Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Polymers (Basel) ; 15(12)2023 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-37376251

RESUMO

Poly(2-hydroxyethyl methacrylate) (polyHEMA) hydrogels are commonly used in biomaterials such as contact lenses. However, water evaporation from these hydrogels can cause discomfort to wearers, and the bulk polymerization method used to synthesize them often results in heterogeneous microstructures, reducing their optical properties and elasticity. In this study, we synthesized polyHEMA gels using a deep eutectic solvent (DES) instead of water and compared their properties to traditional hydrogels. Fourier-transform infrared spectroscopy (FTIR) showed that HEMA conversion in DES was faster than in water. DES gels also demonstrated higher transparency, toughness, and conductivity, along with lower dehydration, than hydrogels. The compressive and tensile modulus values of DES gels increased with HEMA concentration. A DES gel with 45% HEMA showed excellent compression-relaxation cycles and had the highest strain at break value in the tensile test. Our findings suggest that DES is a promising alternative to water for synthesizing contact lenses with improved optical and mechanical properties. Furthermore, DES gels' conduction properties may enable their application in biosensors. This study presents an innovative approach to synthesizing polyHEMA gels and provides insights into their potential applications in the biomaterials field.

2.
Macromol Biosci ; 23(3): e2200368, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36404641

RESUMO

This study focuses on the preparation of stretchable zwitterionic poly(sulfobetaine methacrylate) (PSBMA) hydrogels. To address the weak mechanical properties of chemically crosslinked PSBMA hydrogels, a physical crosslinking method utilizing hydrophobic interactions to crosslink hydrogels to approach tough properties is developed. Here, sodium dodecyl sulfate (SDS)-based micelle is used as a physical crosslinker to prepare physically crosslinked PSBMA (PSBMAphy ) hydrogels, and ethylene glycol dimethylacrylate (EGDMA) is used to prepare a control group of chemically crosslinked PSBMA (PSBMAchem ) hydrogels. The mechanical properties of the two hydrogels are compared, and PSBMAphy hydrogels exhibit greater flexibility than the PSBMAchem hydrogels. When the PSBMAphy hydrogels are subjected to external forces, the micelles act as dynamic crosslinking sites, allowing the stress to disperse and prevent the hydrogel from breaking. In addition, the PSBMAphy hydrogels have nearly 100% self-healing properties within 2.5 min. The PSBMAphy hydrogels exhibit usable adhesive properties to porcine skin and subcutis. MTT and hemolysis tests show that the PSBMAphy hydrogels have excellent biocompatibility and hemocompatibility. This study proposes that the multifunctional PSBMAphy hydrogels with micelles will be potential to carry drugs for use in drug delivery systems in the future.


Assuntos
Hidrogéis , Micelas , Hidrogéis/farmacologia , Hidrogéis/química , Metacrilatos/química , Sistemas de Liberação de Medicamentos
3.
Zhongguo Zhong Yao Za Zhi ; 46(7): 1769-1782, 2021 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-33982481

RESUMO

NAC(NAM/ATAF/CUC) protein plays an important role in plant growth and development, secondary cell wall formation and stress response. In this study, based on the sequencing data of Angelica dahurica, the NAC family was systematically analyzed using bioinformatics methods and its expression pattern was analyzed. Studies showed that 75 candidate genes had been selected from the NAC transcription factor family of A. dahurica, with the protein size of 148-641, all of which were unstable hydrophilic proteins. Most NAC proteins were localized in the nucleus, and had complete NAC domain. Phylogenetic analysis of NAC family proteins of A.dahurica and Arabidopsis thaliana showed that among the 17 subfamilies, NAC members were unevenly distributed in each subfamily, indicating that the evolution of species is developing in multiple directions. Among them, ANAC063 subfamily contained no NAC sequence of A. dahurica, which might be due to the functional evolution of the species. Analysis of protein transmembrane structure and signal peptide showed that NAC transcription factor could carry out transmembrane transportation, but its signal peptide function had not been found. Expression analysis showed that most transcription factors responded to abiotic stress and hormones to varying degrees, and the effects of hormones were obvious, especially ABA and IAA. In different organs of A. dahurica, most members of the NAC family had higher expression in root phloem, followed by root xylem. This study lays a foundation for further research on the function of A. dahurica NAC transcription factor and for solving the biological problems of A. dahurica.


Assuntos
Angelica , Biologia Computacional , Regulação da Expressão Gênica de Plantas , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estresse Fisiológico , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
4.
Zhongguo Zhong Yao Za Zhi ; 44(8): 1524-1530, 2019 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-31090314

RESUMO

In this study,the leaves of autumn-sown Angelica dahurica var. formosana from Sichuan province in different growth years was used to explore the fitting model of photosynthetic response curve and the different photosynthetic physiological characteristics between annual and biennial A. dahurica var. formosana from Sichuan province. The results showed that the fitting model of the optimum light response curve of the leaves of A. dahurica var. formosana from Sichuan province with different growth years was all rectangular hyperbolic correction model. The light saturation points were 1 600,1 700 µmol·m-2·s-1,the light compensation points were17. 98,52. 23 µmol·m-2·s-1 in the leaves of annual and biennial plant,respectively. The diurnal variation curves of net photosynthetic rate,transpiration rate and stomatal conductance in the leaves all acted as a single peak value wave. The daily mean values of net photosynthetic rate and transpiration rate in the leaves of biennial plant were significantly higher than that of annual plant. There was no significant difference in daily mean stomatal conductance. The net photosynthetic rate was significantly positively correlated with stomatal conductance in both of the different growth years. The net photosynthetic rate of annual and biennial A. dahurica var. formosana from Sichuan province had extremely significant and significantly negative correlation with the intercellular CO2 respectively. The transpiration rate of annual plant was positively correlated with the effective photosynthetic radiation intensity and air temperature,but had significantly negative correlation with the intercellular CO2 concentration. The transpiration rate of biennial plant had extremely positive correlation with the effective photosynthetic radiation intensity,and negatively correlated with the intercellular CO2 concentration. In conclusion,the photosynthetic efficiency of the leaves in biennial plant of A. dahurica var. formosana from Sichuan province was higher than that in annual plant,but the ability to utilize weak light was lower than that of annual plant. It should be planted in the sunny field.


Assuntos
Angelica/fisiologia , Fotossíntese , Folhas de Planta/fisiologia , Dióxido de Carbono , China , Transpiração Vegetal , Estações do Ano , Temperatura
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...