Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 6.207
Filtrar
1.
J Environ Sci (China) ; 147: 617-629, 2025 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-39003076

RESUMO

The manganese-cobalt mixed oxide nanorods were fabricated using a hydrothermal method with different metal precursors (KMnO4 and MnSO4·H2O for MnOx and Co(NO3)2⋅6H2O and CoCl2⋅6H2O for Co3O4). Bamboo-like MnO2⋅Co3O4 (B-MnO2⋅Co3O4 (S)) was derived from repeated hydrothermal treatments with Co3O4@MnO2 and MnSO4⋅H2O, whereas Co3O4@MnO2 nanorods were derived from hydrothermal treatment with Co3O4 nanorods and KMnO4. The study shows that manganese oxide was tetragonal, while the cobalt oxide was found to be cubic in the crystalline arrangement. Mn surface ions were present in multiple oxidation states (e.g., Mn4+ and Mn3+) and surface oxygen deficiencies. The content of adsorbed oxygen species and reducibility at low temperature declined in the sequence of B-MnO2⋅Co3O4 (S) > Co3O4@MnO2 > MnO2 > Co3O4, matching the changing trend in activity. Among all the samples, B-MnO2⋅Co3O4 (S) showed the preeminent catalytic performance for the oxidation of toluene (T10% = 187°C, T50% = 276°C, and T90% = 339°C). In addition, the B-MnO2⋅Co3O4 (S) sample also exhibited good H2O-, CO2-, and SO2-resistant performance. The good catalytic performance of B-MnO2⋅Co3O4 (S) is due to the high concentration of adsorbed oxygen species and good reducibility at low temperature. Toluene oxidation over B-MnO2⋅Co3O4 (S) proceeds through the adsorption of O2 and toluene to form O*, OH*, and H2C(C6H5)* species, which then react to produce benzyl alcohol, benzoic acid, and benzaldehyde, ultimately converting to CO2 and H2O. The findings suggest that B-MnO2⋅Co3O4 (S) has promising potential for use as an effective catalyst in practical applications.


Assuntos
Cobalto , Compostos de Manganês , Oxirredução , Óxidos , Tolueno , Óxidos/química , Compostos de Manganês/química , Catálise , Cobalto/química , Tolueno/química , Poluentes Atmosféricos/química
2.
J Environ Sci (China) ; 148: 529-540, 2025 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-39095186

RESUMO

Monolithic catalysts with excellent O3 catalytic decomposition performance were prepared by in situ loading of Co-doped KMn8O16 on the surface of nickel foam. The triple-layer structure with Co-doped KMn8O16/Ni6MnO8/Ni foam was grown spontaneously on the surface of nickel foam by tuning the molar ratio of KMnO4 to Co(NO3)2·6H2O precursors. Importantly, the formed Ni6MnO8 structure between KMn8O16 and nickel foam during in situ synthesis process effectively protected nickel foam from further etching, which significantly enhanced the reaction stability of catalyst. The optimum amount of Co doping in KMn8O16 was available when the molar ratio of Mn to Co species in the precursor solution was 2:1. And the Mn2Co1 catalyst had abundant oxygen vacancies and excellent hydrophobicity, thus creating outstanding O3 decomposition activity. The O3 conversion under dry conditions and relative humidity of 65%, 90% over a period of 5 hr was 100%, 94% and 80% with the space velocity of 28,000 hr-1, respectively. The in situ constructed Co-doped KMn8O16/Ni foam catalyst showed the advantages of low price and gradual applicability of the preparation process, which provided an opportunity for the design of monolithic catalyst for O3 catalytic decomposition.


Assuntos
Compostos de Manganês , Níquel , Óxidos , Ozônio , Óxidos/química , Níquel/química , Compostos de Manganês/química , Ozônio/química , Catálise , Umidade , Cobalto/química , Modelos Químicos , Poluentes Atmosféricos/química
3.
Anal Bioanal Chem ; 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39352470

RESUMO

In this study, a novel aptasensor based on a transition metal oxide-modified pencil graphite electrode (PGE) was developed for the diagnosis of early-stage prostate cancer (PCa) via monitoring the prostate-specific antigen (PSA), which is the main biomarker for PCa. Single-use PGEs modified with pulsed deposited manganese oxide (MnOx) film were used to attach the amino-terminated aptamer specific to the PSA via carbodiimide chemistry. The designed aptasensor was placed in an electrochemical cell containing ferri/ferrocyanide ions as a redox probe to measure the charge transfer resistances (Rct) of the electrode surface by electrochemical impedance spectroscopy (EIS) to follow the response of each modification step. The effect of the medium pH on the ionic structure of the aptamer molecule according to its pI value and, thus, the reversing of the direction of the response (ΔRct) by the pH change was also discussed. The level of PSA secreted from PCa cells was investigated using impedimetric transduction. The specificity of the aptasensor was validated through selectivity studies against non-specific tumor markers like VEGF and different cancer cell lines including breast cancer and androgen-insensitive prostate cancer. The developed system showcases a label-free, fast, specific, and cost-effective approach for PSA detection, highlighting the importance of medium pH and the electrostatic environment on the aptamer's response. Our work emphasizes the potential for such aptasensors in clinical diagnostics and paves the way for further exploration into using transition metal oxides in biosensing applications.

4.
ACS Appl Bio Mater ; 2024 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-39350400

RESUMO

Bacterial resistance to antibiotics can negatively affect the treatment of infected skin wounds. The combination of synergistic antibacterial therapies with photodynamic, photothermal, and chemodynamic therapies has been recognized as one of the most promising approaches. In this study, we have developed MSN@Ce6@MnO2-CS/Ag (MCMA) nanoparticles to serve as powerful antibacterial agents when exposed to both 660 nm visible light and 808 nm near-infrared (NIR) light. Through dual-light irradiation, MCMA can induce hyperthermia and generate reactive oxygen species (ROS), leading to a remarkable enhancement in photothermal antibacterial effects and accelerating wound healing. It has a peroxidase-like catalytic activity and promotes the generation of hydroxyl radicals (·OH) by catalyzing the decomposition of H2O2. In vitro antibacterial experiments demonstrated the excellent antibacterial activity of MCMA. The antibacterial efficacy of MCMA at a concentration of 250 µg ml-1 was found to be 99.6 and 100% toward Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli, respectively, under irradiation with an 808 and 660 nm laser. The results of the animal experiments demonstrated that MCMA can effectively accelerate wound healing through wound ulceration inhabitation. These findings substantiate the assertion that synthetic MCMA represents an efficacious strategy for bacterial inhibition and wound healing.

5.
J Nanobiotechnology ; 22(1): 577, 2024 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-39300539

RESUMO

Treating bone defect concomitant with microbial infection poses a formidable clinical challenge. Addressing this dilemma necessitates the implementation of biomaterials exhibiting dual capabilities in anti-bacteria and bone regeneration. Of particular significance is the altered microenvironment observed in infected bones, characterized by acidity, inflammation, and an abundance of reactive oxygen species (ROS). These conditions, while challenging, present an opportunity for therapeutic intervention in the context of contaminated bone defects. In this study, we developed an oriented composite scaffold containing copper-coated manganese dioxide (MnO2) nanoparticles loaded with parathyroid hormone (PMPC/Gelatin). The characteristics of these scaffolds were meticulously evaluated and confirmed the high sensitivity to H+, responsive drug release and ROS elimination. In vitro antibacterial analysis underscored the remarkable ability of PMPC/Gelatin scaffolds to substantially suppressed bacterial proliferation and colony formation. Furthermore, this nontoxic material demonstrated efficacy in mitigating ROS levels, thereby fostering osteogenic differentiation of bone marrow mesenchymal stem cells and enhancing angiogenic ability. Subsequently, the infected models of bone defects in rat skulls were established to investigate the effects of composite scaffolds on anti-bacteria and bone formation in vivo. The PMPC/Gelatin treatment exhibited excellent antibacterial activity, coupled with enhanced vascularization and osteogenesis at the defect sites. These compelling findings affirm that the PMPC/Gelatin composite scaffold represents a promising avenue for anti-bacteria and bone regeneration.


