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1.
Int J Biol Macromol ; 275(Pt 1): 133567, 2024 Aug.
Article de Anglais | MEDLINE | ID: mdl-38950799

RÉSUMÉ

The purpose of this research was to evaluate the efficacy of sodium lignosulfonate (LS) as a dye adsorbent in the removal of methylene blue (MB) from water by polymer-enhanced ultrafiltration. Various parameters were evaluated, such as membrane molecular weight cut-off, pH, LS dose, MB concentration, applied pressure, and the effect of interfering ions. The results showed that the use of LS generated a significant increase in MB removal, reaching an elimination of up to 98.0 % with 50.0 mg LS and 100 mg L-1 MB. The maximum MB removal capacity was 21 g g-1 using the enrichment method. In addition, LS was reusable for up to four consecutive cycles of dye removal-elution. The removal test in a simulated liquid industrial waste from the textile industry was also effective, with a MB removal of 97.2 %. These findings indicate that LS is highly effective in removing high concentrations of MB dye, suggesting new prospects for its application in water treatment processes.


Sujet(s)
Lignine , Bleu de méthylène , Ultrafiltration , Polluants chimiques de l'eau , Purification de l'eau , Bleu de méthylène/composition chimique , Lignine/composition chimique , Lignine/analogues et dérivés , Ultrafiltration/méthodes , Polluants chimiques de l'eau/composition chimique , Polluants chimiques de l'eau/isolement et purification , Purification de l'eau/méthodes , Concentration en ions d'hydrogène , Agents colorants/composition chimique , Agents colorants/isolement et purification , Adsorption , Polymères/composition chimique
2.
Int J Biol Macromol ; 275(Pt 2): 133685, 2024 Aug.
Article de Anglais | MEDLINE | ID: mdl-38971283

RÉSUMÉ

The urgent need for a simple and cost-effective thermochemical process to produce biochar has prompted this study. The aim was to develop a straightforward thermochemical process under O2-limited conditions for the production of coconut-based biochar (CBB) and to assess its ability to remove methylene blue (MB) through adsorption, comparing it with CBB produced by slow pyrolysis. CBBs were obtained under different atmospheric conditions (O2-limited, muffle furnace biochar (MFB); and inert, pyrolytic reactor biochar (PRB)), at 350, 500, and 700 °C, and for 30 and 90'. MFB and PRB were characterized using FTIR, RAMAN, SEM, EDS, and XRD analyses. Adsorption tests were conducted using 1.0 g L-1 of MFB and PRB, 10 mg L-1 of MB at 25 °C for 48 h. Characterization revealed that atmospheric conditions significantly influenced the yield and structural features of the materials. PRB exhibited higher yields and larger cavities than MFB, but quite similar spectral features. Adsorption tests indicated that MFB and PRB had qt values of 33.1 and 9.2 mg g-1, respectively, which were obtained at 700 °C and 90', and 700 °C and 30', respectively. This alternative method produced an innovative and promising lignocellulose-based material with great potential to be used as a biosorbent.


Sujet(s)
Charbon de bois , Cocos , Lignine , Cocos/composition chimique , Charbon de bois/composition chimique , Lignine/composition chimique , Adsorption , Bleu de méthylène/composition chimique , Température
3.
Int J Biol Macromol ; 274(Pt 2): 133482, 2024 Aug.
Article de Anglais | MEDLINE | ID: mdl-38942409

RÉSUMÉ

Cellulose modified hydrogels can be produced directly from raw biopolymers in novel cellulose solvents such as NaOH/urea aqueous solution. The effect of cellulose characteristics on the synthesis of a cellulose-graft-(net-poly(acrylamide-co-acrylic acid)) and its performance as water absorbent/methylene blue dye removal material is analyzed. Three cellulose samples, one analytical grade and two obtained from teak wood sawdust with different pretreatments (one alkaline and the other, a novel one known as (gas phase) acid pretreatment) were compared. The starting raw celluloses were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD) and viscosity in cupri ethylenediamine hydroxide (CED) solution, whereas the chemically modified materials were characterized by SEM, FTIR, and TGA. The pretreatment used influences composition, crystallinity index and degree of polymerization (DP) of the cellulose obtained. The modified material produced with cellulose from alkaline pretreatment showed the highest swelling ratio in water absorption tests at room temperature (12,714 %); in contrast, the one with cellulose from acid pretreatment showed the lowest swelling ratio (7,470 %). However, this difference is not so significative in dye removal tests, where absorption capacity is 139 and 140 mg/g, respectively. The results indicate that cellulose composition, particularly structures with significant hemicellulose and lignin remaining content, has a major effect on the performance of modified materials for water absorption, and degree of polymerization has a major effect on adsorption capacity of methylene blue.


Sujet(s)
Cellulose , Agents colorants , Lignine , Eau , Bois , Lignine/composition chimique , Cellulose/composition chimique , Eau/composition chimique , Bois/composition chimique , Agents colorants/composition chimique , Résines acryliques/composition chimique , Bleu de méthylène/composition chimique , Spectroscopie infrarouge à transformée de Fourier , Diffraction des rayons X , Purification de l'eau/méthodes , Polluants chimiques de l'eau/composition chimique , Acrylamides/composition chimique
4.
Chemosphere ; 361: 142515, 2024 Aug.
Article de Anglais | MEDLINE | ID: mdl-38830460

RÉSUMÉ

The catalytic performance of modified hydroxyapatite nanoparticles, Ca10-xFex-yWy(PO4)6(OH)2, was applied for the degradation of methylene blue (MB), fast green FCF (FG) and norfloxacin (NOR). XPS analysis pointed to the successful partial replacement of Ca by Fe. Under photo-electro-Fenton process, the catalyst Ca4FeII1·92W0·08FeIII4(PO4)6(OH)2 was combined with UVC radiation and electrogenerated H2O2 in a Printex L6 carbon-based gas diffusion electrode. The application of only 10 mA cm-2 resulted in 100% discoloration of MB and FG dyes in 50 min of treatment at pH 2.5, 7.0 and 9.0. The proposed treatment mechanism yielded maximum TOC removal of ∼80% and high mineralization current efficiency of ∼64%. Complete degradation of NOR was obtained in 40 min, and high mineralization of ∼86% was recorded after 240 min of treatment. Responses obtained from LC-ESI-MS/MS are in line with the theoretical Fukui indices and the ECOSAR data. The study enabled us to predict the main degradation route and the acute and chronic toxicity of the by-products formed during the contaminants degradation.


Sujet(s)
Électrodes , Peroxyde d'hydrogène , Fer , Bleu de méthylène , Nanoparticules , Polluants chimiques de l'eau , Catalyse , Peroxyde d'hydrogène/composition chimique , Fer/composition chimique , Bleu de méthylène/composition chimique , Nanoparticules/composition chimique , Polluants chimiques de l'eau/composition chimique , Polluants chimiques de l'eau/analyse , Norfloxacine/composition chimique , Durapatite/composition chimique , Agents colorants/composition chimique , Processus photochimiques , Rayons ultraviolets
5.
Int J Biol Macromol ; 275(Pt 1): 133208, 2024 Aug.
Article de Anglais | MEDLINE | ID: mdl-38889837

RÉSUMÉ

Jatobá-do-cerrado fruit shells, archetypical of lignocellulosic-based biomass, were used as an adsorbent to remove crystal violet (CV) and methylene blue (MB) from water. The adsorbent was characterized using various techniques, and kinetic studies showed dye adsorption followed second-order kinetics. An experimental design investigated the effects of pH and temperature on removal efficiency, with a quadratic model fitting the data best. The results suggest pH influences MB's adsorption capacity more than temperature and at 25 °C and pH 8, MB had a desirability value of 0.89, with 95 % removal efficiency. For CV, temperature had a greater influence, with a desirability value of 0.874 at 25 °C and pH 10, and 95 % removal efficiency. Adsorption isotherm studies revealed maximum adsorption capacities of 123.0 mg·g-1 and 113.0 mg·g-1 for CV and MB, respectively. Experimental thermodynamic parameters indicated an endothermic and spontaneous process which it was supported by quantum chemistry calculations. The protocols developed confirmed the potential for adsorbing CV and MB dyes in water, achieving over 73.1 and 74.4 mg g-1 dyes removal.


Sujet(s)
Biomasse , Agents colorants , Lignine , Bleu de méthylène , Polluants chimiques de l'eau , Adsorption , Lignine/composition chimique , Agents colorants/composition chimique , Agents colorants/isolement et purification , Polluants chimiques de l'eau/composition chimique , Polluants chimiques de l'eau/isolement et purification , Concentration en ions d'hydrogène , Cinétique , Bleu de méthylène/composition chimique , Bleu de méthylène/isolement et purification , Température , Purification de l'eau/méthodes , Chlorure de méthylrosanilinium/composition chimique , Chlorure de méthylrosanilinium/isolement et purification , Thermodynamique , Théorie de la fonctionnelle de la densité
6.
Chemosphere ; 362: 142656, 2024 Aug.
Article de Anglais | MEDLINE | ID: mdl-38908449

