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1.
Int J Biol Macromol ; 233: 123517, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-36739050

RESUMO

In this work, a lignocellulosic filler, rice straw (RS), was thermoplasticized by acetylation modification process and compounded with plasticized poly(lactic acid) (PLA) through twin-screw extrusion process. The biocomposite films were prepared continuously by using a slit die for PLA/RS and PLA/acetylated RS (ARS) compounds. By the chemical reaction, thermoset microstructure of RS was changed to a more flexible one. Additionally, by the reaction, the interfacial adhesion of lignocellulosic filler/PLA matrix, filler hydrophobicity and PLA wettability was enhanced considerably. The miscibility of partially phase-separated PLA/poly(ethylene glycol) (PEG) mixtures was improved by adding RS-based microfillers, particularly by the acetylated RS. Compared with PLA/unmodified RS films, PLA/ARS biocomposites show better thermal stability, toughness, Young modulus and softening point, especially at certain filler loadings.


Assuntos
Poliésteres , Polietilenoglicóis , Poliésteres/química , Polietilenoglicóis/química , Molhabilidade
2.
Int J Biol Macromol ; 190: 618-623, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34509518

RESUMO

This study aimed to investigate the effect of chia seed mucilage (CSM) - bacterial cellulose nano-fiber (CNF) edible coating on bioactive compounds and antioxidant enzyme activity of strawberries. Strawberries were coated with CSM containing 0.6 and 8.0% (w/w) of CNF. The content of total phenol, flavonoids, anthocyanin, ascorbic acid, protein content, antioxidant activity and the activity of polyphenol oxidase, peroxidase, superoxide dismutase and phenylalanine ammonia-lyase enzymes were evaluated. The use of CSM - CNF edible coatings further preserved the phenolic, flavonoid, ascorbic acid and antioxidant activity of strawberries, and this effect was more evident in the CSM-coated sample containing CNF; However, the accumulation of anthocyanins in the coated samples was lower than the control sample. The activity of polyphenol oxidase and peroxidase enzymes, which lead to the degradation of phenolic compounds and brown color in the product, was also effectively controlled by the edible coating.


Assuntos
Antioxidantes/análise , Celulose/química , Filmes Comestíveis , Conservação de Alimentos , Fragaria/química , Mucilagem Vegetal/química , Salvia hispanica/química , Sementes/química , Antocianinas/análise , Ácido Ascórbico/análise , Catecol Oxidase/metabolismo , Temperatura Baixa , Flavonoides/análise , Gluconacetobacter/química , Peroxidase/metabolismo , Fenóis/análise , Fenilalanina Amônia-Liase/metabolismo , Proteínas de Plantas/análise
3.
Comput Methods Programs Biomed ; 152: 1-14, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29054249

RESUMO

BACKGROUND AND OBJECTIVE: Understanding the dynamics of human immunodeficiency virus (HIV) is essential for depicting, developing, and investigating effective treatment strategies. HIV infects several types of immune cells, but its main target is to destroy helper T-cells. In the lymph nodes, the infected T-cells interact with each other and their environment to obtain more resources. According to infectivity and replicative capacity of T-cells in the HIV infection process, they can be divided into four phenotypes. Although genetic mutations in the reverse transcription that beget these phenotypes are random, the framework by which a phenotype become favored is affected by the environment and neighboring phenotypes. Moreover, the HIV disease has all components of an evolutionary process, including replication, mutation, and selection. METHODS: We propose a novel structure-based game-theoretic model for the evolution of HIV-1-Infected CD4+T-cells and invasion of the immune system. We discuss the theoretical basis of the stable equilibrium states of the evolutionary dynamics of four T-cells types as well as its significant results to understand and control HIV infection. The results include the importance of genetic variations and the process of establishing evolutionary dynamics of the virus quasispecies. RESULTS: Our results show that there is a direct dependency between some parameters such as mutation rates and the stability of equilibrium states in the HIV infection. This is an interesting result because these parameters can be changed by some pharmacotherapies and alternative treatments. Our model indicates that in an appropriate treatment the relative frequency of the wild type of virus quasispecies can be decreased in the population. Consequently, this can cause delaying the emergence of the AIDS phase. To assess the model, we investigate two new treatments for HIV. The results show that our model can predict the treatment results. CONCLUSIONS: The paper shows that a structured-based evolutionary game theory can model the evolutionary dynamics of the infected T-cells and virus quasispecies. The model predicts certain aspects of the HIV infection process under several treatments.


Assuntos
Evolução Biológica , Linfócitos T CD4-Positivos/virologia , Teoria dos Jogos , HIV-1/patogenicidade , Infecções por HIV/tratamento farmacológico , Infecções por HIV/virologia , HIV-1/genética , HIV-1/imunologia , HIV-1/fisiologia , Humanos , Evasão da Resposta Imune , Prognóstico , Replicação Viral
4.
J Biomed Inform ; 68: 167-183, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28300647

RESUMO

Drug repositioning offers an effective solution to drug discovery, saving both time and resources by finding new indications for existing drugs. Typically, a drug takes effect via its protein targets in the cell. As a result, it is necessary for drug development studies to conduct an investigation into the interrelationships of drugs, protein targets, and diseases. Although previous studies have made a strong case for the effectiveness of integrative network-based methods for predicting these interrelationships, little progress has been achieved in this regard within drug repositioning research. Moreover, the interactions of new drugs and targets (lacking any known targets and drugs, respectively) cannot be accurately predicted by most established methods. In this paper, we propose a novel semi-supervised heterogeneous label propagation algorithm named Heter-LP, which applies both local and global network features for data integration. To predict drug-target, disease-target, and drug-disease associations, we use information about drugs, diseases, and targets as collected from multiple sources at different levels. Our algorithm integrates these various types of data into a heterogeneous network and implements a label propagation algorithm to find new interactions. Statistical analyses of 10-fold cross-validation results and experimental analyses support the effectiveness of the proposed algorithm.


Assuntos
Algoritmos , Descoberta de Drogas , Reposicionamento de Medicamentos , Humanos , Proteínas
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