Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Spectrochim Acta A Mol Biomol Spectrosc ; 316: 124355, 2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-38701575

RESUMO

As a water pollutant with excellent solubility, 2,4,6-trinitrophenol (also known as picric acid, PA) poses a potential threat to the natural environment and human health, so it is crucial important to detect PA in water. In this study, a novel composite material (MIL-53(Al)@R6G) was successfully synthesized by encapsulating Rhodamine 6G into a metal-organic frame material, which was used for fluorescence detection of picric acid (PA) in water. The composite exhibits bright yellow fluorescence emission with a fluorescence quantum yield of 58.23 %. In the process of PA detection, the composite has excellent selectivity and anti-interference performance, and PA can significantly quench the fluorescence intensity of MIL-53(Al)@R6G. MIL-53(Al)@R6G has the advantages of fast detection time (20 s), wide linear range (1-100 µM) and low detection limit (4.8 nM). In addition, MIL-53(Al)@R6G has demonstrated its potential for the detection of PA in environmental water samples with satisfactory results.

2.
ACS Omega ; 9(14): 16147-16159, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38617641

RESUMO

In low-permeability coal reservoirs, utilizing the organic solvent N-methyl-2-pyrrolidone (NMP) has emerged as an effective approach to improving the coal pore structure and enhancing coalbed methane productivity. However, the exact mechanisms of how solvent erosion alters functional groups and develops pores remain incompletely understood. This study utilized Fourier transform infrared spectroscopy and low-field nuclear magnetic resonance to assess the impact of NMP on the functional groups and pore structures of lignite, bituminous coal, and anthracite. The results indicate that a 6 h treatment with NMP led to an increased proportion of oxygen-containing functional groups in all coal samples, accompanied by a decrease in hydroxyls and aliphatic hydrocarbons. The aromaticity of the coal samples was enhanced to varying degrees, most notably for lignite. In terms of pore modification, the porosity of lignite and bituminous coal increased by 84.82 and 43.56%, while anthracite experienced a porosity increase of 3.04%, indicating a diminished effectiveness of NMP as the coal rank increased. These findings suggest that NMP selectively dissolves specific organic molecules in coals, thereby enhancing pore connectivity and promoting a transition from micro- to meso- and macropores. These findings highlight the potential of NMP in enhancing coalbed methane production and advance our understanding of the mechanisms behind solvent erosion.

3.
Spectrochim Acta A Mol Biomol Spectrosc ; 310: 123883, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38237497

RESUMO

Residual heavy metal ions in water pose a major hazard to ecology as well as human health, and Cu2+, as the most common heavy metal ion in water bodies, can cause a variety of diseases in human beings with prolonged exposure, therefore, a rational sensing platform is needed for the specific detection of Cu2+. In this work, based on the solvothermal method, we successfully prepared the composite UIO-66@FS by encapsulating the dye fluorescein sodium molecule (FS) with a metal-organic framework material (UIO-66). The composite material has bright fluorescence emission properties with a fluorescence quantum yield of 62.03 %, and the composite material has been used to construct a fluorescence sensing platform for detecting the heavy metal Cu2+ in the aqueous environment. The fluorescence of UIO-66@FS can be greatly quenched by Cu2+, which is visible to the naked eye under UV lamp. The sensing platform is able to withstand environmental interference and has the advantages of high selectivity, excellent sensitivity, fast response, wide linear range (2.5 µM-500 µM), and low detection limit (0.246 µM) in the fluorescence quenching detection of Cu2+. In addition, the sensor has been used to detect Cu2+ in real water samples with satisfactory recoveries. Therefore, this sensing probe can be an excellent candidate for Cu2+ detection and has wonderful potential for real water sample detection.

4.
Molecules ; 27(20)2022 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-36296669

RESUMO

CH4 can be separated from low-concentration coal bed methane (LCCBM) by using the hydrate-based gas separation (HBGS) method. To study the contribution of different cyclic organic compounds to the separation of CH4 in LCCBM, an LCCBM hydrate model was constructed. Based on the Monte Carlo and molecular dynamics theory, we simulated the effect of three cyclic organic compounds-cyclopentane (CP), cyclopentanone (CP-one), and cyclopentanol (CP-ol)-on the stability of the LCCBM hydrate at P = 2 MPa, various temperatures, and discussed the structural stability of the hydrate in depth in terms of final snapshots, radial distribution function, mean square displacement, diffusion coefficient, and potential energy change. The results showed that for the CH4-N2 LCCMM gas mixture, CP showed the best facilitation effect compared to the other two cyclic compounds by maintaining the stability of the LCCBM hydrate well at T = 293 K. The promotion effect of CP-one is between CP and CP-ol, and when the temperature increases to T = 293 K, the oxygen atoms in the water molecule can maintain the essential stability of the hydrate structure, although the orderliness decreases significantly. Moreover, the structure of the hydrate model containing CP-ol is destroyed at T = 293 K, and the eventual escape of CH4 and N2 molecules in solution occurs as bubbles. The research results are important for further exploration of the mechanism of action of cyclic promoter molecules with LCCBM hydrate molecules and promoter preferences.


Assuntos
Dióxido de Carbono , Metano , Dióxido de Carbono/química , Metano/química , Água/química , Simulação de Dinâmica Molecular , Ciclopentanos , Carvão Mineral , Oxigênio
5.
Diagnostics (Basel) ; 11(12)2021 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-34943615

RESUMO

Parkinson's disease (PD) is a common neurodegenerative disease that has a significant impact on people's lives. Early diagnosis is imperative since proper treatment stops the disease's progression. With the rapid development of CAD techniques, there have been numerous applications of computer-aided diagnostic (CAD) techniques in the diagnosis of PD. In recent years, image fusion has been applied in various fields and is valuable in medical diagnosis. This paper mainly adopts a multi-focus image fusion method primarily based on deep convolutional neural networks to fuse magnetic resonance images (MRI) and positron emission tomography (PET) neural photographs into multi-modal images. Additionally, the study selected Alexnet, Densenet, ResNeSt, and Efficientnet neural networks to classify the single-modal MRI dataset and the multi-modal dataset. The test accuracy rates of the single-modal MRI dataset are 83.31%, 87.76%, 86.37%, and 86.44% on the Alexnet, Densenet, ResNeSt, and Efficientnet, respectively. Moreover, the test accuracy rates of the multi-modal fusion dataset on the Alexnet, Densenet, ResNeSt, and Efficientnet are 90.52%, 97.19%, 94.15%, and 93.39%. As per all four networks discussed above, it can be concluded that the test results for the multi-modal dataset are better than those for the single-modal MRI dataset. The experimental results showed that the multi-focus image fusion method according to deep learning can enhance the accuracy of PD image classification.

6.
Front Psychiatry ; 11: 405, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32528321

RESUMO

The occurrence of epilepsy can increase the incidence of depression, and the risk of epilepsy in the patients with depression is also high, both of which have an adverse effect on the life and the psychology of the patient, which is not conducive to the prognosis of the patients with epilepsy. With lucubrating the function of exosomes and microRNAs, some scholars found that the exosomes and its microRNAs have development prospect in the diagnosis and treatment of the disease. MicroRNAs are involved in the regulation of seizures and depression, as biomarkers, that can significantly improve the management of epileptic patients and play a preventive role in the occurrence of epilepsy and epilepsy depressive disorder. Moreover, due to its regulation to genes, appropriate application of microRNAs may have therapeutic effect on epilepsy and depression with the characteristics of long distance transmission and stability of exosomes, to a certain extent. This provides a great convenience for the diagnosis and treatment of epileptic comorbidity depression.

7.
Molecules ; 24(10)2019 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-31121976

RESUMO

A new lignan (T4) and three known lignans (T1, T2, and T3) were isolated from the methanol extract of the roots of Phryma leptostachya using bioassay-guided method, and their structures were identified as phrymarolin I (T1), II (T2), haedoxan A (T3), and methyl 4-((6a-acetoxy-4-(6-methoxybenzo[d][1,3]dioxol-5-yl)tetrahydro-1H,3H-furo[3,4-c]furan-1-yl)oxy)-1-hydroxy-2,2-dimethoxy-5-oxocyclopent-3-ene-1-carboxylate (T4) byNMR and ESI-MS spectral data. Bioassay results revealed that haedoxan A exhibited remarkably high insecticidal activity against Mythimna separata with a stomach toxicity LC50 value of 17.06 mg/L and a topical toxicity LC50 value of 1123.14 mg/L at 24 h, respectively. Phrymarolin I and compound T4 also showed some stomach toxicity against M. separata with KD50 values of 3450.21 mg/L at 4 h and 2807.10 mg/L at 8 h, respectively. In addition, phrymarolin I and haedoxan A exhibited some stomach toxicity against Plutella xylostella with an LC50 value of 1432.05 and 857.28 mg/L at 48 h, respectively. In conclusion, this study demonstrated that lignans from P. leptostachya are promising as a novel class of insecticides or insecticide lead compounds for developing botanical pesticides.


Assuntos
Inseticidas/isolamento & purificação , Lamiales/química , Lignanas/isolamento & purificação , Animais , Benzodioxóis/química , Benzodioxóis/isolamento & purificação , Benzodioxóis/farmacologia , Brassica/parasitologia , Inseticidas/química , Inseticidas/farmacologia , Lepidópteros/efeitos dos fármacos , Lignanas/química , Lignanas/farmacologia , Estrutura Molecular , Extratos Vegetais/química , Triticum/parasitologia
8.
Eur J Med Chem ; 107: 192-203, 2016 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-26595184

RESUMO

To explore novel high efficiency and low toxicity antitumor agents, a series of dihydroartemisinin-cinnamic acid ester derivatives modified on C-12 and/or C-9 position (s) were synthesized and the in vitro antitumor activities against PC-3, SGC-7901, A549 and MDA-MB-435s cancer cell lines were assessed. The hybrids (3-36) were prepared by esterification of 9α-hydroxyl-dihydroartemisinin (9α-OH DHA), the biotransformation product of dihydroartemisinin (DHA), and cinnamic acid derivatives. Compound 17 (IC50 = 0.20 µM) was the most potent anti-proliferative agent against the human lung carcinoma A549 cells, although it displayed low cytotoxicity on normal hepatic L-02 cells. The mechanism of action of compound 17 was further investigated by analysis of cell apoptosis and intracellular ROS generation. The results indicated that both ROS and ferrous ion contributed to the compound 17-induced cell death. Meanwhile, high intracellular ferrous ion and endogenous oxidative stress in A549 cells made them easier to suffer to compound 17-induced apoptosis. Our promising findings indicated the compound 17 could stand as drug candidate against lung cancer for further investigation.


Assuntos
Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Artemisininas/química , Cinamatos/química , Antineoplásicos Fitogênicos/síntese química , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral/efeitos dos fármacos , Técnicas de Química Sintética , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Humanos , Ferro/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...