Assuntos
Antibacterianos , Regeneração Óssea , Gelatina , Compostos de Manganês , Células-Tronco Mesenquimais , Osteogênese , Óxidos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio , Alicerces Teciduais , Animais , Osteogênese/efeitos dos fármacos , Alicerces Teciduais/química , Ratos , Regeneração Óssea/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/química , Células-Tronco Mesenquimais/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Gelatina/química , Óxidos/química , Óxidos/farmacologia , Compostos de Manganês/química , Compostos de Manganês/farmacologia , Masculino , Crânio/efeitos dos fármacos , Nanopartículas/química , Cobre/química , Cobre/farmacologia , Diferenciação Celular/efeitos dos fármacos , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia
6.
Adv Mater ; : e2410652, 2024 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-39308225

RESUMO

The outbreak of antibiotic-resistant bacteria, or "superbugs", poses a global public health hazard due to their resilience against the most effective last-line antibiotics. Identifying potent antibacterial agents capable of evading bacterial resistance mechanisms represents the ultimate defense strategy. This study shows that -the otherwise essential micronutrient- manganese turns into a broad-spectrum potent antibiotic when coordinated with a carboxylated nitrogen-doped graphene. This antibiotic material (termed NGA-Mn) not only inhibits the growth of a wide spectrum of multidrug-resistant bacteria but also heals wounds infected by bacteria in vivo and, most importantly, effectively evades bacterial resistance development. NGA-Mn exhibits up to 25-fold higher cytocompatibility to human cells than its minimum bacterial inhibitory concentration, demonstrating its potential as a next-generation antibacterial agent. Experimental findings suggest that NGA-Mn acts on the outer side of the bacterial cell membrane via a multimolecular collective binding, blocking vital functions in both Gram-positive and Gram-negative bacteria. The results underscore the potential of single-atom engineering toward potent antibiotics, offering simultaneously a long-sought solution for evading drug resistance development while being cytocompatible to human cells.

7.
Small ; : e2405879, 2024 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-39308438

RESUMO

Renewable electricity-driven CO2 electroreduction to value-added chemicals is a feasible approach to alleviate both environmental and energy issues. However, CO2 reduction reaction (CO2RR) systems in alkaline electrolytes are constrained by intrinsic limitations such as salt accumulation that impede further industrialization. Herein, an atomically dispersed Mn doped-nitrogen carbon (AD MnNC) catalyst is developed to electrochemically reduce CO2 to CO in both neutral and acidic media. Benefiting from well-dispersed MnNx sites, the maximum CO Faradaic efficiency (FECO) reaches ≈100% at -0.73 V versus reversible hydrogen electrode (RHE) with CO current density (JCO) of 20.4 mA cm-2 in neutral 0.5 m KHCO3. Due to diminished *H adsorption, AD MnNC achieves a FECO of 85.3% at pH 2.0, effectively suppressing the hydrogen evolution reaction (HER) in an acidic electrolyte. The mechanistic study reveals that AD MnNC accelerates the production of *COOH intermediates through a proton-coupled electron transfer (PCET) pathway and thus promotes CO formation.

