RÉSUMÉ
Cadmium (Cd) and arsenic (As) co-contamination has threatened rice production and food safety. It is challenging to mitigate Cd and As contamination in rice simultaneously due to their opposite geochemical behaviors. Mg-loaded biochar with outstanding adsorption capacity for As and Cd was used for the first time to remediate Cd/As contaminated paddy soils. In addition, the effect of zero-valent iron (ZVI) on grain As speciation accumulation in alkaline paddy soils was first investigated. The effect of rice straw biochar (SC), magnesium-loaded rice straw biochar (Mg/SC), and ZVI on concentrations of Cd and As speciation in soil porewater and their accumulation in rice tissues was investigated in a pot experiment. Addition of SC, Mg/SC and ZVI to soil reduced Cd concentrations in rice grain by 46.1%, 90.3% and 100%, and inorganic As (iAs) by 35.4%, 33.1% and 29.1%, respectively, and reduced Cd concentrations in porewater by 74.3%, 96.5% and 96.2%, respectively. Reductions of 51.6% and 87.7% in porewater iAs concentrations were observed with Mg/SC and ZVI amendments, but not with SC. Dimethylarsinic acid (DMA) concentrations in porewater and grain increased by a factor of 4.9 and 3.3, respectively, with ZVI amendment. The three amendments affected grain concentrations of iAs, DMA and Cd mainly by modulating their translocation within plant and the levels of As(III), silicon, dissolved organic carbon, iron or Cd in porewater. All three amendments (SC, Mg/SC and ZVI) have the potential to simultaneously mitigate Cd and iAs accumulation in rice grain, although the pathways are different.
Sujet(s)
Arsenic , Cadmium , Charbon de bois , Magnésium , Oryza , Polluants du sol , Sol , Oryza/composition chimique , Cadmium/analyse , Cadmium/composition chimique , Charbon de bois/composition chimique , Polluants du sol/analyse , Arsenic/analyse , Sol/composition chimique , Magnésium/composition chimique , Fer/composition chimique , Assainissement et restauration de l'environnement/méthodesRÉSUMÉ
Osteosarcoma, a malignant bone tumor often characterized by high hedgehog signaling activity, residual tumor cells, and substantial bone defects, poses significant challenges to both treatment response and postsurgical recovery. Here, we developed a nanocomposite hydrogel for the sustained co-delivery of bioactive magnesium ions, anti-PD-L1 antibody (αPD-L1), and hedgehog pathway antagonist vismodegib, to eradicate residual tumor cells while promoting bone regeneration post-surgery. In a mouse model of tibia osteosarcoma, this hydrogel-mediated combination therapy led to remarkable tumor growth inhibition and hence increased animal survival by enhancing the activity of tumor-suppressed CD8+ T cells. Meanwhile, the implanted hydrogel improved the microenvironment of osteogenesis through long-term sustained release of Mg2+, facilitating bone defect repair by upregulating the expression of osteogenic genes. After 21 days, the expression levels of ALP, COL1, RUNX2, and BGLAP in the Vis-αPD-L1-Gel group were approximately 4.1, 5.1, 5.5, and 3.4 times higher than those of the control, respectively. We believe that this hydrogel-based combination therapy offers a potentially valuable strategy for treating osteosarcoma and addressing the tumor-related complex bone diseases.
Sujet(s)
Tumeurs osseuses , Hydrogels , Immunothérapie , Nanocomposites , Ostéosarcome , Ostéosarcome/anatomopathologie , Ostéosarcome/traitement médicamenteux , Ostéosarcome/thérapie , Animaux , Hydrogels/composition chimique , Nanocomposites/composition chimique , Tumeurs osseuses/traitement médicamenteux , Tumeurs osseuses/anatomopathologie , Tumeurs osseuses/thérapie , Souris , Immunothérapie/méthodes , Lignée cellulaire tumorale , Régénération osseuse/effets des médicaments et des substances chimiques , Humains , Ostéogenèse/effets des médicaments et des substances chimiques , Antigène CD274/métabolisme , Souris de lignée BALB C , Magnésium/composition chimiqueRÉSUMÉ
Hardness is one of the basic parameters of water, and a high-level hardness of drinking water may be harmful to human health. Thus, it is very important to monitor drinking water hardness. In this work, a portable lateral flow distance-based paper sensor for the semi-quantitative detection of drinking water hardness is demonstrated. In the presence of Ca2+/Mg2+, the hydrogel can be formed via the chelation between sodium alginate and Ca2+/Mg2+, inducing a phase separation process. The viscosity change of the sodium alginate solution is directly related to the Ca2+/Mg2+ concentration and can be determined by the water lateral flow distance on test strips. The sensor successfully realizes the quantification of Ca2+ and Mg2+ in the range of 0-10 mmol L-1 and 4-20 mmol L-1, respectively. The recoveries are found varied from 95% to 108.9%. The water hardness is acceptable for drinking if the Cr values lies in the range of 0.259 to 0.419, and it is high with the Cr value above 0.595. Remarkably, the performance of the sensor is comparable with the commercial kit for real water samples, which avoids the subjective judgment. Overall, this method provides a portable approach for semi-quantitative detection of drinking water hardness with the merits of convenience and low cost, which shows great potential for the potential application.
Sujet(s)
Calcium , Eau de boisson , Magnésium , Papier , Eau de boisson/analyse , Eau de boisson/composition chimique , Magnésium/analyse , Calcium/analyse , Alginates/composition chimique , Alginates/analyse , Viscosité , Dureté , HumainsRÉSUMÉ
Thyroid cancer is the most frequently observed endocrine-related malignancy among which anaplastic thyroid cancer (ATC) is the most fatal subtype. The synthesis of protein is active to satisfy the rapid growth of ATC tumor, but the mechanisms regulating protein synthesis are still unknown. Our research revealed that kinetochore protein NUF2 played an essential role in protein synthesis and drove the progression of ATC. The prognosis of patients with thyroid carcinoma was positively correlated with high NUF2 expression. Depletion of NUF2 in ATC cells notably inhibited the proliferation and induced apoptosis, while overexpression of NUF2 facilitated ATC cell viability and colony formation. Deletion of NUF2 significantly suppressed the growth and metastasis of ATC in vivo. Notably, knockdown of NUF2 epigenetically inhibited the expression of magnesium transporters through reducing the abundance of H3K4me3 at promoters, thereby reduced intracellular Mg2+ concentration. Furthermore, we found the deletion of NUF2 or magnesium transporters significantly inhibited the protein synthesis mediated by the PI3K/Akt/mTOR pathway. In conclusion, NUF2 functions as an emerging regulator for protein synthesis by maintaining the homeostasis of intracellular Mg2+, which finally drives ATC progression.
Sujet(s)
Évolution de la maladie , Homéostasie , Magnésium , Carcinome anaplasique de la thyroïde , Humains , Carcinome anaplasique de la thyroïde/métabolisme , Carcinome anaplasique de la thyroïde/anatomopathologie , Carcinome anaplasique de la thyroïde/génétique , Magnésium/métabolisme , Lignée cellulaire tumorale , Animaux , Prolifération cellulaire , Biosynthèse des protéines , Souris , Tumeurs de la thyroïde/anatomopathologie , Tumeurs de la thyroïde/métabolisme , Tumeurs de la thyroïde/génétique , Souris nude , Transporteurs de cations/métabolisme , Transporteurs de cations/génétique , Femelle , Mâle , Régulation de l'expression des gènes tumoraux , Apoptose , Transduction du signal , Protéines du cycle cellulaire/métabolisme , Protéines du cycle cellulaire/génétique , Sérine-thréonine kinases TOR/métabolisme , Protéines proto-oncogènes c-akt/métabolismeRÉSUMÉ
BACKGROUND: Systemic Lupus Erythematosus (SLE) has a strong genetic susceptibility, but little is known about the impact of diet on disease severity. The Western diet is typically deficient in magnesium (Mg), and given the immunomodulatory effects of Mg, we hypothesized that the low Mg intake increases disease risk and that increasing Mg intake would reduce severity of murine lupus. Here, we placed 12-week old MRL/lpr female lupus mice on a normal (Mg500) or a high (Mg2800) Mg diet for 9 weeks. Urine and blood were collected during the study for quantification of urinary albumin, BUN, anti-dsDNA antibodies, and immune phenotyping. RESULTS: MRL/lpr lupus mice on high Mg2800 diet had significantly fewer skin lesions and less severe skin histology score, and reduced levels of pathogenic anti-dsDNA antibodies, compared with the Mg500 group (143.8±75.0 vs. 47.4±36.2 × 106U/ml; P < 0.05). The high Mg2800 group had a nearly two-fold increase in the percentage of CD4+FOXP3+ Treg cells compared to controls (19.9±5.4 vs. 11.4±5.5%; P < 0.05). Treg percentages inversely correlated with the concentration of anti-dsDNA. None of the mice developed arthritis during the observation period and there were no significant differences in weight, proteinuria, BUN or kidney histology. CONCLUSION: In conclusion, oral supplementation of Mg has a protective effect in a murine lupus model and may represent an inexpensive and safe adjuvant in the treatment of SLsE.
Sujet(s)
Anticorps antinucléaires , Lupus érythémateux disséminé , Magnésium , Lymphocytes T régulateurs , Animaux , Lupus érythémateux disséminé/immunologie , Femelle , Souris , Anticorps antinucléaires/immunologie , Anticorps antinucléaires/sang , Magnésium/administration et posologie , Lymphocytes T régulateurs/immunologie , Modèles animaux de maladie humaine , Administration par voie orale , Souris de lignée MRL lpr , Autoanticorps/immunologie , Autoanticorps/sang , Peau/anatomopathologie , Peau/immunologie , Peau/effets des médicaments et des substances chimiques , Maladies de la peau/immunologie , Maladies de la peau/traitement médicamenteux , Maladies de la peau/anatomopathologieRÉSUMÉ
Background: Bone fractures represent a significant health issue and impose a considerable burden on healthcare systems globally. However, data pertaining to bone fractures, especially among reproductive-age women in Malaysia, are very limited. Micronutrients like calcium, magnesium and phosphorus play vital roles in bone health, influencing bone mineral density and fracture risk. The objective of this study was to determine the prevalence of bone fractures among reproductive-age women and the association with dietary micronutrient intakes. Methods: In this cross-sectional study, a total of 1,730 participants of reproductive-age women from the Malaysia Prospective Urban and Rural Epidemiological (PURE) study were recruited. The participants' dietary intakes were assessed using a validated semi-quantitative food frequency questionnaire (FFQ). Selected micronutrients in the participants' diets were calculated using the Malaysian food composition and the US Department of Agriculture food composition databases. The association between micronutrient intakes, comorbidities and physical activity levels with bone fractures were evaluated to identify predictors of bone fractures among reproductive-age women. Results: The prevalence of bone fractures among Malaysian reproductive-age women was low (3.7%). The multiple logistic regression analysis showed that none of the micronutrients was associated with bone fractures. However, factors of diabetes and passive smoking in this study showed 2.6- and 4.0-times-higher odds of having bone fractures, respectively (AOR 2.580; 95% CI: 1.173-5.672) and (AOR 4.012; 95% CI: 2.265-7.107). Conclusions: It was found that the majority of women in this study were taking lower micronutrient intakes of calcium, magnesium, and vitamin K than the Malaysia recommended nutrient intakes (RNI). Although this study showed that a low micronutrient intake is not significantly associated with bone fractures, it is recommended that future studies focus on controlled trials or prospective data analyses to establish causal relationships and the optimal micronutrient requirements for maintaining strong and healthy bones in women of reproductive age.
Sujet(s)
Régime alimentaire , Fractures osseuses , Micronutriments , Humains , Malaisie/épidémiologie , Femelle , Micronutriments/administration et posologie , Adulte , Études transversales , Fractures osseuses/épidémiologie , Prévalence , Jeune adulte , Magnésium/administration et posologie , Études prospectives , Adulte d'âge moyen , Exercice physique , Modèles logistiques , Facteurs de risqueRÉSUMÉ
While decreased renal function is a known risk factor for hypermagnesemia caused by magnesium oxide (MgO), few studies have comprehensively investigated other contributing factors. In this study, the researchers analyzed the risk factors for hypermagnesemia development in 256 inpatients receiving MgO treatment at the Matsuyama Shimin Hospital. Multivariate analysis identified blood urea nitrogen â§22 mg/dL, estimated glomerular filtration rate â¦43.1 mL/min, and MgO â§1000 mg/d as risk factors. Additionally, the researchers' findings suggest a correlation between the number of risk factors and the incidence of hypermagnesemia, including the prevalence of Grade 3 cases. Interestingly, low body mass index emerged as a potential risk factor even in patients without the three identified factors. These findings highlight the importance for pharmacists to advocate for routine serum Mg level monitoring in patients with the risk factors identified in this study.
Sujet(s)
Azote uréique sanguin , Indice de masse corporelle , Oxyde de magnésium , Magnésium , Oxyde de magnésium/effets indésirables , Oxyde de magnésium/administration et posologie , Humains , Facteurs de risque , Magnésium/sang , Femelle , Mâle , Sujet âgé , Débit de filtration glomérulaire , Adulte d'âge moyen , Sujet âgé de 80 ans ou plus , Analyse multifactorielle , AdulteSujet(s)
Implant résorbable , Magnésium , Humains , Résultat thérapeutique , Structures d'échafaudage tissulaires , Intervention coronarienne percutanée/instrumentation , Intervention coronarienne percutanée/méthodes , Maladie des artères coronaires/thérapie , Maladie des artères coronaires/chirurgie , Mâle , Conception de prothèse , Femelle , Adulte d'âge moyen , Endoprothèses à élution de substancesRÉSUMÉ
BACKGROUND: Pediatric palliative care (PPC) patients are at an elevated risk of malnutrition. Nutritional inadequacy can also cause micronutrient deficiencies. These factors can lead to weight loss, stunted growth, and poor quality of life. Despite the prevalence of these issues, limited research exists in the micronutrient status of PPC patients. The purpose of this study was to determine the vitamin B12 and D, iron, ferritin, folate, calcium, phosphorus, and magnesium levels of PPC patients to contribute to a better understanding of their micronutrient needs as well as the appropriate management of diet and treatment approaches. METHODS: This was a single-center observational cross-sectional retrospective study. This study evaluated the levels of vitamin B12, 25-hydroxyvitamin D, iron, ferritin, folate, calcium, phosphorus, and magnesium in PPC patients. The patients were classified according to the Chronic Complex Conditions (CCC) v2 and then compared. RESULTS: A total of 3,144 micronutrient data points were collected from 822 hospitalizations of 364 patients. At least one micronutrient deficiency was identified in 96.9% of the patients. The most prevalent deficiencies were observed for iron, calcium, and phosphate. In addition, 25-hydroxyvitamin D deficiency was observed in one-third of patients. Calcium, magnesium, phosphorus, folate, and 25-hydroxyvitamin D were negatively correlated with age. CONCLUSION: The results of this study indicate that micronutrient deficiencies are highly prevalent in PPC patients. These findings have the potential to contribute to improvements in the nutritional and therapeutic management of patients.
Sujet(s)
Calcium , Ferritines , Fer , Magnésium , Soins palliatifs , Phosphore , Vitamine D , Humains , Études transversales , Femelle , Mâle , Magnésium/sang , Phosphore/sang , Soins palliatifs/méthodes , Soins palliatifs/normes , Enfant d'âge préscolaire , Études rétrospectives , Enfant , Ferritines/sang , Vitamine D/sang , Vitamine D/analogues et dérivés , Calcium/sang , Fer/sang , Acide folique/sang , Nourrisson , Vitamine B12/sang , AdolescentRÉSUMÉ
Succinic acid (SA), a dicarboxylic acid of industrial importance, can be efficiently produced by metabolically engineered Mannheimia succiniciproducens. Although the importance of magnesium (Mg2+) ion on SA production has been evident from our previous studies, the role of Mg2+ ion remains largely unexplored. In this study, we investigated the impact of Mg2+ ion on SA production and developed a hyper-SA producing strain of M. succiniciproducens by reconstructing the Mg2+ ion transport system. To achieve this, optimal alkaline neutralizer comprising Mg2+ ion was developed and the physiological effect of Mg2+ ion was analyzed. Subsequently, the Mg2+ ion transport system was reconstructed by introducing an efficient Mg2+ ion transporter from Salmonella enterica. A high-inoculum fed-batch fermentation of the final engineered strain produced 152.23 ± 0.99 g/L of SA, with a maximum productivity of 39.64 ± 0.69 g/L/h. These findings highlight the importance of Mg2+ ions and transportation system optimization in succinic acid production by M. succiniciproducens.
Sujet(s)
Fermentation , Magnésium , Mannheimia , Acide succinique , Acide succinique/métabolisme , Magnésium/métabolisme , Mannheimia/métabolisme , Mannheimia/génétique , Génie métabolique/méthodes , Protéines bactériennes/métabolisme , Protéines bactériennes/génétique , Transporteurs de cations/métabolisme , Transporteurs de cations/génétiqueRÉSUMÉ
Traditional chemotherapy drugs for cervical cancer often cause significant toxic side effects and drug resistance problems, highlighting the urgent need for more innovative and effective treatment strategies. Magnesium alloy is known to be degradable and biocompatible. The release of degradation products Mg2+, OH-, and H2 from magnesium alloy can alter the tumor microenvironment, providing potential anti-tumor properties. We explored the innovative use of magnesium alloy biomaterials in the treatment of cervical cancer, investigating how various concentrations of Mg2+ on the proliferation and cell death of cervical cancer cells. The results revealed that varying concentrations of Mg2+ significantly inhibited cervical cancer by arresting the cell cycle in the G0/G1 phase and inducing apoptosis in SiHa cells, effectively reducing tumor cell proliferation. In vivo experiments demonstrated that 20 mM Mg2+ group had the smallest tumor volume, exhibiting a potent inhibitory effect on the biological characteristics of cervical cancer. This enhances the therapeutic potential of this biomaterial as a local anti-tumor therapy and lays a theoretical foundation for the potential application of magnesium in the treatment of cervical cancer.
Sujet(s)
Apoptose , Matériaux biocompatibles , Prolifération cellulaire , Magnésium , Tumeurs du col de l'utérus , Tumeurs du col de l'utérus/traitement médicamenteux , Tumeurs du col de l'utérus/anatomopathologie , Tumeurs du col de l'utérus/métabolisme , Femelle , Magnésium/pharmacologie , Magnésium/composition chimique , Humains , Prolifération cellulaire/effets des médicaments et des substances chimiques , Animaux , Apoptose/effets des médicaments et des substances chimiques , Lignée cellulaire tumorale , Matériaux biocompatibles/pharmacologie , Matériaux biocompatibles/composition chimique , Souris , Antinéoplasiques/pharmacologie , Antinéoplasiques/composition chimique , Alliages/pharmacologie , Alliages/composition chimique , Tests d'activité antitumorale sur modèle de xénogreffe , Cycle cellulaire/effets des médicaments et des substances chimiquesRÉSUMÉ
Magnesium, an essential mineral for various physiological functions, is subject to tight regulation within the body. Understanding its absorption across epithelial cell monolayers is crucial for optimizing dietary magnesium intake and therapeutic strategies. The Caco-2 monolayer model, widely recognized for its relevance to the human intestinal epithelium, provides a suitable platform for this investigation. This protocol covers the step-by-step procedures for the cultivation of Caco-2 monolayer preparation of transwell systems. It provides guidance on the setup of magnesium transport experiments, which involve the application of magnesium salts to the apical side of the Caco-2 monolayer and monitoring their transport to the basolateral side.
Sujet(s)
Muqueuse intestinale , Magnésium , Humains , Cellules Caco-2 , Muqueuse intestinale/métabolisme , Magnésium/métabolisme , Perméabilité , Transport biologique , Techniques de culture cellulaire/méthodes , Absorption intestinale/effets des médicaments et des substances chimiques , Sels/métabolismeRÉSUMÉ
Neurodegenerative diseases represent an increasing economic, social, and, above all, medical burden worldwide. The second most prevalent disease in this category is Parkinson's disease, surpassed only by Alzheimer's. It is a treatable but still incurable systemic disease with a pathogenesis that has not yet been elucidated. Several theories are currently being developed to explain the causes and progression of Parkinson's disease. Magnesium is one of the essential macronutrients and is absolutely necessary for life as we know it. The magnesium cation performs several important functions in the cell in the context of energetic metabolism, substrate metabolism, cell signalling, and the regulation of the homeostasis of other ions. Several of these cellular processes have been simultaneously described as being disrupted in the development and progression of Parkinson's disease. The relationship between magnesium homeostasis and the pathogenesis of Parkinson's disease has received little scientific attention to date. The aim of this review is to summarise and critically evaluate the current state of knowledge on the possible role of magnesium in the pathogenesis of Parkinson's disease and to outline possible future directions for research in this area.
Sujet(s)
Magnésium , Maladie de Parkinson , Maladie de Parkinson/métabolisme , Maladie de Parkinson/anatomopathologie , Humains , Magnésium/métabolisme , Homéostasie , AnimauxRÉSUMÉ
The choice of dialysate buffer in hemodialysis is crucial, with acetate being widely used despite complications. Citrate has emerged as an alternative because of its favorable effects, yet concerns persist about its impact on calcium and magnesium levels. This study investigates the influence of citrate dialysates (CDs) with and without additional magnesium supplementation on CKD-MBD biomarkers and assesses their ability to chelate divalent metals compared to acetate dialysates (ADs). A prospective crossover study was conducted in a single center, involving patients on thrice-weekly online hemodiafiltration (HDF). The following four dialysates were compared: two acetate-based and two citrate-based. Calcium, magnesium, iPTH, iron, selenium, cadmium, copper, zinc, BUN, albumin, creatinine, bicarbonate, and pH were monitored before and after each dialysis session. Seventy-two HDF sessions were performed on eighteen patients. The CDs showed stability in iPTH levels and reduced post-dialysis total calcium, with no significant increase in adverse events. Magnesium supplementation with CDs prevented hypomagnesemia. However, no significant differences among dialysates were observed in the chelation of other divalent metals. CDs, particularly with higher magnesium concentrations, offer promising benefits, including prevention of hypomagnesemia and stabilization of CKD-MBD parameters, suggesting citrate as a viable alternative to acetate. Further studies are warranted to elucidate long-term outcomes and optimize dialysate formulations. Until then, given our results, we recommend that when a CD is used, it should be used with a 0.75 mmol/L Mg concentration rather than a 0.5 mmol/L one.
Sujet(s)
Acétates , Acide citrique , Études croisées , Hémodiafiltration , Magnésium , Humains , Mâle , Femelle , Hémodiafiltration/méthodes , Adulte d'âge moyen , Magnésium/administration et posologie , Sujet âgé , Études prospectives , Solutions de dialyse/composition chimique , CalciumRÉSUMÉ
Synthetic DNA motifs form the basis of nucleic acid nanotechnology. The biochemical and biophysical properties of these motifs determine their applications. Here, we present a detailed characterization of switchback DNA, a globally left-handed structure composed of two parallel DNA strands. Compared to a conventional duplex, switchback DNA shows lower thermodynamic stability and requires higher magnesium concentration for assembly but exhibits enhanced biostability against some nucleases. Strand competition and strand displacement experiments show that component sequences have an absolute preference for duplex complements instead of their switchback partners. Further, we hypothesize a potential role for switchback DNA as an alternate structure in sequences containing short tandem repeats. Together with small molecule binding experiments and cell studies, our results open new avenues for switchback DNA in biology and nanotechnology.
Sujet(s)
ADN , Conformation d'acide nucléique , Thermodynamique , ADN/composition chimique , ADN/métabolisme , Magnésium/composition chimique , Magnésium/métabolisme , Nanotechnologie/méthodes , HumainsRÉSUMÉ
Miyoshi myopathy/dysferlinopathy (MMD) is a rare muscle disease caused by DYSF gene mutations. Apart from skeletal muscles, DYSF is also expressed in the brain. However, the impact of MMD-causing DYSF variants on brain structure and function remains unexplored. To investigate this, we utilized magnetic resonance (MR) modalities (MR volumetry and 31P MR spectroscopy) in a family with seven children, four of whom have the illness. The MMD siblings showed distinct differences from healthy controls: (1) a significant (p < 0.001) right-sided volume asymmetry (+ 232 mm3) of the inferior lateral ventricles; and (2) a significant (p < 0.001) decrease in [Mg2+], along with a modified energy metabolism profile and altered membrane turnover in the hippocampus and motor and premotor cortices. The patients' [Mg2+], energy metabolism, and membrane turnover measures returned to those of healthy relatives after a month of 400 mg/day magnesium supplementation. This work is the first to describe anatomical and functional abnormalities characteristic of neurodegeneration in the MMD brain. Therefore, we call for further examination of brain functions in larger cohorts of MMD patients and testing of magnesium supplementation, which has proven to be an effective corrective approach in our study.
Sujet(s)
Encéphale , Magnésium , Humains , Mâle , Femelle , Enfant , Encéphale/métabolisme , Encéphale/imagerie diagnostique , Encéphale/anatomopathologie , Magnésium/métabolisme , Dysferline/métabolisme , Dysferline/génétique , Imagerie par résonance magnétique , Métabolisme énergétique , Adolescent , Dystrophies musculaires des ceintures/métabolisme , Dystrophies musculaires des ceintures/anatomopathologie , Dystrophies musculaires des ceintures/génétique , Mutation , Spectroscopie par résonance magnétique , Adulte , Amyotrophie , Myopathies distalesRÉSUMÉ
The Mg-ion battery faces significant limitations due to its liquid electrolyte, which suffers from inherent issues such as leakage and the growth of Mg dendrites. In contrast, gel polymer electrolytes (GPEs) offer heightened safety, a wide voltage window, and excellent flexibility, making them a promising alternative with outstanding electrochemical performance. In this study, a cyano-modified cellulose (CEC) GPE was engineered to aim at enhancing ion transportation and promoting uniform ion-flux through interactions between N and Mg2+ ions. The resulting CEC-based GPE demonstrated a high ionic conductivity of 1.73 mS cm-1 at room temperature. Furthermore, it exhibited remarkable Mg plating/stripping performance (coulombic efficiency â¼96.7 %) and compatibility with electrodes. Importantly, when employed in a Mo6S8//Mg battery configuration, the CEC GPE displayed exceptional cycle stability, with virtually no degradation observed even after 650 cycles at 1C, thereby significantly advancing Mg-ion battery technology due to its excellent electrochemical properties. This study provides valuable insights into the molecular engineering of cellulose-based GPEs.
Sujet(s)
Cellulose , Alimentations électriques , Électrolytes , Gels , Magnésium , Électricité statique , Cellulose/composition chimique , Électrolytes/composition chimique , Gels/composition chimique , Magnésium/composition chimique , Conductivité électrique , Ions/composition chimique , ÉlectrodesRÉSUMÉ
This study evaluated the effect of solvent acids on the structure and corrosion resistance performance of chitosan (CS) film on MAO-treated AZ31B magnesium (Mg) alloy. Initially, CS solutions were prepared in four solvent acids: acetic acid (HAc), lactic acid (LA), hydrochloric acid (HCl), and citric acid (CA). The CS films were subsequently deposited on MAO-treated AZ31B Mg alloy via a dip-coating technique. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction analysis (XRD), Fourier-transform infrared spectroscopy (FT-IR), contact angle measurement, and atomic force microscopy (AFM) were employed to characterize the surface and cross-sectional morphology as well as chemical composition. Furthermore, the samples were subjected to potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) tests to assess their resistance against corrosion in simulated body fluid (SBF). These results indicated that the CS film prepared with LA exhibited the lowest surface roughness (Ra = 31.2 nm), the largest contact angle (CA = 98.50°), and the thickest coating (36 µm). Additionally, it demonstrated superior corrosion protection performance, with the lowest corrosion current density (Icorr = 3.343 × 10-7 A/cm2), highest corrosion potential (Ecorr = -1.49 V), and highest polarization resistance (Rp = 5.914 × 104 Ω·cm2) in SBF. These results indicated that solvent acid types significantly influenced their interactions with CS. Thus, the structure and corrosion protection performance of CS films can be optimized by selecting an appropriate solvent acid.
