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Chemosphere Feb 2024In this study, the magnesium oxide (MgO)-based adsorbents [granulated MgO aggregates (GA-MgO) and surface-modified MgO powder (SM-MgO)] were developed to remediate a...
In this study, the magnesium oxide (MgO)-based adsorbents [granulated MgO aggregates (GA-MgO) and surface-modified MgO powder (SM-MgO)] were developed to remediate a fluoride-contaminated groundwater site. Both GA-MgO and SM-MgO had porous, spherical, and crystalline structures. Diameters for GA-MgO and SM-MgO were 1-1.7 mm and 1-10 μm, respectively. The pseudo second-order dynamic adsorption and the Freundlich isotherm could be applied to express the chemical adsorption phenomena. The monolayer adsorption was the dominant mechanism at the initial adsorption period. During the latter part of fluoride adsorption, the multilayer adsorption became the dominant mechanism for fluoride removal from the water phase, which also resulted in the increased adsorption capacity. Higher hydroxide, phosphate, and carbonate concentrations caused a decreased fluoride removal efficiency due to the competition of sorption sites between fluoride and other anions with similar electronic properties. Fluoride removal mechanism using GA-MgO and SM-MgO as the adsorbents was mainly carried out by the chemical adsorption. Reaction paths contained two main processes: (1) formation of magnesium hydroxide after the reaction of MgO with water, and (2) the hydroxyl group of the magnesium hydroxide was replaced by fluoride ions to form magnesium fluoride precipitation. Results from column tests show that up to 61 and 73% of fluoride removal (initial fluoride concentration = 9.3 mg/L) could be obtained after 50 pore volumes of groundwater pumping with GA-MgO and SM-MgO injection, respectively. The GA-MgO system could be applied to contain and remediate fluoride-contaminated groundwater, and SM-MgO could be applied as an immediate fluoride removal alternative to achieve a rapid pollutant removal for emergency responses. Up to 71% of fluoride removal (fluoride concentration = 10.8 mg/L) could be obtained with GA-MgO injection after 30 days of operation. The developed GA-MgO system is a potential and green remediation alternative to contain the fluoride plume significantly.
Topics: Magnesium Oxide; Fluorides; Magnesium Hydroxide; Water Pollutants, Chemical; Adsorption; Groundwater; Water; Kinetics; Hydrogen-Ion Concentration
PubMed: 38160954
DOI: 10.1016/j.chemosphere.2023.141035 -
Electrolyte & Blood Pressure : E & BP Dec 2023Hypermagnesemia is a rare but potentially fatal electrolyte disorder often overlooked because of its unfamiliarity. Magnesium is regulated through a balance of bone,...
Hypermagnesemia is a rare but potentially fatal electrolyte disorder often overlooked because of its unfamiliarity. Magnesium is regulated through a balance of bone, intestinal absorption, and renal excretion. Hypermagnesemia typically arises from excessive magnesium intake or reduced renal excretion; however, it also occurs in patients with normal kidney function. Herein, we report two cases of hypermagnesemia in patients taking magnesium hydroxide for constipation. The first case involved an 82-year-old woman with end-stage renal disease who developed metabolic encephalopathy due to hypermagnesemia, after taking 3,000 mg of magnesium hydroxide daily for constipation. Her magnesium level was 9.9 mg/dL. Her treatment involved discontinuing magnesium hydroxide and continuing hemodialysis, which led to her recovery. In the second case, a 50-year-old woman with a history of cerebral hemorrhage and mental retardation developed hypermagnesemia despite having normal renal function. She was also taking magnesium hydroxide for constipation, and her magnesium level was 11.0 mg/dL. She experienced cardiac arrest while preparing for continuous renal replacement therapy (CRRT). After achieving return of spontaneous circulation, CRRT was initiated, and her magnesium level showed a decreasing trend. However, vital signs and lactate levels did not recover, leading to death. These cases highlight the importance of prompt diagnosis and intervention for hypermagnesemia and the need to regularly monitor magnesium levels in individuals receiving magnesium-containing preparations, especially those with impaired kidney function.
