Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
J Microencapsul ; 40(8): 613-629, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37815151

RESUMO

This study aims to evaluate the radioprotective effects of liposomes encapsulating curcumin (Lip-CUR), silibinin (Lip-SIL), α-tocopherol (Lip-TOC), quercetin (Lip-QUE) and resveratrol (Lip-RES) in alleviating the adverse effects of ionising irradiation on human lymphoctyes and skin cells in radiotherapy. Liposomes encapsulating the above natural radioprotectants (Lip-NRPs) were prepared by the film hydration method combined with sonication. Their radioprotective effects for the cells against X-irradiation was evaluated using trypan-blue assay and γ-H2AX assay. All prepared Lip-NRPs had a mean diameter less than 240 nm, polydispersity index less than 0.32, and zeta potential more than -23 mV. Among them, the radioprotective effect of Lip-RES was lowest, while that of Lip-QUE was highest. Lip-SIL also exhibited a high radioprotective effect despite its low DPPH-radical scavenging activity (12.9%). The radioprotective effects of Lip-NRPs do not solely depend on the free radical scavenging activity of NRPs but also on their ability to activate cellular mechanisms.


Assuntos
Curcumina , Lipossomos , Humanos , Resveratrol , Pele , Curcumina/farmacologia , Linfócitos
2.
Heliyon ; 9(10): e20466, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37810813

RESUMO

The persistent presence of organic pollutants like dyes in water environment necessitates innovative approaches for efficient degradation. In this research, we developed an advanced hybrid catalyst by combining metal oxides (Cu2O, Fe3O4) with UiO-66, serving as a heterogeneous Fenton catalyst for for efficient RB19 breakdown in water with H2O2. The control factors to the catalytic behavior were also quantified by machine learning. Experimental results show that the catalytic performance was much better than its individual components (P < 0.05 & non-zero 95% C.I). The improved catalytic efficiency was linked to the occurrence of active metal centers (Fe, Cu, and Zr), with Cu(I) from Cu2O playing a crucial role in promoting increased production of HO•. Also, UiO-66 served as a catalyst support, attracting pollutants to the reaction center, while magnetic Fe3O4 aids catalyst recovery. The optimal experimental parameters for best performance were pH at 7, catalyst loading of 1.6 g/L, H2O2 strength of 0.16 M, and reaction temperature of 25 °C. The catalyst can be magnetically separated and regenerated after five recycling times without significantly reducing catalytic activity. The reaction time and pH were ranked as the most influencing factors on catalytic efficiency via Random Forest and SHapley Additive exPlanations models. The findings show that developed catalyst is a suitable candidate to remove dyes in water by Fenton heterogeneous reaction.

3.
Environ Res ; 215(Pt 1): 114213, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36055393

RESUMO

New wood-based composite materials with thermal conductivity are greatly desired in the fields of packaging materials for electronic components. In this study, a new multifunctional composite material (M@FC) is prepared by simply blending clay-like Ti3C2Tx MXene and delignified wood fibers together, and then followed by an infusing epoxy resin with environmentally friendly vacuum assisted resin transfer molding (VARTM) process. The resulting M@FC (0.92 W m-1 K-1) possesses superior thermal conductivity as compared to natural wood (0.099 W m-1 K-1) and most polymers. Furthermore, after the VARTM process, the structure of the M@FC is tighter, and thus showing excellent mechanical properties (tensile strength of 93.0 MPa and flexural strength of 172.7 MPa). In addition, good water resistance and excellent flame retardant property are observed for M@FC. The improvement of thermal conductivity provides the possibility for its application for packaging materials in electronic components. This study using waste wood as the important component provides a new idea for carbon cycling and recycling of natural resources.


Assuntos
Pegada de Carbono , Retardadores de Chama , Carbono/química , Argila , Resinas Epóxi , Lignina , Polímeros/química , Condutividade Térmica , Água/química
4.
Environ Res ; 198: 110481, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33220248

RESUMO

In this study, natural core-shell structure activated carbon beads (ACBs) from Litsea glutinosa seeds were successfully produced, characterized, and applied for adsorption of methylene blue (MB). The ACBs were prepared using single-step carbonization-activation with NaHCO3 at the optimized activation temperature, time, and activating agent concentration of 450 °C, 60 min, and 5%, respectively. Batch experiments were performed to determine the optimum adsorption conditions, suitable kinetic and isotherm models, and thermodynamic parameters for the adsorption of MB onto ACBs. The results showed that the ACBs were displayed as highly porous natural core-shell spheres with a diameter of about 5 mm. The adsorption of MB dye on ACBs was a spontaneous endothermic process, followed the Langmuir isotherm and the pseudo-second-order kinetic models with the rate-controlling step of both external diffusion and intra-particle diffusion. At the optimum conditions (pH of 9, the contact time of 10 h, the temperature of 40 °C, and an adsorbent dosage of 6 g/L), the maximum adsorption capacity reached 29.03 mg/g. The thermal method turned out to be more suitable for regenerating ACBs compared to the chemical method. The ACBs exhibited high reusability and stability, its adsorption efficiency could maintain more than 90% after five consecutive cycles of use. The electrostatic attraction, π-π interaction, hydrogen bonding, and pore-filling were identified as primary contributions to the adsorption mechanism. The overall results revealed that the ACBs could be used as a potential adsorbent for removing MB from water media.