RÉSUMÉ

Feedstock characteristics impact biochar physicochemical properties, and reproducible biochar properties are essential for any potential application. However, in most articles, feedstock aspects (i.e., taxonomic name of the species, part of the plant, and phenological phase) are scarcely reported. This research aimed at studying the effect of species and phenological stage of the feedstock on the properties of the derived biochars and, thus, adsorption capacities in water treatment. In this study, we analysed the anatomical characteristics of three different woody bamboo species [Guadua chacoensis (GC), Phyllostachys aurea (PA), and Bambusa tuldoides (BT)] in culms harvested at two different phenological phases (young and mature), and statistically correlated them with the characteristics of the six derived biochars, including their adsorption performance in aqueous media. Sclerenchyma fibres and parenchyma cells diameter and cell-wall width significantly differed among species. Additionally, sclerenchyma fibres and parenchyma cell-wall width as well as sclerenchyma fibre cell diameters are dependent on the phenological phase of the culms. Consequently, differences in biochar characteristics (i.e., yield and average pore diameter) were also observed, leading to differential methylene blue (MB) adsorption capacities between individuals at different phenological phases. MB adsorption capacities were higher for biochar produced from young culms compared to those obtained from matures ones (i.e., GC: 628.66 vs. 507.79; BT: 537.45 vs. 477.53; PA: 477.52 vs. 462.82 mg/g), which had smaller cell wall widths leading to a lower percentage of biochar yield. The feedstock anatomical properties determined biochar characteristics which modulated adsorption capacities.


Sujet(s)
Bambusa , Charbon de bois , Bleu de méthylène , Charbon de bois/composition chimique , Bleu de méthylène/composition chimique , Adsorption , Bambusa/composition chimique , Purification de l'eau/méthodes , Bois/composition chimique
7.
Environ Res ; 258: 119422, 2024 Oct 01.
Article de Anglais | MEDLINE | ID: mdl-38942261

RÉSUMÉ

The aim of the present research is to show the development of a sustainability-oriented lab that teaches adsorption concepts in a virtual environment based on the premise "learning-through-play". Kinetic results in the virtual environment are contrasted to those obtained experimentally when diverse adsorbents prepared from Agave Bagasse (Raw Fibers, Hydrothermal Fibers, and Activated Fibers) were synthesized. Comparison between virtual and real-life experiments involving removal of methylene blue in solution showed that a pseudo-first-order model could describe adsorption kinetics satisfactorily. The study is complemented with a characterization of the adsorbents through SEM, nitrogen adsorption isotherms, FTIR and Raman. In addition, the environmental impact of the synthesis of adsorbents was evaluated through well-known methodologies (GAPI, NEMI, and Eco-Scale), which agree that raw fibers are the most eco-friendly material. This research provides an exciting opportunity to advance our knowledge on developing new technologies for teaching in engineering and to compliment real-life practices that consider environmental impacts with virtual experiments.


Sujet(s)
Polluants chimiques de l'eau , Adsorption , Cinétique , Polluants chimiques de l'eau/composition chimique , Polluants chimiques de l'eau/analyse , Universités , Bleu de méthylène/composition chimique , Laboratoires , Purification de l'eau/méthodes , Cellulose/composition chimique , Modèles chimiques , Conservation des ressources naturelles/méthodes
8.
Environ Res ; 258: 119371, 2024 Oct 01.
Article de Anglais | MEDLINE | ID: mdl-38876420

RÉSUMÉ

Cu2ZnSnS4 (CZTS) was synthesized following hot injection method and the process was optimized by varying temperature conditions. Four samples at different temperatures viz., 200, 250, 300 and 350 °C were prepared and analyzed using different characterization techniques. Based on the correlation between XRD, Raman and XPS, we conclude that the formation of ZnS and SnS2 occurs at 350 °C but at 200 °C there is no breakdown of the complex as per XRD. According to Raman and XPS analysis, as the temperature rises, the bonds between the metals become weaker, which is visibly seen in Raman and XPS due to the minor peaks of copper sulfide. Scanning electron microscopic analysis confirmed nanometric particles which increase in size with temperature. The photocatalytic evaluation showed that CZTS synthesized at 200 °C performed efficiently in the removal of the two colorants, methylene blue and Rhodamine 6G, achieving 92.80% and 90.65%, respectively. The photocatalytic degradation efficiencies decreased at higher temperatures due to bigger sized CZTS particles as confirmed by SEM results. Computational simulations confirm that CZTS has a highly negative energy -25,764 Ry, confirming its structural stability and higher covalent than ionic character.


Sujet(s)
Cuivre , Bleu de méthylène , Rhodamines , Sulfures , Rhodamines/composition chimique , Bleu de méthylène/composition chimique , Sulfures/composition chimique , Cuivre/composition chimique , Catalyse , Composés de l'étain/composition chimique , Température élevée , Polluants chimiques de l'eau/composition chimique
9.
Photodermatol Photoimmunol Photomed ; 40(4): e12978, 2024 Jul.
Article de Anglais | MEDLINE | ID: mdl-38845020

RÉSUMÉ

BACKGROUND: Infections are complications in the wound healing process, and their treatment can lead to antibiotic overuse and bacterial resistance. Antimicrobial photodynamic therapy (aPDT) is used to treat infectious diseases caused by fungi, viruses, or bacteria. Methylene blue (MB) and its derivatives are commonly used dyes in antimicrobial photodynamic therapy (aPDT-MB). METHODS: This study is a PRISMA systematic review of animal models used to discuss the usefulness and therapeutic parameters of aPDT-MB or its derivatives for treating infected skin wounds. RESULTS: After an extensive literature review, 13 controlled trials totaling 261 animals were selected to evaluate skin infection by leishmaniasis and cutaneous bacterial and fungal infections. All studies found results favoring the use of aPDT-MB. Great variability in parameters was found for radiant exposure from 12 to 360 J/cm2, MB diluted in saline solution or distilled water, irradiation time from 40 to 3600 s, irradiance most commonly at a maximum of 100 mW/cm2, and wavelength used mainly in the 630-670 nm range. CONCLUSION: MB is a safe and promising agent used as a photosensitizer in aPDT for skin-infected lesions. There is great variability in the parameters found. Comparisons concerning concentration, irradiation time, and light intensity need to be performed.


Sujet(s)
Bleu de méthylène , Photothérapie dynamique , Photosensibilisants , Animaux , Modèles animaux de maladie humaine , Bleu de méthylène/pharmacologie , Bleu de méthylène/usage thérapeutique , Photothérapie dynamique/méthodes , Photosensibilisants/pharmacologie , Photosensibilisants/usage thérapeutique
10.
J Photochem Photobiol B ; 256: 112943, 2024 Jul.
Article de Anglais | MEDLINE | ID: mdl-38788534

RÉSUMÉ

With the rapid development of nanotechnology, various functional nanomaterials have shown exciting potential in biomedical areas such as drug delivery, antitumor, and antibacterial therapy. These nanomaterials improve the stability and selectivity of loaded drugs, reduce drug-induced side effects, realize controlled and targeted drug release, and increase therapeutic efficacy. The increased resistance to antifungal microbicides in medical practice and their side effects stimulate interest in new therapies, such as Photodynamic Therapy (PDT), which do not generate resistance in microorganisms and effectively control the pathology. The present study aimed to evaluate, in vitro, the efficacy of photodynamic therapy on Candida albicans using 1,9-Dimethyl-Methylene Blue (DMMB) as photosensitizer, red LED (λ630), and nanoencapsulation of DMMB (RL-NPs/DMMB) using rhamnolipids produced by Pseudomonas aeruginosa to evaluate if there is better performance of DMMB + RL particles compared to DMMB alone via the characterization of DMMB + RL and colony forming count. The tests were carried out across six experimental groups (Control, DMMB, RL-NPs, RL-NPs/DMMB, PDT and PDT + RL-NPs/DMMB) using in the groups with nanoparticles, DMMB (750 ng/mL) encapsulated with rhamnolipids in a 1:1 ratio, the light source consisted of a prototype built with a set of red LEDs with an energy density of 20 J/cm2. The results showed that applying PDT combined with encapsulation (RL-NPs/DMMB) was a more practical approach to inhibit Candida albicans (2 log reduction) than conventional applications, with a possible clinical application protocol.


Sujet(s)
Candida albicans , Glycolipides , Bleu de méthylène , Nanoparticules , Photothérapie dynamique , Photosensibilisants , Pseudomonas aeruginosa , Candida albicans/effets des médicaments et des substances chimiques , Glycolipides/composition chimique , Glycolipides/pharmacologie , Bleu de méthylène/composition chimique , Photosensibilisants/composition chimique , Photosensibilisants/pharmacologie , Nanoparticules/composition chimique , Pseudomonas aeruginosa/effets des médicaments et des substances chimiques , Antifongiques/composition chimique , Antifongiques/pharmacologie , Préparation de médicament
11.
J Appl Oral Sci ; 32: e20230447, 2024.
Article de Anglais | MEDLINE | ID: mdl-38695448

RÉSUMÉ

OBJECTIVE: To evaluate whether antimicrobial photodynamic therapy (aPDT) repairs bisphosphonate-related osteonecrosis of the jaw (BRONJ) modulated by the reduction of NF-kB protein in a murine model. METHODOLOGY: Male Wistar rats (N=30) were divided into the following groups (n=6/group): negative control (NC); experimental osteonecrosis (ONE); ONE + photosensitizer (PS); ONE + photobiomodulation (PBM); and ONE + aPDT. Over 8 weeks, ONE was induced by zoledronic acid 250 µg/kg injections, except in the NC group, which received sterile 0.9% saline, followed by extraction of the lower left first molar. Red light laser irradiation (wavelength ~660 nm, power 50 mW, energy of 2 J, energy dose of 66.67 J/cm2 for 40 s) was performed once a week for 4 weeks. Methylene blue 0.3% was used as PS. The animals were euthanized and examined macroscopically for the presence of exposed bone and epithelial repair and microscopically by histochemical (hematoxylin-eosin and Masson's trichrome staining) and immunohistochemical (anti-NF-kB) methods. Macroscopic and histomorphometric data were analyzed by one-way ANOVA and Tukey's post-test (p<0.05). RESULTS: Mucosal repair, viable osteocytes, and NF-kB immunostaining were observed in the NC, ONE+PS, ONE+PBM, and ONE+aPDT groups. The ONE group showed no mucosal repair, showing empty lacunae and multifocal immunostaining for NF-kB. The ONE+PBM and ONE+aPDT groups had greater deposition of extracellular matrix and less necrotic bone tissue (p<0.05). CONCLUSION: PBM and aPDT treatments for BRONJ were effective for bone and epithelial repair, in addition to reducing inflammation mediated by the decrease of NF-kB protein in the irradiated regions.


Sujet(s)
Ostéonécrose de la mâchoire associée aux biphosphonates , Modèles animaux de maladie humaine , Immunohistochimie , Facteur de transcription NF-kappa B , Photothérapie dynamique , Photosensibilisants , Rat Wistar , Animaux , Mâle , Photothérapie dynamique/méthodes , Ostéonécrose de la mâchoire associée aux biphosphonates/anatomopathologie , Facteur de transcription NF-kappa B/analyse , Photosensibilisants/pharmacologie , Facteurs temps , Reproductibilité des résultats , Acide zolédronique/pharmacologie , Résultat thérapeutique , Imidazoles/pharmacologie , Diphosphonates/pharmacologie , Photothérapie de faible intensité/méthodes , Bleu de méthylène/pharmacologie , Bleu de méthylène/usage thérapeutique , Analyse de variance , Répartition aléatoire , Agents de maintien de la densité osseuse/pharmacologie
12.
Environ Sci Pollut Res Int ; 31(23): 34097-34111, 2024 May.
Article de Anglais | MEDLINE | ID: mdl-38693458

RÉSUMÉ

Dye effluents cause diverse environmental problems. Methylene blue (MB) dye stands out since it is widely used in the textile industry. To reduce the pollution caused by the MB, we developed biosorbents from tucumã seeds, where the in natura seeds were treated with NaOH (BT) and H3PO4 (AT) solutions and characterized by Boehm titration, point of zero charges, FTIR, TGA, BET, and SEM. It was observed that the acid groups predominate on the surface of the three biosorbents. The process was optimized for all biosorbents at pH = 8, 7.5 g/L, 240 min, C0 = 250 mg/L, and 45 ℃. BT was more efficient in removing MB (96.20%; QMax = 35.71 mg/g), while IT and AT removed around 60% in similar conditions. The adsorption process best fits Langmuir and Redlich-Peterson isotherms, indicating a hybrid adsorption process (monolayer and multilayer) and pseudo-second-order kinetics. Thermodynamic data confirmed an endothermic and spontaneous adsorption process, mainly for BT. MB was also recovered through a desorption process with ethanol, allowing the BT recycling and reapplication of the dye. Thus, an efficient and sustainable biosorbent was developed, contributing to reducing environmental impacts.


Sujet(s)
Bleu de méthylène , Graines , Thermodynamique , Polluants chimiques de l'eau , Bleu de méthylène/composition chimique , Cinétique , Adsorption , Graines/composition chimique , Polluants chimiques de l'eau/composition chimique
13.
Arch Oral Biol ; 164: 105978, 2024 Aug.
Article de Anglais | MEDLINE | ID: mdl-38718465

RÉSUMÉ

OBJECTIVE: To evaluate the effect of the association of potassium iodide to antimicrobial photodynamic therapy on human carious dentin produced with a microcosm biofilm model. METHODS: A microcosm biofilm model was used to generate a caries lesion on human dentin. Pooled human saliva diluted with glycerol was used as an inoculum on specimens immersed on McBain artificial saliva enriched with 1 % sucrose (24 h at 37 °C in 5 % CO2). After refreshing culture media for 7 days, the dentin specimens were divided in 5 groups (3 specimens per group, in triplicate; n = 9): C (NaCl 0.9 %), CX (2 % chlorhexidine), PKI (0.01 % methylene blue photosensitizer+50 mM KI), L (laser at 15 J, 180 s, 22.7 J/cm2), and PKIL (methylene blue + KI + Laser). After the treatments, dentin was collected, and a 10-fold serial dilution was performed. The number of total microorganisms, total lactobacilli, total streptococci, and Streptococcus mutans was analyzed by microbial counts (CFU/mL). After normality and homoscedasticity analysis, the Welch's ANOVA and Dunnett's tests were used for CFU. All tests used a 5 % significance level. RESULTS: CX and PKIL groups showed significant bacterial decontamination of dentin, compared to group C (p < 0.05) reaching reductions up to 3.8 log10 for CX for all microorganisms' groups and PKIL showed 0.93, 1.30, 1.45, and 1.22 log10 for total microorganisms, total lactobacilli, total streptococci, and S. mutans, respectively. CONCLUSION: aPDT mediated by the association of KI and methylene blue with red laser reduced the viability of microorganisms from carious dentin and could be a promising option for cavity decontamination.


Sujet(s)
Biofilms , Caries dentaires , Dentine , Bleu de méthylène , Photothérapie dynamique , Photosensibilisants , Iodure de potassium , Streptococcus mutans , Humains , Bleu de méthylène/pharmacologie , Bleu de méthylène/usage thérapeutique , Photothérapie dynamique/méthodes , Caries dentaires/microbiologie , Caries dentaires/traitement médicamenteux , Caries dentaires/thérapie , Dentine/microbiologie , Dentine/effets des médicaments et des substances chimiques , Iodure de potassium/pharmacologie , Iodure de potassium/usage thérapeutique , Biofilms/effets des médicaments et des substances chimiques , Streptococcus mutans/effets des médicaments et des substances chimiques , Photosensibilisants/usage thérapeutique , Photosensibilisants/pharmacologie , Salive/microbiologie , Lactobacillus/effets des médicaments et des substances chimiques , Streptococcus/effets des médicaments et des substances chimiques , Chlorhexidine/pharmacologie , Chlorhexidine/usage thérapeutique , Techniques in vitro , Numération de colonies microbiennes , Salive artificielle , Lasers
14.
Braz J Cardiovasc Surg ; 39(3): e20230066, 2024 Apr 03.
Article de Anglais | MEDLINE | ID: mdl-38569061

RÉSUMÉ

Microvasculature failure is expected in sepsis and at higher amine concentrations. Therefore, special attention focused individually on microcirculation is needed. Here, we present that methylene blue can prevent leukocytes from adhering to the endothelium in a rat model of lipopolysaccharide-induced endotoxemia. As hypothesis evidence, an intravital microscopy image is presented.


Sujet(s)
Sepsie , Vasoplégie , Rats , Animaux , Bleu de méthylène/pharmacologie , Bleu de méthylène/usage thérapeutique , Vasoconstricteurs , Vasoplégie/traitement médicamenteux , Sepsie/traitement médicamenteux , Microscopie intravitale
15.
Int J Mol Sci ; 25(8)2024 Apr 15.
Article de Anglais | MEDLINE | ID: mdl-38673952

RÉSUMÉ

This study focuses on synthesizing and characterizing a graphene oxide/ZnTiO3/TiO2 (GO/ZTO/TO) composite to efficiently remove methylene blue (MB) from water, presenting a novel solution to address industrial dye pollution. GO and ZTO/TO were synthesized by the modified Hummers and sol-gel methods, respectively, while GO/ZTO/TO was prepared using a hydrothermal process. The structural and surface properties of the composite were characterized using various analytical techniques confirming the integration of the constituent materials and suitability for dye adsorption. The study revealed that GO/ZTO/TO exhibits an adsorption capacity of 78 mg g-1 for MB, with only a 15% reduction in adsorption efficiency until the fifth reuse cycle. Furthermore, the study suggests optimal adsorption near neutral pH and enhanced performance at elevated temperatures, indicating an endothermic reaction. The adsorption behavior fits the Langmuir isotherm, implying monolayer adsorption on homogeneous surfaces, and follows pseudo-second-order kinetics, highlighting chemical interactions at the surface as the rate-limiting step. The photocatalytic degradation of MB by GO/ZTO/TO follows pseudo-first-order kinetics, with a higher rate constant than that of GO alone, demonstrating the enhanced photocatalytic activity of the composite. In conclusion, GO/ZTO/TO emerges as a promising and sustainable approach for water purification, through an adsorption process and subsequent photocatalytic degradation.