PubMed: 38152602
DOI: 10.5049/EBP.2023.21.2.66 -
Small (Weinheim An Der Bergstrasse,... Jun 2024Achieving satisfactory bone tissue regeneration in osteoporotic patients with ordinary biomaterials is challenging because of the decreased bone mineral density and...
Achieving satisfactory bone tissue regeneration in osteoporotic patients with ordinary biomaterials is challenging because of the decreased bone mineral density and aberrant bone microenvironment. In addressing this issue, a biomimetic scaffold (PMEH/SP), incorporating 4-hexylresorcinol (4HR), and substance P (SP) into the poly(lactic-go-glycolic acid) (PLGA) scaffold with magnesium hydroxide (M) and extracellular matrix (E) is introduced, enabling the consecutive release of bioactive agents. 4HR and SP induced the phosphorylation of p38 MAPK and ERK in human umbilical vein endothelial cells (HUVECs), thereby upregulating VEGF expression level. The migration and tube-forming ability of endothelial cells can be promoted by the scaffold, which accelerates the formation and maturation of the bone. Moreover, 4HR played a crucial role in the inhibition of osteoclastogenesis by interrupting the IκB/NF-κB signaling pathway and exhibiting SP, thereby enhancing the migration and angiogenesis of HUVECs. Based on such a synergistic effect, osteoporosis can be suppressed, and bone regeneration can be achieved by inhibiting the RANKL pathway in vitro and in vivo, which is a commonly known mechanism of bone physiology. Therefore, the study presents a promising approach for developing a multifunctional regenerative material for sophisticated osteoporotic bone regeneration.
Topics: Bone Regeneration; Humans; Polylactic Acid-Polyglycolic Acid Copolymer; Human Umbilical Vein Endothelial Cells; Tissue Scaffolds; Osteoporosis; Animals; Biomimetic Materials; Osteogenesis
PubMed: 38143290
DOI: 10.1002/smll.202310734 -
International Journal of Clinical... Sep 2023To evaluate and compare the cytotoxicity and antimicrobial activity of various inorganic metal oxide nanoparticles along with vehicles when used as intracanal...
AIM AND OBJECTIVE
To evaluate and compare the cytotoxicity and antimicrobial activity of various inorganic metal oxide nanoparticles along with vehicles when used as intracanal medicaments in the root canal system.
MATERIALS AND METHODS
The study included triplicates ( = 36 times) that were subjected to n calcium oxide (CaO), zinc oxide (ZnO), magnesium oxide (MgO), and metapaste as intracanal medicaments. The efficacy of novel intracanal medicaments was evaluated for biocompatibility assay using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) reagent following antimicrobial efficacy against ( was evaluated using zone of inhibition (ZOI) and minimum inhibitory concentration (MIC). The statistical analysis Kruskal-Wallis test, student -test, and analysis of variance (ANOVA) using Statistical Package for the Social Sciences (SPSS) software (v.20.0).
RESULTS
The order of proliferative activity of experimental groups on L929 mouse fibroblast cells using MTT assay was: metapaste > CaO > MgO > ZnO). After evaluation of antimicrobial efficacy, group I: CaO showed maximum ZOI and MIC against which showed high statistically significant differences between all four groups after ANOVA ( < 0.0001*).
CONCLUSION
calcium oxide (CaO) mixed with propylene glycol (PPG) 400 has a potential role as an intracanal medicament with minimum cytotoxic effect and maximum antimicrobial activity against endodontic pathogens.
CLINICAL SIGNIFICANCE
Nanoparticles-based intracanal medicament can provide a promising future in reducing endodontic flareups when used as intracanal medicament.
HOW TO CITE THIS ARTICLE
Barge P, Gugawad S, Devendrappa SN, Comparative Evaluation of Nano Inorganic Metal Oxides as Intracanal Medicaments for Cytotoxicity and Antimicrobial Activity in the Root Canal System. Int J Clin Pediatr Dent 2023;16(S-2):S168-S175.