Assuntos
Litsea , Poluentes Químicos da Água , Purificação da Água , Adsorção , Carvão Vegetal , Concentração de Íons de Hidrogênio , Cinética , Azul de Metileno/análise , Sementes/química , Termodinâmica , Poluentes Químicos da Água/análise
5.
Environ Technol ; 41(21): 2817-2832, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30767655

RESUMO

Magnetic activated carbon/chitosan composite (MACCS) beads from spent coffee grounds and shrimp shells were synthesized using green tea extract as a crosslinker. The adsorbent was then applied for removal of Ni(II) ions from aqueous solution after carefully characterizing it by various techniques (XRD, FTIR, FE-SEM, EDX, VSM and BET). The adsorption kinetics, isotherms, thermodynamics, the effects of key adsorption factors such as the pH value, initial Ni(II) concentration, contact time, adsorbent dose and temperature were investigated in detail. A possible adsorption mechanism was proposed. The results indicated that the adsorption process was thermodynamically favourable, spontaneous, endothermic, and was best described by the Langmuir isotherm and pseudo-second-order kinetic models. The MACCS beads with an optimum CS to MAC weight ratio estimated as 60:40 gave the maximum monolayer adsorption capacity for Ni(II) ions of 108.70 mg g-1 at 25°C, pH of 6, adsorbent dose of 1.0g L-1 and a contact time of 6 h. The recycling study confirmed that the adsorption ability of MACCS beads towards Ni(II) ions maintained well after five consecutive cycles with the removal efficiency greater than 86.25%. Eventually, the MACCS beads could be used as an environmentally-friendly and highly efficient adsorbent for removal of Ni(II) ions from wastewater due to the advantages of high efficiency, rapid separation and good reusability.


Assuntos
Quitosana , Poluentes Químicos da Água , Adsorção , Carvão Vegetal , Café , Concentração de Íons de Hidrogênio , Íons , Cinética , Fenômenos Magnéticos , Extratos Vegetais , Chá
6.
J Microencapsul ; 36(2): 156-168, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31030591

RESUMO

This study aimed to compare the in vivo effectiveness between curcumin-oligochitosan nanoplexes (CUR-OCH nanoplexes) and oligochitosan-coated curcumin-encapsulated liposomes (OCH-Lip-CUR) with respect to wound healing and scar treatment. Firstly, CUR-OCH nanoplexes was prepared by drug-polysaccharide complexation method and OCH-Lip-CUR was prepared by a combining method of lipid-film hydration and sonication. Their in vitro cytotoxicity and in vivo wound healing and scar treatment effectiveness were evaluated using 3T3 cells and mice Mus musculus var. Albino, respectively. The resutls indicated that both of them were in nanosize with a moderate PDI (less than 0.3), and exhibited negligible cytotoxicity at low CUR concentration (0.01 mg/mL). Moreover, their application onto wounds resulted in faster healing and higher scar treatment effectiveness than control samples. Interestingly, OCH-Lip-CUR exhibited higher in vivo effectiveness than CUR-OCH nanoplexes. However, based on their own advantages, both of them were good candidates for a commercial formulation for wound healing and scar treatment.


Assuntos
Anti-Inflamatórios não Esteroides/administração & dosagem , Cicatriz/tratamento farmacológico , Curcumina/administração & dosagem , Cicatrização/efeitos dos fármacos , Células 3T3 , Animais , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/uso terapêutico , Quitina/análogos & derivados , Quitina/química , Quitosana , Curcumina/análogos & derivados , Curcumina/uso terapêutico , Liberação Controlada de Fármacos , Lipossomos/química , Masculino , Camundongos , Nanoconjugados/química , Oligossacarídeos
7.
Adv Healthc Mater ; 7(12): e1800074, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29749708

RESUMO

Fiber-based sensors integrated on textiles or clothing systems are required for the next generation of wearable electronic platforms. Fiber-based physical sensors are developed, but the development of fiber-based temperature sensors is still limited. Herein, a new approach to develop wearable temperature sensors that use freestanding single reduction graphene oxide (rGO) fiber is proposed. A freestanding and wearable temperature-responsive rGO fiber with tunable thermal index is obtained using simple wet spinning and a controlled graphene oxide reduction time. The freestanding fiber-based temperature sensor shows high responsivity, fast response time (7 s), and good recovery time (20 s) to temperature. It also maintains its response under an applied mechanical deformation. The fiber device fabricated by means of a simple process is easily integrated into fabric such as socks or undershirts and can be worn by a person to monitor the temperature of the environment and skin temperature without interference during movement and various activities. These results demonstrate that the freestanding fiber-based temperature sensor has great potential for fiber-based wearable electronic platforms. It is also promising for applications in healthcare and biomedical monitoring.


Assuntos
Têxteis , Termometria/instrumentação , Termometria/métodos , Dispositivos Eletrônicos Vestíveis , Adulto , Humanos , Masculino , Monitorização Fisiológica/instrumentação , Monitorização Fisiológica/métodos , Temperatura
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA