Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 3 de 3
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
ACS Appl Mater Interfaces ; 16(5): 6008-6024, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38282284

RESUMO

The synthesis of low-temperature poly(heptazine imide) (PHI) presents a significant challenge. In this context, we have developed a novel low-temperature synthesis strategy for PHI in this work. This strategy involves the introduction of Na+ ions, which etch and disrupt the conjugated structure of carbon nitride (CN) during assisted thermal condensation. This disruption leads to the partial decomposition of the heptazine ring structure, resulting in the formation of C≡N functionalities on the CN surface, which are enriched with hydroxyl groups and undergo cyano modification. The formation of heterojunctions between CN and ZnO, which facilitate charge transfer along an immobilization pathway, accelerated charge transfer processes and improved reactant adsorption as well as electron utilization efficiency. The resulting catalyst was employed for the room temperature, atmospheric pressure, and solvent-free photocatalytic selective oxidation of cumene (CM), achieving a cumene conversion rate of 28.7% and a remarkable selectivity of 92.0% toward the desired product, cumene hydroperoxide (CHP). Furthermore, this CHP induced oxidative reactions, as demonstrated by the successful oxidation of benzylamine to imine and the oxidation of sulfide to sulfoxide, both yielding high product yields. Additionally, the utilization of a continuous-flow device significantly reduces the reaction time required for these oxidation processes. This work not only introduces an innovative approach to environmentally friendly, sustainable, clean, and efficient PHI synthesis but also underscores the promising potential and advantages of carbon nitride-based photocatalysts in the realm of sustainable and green organic transformations.

2.
RSC Adv ; 10(33): 19669-19685, 2020 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-35515434

RESUMO

Graphitic carbon nitride (g-C3N4) was prepared by a simple thermal polymerization method in this work. The effects of precursor type, thermal polymerization temperature, constant temperature time and atmosphere on the crystal structure, morphology, elemental composition, valence distribution, light absorption properties and photocatalytic activity of the prepared photocatalytic materials were investigated. Taking rhodamine B (RhB) as the target degradant, the blue light catalytic activity of the photocatalytic material was studied in detail. The experimental results showed that the final pyrolysis temperature and constant temperature time are positively related to the adsorption characteristics and photocatalytic ability of the prepared materials. In addition, the adsorption capacity and photocatalytic activity of the products obtained in Ar and H2 atmospheres are better than those produced in CO and CH4, which can be attributed to the combined effect of large specific surface area and structural defects of the materials. The sample's large specific surface area, wide band gap, and excellent photogenerated carrier separation and transfer capabilities make the adsorption performance and photocatalytic performance of the products obtained with ammonium thiocyanate and thiourea as precursors better than those prepared from melamine and dicyandiamide. g-C3N4 prepared by using ammonium thiocyanate as precursor at 550 °C for 5 h under a hydrogen atmosphere showed the best catalytic activity for the degradation of RhB under blue light. It was demonstrated that g-C3N4 prepared exhibited good stability and reusability after four repeat experiments. The active components that play major roles in the degradation of RhB described herein were holes and superoxide radicals, which was inferred by free radical trapping experiments. This work provides a theoretical basis for the idea of converting the mixed salts of desulfurization waste liquid containing ammonium thiocyanate into an excellent photocatalyst g-C3N4 with visible light response.

3.
J Ethnopharmacol ; 162: 244-52, 2015 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-25577992

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Jinlida (JLD) is a compound preparation formulated on the basis of traditional Chinese medicine and is officially approved for the treatment of type 2 diabetes (T2DM) in China. We aimed to elucidate the mechanism of JLD treatment, in comparison to metformin treatment, on ameliorating insulin sensitivity in insulin resistant rats and to reveal its anti-oxidant properties. MATERIALS AND METHODS: Rats were fed with standard or high-fat diet for 6 weeks. After 6 weeks, the high-fat fed rats were subdivided into five groups and orally fed with JLD or metformin for 8 weeks. Fasting blood glucose (FBG), fasting blood insulin, blood lipid and antioxidant enzymes were measured. Intraperitoneal glucose tolerance test (IPGTT) and hyperinsulinemic euglycemic clamp technique were carried out to measure insulin sensitivity. Gene expression of the major signaling pathway molecules that regulate glucose uptake, including insulin receptor (INSR), insulin receptor substrate-1 (IRS-1), phosphoinositide-3-kinase (PI3K), protein kinase beta (AKT), and glucose transporter type 2 (GLUT2), were assessed by quantitative RT-PCR. The totle and phosphorylation expression of IRS-1, AKT, JNK and p38MAPK were determined by Western blot. RESULTS: Treatment with JLD effectively ameliorated the high-fat induced hyperglycemia, hyperinsulinemia and hyperlipidemia. Similar to metformin, the high insulin resistance in high-fat fed rats was significantly decreased by JLD treatment. JLD displayed anti-oxidant effects, coupled with up-regulation of the insulin signaling pathway. The attenuation of hepatic oxidative stress by JLD treatment was associated with reduced phosphorylation protein levels of JNK and p38MAPK. CONCLUSIONS: Treatment with JLD could moderate glucose and lipid metabolism as well as reduce hepatic oxidative stress, most likely through the JNK and p38MAPK pathways.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/etiologia , Gorduras na Dieta/efeitos adversos , Medicamentos de Ervas Chinesas/farmacologia , Resistência à Insulina , Estresse Oxidativo/efeitos dos fármacos , Animais , Gorduras na Dieta/administração & dosagem , Hipoglicemiantes/farmacologia , Masculino , Metformina/farmacologia , Ratos , Ratos Sprague-Dawley
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...