8.
Molecules ; 29(17)2024 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-39274869

RESUMO

Antimony (Sb) is one of the most concerning toxic metals globally, making the study of methods for efficiently removing Sb(III) from water increasingly urgent. This study uses graphene oxide and chitosan as the matrix (GOCS), modifying them with FeCl2 and four MnOx to form iron-manganese oxide (FM/GC) at a Fe/Mn molar ratio of 4:1. FM/GC quaternary composite microspheres are prepared, showing that FM/GC obtained from different MnOx exhibits significant differences in the ability to remove Sb(III) from neutral solutions. The order of Sb(III) removal effectiveness is MnSO4 > KMnO4 > MnCl2 > MnO2. The composite microspheres obtained by modifying GOCS with FeCl2 and MnSO4 are selected for further batch experiments and characterization tests to analyze the factors and mechanisms influencing Sb(III) removal. The results show that the adsorption capacity of Sb(III) decreases with increasing pH and solid-liquid ratio, and gradually increases with the initial concentration and reaction time. The Langmuir model fitting indicates that the maximum adsorption capacity of Sb(III) is 178.89 mg/g. The adsorption mechanism involves the oxidation of the Mn-O group, which converts Sb(III) in water into Sb(V). This is followed by ligand exchange and complex formation with O-H in FeO(OH) groups, and further interactions with C-OH, C-O, O-H, and other functional groups in GOCS.

9.
Molecules ; 29(17)2024 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-39275034

RESUMO

Morphological control of metal-organic frameworks (MOFs) at the micro/nanoscopic scale is critical for optimizing the electrochemical properties of them and their derivatives. In this study, manganese organic phosphate (Mn-MOP) with three distinct two-dimensional (2D) morphologies was synthesized by varying the molar ratio of Mn2+ to phenyl phosphonic acid, and one of the morphologies is a unique palm leaf shape. In addition, a series of 2D Mn-MOP derivatives were obtained by calcination in air at different temperatures. Electrochemical studies showed that 2D Mn-MOP derivative calcined at 550 °C and exhibited a superior specific capacitance of 230.9 F g-1 at 0.5 A g-1 in 3 M KOH electrolyte. The aqueous asymmetric supercapacitor and the constructed flexible solid-state device demonstrated excellent rate performance. This performance reveals the promising application of 2D Mn-MOP materials for energy storage.

10.
Nutrients ; 16(17)2024 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-39275304

RESUMO

BACKGROUND: An appropriate diet is the basis for the treatment of type 2 diabetes (T2DM). However, there are no strict recommendations regarding the content of micronutrients and their modifications in the presence of chronic kidney disease (CKD). Therefore, we decided to investigate whether T2DM patients, including those with CKD, have different levels of chromium, nickel, cobalt, magnesium, and zinc in various blood elements compared to healthy individuals. METHODS: We divided our subjects into three groups: the control group (individuals without T2DM and proper renal function), those with T2DM and proper renal function, and those with T2DM and GFR < 60 mL/min/1.73 m2. RESULTS: We observed higher levels of chromium in all materials examined in patients with T2DM and impaired renal function. Both study groups found higher levels of nickel in samples of whole blood and red blood cells. Patients with T2DM and proper renal function had higher levels of serum manganese. Both study groups had lower levels of serum zinc. We observed higher levels of chromium in all materials examined in patients with T2DM and impaired renal function. Both study groups found higher levels of nickel in samples of whole blood and red blood cells. Patients with T2DM and proper renal function had higher levels of serum manganese. Both study groups had lower levels of serum zinc. CONCLUSIONS: In order to ensure effective care for patients with T2DM, it is necessary to improve the standard diet, including the content of micronutrients and their modification in patients with concomitant CKD.


Assuntos
Diabetes Mellitus Tipo 2 , Insuficiência Renal Crônica , Oligoelementos , Humanos , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/complicações , Oligoelementos/sangue , Masculino , Feminino , Pessoa de Meia-Idade , Insuficiência Renal Crônica/sangue , Idoso , Níquel/sangue , Cromo/sangue , Adulto , Taxa de Filtração Glomerular , Zinco/sangue , Magnésio/sangue , Células Sanguíneas , Estudos de Casos e Controles
11.
Sensors (Basel) ; 24(17)2024 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-39275429

RESUMO

A paramagnetic A3B-type Mn(III)-porphyrin was synthesized and characterized by physical-chemical methods (UV-Vis, FT-IR, 1H-NMR spectroscopy). The obtained compound was tested as a sensitive material for the spectrophotometric and potentiometric detection of iodine species. Using UV-Vis spectroscopy, the triiodide anions could be detected with high precision in the concentration interval of 1.02 × 10-5 to 2.3 × 10-5 M, with an LOD of 9.44 × 10-6 M. The PVC-based electrode using DOP as a plasticizer showed a sensitivity toward iodide in a wide concentration range of 1.0 × 10-5 to 1.0 × 10-1 M, with an LOD of 8.0 × 10-6 M. Both methods are simple, low-cost, and efficient for the detection of iodine species in synthetic samples and pharmaceuticals.

12.
J Hazard Mater ; 480: 135777, 2024 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-39276745

RESUMO

Cadmium (Cd) is a toxic heavy metal that poses risks to crop production and food safety worldwide. This study evaluated whether manganese (Mn) addition could mitigate Cd toxicity and reduce Cd accumulation in barley seedlings. Hydroponically grown seedlings of Cd-tolerant (WSBZ) and Cd-sensitive (Dong17) barley cultivars were treated with 0.1 µM and 1 µM Cd as well as 0.2 mM Mn alone and in a combination with 0.1 or 1.0 µM Cd for 21 days. Cd exposure caused the dramatic alteration of growth and physiological parameters by disrupting chloroplast, and increased Cd accumulation in both genotypes. However, Mn addition markedly alleviated the negative impacts of all examined parameters caused by Cd stress. Cd addition enhanced expression of anti-oxidative enzyme related genes, including HvSOD, HvCAT, HvAPX, HvPOD in the two barley genotypes exposed to Cd stress. The expression analysis showed nearly all HvNRAMPs genes are dramatically up regulated by both Mn and Cd, with WSBZ having higher expression than Dong 17. Notably, HvNRAMP1 showed the highest expression due to Mn addition, highlighting its crucial role in Mn uptake and transportation in barley. Moreover, Cd stress and Mn addition increased and suppressed the expression of HvYSL5, HvHMA2 and HvHMA3, respectively. Conversely, the expression of HvYSL2, HvIRT1 and HvMTP8 was upregulated by both Mn and Cd treatments, with a further increase observed in the combined Cd and Mn treatments. It may be concluded that sufficient Mn supply is quite important for reducing Cd uptake and accumulation in plants.

13.
Nano Lett ; 24(37): 11512-11519, 2024 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-39230027

RESUMO

Metal-oxo clusters show great promise in lithium ion battery applications as anode materials by virtue of their native nature of well-defined nanostructures and multielectron redox activities. However, their intrinsic unsatisfactory electrical conductivity and tendency to aggregation make them difficult to fully utilize. Herein, a well-dispersed Mn12O12(CH3COO)16(H2O)4 (denoted as Mn12) cluster is constructed by rationally adopting carbon dots (CDs) with nanosize and high conductivity as stabilizers. Thanks to the fully exposed redox sites of Mn12 clusters and additional interfacial energy storage mechanism, the optimized Mn12/CDs-1:20 anode delivers a high specific capacity of 1643 mAh g-1 at 0.2 A g-1 (0.25 C) and exhibits outstanding rate and cycling capabilities. This paper provides a green and efficient paradigm to synthesize well-dispersed manganese-oxo clusters for the first time and builds a new platform for cluster-based energy storage.