Sujet(s)
Graphite , Bleu de méthylène , Titane , Polluants chimiques de l'eau , Purification de l'eau , Bleu de méthylène/composition chimique , Bleu de méthylène/isolement et purification , Titane/composition chimique , Adsorption , Graphite/composition chimique , Catalyse , Polluants chimiques de l'eau/composition chimique , Polluants chimiques de l'eau/isolement et purification , Purification de l'eau/méthodes , Cinétique , Processus photochimiques , Concentration en ions d'hydrogène , Zinc/composition chimique
16.
Photodiagnosis Photodyn Ther ; 46: 104066, 2024 Apr.
Article de Anglais | MEDLINE | ID: mdl-38552814

RÉSUMÉ

Balanoposthitis can affect men in immunocompromised situations, such as HIV infection and diabetes. The main associated microorganism is Candida albicans, which can cause local lesions, such as the development of skin cracks associated with itching. As an alternative to conventional treatment, there is a growing interest in the photodynamic inactivation (PDI). It has been shown that the association of photosensitizers with metallic nanoparticles may improve the effectiveness of PDI via plasmonic effect. We have recently shown that the association of methylene blue (MB), a very known photosensitizer, with silver prismatic nanoplatelets (AgNPrs) improved PDI of a resistant strain of Staphylococcus aureus. To further investigate the experimental conditions involved in PDI improvement, in the present study, we studied the effect of MB concentration associated with AgNPrs exploring spectral analysis, zeta potential measurements, and biological assays, testing the conjugated system against C. albicans isolated from a resistant strain of balanoposthitis. The AgNPrs were synthesized through silver anisotropic seed growth induced by the anionic stabilizing agent poly(sodium 4-styrenesulfonate) and showed a plasmon band fully overlapping the MB absorption band. MB and AgNPrs were conjugated through electrostatic association and three different MB concentrations were tested in the nanosystems. Inactivation using red LED light (660 nm) showed a dose dependency in respect to the MB concentration in the conjugates. Using the highest MB concentration (100 µmol⋅L-1) with AgNPr, it was possible to completely inactivate the microorganisms upon a 2 min irradiation exposure. Analyzing optical changes in the conjugates we suggest that these results indicate that AgNPrs are enhancers of MB photodynamic action probably by a combined mechanism of plasmonic effect and reduction of MB dimerization. Therefore, MBAgNPrs can be considered a suitable choice to be applied in PDI of resistant microorganisms.


Sujet(s)
Candida albicans , Bleu de méthylène , Photothérapie dynamique , Photosensibilisants , Argent , Candida albicans/effets des médicaments et des substances chimiques , Bleu de méthylène/pharmacologie , Photosensibilisants/pharmacologie , Photothérapie dynamique/méthodes , Argent/pharmacologie , Nanoparticules métalliques/usage thérapeutique , Nanoparticules métalliques/composition chimique , Balanite/traitement médicamenteux , Balanite/microbiologie , Humains
17.
Environ Sci Pollut Res Int ; 31(11): 16453-16472, 2024 Mar.
Article de Anglais | MEDLINE | ID: mdl-38321273

RÉSUMÉ

The synthesis and characterization of a hydrochar/CeO2 composite along with its evaluation in methylene blue degradation under visible light are presented. The methodology consisted of a single-pass hydrothermal method, having as synthesis conditions 9 h of reaction time, 210 °C, autogenous pressure, and a biomass/CeO2 ratio of 100:1. The composite characterization revealed good dispersion of CeO2 in the carbonaceous matrix and significant synergy in the composite activation using visible irradiation. The photodegradation experiments showed an efficiency of 98% for white LED light, 91% for UV light, 96% for solar irradiation, and 85% for blue LED light using as conditions pH 7.0, 50 mg of composite, 50 mL of solution, 10 mg/L of dye initial concentration, and 120 min of contact time. Meanwhile, the reusability experiments evidenced a reuse capacity of up to five times with a constant photodegradation efficiency (99%); moreover, it was determined that the presence of electrolytes at pH below 7.0 during degradation negatively affected methylene blue degradation. Finally, the results of this work demonstrate that the hydrochar/CeO2 composite can be synthesized by a green method and used for the efficient treatment of water contaminated with methylene blue.