PubMed: 38078022
DOI: 10.5005/jp-journals-10005-2635 -
Materials (Basel, Switzerland) Nov 2023Large amounts of chloride ions (Cl) and sulfate ions (SO) are present in salt-washing wastewater, making it unsuitable for direct release. Adsorption can be used to...
Large amounts of chloride ions (Cl) and sulfate ions (SO) are present in salt-washing wastewater, making it unsuitable for direct release. Adsorption can be used to eliminate Cl and SO from salt-washing wastewater, and hydrotalcite is an excellent adsorbent with high adsorption properties for these ions because of a layered bimetallic hydroxide structure. The selective extraction of various metals, such as calcium, magnesium, aluminum, and iron, from steel slag via acid leaching facilitates the utilization of steel slag in the preparation of hydrotalcite. In this study, the leaching mechanism of metal in steel slag was investigated using steel slag as a raw material and acetic acid as the reaction medium. The study obtained the optimal leaching mechanism for preparing hydrotalcite. Hydrotalcite was synthesized from the steel slag leaching solution by hydrothermal synthesis, and its structure was characterized. The adsorption performance of Cl and SO in salt-washing wastewater was investigated by solution adsorption experiments. The removal rates of Cl and SO in salt-washing wastewater reached 12.8% and 38.0%, respectively. After multiple adsorption cycles, the removal rates increased to 98.0% for Cl and 96.4% for SO.
PubMed: 38068146
DOI: 10.3390/ma16237402 -
Advanced Science (Weinheim,... Feb 2024Rheumatoid arthritis (RA) is a chronic autoimmune disease featuring an abnormal immune microenvironment and resultant accumulation of hydrogen ions (H ) produced by...
Rheumatoid arthritis (RA) is a chronic autoimmune disease featuring an abnormal immune microenvironment and resultant accumulation of hydrogen ions (H ) produced by activated osteoclasts (OCs). Currently, clinic RA therapy can hardly achieve sustained or efficient therapeutic outcomes due to the failures in generating sufficient immune modulation and manipulating the accumulation of H that deteriorates bone damage. Herein, a highly effective immune modulatory nanocatalytic platform, nanoceria-loaded magnesium aluminum layered double hydroxide (LDH-CeO ), is proposed for enhanced immune modulation based on acid neutralization and metal ion inherent bioactivity. Specifically, the mild alkaline LDH initiates significant M2 repolarization of macrophages triggered by the elevated antioxidation effect of CeO via neutralizing excessive H in RA microenvironment, thus resulting in the efficient recruitment of regulatory T cell (Treg) and suppressions on T helper 17 cell (Th 17) and plasma cells. Moreover, the osteogenic activity is stimulated by the Mg ion released from LDH, thereby promoting the damaged bone healing. The encouraging therapeutic outcomes in adjuvant-induced RA model mice demonstrate the high feasibility of such a therapeutic concept, which provides a novel and efficient RA therapeutic modality by the immune modulatory and bone-repairing effects of inorganic nanocatalytic material.
Topics: Mice; Animals; Arthritis, Rheumatoid; Bone and Bones; Macrophages; Osteogenesis; Hydroxides
PubMed: 38064119
DOI: 10.1002/advs.202307094 -
Advanced Science (Weinheim,... Feb 2024In order to repair critical-sized bone defects, various polylactic acid-glycolic acid (PLGA)-based hybrid scaffolds are successfully developed as bone substitutes....
Three Birds, One Stone: An Osteo-Microenvironment Stage-Regulative Scaffold for Bone Defect Repair through Modulating Early Osteo-Immunomodulation, Middle Neovascularization, and Later Osteogenesis.
In order to repair critical-sized bone defects, various polylactic acid-glycolic acid (PLGA)-based hybrid scaffolds are successfully developed as bone substitutes. However, the byproducts of these PLGA-based scaffolds are known to acidify the implanted site, inducing tiresome acidic inflammation. Moreover, these degradation productions cannot offer an osteo-friendly microenvironment at the implanted site, matching natural bone healing. Herein, inspired by bone microenvironment atlas of natural bone-healing process, an osteo-microenvironment stage-regulative scaffold (P80/D10/M10) is fabricated by incorporating self-developed decellularized bone matrix microparticles (DBM-MPs) and multifunctional magnesium hydroxide nanoparticles (MH-NPs) into PLGA with an optimized proportion using low-temperature rapid prototyping (LT-RP) 3D-printing technology. The cell experiments show that this P80/D10/M10 exhibits excellent properties in mechanics, biocompatibility, and biodegradability, meanwhile superior stimulations in osteo-immunomodulation, angiogenesis, and osteogenesis. Additionally, the animal experiments determined that this P80/D10/M10 can offer an osteo-friendly microenvironment in a stage-matched pattern for enhanced bone regeneration, namely, optimization of early inflammation, middle neovascularization, and later bone formation. Furthermore, transcriptomic analysis suggested that the in vivo performance of P80/D10/M10 on bone defect repair is mostly attributed to regulating artery development, bone development, and bone remodeling. Overall, this study reveals that the osteo-microenvironment stage-regulative scaffold provides a promising treatment for bone defect repair.
Topics: Animals; Osteogenesis; Biocompatible Materials; Tissue Scaffolds; Bone Regeneration; Neovascularization, Pathologic; Inflammation; Glycolates
PubMed: 38060833
DOI: 10.1002/advs.202306428 -
Journal of Anaesthesiology, Clinical... 2023The management of post-operative pain after surgical repair of pectus excavatum with the Ravitch procedure is challenging. Although previous studies have compared...
BACKGROUND AND AIMS
The management of post-operative pain after surgical repair of pectus excavatum with the Ravitch procedure is challenging. Although previous studies have compared various methods of pain control in these patients, few have compared different local anesthetics. This retrospective analysis compares the use of bupivacaine to its longer-acting form, liposomal bupivacaine, in patients who had undergone pectus excavatum repair with the Ravitch method.
MATERIAL AND METHODS
Eleven patients who received local infiltration with liposomal bupivacaine were matched to 11 patients who received local infiltration utilizing bupivacaine with epinephrine. The primary outcome was total morphine milligram equivalents per kilogram body weight (MME/kg) over the complete length of hospital stay. Secondary outcomes included total cumulative diazepam, acetaminophen, ondansetron, and NSAID dose per kilogram body weight (mg/kg) over the course of the hospital stay, chest tube drainage (ml/kg body weight), number of post-operative hours until the first bowel movement, Haller Index, patient request for magnesium hydroxide, average pain scores from post-operative day 1 to post-operative day 5, and length of hospital stay. Continuous variables were reported as medians with inter-quartile ranges, and categorical values were reported as percentages and frequencies.
RESULTS
The total MME/kg [1.7 (1.2-2.4) vs 2.9 (2.0-3.9), = 0.007] and hydromorphone (mg/kg) [0.1 (0.0-0.2) vs 0.3 (0.1-0.4), = 0.006] use in the liposomal bupivacaine group versus bupivacaine with epinephrine was significantly reduced over total length of hospital stay. Similarly, there was a reduction in diazepam use in the liposomal bupivacaine group versus the bupivacaine group [0.4 (0.1-0.8) vs 0.6 (0.4-0.7), = 0.249], but this did not reach statistical significance. The total dose of ondansetron (mg/kg) was not statistically different when comparing the liposomal bupivacaine group to the bupivacaine group [0.3 (0.0-0.5) vs 0.3 (0.2-0.6), = 0.332]. Interestingly, the total dose of acetaminophen (mg/kg) was statistically increased in the liposomal bupivacaine group compared to the bupivacaine with epinephrine group [172 (138-183) vs 74 (55-111), = 0.007]. Additionally, the total chest tube drainage (ml/kg) was significantly reduced in the liposomal bupivacaine group [9.3 (7.5-10.6) vs 12.8 (11.3-18.5), = 0.027]. Finally, the percentage of patients without requests for magnesium hydroxide to promote laxation was significantly higher in the liposomal bupivacaine group than in the bupivacaine group (63.6% vs 18.2%, = 0.027).
CONCLUSION
The use of liposomal bupivacaine for local infiltration in patients who undergo the Ravitch procedure for pectus repair offers advantages over plain bupivacaine, including reduced opioid consumption and opioid-related side effects. However, more data are needed to understand the significance of these findings.
PubMed: 38025581
DOI: 10.4103/joacp.joacp_336_21 -
Polymers Nov 2023The thermal decomposition product of magnesium hydroxide (MH) is magnesium oxide (MgO), which serves as the foundational material for fireproof layer construction in the...
The thermal decomposition product of magnesium hydroxide (MH) is magnesium oxide (MgO), which serves as the foundational material for fireproof layer construction in the condensed phase. However, the weak interaction force between particles of MgO generated by thermal decomposition leads to the insufficient strength and poor adhesion ability of the fireproof layer. The fireproof layer was easily damaged and detached in this study, resulting in the low flame-retardant efficiency of MH. In this work, polycarbosilane (PCS) and divinyl benzene (DVB) were used to modify MH, and EVA/MH/PCS/DVB composites were made via melt blending. The flame-retardant properties of EVA/MH/PCS/DVB were evaluated using the limiting oxygen index (LOI), vertical combustion (UL-94), and a cone calorimeter (CONE). The thermal stability of the composites and flame retardants was analyzed using a thermogravimetric analyzer. The char layer structure was observed and analyzed using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), respectively. The results indicate that the LOI of the EVA/MH/PCS/DVB with 50 wt.% flame retardants in total was as high as 65.1, which increased by 160% in comparison with EVA/MH. Furthermore, the total smoke production (TSP) of the EVA/MH/PCS/DVB composite decreased by 22.7% compared to EVA/MH/PCS; the thermal stability of the MH/PCS/DVB and EVA/MH/PCS/DVB improved to some extent; and the compact residual char after the combustion of EVA/MH/PCS/DVB had fewer cracks due to the adhesive effect induced by PCS/DVB.
PubMed: 38006164
DOI: 10.3390/polym15224440 -
Journal of Functional Biomaterials Nov 2023In this study, we have developed innovative polymer nanocomposites by integrating magnesium-aluminum layered double hydroxide (LDH)-based nanocarriers modified with...
New Functional Bionanocomposites by Combining Hybrid Host-Guest Systems with a Fully Biobased Poly(lactic acid)/Poly(butylene succinate-co-adipate) (PLA/PBSA) Binary Blend.
In this study, we have developed innovative polymer nanocomposites by integrating magnesium-aluminum layered double hydroxide (LDH)-based nanocarriers modified with functional molecules into a fully biobased poly(lactic acid)/poly(butylene succinate-co-adipate) (PLA/PBSA) matrix. These LDH-based hybrid host-guest systems contain bioactive compounds like rosmarinic acid, ferulic acid, and glycyrrhetinic acid, known for their antioxidant, antimicrobial, and anti-inflammatory properties. The bioactive molecules can be gradually released from the nanocarriers over time, allowing for sustained and controlled delivery in various applications, such as active packaging or cosmetics. The morphological analysis of the polymer composites, prepared using a discontinuous mechanical mixer, revealed the presence of macroaggregates and nano-lamellae at the polymer interface. This resulted in an enhanced water vapor permeability compared to the original blend. Furthermore, the migration kinetics of active molecules from the thin films confirmed a controlled release mechanism based on their immobilization within the lamellar system. Scaling-up experiments evaluated the materials' morphology and mechanical and thermal properties. Remarkably, stretching deformation and a higher shear rate during the mixing process enhanced the dispersion and distribution of the nanocarriers, as confirmed by the favorable mechanical properties of the materials.
PubMed: 37998118
DOI: 10.3390/jfb14110549