14.
J Hazard Mater ; 480: 135808, 2024 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-39288524

RESUMO

There is a correlation between long-term manganese (Mn) exposure and the Parkinson's-like disease (PD), with depression as an early symptom of PD. However, the direct relationship between Mn exposure and depression, and the mechanisms involved, remain unclear. We found that Mn exposure led to depressive-like behavior and mild cognitive impairment in mice, with Mn primarily accumulating in the cornu ammonis 3 (CA3) area of the hippocampus. Mice displayed a reduction in neuronal dendritic spines and damage to astrocytes specifically in the CA3 area. Spatial metabolomics revealed that Mn downregulated glutamic acid decarboxylase 1 (GAD1) expression in astrocytes, disrupting the Glutamine-Glutamate-γ-aminobutyric acid (GlnGluGABA) metabolic cycle in the hippocampus, leading to neurotoxicity. We established an in vitro astrocyte Gad1 overexpression (OEX) model and found that the cultured medium from Gad1 OEX astrocytes reversed neuronal synaptic damage and the expression of gamma-aminobutyric acid (GABA) related receptors. Using the astrocyte Gad1 OEX mouse model, results showed that OEX of Gad1 ameliorated depressive-like behavior and cognitive dysfunction in mice. These findings provide new insight into the important role of GAD1 mediated GlnGluGABA metabolism disorder in Mn exposure induced depressive-like behavior. This study offers a novel sight to understanding abnormal emotional states following central nervous system damage induced by Mn exposure.

15.
Microbiol Spectr ; : e0157124, 2024 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-39315785

RESUMO

Science is challenging because we do not know what we do not know. Commercial chemicals are often marketed with >99% purity, but 0.5-1% impurity can impact results and cloud data interpretation. We recently developed an assay for farnesol and aromatic fusel alcohols from Candida albicans. During proof-of-concept experiments using RPMI-1640 growth media, the buffering compound was switched from MOPS obtained from Acros Organics to MOPS obtained from Sigma-Aldrich, both labeled 99% + purity. We observed a twofold decrease in growth, along with a three- to fivefold increase in farnesol production per cell upon the switch. ICP-MS showed that trace Mn(II) was present in Acros MOPS but absent in Sigma MOPS. Optimal growth was achieved by the addition of Mn(II), Zn(II), and Fe(II). We established upper and lower limits for Fe(II), Zn(II), Cu(II), and Mn(II) that allowed similar growth and then assessed 16 different mineral combinations in RPMI-1640 base media. The results show an increased production of farnesol and the aromatic fusel alcohols when Zn(II) is abundant, and a further increase in the aromatic fusel alcohols when both Fe(II) and Zn(II) are abundant. Finally, antifungal susceptibility testing displayed no significant difference between RPMI/MOPS with and without mineral supplementation. Supplemental Mn(II) was most needed for cell growth, while supplemental Zn(II) was most needed for the production of farnesol and the aromatic fusel alcohols. To avoid these artifacts due to metal contamination, we now use a modified RPMI supplemented with 1 mg/ L of Cu(II), Zn(II), Mn(II), and Fe(II). IMPORTANCE: The dimorphic fungus Candida albicans is a major opportunistic pathogen of humans. RPMI-1640 is a chemically defined growth medium commonly used with C. albicans. We identified over 32,000 publications with keywords RPMI and C. albicans. Additionally, Antifungal Susceptibility Testing (AFST) protocols in the United States (CLSI) and Europe (EUCAST) utilize RPMI as a base media to assess drug efficacy against clinical fungal isolates. RPMI contains many nutrients but no added trace metals. We found that the growth characteristics with RPMI were dependent on which MOPS buffer was chosen and the contamination of that buffer by trace levels of Mn(II) and Zn(II). Added Mn(II) was most needed for cell growth while added Zn(II) was most needed for secretion of farnesol and other signaling molecules.

16.
Bioimpacts ; 14(5): 30193, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39296800

RESUMO

Introduction: Wound healing is a major therapeutic concern in regenerative medicine. The current study aimed to investigate the second-degree burn wound treatment in rats using rat adipose- derived stem cells (ADSCs) and manganese nanoparticles (MnO2-NPs) in a polycaprolactone/gelatin electrospun nanofiber scaffold. Methods: After the synthesis of nanoparticles and electrospinning of nanofibers, the SEM analysis, contact angle, mechanical strength, blood compatibility, porosity, swelling, biodegradability, cell viability, and adhesion assays were performed. According to the results, the PCL/Gel/5%MnO2-NPs nanofiber (Mn-5%) was determined to be the most suitable scaffold. The ADSCs-seeded Mn-5% scaffolds were applied as a burn wound dressing. The wound closure rate, IL-1ß, and IL-6 level, hydroxyproline, and glycosaminoglycans content were measured, and the hematoxylin and eosin, Masson's trichrome, and immunohistochemistry stainings were carried out. Results: Based on the results, in Mn+S (ADSCs+PCL/Gel/5%MnO2-NPs nanofiber) and N+S (ADSCs+PCL/Gel nanofiber) groups, the IL-6 and IL-1ß levels were reduced, and the percentage of wound closure, glycosaminoglycans, and hydroxyproline content were increased compared to the control group (P<0.05). Also, the lowest amount of α-SMA was observed in these two groups, demonstrating stem cells' role in reducing α-SMA levels and thus preventing fibrosis. Moreover, the amount of α-SMA in the Mn+S group is lower than in the N+S group and, is closer to healthy skin. According to histology results, the best type of treatment was observed in the Mn+S group. Conclusion: In conclusion, the ADSCs-seeded PCL/Gel/5%MnO2-NPs scaffold demonstrated considerable therapeutic effects in burn wound healing.

17.
Sci Total Environ ; 953: 176167, 2024 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-39260499

RESUMO

Flooding of paddy fields enhances methane (CH4) emissions and arsenic (As) mobilisation, which are crucial issues for agricultural greenhouse gas emissions and food safety. Birnessite (δ-MnO2) is a common natural oxidant and scavenger for heavy metals. In this study, birnessite was applied to As-contaminated paddy soil. The capacity for simultaneously alleviating CH4 emissions and As mobility was explored. Soil microcosm incubation results indicated that birnessite addition simultaneously reduced CH4 emissions by 47 %-54 % and As release by 38 %-85 %. The addition of birnessite decreased the dissolved organic carbon (DOC) contents and altered its chemical properties. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) results showed that birnessite reduced the labile fractions of proteins, carbohydrates, lignins, tannins, and unsaturated hydrocarbons, however, increased the abundance of condensed aromatic structures, suggesting the polymerisation of dissolved organic matter (DOM) by birnessite. The degradation of labile fractions and the polymerisation of DOM resulted in an inventory of recalcitrant DOM, which is difficult for microbes to metabolise, thus inhibiting methanogenesis. In contrast, birnessite addition increased CH4 oxidation, as the particulate methane monooxygenase (pmoA) gene abundance increased by 30 %. The enhanced polymerisation of DOM by birnessite also increased As complexation with organics, leading to the transfer of As to the organic bound phase. In addition, the decrease in ferrous ion [Fe(II)] concentrations with birnessite indicated that the reductive dissolution of Fe oxides was suppressed, which limited the release of arsenite [As(III)] under reducing conditions. Furthermore, birnessite decreased As methylation and shaped the soil microbial community structure by enriching the metal-reducing bacterium Bacillus. Overall, our results provide a promising method to suppress greenhouse gas emissions and the risk of As contamination in paddy soils, although further studies are needed to verify its efficacy and effectiveness under field conditions.


Assuntos
Arsênio , Metano , Óxidos , Poluentes do Solo , Solo , Arsênio/análise , Poluentes do Solo/análise , Óxidos/química , Solo/química , Inundações , Agricultura/métodos , Oryza , Poluentes Atmosféricos/análise , Microbiologia do Solo
18.
Int J Biol Macromol ; 280(Pt 2): 135764, 2024 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-39299429