Sujet(s)
Lumière , Bleu de méthylène , Bleu de méthylène/composition chimique , Rayons ultraviolets , Photolyse , Blue Light
18.
Crit Care ; 28(1): 46, 2024 02 16.
Article de Anglais | MEDLINE | ID: mdl-38365828

RÉSUMÉ

Septic shock typically requires the administration of vasopressors. Adrenergic agents remain the first choice, namely norepinephrine. However, their use to counteract life-threatening hypotension comes with potential adverse effects, so that non-adrenergic vasopressors may also be considered. The use of agents that act through different mechanisms may also provide an advantage. Nitric oxide (NO) is the main driver of the vasodilation that leads to hypotension in septic shock, so several agents have been tested to counteract its effects. The use of non-selective NO synthase inhibitors has been of questionable benefit. Methylene blue, an inhibitor of soluble guanylate cyclase, an important enzyme involved in the NO signaling pathway in the vascular smooth muscle cell, has also been proposed. However, more than 25 years since the first clinical evaluation of MB administration in septic shock, the safety and benefits of its use are still not fully established, and it should not be used routinely in clinical practice until further evidence of its efficacy is available.


Sujet(s)
Hypotension artérielle , Choc septique , Humains , Bleu de méthylène/effets indésirables , Choc septique/traitement médicamenteux , Choc septique/métabolisme , Hypotension artérielle/traitement médicamenteux , Soluble guanylyl cyclase , Norépinéphrine , Vasoconstricteurs/effets indésirables
19.
Environ Sci Pollut Res Int ; 31(41): 53706-53717, 2024 Sep.
Article de Anglais | MEDLINE | ID: mdl-38267649

RÉSUMÉ

The present study focuses on the elaboration of magnetic nanocomposites by the in situ incorporation of magnetite (Fe3O4) nanoparticles (NPs) with spherical and nanoflower-like morphologies in graphitic carbon nitride (g-C3N4) sheets using two different synthetic routes. Nanomaterials are characterized by TEM, SEM, XRD, FTIR, BET, zetametry, vibrating sample magnetometry, and UV-vis absorption spectroscopy. The decoration of the carbon nitride matrix with the magnetic NPs enhanced optical and textural properties. The influence of the morphology of the magnetic NPs on the adsorptive and photocatalytic properties of the nanocomposites under different pH conditions (4.5, 6.9, and 10.6) was assessed from batch tests to remove methylene blue (MB) from aqueous solutions. In extreme pH conditions, the nanocomposites exhibited lower or equivalent MB removal capacity compared to the pure g-C3N4. However, at neutral medium, the nanocomposite with incorporated Fe3O4 nanoflowers showed a significantly higher removal efficiency (80.7%) due to the combination of a high adsorption capacity and a good photocatalytic activity in this pH region. The proposed nanocomposite is a promising alternative to remove cationic dyes from water by magnetic assistance, since no pH adjustment of the polluted effluent is required, reducing costs and environmental impact in the dyeing industry.


Sujet(s)
Bleu de méthylène , Nanocomposites , Nitriles , Polluants chimiques de l'eau , Bleu de méthylène/composition chimique , Nanocomposites/composition chimique , Concentration en ions d'hydrogène , Polluants chimiques de l'eau/composition chimique , Nitriles/composition chimique , Adsorption , Purification de l'eau/méthodes , Agents colorants/composition chimique , Graphite/composition chimique , Composés de l'azote
20.
J Biophotonics ; 17(4): e202300412, 2024 04.
Article de Anglais | MEDLINE | ID: mdl-38253349

RÉSUMÉ

This study aimed to evaluate the clinical evolution of patients with diabetic foot ulcer treated with antimicrobial photodynamic therapy (aPDT) using the Bates-Jensen (BJ) scale. A total of 21 patients were monitored, with an average age of 58 years. Patients underwent the standard treatment protocol of the institution, supplemented with aPDT utilizing 0.01% methylene blue (MB) and laser irradiation (660 nm, 100 mW, 6 J per point). Following aPDT, the lesions were protected with hydrofiber dressings containing silver. The Bates-Jensen Scale was employed at pre-treatment and post-aPDT sessions to assess lesion progression. The results demonstrated a significant difference between pre- and post-treatment values in the overall BJ score. The use of MB in aPDT proved to be an effective, safe, well-tolerated treatment with high patient adherence and the potential for implementation in the care of diabetic foot conditions.


Sujet(s)
Anti-infectieux , Diabète , Pied diabétique , Photothérapie dynamique , Humains , Adulte d'âge moyen , Photosensibilisants/usage thérapeutique , Pied diabétique/traitement médicamenteux , Photothérapie dynamique/méthodes , Résultat thérapeutique , Bleu de méthylène/pharmacologie , Bleu de méthylène/usage thérapeutique
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