Sujet(s)
Alliages , Chitosane , Solvants , Chitosane/composition chimique , Corrosion , Alliages/composition chimique , Solvants/composition chimique , Magnésium/composition chimique , Spectroscopie infrarouge à transformée de Fourier , Acides/composition chimique , Propriétés de surface , Diffraction des rayons XRÉSUMÉ
The 10-23 DNAzyme, a catalytic DNA molecule with RNA-cleaving activity, has garnered significant interest for its potential therapeutic applications as a gene-silencing agent. However, the lack of a detailed understanding about its mechanism has hampered progress. A recent structural analysis has revealed a highly organized conformation thanks to the stabilization of specific interactions within the catalytic core of the 10-23 DNAzyme, which facilitate the cleavage of RNA. In this configuration, it has been shown that G14 is in good proximity to the cleavage site which suggests its role as a general base, by activating the 2'-OH nucleophile, in the catalysis of the 10-23 DNAzyme. Also, the possibility of a hydrated metal acting as a general acid has been proposed. In this study, through activity assays, we offer evidence of the involvement of general acid-base catalysis in the mechanism of the 10-23 DNAzyme by analyzing its pH-rate profiles and the role of G14, and metal cofactors like Mg2+ and Pb2+. By substituting G14 with its analogue 2-aminopurine and examining the resultant pH-rate profiles, we propose the participation of G14 in a catalytically relevant proton transfer event, acting as a general base. Further analysis, using Pb2+ as a cofactor, suggests the capability of the hydrated metal ion to act as a general acid. These functional results provide critical insights into the catalytic strategies of RNA-cleaving DNAzymes, revealing common mechanisms among nucleic acid enzymes that cleave RNA.
Sujet(s)
ADN catalytique , ADN catalytique/composition chimique , ADN catalytique/métabolisme , Concentration en ions d'hydrogène , Biocatalyse , Cinétique , Magnésium/composition chimique , Magnésium/métabolisme , Catalyse , Plomb/composition chimique , Plomb/métabolisme , ADN simple brinRÉSUMÉ
BACKGROUND: Periodontal Disease (PD) associated with Type 2 Diabetes Mellitus (T2DM) is a chronic condition that affects the oral cavity of people living with T2DM. The mechanisms of the interaction between type 2 Diabetes Mellitus and Periodontal diseases are complex and involve multiple pathophysiological pathways related to the systemic inflammatory process and oxidative stress. Non-surgical periodontal treatment (NSTP) is considered the standard for the management of this disease; however, patients with systemic conditions such as type 2 Diabetes Mellitus do not seem to respond adequately. For this reason, the use of complementary treatments has been suggested to support non-surgical periodontal treatment to reduce the clinical consequences of the disease and improve the systemic conditions of the patient. The use of zinc gluconate and magnesium oxide as an adjunct to non-surgical periodontal treatment and its effects on periodontal clinical features and oxidative stress in patients with Periodontal diseases -type 2 Diabetes Mellitus is poorly understood. METHODS: A quasi-experimental study was performed in patients with periodontal diseases associated with T2DM. Initially, 45 subjects who met the selection criteria were included. 19 were assigned to a control group [non-surgical periodontal treatment] and 20 to the experimental group (non-surgical periodontal treatment + 500 mg of magnesium oxide and 50 mg of zinc gluconate for oral supplementation for 30 days) and the data of 6 patients were eliminated. Sociodemographic characteristics, physiological factors, biochemical parameters, and clinical features of periodontal diseases were assessed. RESULTS: In this research a change in periodontal clinical characteristics was observed, which has been associated with disease remission. Additionally, a shift in MDA levels was presented for both groups. Furthermore, the supplementation group showed an increase in antioxidant enzymes when compared to the group that only received NSPT. CONCLUSION: The use of Zinc gluconate and magnesium oxide can serve as a complementary treatment to non-surgical periodontal treatment, that supports the remission of PD as a result of regulation-reduction of oxidative biomarkers and increase in antioxidant enzymes activity. TRIAL REGISTRATION: https://www.isrctn.com ISRCTN 14,092,381. September 13º 2023. Retrospective Registration.