RESUMO

Chronic hepatitis B virus (HBV) infection continues to pose a significant global health challenge. However, therapeutic measures for a cure are lacking in clinical practice. Manganese, an essential trace element, has garnered attention due to its potential to activate innate immune pathways and its significant role in antiviral and antitumor immunity. Yet, the specific impact of manganese on chronic hepatitis B has been largely unexplored. Our research reveals that manganese substantially inhibits HBV replication in hepatocellular carcinoma cells at non-toxic levels. This suppression occurs independently of well-known anti-HBV innate immune pathways, such as the cGAS-STING pathway. Mechanistically, manganese decreases HBV transcription by diminishing the levels of liver-specific transcription factors. Furthermore, it activates the mTOR pathway, enhancing HBsAg ubiquitination through the upregulation of the ubiquitin ligase ß-TrCP and increasing proteasome activity via the augmentation of its subunits, leading to a ubiquitin-dependent degradation of HBsAg. Significantly, our study also uncovers a notable clinical correlation between manganese levels and chronic hepatitis B infection. These findings position manganese as a critical element in diminishing HBV replication, offering a new direction in the management of chronic hepatitis B.

19.
Biomed Pharmacother ; 179: 117402, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39243428

RESUMO

In recent years, the integration of radiotherapy and nanocatalytic medicine has gained widespread attention in the treatment of breast cancer. Herein, the glucose oxidase (GOx) and MnO2 nanoparticles co-modified multifunctional liposome of GOx-MnO2@Lip was constructed for enhanced radiotherapy. Introduction of GOx would not only elevate the glucose consumption to starve the cancer cells, but also increased the endogenous H2O2 level. Meanwhile, high intracellular GSH concentration facilitated the release of Mn2+ to amplify the cytotoxic ·OH through cascade catalytic reactions within the tumor microenvironment, resulting in a favorable tumor suppression rate of 74.45 %. Furthermore, the blood biochemical and blood routine demonstrated that GOx-MnO2@Lip had no obvious toxic side effects. Therefore, this work provided a potential vehicle for synergistic cancer starving therapy, chemodynamic therapy and radiotherapy for improving therapeutic efficacy of breast cancer.


Assuntos
Neoplasias da Mama , Glucose Oxidase , Lipossomos , Compostos de Manganês , Óxidos , Radiossensibilizantes , Compostos de Manganês/química , Compostos de Manganês/farmacologia , Glucose Oxidase/metabolismo , Feminino , Óxidos/química , Óxidos/farmacologia , Neoplasias da Mama/patologia , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/radioterapia , Radiossensibilizantes/farmacologia , Animais , Humanos , Linhagem Celular Tumoral , Peróxido de Hidrogênio/metabolismo , Camundongos Endogâmicos BALB C , Catálise , Camundongos , Nanopartículas/química , Microambiente Tumoral/efeitos dos fármacos
20.
Chemosphere ; 365: 143251, 2024 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-39233301

RESUMO

Activated carbon (AC) systems and reverse osmosis (RO) systems are commonly used point-of-use (POU) water filtration systems for removing trace-level contaminants in tap water to protect human health. However, limited research has been done to evaluate their effectiveness in removing heavy metals like manganese (Mn) and uranium (U), or to assess the potential for undesired microbial growth within POU systems, which can reduce their treatment efficiency. This study aimed to systematically evaluate the removal of metals and assimilable organic carbon (AOC) in POU systems. AC systems were operated to 200% of their designed treatment capacities and RO systems were run for three weeks. The results showed that AC systems were generally ineffective at removing metals from drinking water, while RO systems effectively removed them. Both Mn and U were poorly removed by AC systems. Calcium (Ca) and magnesium (Mg) were poorly removed by AC systems, with efficiencies of less than 1%. Iron (Fe) removal by AC systems varied between 61% and 84%. Copper (Fe), likely due to its low influent concentration (<30 µg L-1), was effectively removed by AC systems with efficiencies over 95%. In contrast, RO systems consistently removed all metals effectively. Mn and U removal in RO systems exceeded 95%, while Ca, Mn, Fe, and Cu were all removed with efficiencies greater than 98%. AOC was effectively removed from all AC and RO systems, but with high variability in removal efficiency, which is likely attributed to the heterogeneity of biofilm and microbial growth within the POU systems. The new knowledge generated from this study can improve our understanding of chemical contaminant removal in POU systems and inform the development of better strategies for designing and operating POU systems to remove chemical contaminants in drinking water and mitigate their associated health risks.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA