyclase C (GC-C)-independent signaling pathway in astrocytes, which are a suitable model due to their lack of GC-C expression.

Methods: Patch clamp was performed and intracellular Ca2+ concentrations and pH were measured in primary astrocyte cultures and brain slices of wild type (WT) and GC-C knockout (KO) mice. The function of GC-C-independent signaling pathway in the cerebellum was determined by behavior tests in uroguanylin (UGN) KO and GC-C KO mice. Read More

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Exploring the Conformational Changes Induced by Nanosecond Pulsed Electric Fields on the Voltage Sensing Domain of a Ca Channel.

Membranes (Basel) 2021 Jun 26;11(7). Epub 2021 Jun 26.

Computational Biology Lab, Fundación Ciencia & Vida, Zañartu 1482, Ñuñoa, Santiago 7780272, Chile.

Nanosecond Pulsed Electric Field (nsPEF or Nano Pulsed Stimulation, NPS) is a technology that delivers a series of pulses of high-voltage electric fields during a short period of time, in the order of nanoseconds. The main consequence of nsPEF upon cells is the formation of nanopores, which is followed by the gating of ionic channels. Literature is conclusive in that the physiological mechanisms governing ion channel gating occur in the order of milliseconds. Read More

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Gender-Dependent Phenotype in Polycystic Kidney Disease Is Determined by Differential Intracellular Ca Signals.

Int J Mol Sci 2021 Jun 2;22(11). Epub 2021 Jun 2.

Physiological Institute, University of Regensburg, University Street 31, D-93053 Regensburg, Germany.

Autosomal dominant polycystic kidney disease (ADPKD) is caused by loss of function of PKD1 (polycystin 1) or PKD2 (polycystin 2). The Ca-activated Cl channel TMEM16A has a central role in ADPKD. Expression and function of TMEM16A is upregulated in ADPKD which causes enhanced intracellular Ca signaling, cell proliferation, and ion secretion. Read More

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Effects of intravenous magnesium sulfate on serum calcium-regulating hormones and plasma and urinary electrolytes in healthy horses.

PLoS One 2021 28;16(6):e0247542. Epub 2021 Jun 28.

College of Veterinary Medicine, The Ohio State University, Columbus, OH, United States of America.

Intravenous magnesium sulfate (MgSO4) is used in equine practice to treat hypomagnesemia, dysrhythmias, neurological disorders, and calcium dysregulation. MgSO4 is also used as a calming agent in equestrian events. Hypercalcemia affects calcium-regulating hormones, as well as plasma and urinary electrolytes; however, the effect of hypermagnesemia on these variables is unknown. Read More

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Molecular mechanisms from insulin-mimetic effect of vitamin D: treatment alternative in Type 2 diabetes mellitus.

Food Funct 2021 Jun 24. Epub 2021 Jun 24.

Universidad Latino, Periférico Norte, Mérida, Yucatán, Mexico.

Diabetes mellitus is a complex and multifactorial disease with a global prevalence that exceeds 425 million people. Type 2 diabetes mellitus (T2DM) is characterized by a state of insulin resistance, which leads to metabolic alterations that aggravate the state of health of people. Vitamin D deficiency appears to play an important role in the triggering mechanisms of insulin resistance. Read More

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Solid-State NMR Study to Probe the Effects of Divalent Metal Ions (Ca and Mg) on the Magnetic Alignment of Polymer-Based Lipid Nanodiscs.

Langmuir 2021 06 15;37(25):7780-7788. Epub 2021 Jun 15.

Biophysics Program and Department of Chemistry, Biomedical Engineering, and Macromolecular Science and Engineering, The University of Michigan, Ann Arbor, Michigan 48109-1055, United States.

Divalent cations, especially Ca and Mg, play a vital role in the function of biomolecules and making them important to be constituents in samples for in vitro biophysical and biochemical characterizations. Although lipid nanodiscs are becoming valuable tools for structural biology studies on membrane proteins and for drug delivery, most types of nanodiscs used in these studies are unstable in the presence of divalent metal ions. To avoid the interaction of divalent metal ions with the belt of the nanodiscs, synthetic polymers have been designed and demonstrated to form stable lipid nanodiscs under such unstable conditions. Read More

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Palmitic acid induces insulin resistance by a mechanism associated with energy metabolism and calcium entry in neuronal cells.

FASEB J 2021 07;35(7):e21712

Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad de México, Mexico.

Palmitic acid (PA) is a saturated fatty acid whose high consumption has been largely associated with the development of different metabolic alterations, such as insulin resistance, metabolic syndrome, and type 2 diabetes. Particularly in the brain, insulin signaling disruption has been linked to cognitive decline and is considered a risk factor for Alzheimer's disease. Cumulative evidence has demonstrated the participation of PA in the molecular cascade underlying cellular insulin resistance in peripheral tissues, but its role in the development of neuronal insulin resistance and the mechanisms involved are not fully understood. Read More

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The interaction of chondroitin sulfate with a lipid monolayer observed by using nonlinear vibrational spectroscopy.

Phys Chem Chem Phys 2021 Jun;23(23):13389-13395

School of Analytical Sciences Adlershof, Humboldt-Universität zu Berlin, Albert-Einstein-Straße 5-11, 12489 Berlin, Germany.

The first vibrational sum-frequency generation (VSFG) spectra of chondroitin sulfate (CS) interacting with dipalmitoyl phosphatidylcholine (DPPC) at air-liquid interface are reported here, collected at a laser repetition rate of 100 kHz. By studying the VSFG spectra in the regions of 1050-1450 cm-1, 2750-3180 cm-1, and 3200-3825 cm-1, it was concluded that in the presence of Ca2+ ions, the head groups together with the head-group-bound water molecules in the DPPC monolayer are strongly influenced by the interaction with CS, while the organization of the phospholipid tails remains mostly unchanged. The interactions were observed at a CS concentration below 200 nM, which exemplifies the potential of VSFG in studying biomolecular interactions at low physiological concentrations. Read More

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Arginase inhibition by rhaponticin increases L-arginine concentration that contributes to Ca2+-dependent eNOS activation.

BMB Rep 2021 Jun 3. Epub 2021 Jun 3.

Department of Biological Sciences, Kangwon National University, Chuncheon 24341, Korea.

Although arginase primarily participates in the last reaction of the urea cycle, we have previously demonstrated that arginase II is an important cytosolic calcium regulator through spermine production in a p32-dependent manner. Here, we demonstrated that rhaponticin (RPT) is a novel medicinal-plant arginase inhibitor and investigated its mechanism of action on Ca2+-dependent endothelial nitric oxide synthase (eNOS) activation. RPT was uncompetitively inhibited for both arginases I and II prepared from mouse liver and kidney. Read More

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Effect of Media with Different Glycerol Concentrations on Sheep Red Blood Cells' Viability In Vitro.

Animals (Basel) 2021 May 28;11(6). Epub 2021 May 28.

Department of Veterinary Medicine, University of Sassari, 07100 Sassari, Italy.

The use of high doses of glycerol as a livestock feed supplement is followed by a rapid increase in plasma concentrations and consequently in plasma osmolality. Moreover, glycerol is a highly diffusible molecule that can readily permeate the red blood cell (RBC) membrane following a concentration gradient. A rise in glycerol plasma concentrations can thus alter RBC homeostasis. Read More

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In Vitro Synergistic Inhibition of HT-29 Proliferation and 2H-11 and HUVEC Tubulogenesis by Bacopaside I and II Is Associated with Ca Flux and Loss of Plasma Membrane Integrity.

Pharmaceuticals (Basel) 2021 May 6;14(5). Epub 2021 May 6.

Solid Tumour Group, Basil Hetzel Institute for Translational Health Research, The Queen Elizabeth Hospital, Woodville South, SA 5011, Australia.

We previously showed how triterpene saponin bacopaside (bac) II, purified from the medicinal herb , induced cell death in colorectal cancer cell lines and reduced endothelial cell migration and tube formation, and further demonstrated a synergistic effect of a combination of bac I and bac II on the inhibition of breast cancer cell line growth. Here, we assessed the effects of bac I and II on the colorectal cancer HT-29 cell line, and mouse (2H-11) and human umbilical vein endothelial cell (HUVEC) lines, measuring outcomes including cell viability, proliferation, migration, tube formation, apoptosis, cytosolic Ca levels and plasma membrane integrity. Combined bac I and II, each applied at concentrations below IC values, caused a synergistic reduction of the viability and proliferation of HT-29 and endothelial cells, and impaired the migration of HT-29 and tube formation of endothelial cells. Read More

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Deregulation of Ca-Signaling Systems in White Adipocytes, Manifested as the Loss of Rhythmic Activity, Underlies the Development of Multiple Hormonal Resistance at Obesity and Type 2 Diabetes.

Int J Mol Sci 2021 May 12;22(10). Epub 2021 May 12.

Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, 142290 Pushchino, Russia.

Various types of cells demonstrate ubiquitous rhythmicity registered as simple and complex Ca-oscillations, spikes, waves, and triggering phenomena mediated by G-protein and tyrosine kinase coupled receptors. Phospholipase C/IP-receptors (PLC/IPR) and endothelial NO-synthase/Ryanodine receptors (NOS/RyR)-dependent Ca signaling systems, organized as multivariate positive feedback generators (PLC-G and NOS-G), underlie this rhythmicity. Loss of rhythmicity at obesity may indicate deregulation of these signaling systems. Read More

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Differential effects of the formin inhibitor SMIFH2 on contractility and Ca handling in frog and mouse cardiomyocytes.

Genes Cells 2021 Jun 1. Epub 2021 Jun 1.

Department of Pharmacology, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan.

Genetic mutations in actin regulators have been emerging as a cause of cardiomyopathy, although the functional link between actin dynamics and cardiac contraction remains largely unknown. To obtain insight into this issue, we examined the effects of pharmacological inhibition of formins, a major class of actin-assembling proteins. The formin inhibitor SMIFH2 significantly enhanced the cardiac contractility of isolated frog hearts, thereby augmenting cardiac performance. Read More

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Cytosolic and Mitochondrial Ca Imaging in Drosophila Dopaminergic Neurons.

Methods Mol Biol 2021 ;2322:207-214

Department of Research for Parkinson's Disease, Juntendo University Graduate School of Medicine, Tokyo, Japan.

The ATP-producing organelle mitochondrion controls cellular or synaptic Ca concentrations through temporal uptake of Ca outside of the mitochondria. Although intracellular Ca influx occurs during neuronal activity, a persistently higher concentration of intracellular Ca is neurotoxic. Healthy mitochondria ensure rapid Ca uptake, which is necessary for proper neuronal activity. Read More

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January 2021

Intravital imaging identifies the VEGF-TXA2 axis as a critical promoter of PGE2 secretion from tumor cells and immune evasion.

Cancer Res 2021 May 25. Epub 2021 May 25.

Laboratory of Bioimaging and Cell Signaling, Kyoto University, Graduate School of Biostudies.

Prostaglandin E2 (PGE2) promotes tumor progression through evasion of anti-tumor immunity. In stark contrast to cyclooxygenase-dependent production of PGE2, little is known whether or not PGE2 secretion is regulated within tumor tissues. Here, we show that VEGF-dependent release of thromboxane A2 (TXA2) triggers Ca2+ transients in tumor cells, culminating in PGE2 secretion and subsequent immune evasion in the early stages of tumorigenesis. Read More

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EGCG decreases myocardial infarction in both I/R and MIRI rats through reducing intracellular Ca2+ and increasing TnT levels in cardiomyocytes.

Adv Clin Exp Med 2021 Jun;30(6):607-616

Department of Cardiovascular Medicine, The Third Affiliated Hospital of Zunyi Medical University (The First People's Hospital of Zunyi), China.

Background: Myocardial ischemia/reperfusion injury (MIRI) usually induces serious health problems.

Objectives: This study attempted to explore protective effects of (-)-epigallocatechin-3-gallate (EGCG) on MIRI and the associated mechanism.

Material And Methods: Ischemia/reperfusion of an isolated rat heart (I/R model) and the MIRI model were used in this study. Read More

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Inhibitory synaptic transmission is impaired at higher extracellular Ca concentrations in Scn1a mouse model of Dravet syndrome.

Sci Rep 2021 May 20;11(1):10634. Epub 2021 May 20.

Research Institute for the Molecular Pathogeneses of Epilepsy, Fukuoka University, Fukuoka, Japan.

Dravet syndrome (DS) is an intractable form of childhood epilepsy that occurs in infancy. More than 80% of all patients have a heterozygous abnormality in the SCN1A gene, which encodes a subunit of Na channels in the brain. However, the detailed pathogenesis of DS remains unclear. Read More

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Electrical therapies act on the Ca /CaM signaling pathway to enhance bone regeneration with bioactive glass [S53P4] and allogeneic grafts.

J Biomed Mater Res B Appl Biomater 2021 May 18. Epub 2021 May 18.

Graduate Program in Biomedical Sciences, University Center of Hermínio Ometto Foundation - FHO, Araras, Brazil.

This study aimed to investigate the application of low-intensity electrostimulation (ES) and electromagnetic stimulation (EM) associated with bioactive glass (BG) or allogeneic grafts (BB) in bone regeneration. A cell viability test on osteoblasts (UMR-106) was performed in the presence of BB and BG grafts associated with ES (10 μA/5 min) and EM (500 Hz/2 min). Critical defects (25 mm ) in calvaria were generated in male Wistar rats, and bone regeneration was evaluated on the 30th, 60th, and 120th days after surgery. Read More

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Region-Specific and State-Dependent Astrocyte Ca Dynamics during the Sleep-Wake Cycle in Mice.

J Neurosci 2021 Jun 18;41(25):5440-5452. Epub 2021 May 18.

Super-network Brain Physiology, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan.

Neural activity is diverse, and varies depending on brain regions and sleep/wakefulness states. However, whether astrocyte activity differs between sleep/wakefulness states, and whether there are differences in astrocyte activity among brain regions remain poorly understood. Therefore, in this study, we recorded astrocyte intracellular calcium (Ca) concentrations of mice during sleep/wakefulness states in the cortex, hippocampus, hypothalamus, cerebellum, and pons using fiber photometry. Read More

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Three-Dimensional Model of Sub-Plasmalemmal Ca Microdomains Evoked by the Interplay Between ORAI1 and InsP Receptors.

Front Immunol 2021 28;12:659790. Epub 2021 Apr 28.

Unit of Theoretical Chronobiology, Faculté des Sciences CP231, Université Libre de Bruxelles (ULB), Brussels, Belgium.

Ca signaling plays an essential role in T cell activation, which is a key step to start an adaptive immune response. During the transition from a quiescent to a fully activated state, Ca microdomains characterized by reduced spatial and temporal extents are observed in the junctions between the plasma membrane (PM) and the endoplasmic reticulum (ER). Such Ca responses can also occur in response to T cell adhesion to other cells or extracellular matrix proteins in otherwise unstimulated T cells. Read More

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Electric fields regulate cellular elasticity through intracellular Ca concentrations.

J Cell Physiol 2021 May 16. Epub 2021 May 16.

Department of Biomedical Engineering, Kyung Hee University, Seoul, Korea.

Cellular elasticity is a key factor related to a broad range of physiological and pathological processes. The elasticity of a single cell has thus emerged as a potential biomarker to characterize the cellular state. Both internal and external stimuli affect cellular elasticity, and changes in elasticity can cause alterations in cellular characteristics or function. Read More

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Inhibition of Small-Conductance, Ca-Activated K Current by Ondansetron.

Front Pharmacol 2021 22;12:651267. Epub 2021 Apr 22.

Division of Cardiology, Department of Medicine, The Krannert Institute of Cardiology, Indiana University School of Medicine, Indianapolis, IN, United States.

Small-conductance Ca-activated K channels (SK channels) have been proposed as antiarrhythmic targets for the treatment of atrial fibrillation. We previously demonstrated that the 5-HT receptor antagonist ondansetron inhibits heterologously expressed, human SK2 (hSK2) currents as well as native cardiac SK currents in a physiological extra-/intracellular [K] gradient at therapeutic (i.e. Read More

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Effective decontamination of Ca and Mg hardness from groundwater using innovative muscovite based sodalite in batch and fixed-bed column studies; dynamic and equilibrium studies.

J Contam Hydrol 2021 May 3;241:103817. Epub 2021 May 3.

Geology Department, Faculty of Science, Beni-Suef University, Beni-Suef 65211, Egypt; Materials Technologies and their Applications Lab, Geology Department, Faculty of Science, Beni-Suef University, Beni-Suef, Egypt. Electronic address:

A novel form of sodalite was synthesized from muscovite (M.SD) as low-cost softening material for both Ca and Mg ions from real groundwater in batch and column studies. The sodalite sample showed significant surface area (105 m/g) and ion exchange capacity (87. Read More

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