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81.
Nonlinear Dynamics - Drilling operations in the oil and gas industry present a highly complex dynamic. In this paper, the coupled lateral–torsional vibrations of a drill string are... 相似文献
82.
Maria Cristina Marcucci Carlos Rocha Oliveira Daniel Spindola Alyne A. Antunes Leila Y. K. Santana Victor Cavalaro Isabelle B. Costa Ana C. de Carvalho Thiago A. M. Veiga Livia S. Medeiros Lucas dos Santos Zamarioli Carolina P. Gonalves Milena F. Santos Simone S. Grecco Vanessa Y. Suzuki Lydia Masako Ferreira Daniel M. Garcia 《Molecules (Basel, Switzerland)》2022,27(17)
The aim of this study was to investigate the cytotoxic activity of the Coriandrum sativum (C. sativum) ethanolic extract (CSEE) in neuroblastoma cells, chemically characterize the compounds present in the CSEE, and predict the molecular interactions and properties of ADME. Thus, after obtaining the CSEE and performing its chemical characterization through dereplication methods using UPLC/DAD-ESI/HRMS/MS, PM6 methods and the SwissADME drug design platform were used in order to predict molecular interactions and ADME properties. The CSEE was tested for 24 h in neuroblastoma cells to the establishment of the IC50 dose. Then, the cell death was evaluated, using annexin-PI, as well as the activity of the effector caspase 3, and the protein and mRNA levels of Bax and Bcl-2 were analyzed by ELISA and RT-PCR, respectively. By UHPLC/DAD/HRMS-MS/MS analysis, the CSEE showed a high content of isocoumarins-dihydrocoriandrin, coriandrin, and coriandrones A and B, as well as nitrogenated compounds (adenine, adenosine, and tryptophan). Flavonoids (apigenin, hyperoside, and rutin), phospholipids (PAF C-16 and LysoPC (16:0)), and acylglicerol were also identified in lower amount as important compounds with antioxidant activity. The in silico approach results showed that the compounds 1 to 6, which are found mostly in the C. sativum extract, obey the “Five Rules” of Lipinski, suggesting a good pharmacokinetic activity of these compounds when administered orally. The IC50 dose of CSEE (20 µg/mL) inhibited cell proliferation and promoted cell death by the accumulation of cleaved caspase-3 and the externalization of phosphatidylserine. Furthermore, CSEE decreased Bcl-2 and increased Bax, both protein and mRNA levels, suggesting an apoptotic mechanism. CSEE presents cytotoxic effects, promoting cell death. In addition to the promising results predicted through the in silico approach for all compounds, the compound 6 showed the best results in relation to stability due to its GAP value. 相似文献
83.
Kézia Santana de Moura Hugo Rafael Chaves da Silva Leonardo Prezzi Dornelles Luana Cassandra Breitenbach Barroso Coelho Thiago Henrique Napoleão Maria Danielly Lima de Oliveira Patrícia Maria Guedes Paiva 《Applied biochemistry and biotechnology》2016,180(7):1361-1371
Moringa oleifera seeds contain a water-soluble lectin [water-soluble M. oleifera lectin (WSMoL)] that has shown coagulant activity. Magnesium ions are able to interfere with the ability of this lectin to bind carbohydrates. In this study, we performed structural characterization of WSMoL and analyzed its effect on the electrical resistance of a kaolin clay suspension in both presence and absence of monosaccharides (N-acetylglucosamine, glucose, or fructose) and magnesium ions. The coagulant activity of WSMoL was monitored by measuring optical density and electrical resistance over a period of 60 min. Native WSMoL had a molecular mass of 60 kDa and exhibited anionic nature (pI 5.5). In sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE), it appeared as three polypeptide bands of 30, 20, and 10 kDa. WSMoL reduced the optical density and electrical resistance of the kaolin suspension, which suggests that suspended particles are destabilized and that this is followed by formation of complexes. The coagulant activity of lectin decreased in the presence of Mg2+ ions and carbohydrates at concentrations that also inhibited hemagglutinating activity. This was most likely due to conformational changes in lectin structure. Our findings suggest that the coagulant activity of WSMoL is enhanced by lowering of electrical resistance of the medium and is impaired by lectin–carbohydrate and lectin–Mg2+ interactions. 相似文献
84.
Aida B. Magalhes Giorgio S. Senesi Anielle Ranulfi Thiago Massaiti Bruno S. Marangoni Marina Nery da Silva Paulino R. Villas Boas Ednaldo Ferreira Valdenice M. Novelli Maringela Cristofani-Yaly Dbora M. B. P. Milori 《Molecules (Basel, Switzerland)》2021,26(11)
The correct recognition of sweet orange (Citrus sinensis L. Osbeck) variety accessions at the nursery stage of growth is a challenge for the productive sector as they do not show any difference in phenotype traits. Furthermore, there is no DNA marker able to distinguish orange accessions within a variety due to their narrow genetic trace. As different combinations of canopy and rootstock affect the uptake of elements from soil, each accession features a typical elemental concentration in the leaves. Thus, the main aim of this work was to analyze two sets of ten different accessions of very close genetic characters of three varieties of fresh citrus leaves at the nursery stage of growth by measuring the differences in elemental concentration by laser-induced breakdown spectroscopy (LIBS). The accessions were discriminated by both principal component analysis (PCA) and a classifier based on the combination of classification via regression (CVR) and partial least square regression (PLSR) models, which used the elemental concentrations measured by LIBS as input data. A correct classification of 95.1% and 80.96% was achieved, respectively, for set 1 and set 2. These results showed that LIBS is a valuable technique to discriminate among citrus accessions, which can be applied in the productive sector as an excellent cost–benefit tool in citrus breeding programs. 相似文献
85.
Cunha Anna C. Ferreira Vitor F. Vaz Maria G. F. Cassaro Rafael A. Allão Resende Jackson A. L. C. Sacramento Carolina Q. Costa Jéssica Abrantes Juliana L. Souza Thiago Moreno L. Jordão Alessandro K. 《Molecular diversity》2021,25(4):2035-2043
Molecular Diversity - HSV disease is distributed worldwide. Anti-herpesvirus drugs are a problem in clinical settings, particularly in immunocompromised individuals undergoing herpes simplex virus... 相似文献
86.
Thiago J. Peglow Ricardo F. Schumacher Roberta Cargnelutti Angélica S. Reis Cristiane Luchese Ethel A. Wilhelm Gelson Perin 《Tetrahedron letters》2017,58(38):3734-3738
We describe here an alternative method to prepare bis(2-pyridyl) diselenide derivatives using reduced selenium species, generated in situ, and different 2-chloropyridines promoted by p-TSOH in PEG-400 as solvent. This is a straightforward protocol to prepare bis(3-amino-2-pyridyl) diselenides unprecedented to date. Still, this article describe the employment of synthesized bis(3-amino-2-pyridyl) diselenide and a diverse array of aryl aldehydes to afford the corresponding 2-aryl-selenazolo[5,4-b]pyridines in satisfactory yields and, in a short reaction time under basic condition. Furthermore, when the bis(3-amino-2-pyridyl) diselenide reacted with aliphatic halides, in the presence of NaBH4, a wide range of unsymmetrical diorganyl selenides was obtained. To complete this investigation the bis(3-amino-2-pyridyl) diselenide was evaluated for its inhibitory effect on the acetylcholinesterase (AChE) activity and free radical-scavenging capacity. Results demonstrated that this compound was antioxidant and inhibitor of the AChE activity, being a promising therapeutic agent for the treatment of Alzheimer’s disease and other neurodegenerative disorders. 相似文献
87.
To design complex networks to minimize traffic congestion, it is necessary to understand how traffic flow depends on network structure. We study data packet flow on complex networks, where the packet delivery capacity of each node is not fixed. The optimal configuration of capacities to minimize traffic congestion is derived and the critical packet generating rate is determined, below which the network is at a free flow state but above which congestion occurs. Our analysis reveals a direct relation between network topology and traffic flow. Optimal network structure, free of traffic congestion, should have two features: uniform distribution of load over all nodes and small network diameter. This finding is confirmed by numerical simulations. Our analysis also makes it possible to theoretically compare the congestion conditions for different types of complex networks. In particular, we find that network with low critical generating rate is more susceptible to congestion. The comparison has been made on the following complex-network topologies: random, scale-free, and regular. 相似文献
88.
10β‐Acetoxy‐8α,9α‐epoxy‐14β‐hydroxy‐7‐oxodolastane – A New Diterpene Isolated from the Brazilian Brown Macroalga Canistrocarpus cervicornis
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Éverson Miguel Bianco Thiago Martins Francisco Carlos Basílio Pinheiro Rodrigo Bagueira de Vasconcellos Azeredo Valéria Laneuville Teixeira Renato Crespo Pereira 《Helvetica chimica acta》2015,98(6):785-794
Chemical investigation on the nonpolar extract of the Brazilian brown alga Canistrocarpus cervicornis (Dictyotaceae) has led to the isolation of a new diterpene 1 and four known seco‐dolastane diterpenes 2 – 5 . Their chemical structures were elucidated by 1D‐ and 2D‐NMR spectroscopy, and the data was compared with the literature. A full X‐ray diffraction analysis confirmed the absolute configuration of 1 . 相似文献
89.
Thiago F. Noronha Mauricio G. C. Resende Celso C. Ribeiro 《Journal of Global Optimization》2011,50(3):503-518
The problem of routing and wavelength assignment in wavelength division multiplexing optical networks consists in routing
a set of lightpaths and assigning a wavelength to each of them, such that lightpaths whose routes share a common fiber are
assigned different wavelengths. This problem was shown to be NP-hard when the objective is to minimize the total number of
wavelengths used. We propose a genetic algorithm with random keys for routing and wavelength assignment with the goal of minimizing
the number of different wavelengths used in the assignment. This algorithm extends the best heuristic in the literature by
embedding it into an evolutionary framework. Computational results show that the new heuristic improves the state-of-the-art
algorithms in the literature. 相似文献
90.
Use of copper and gold electrodes as sensitive elements for fabrication of an electronic tongue: Discrimination of wines and whiskies 总被引:1,自引:0,他引:1
A low-cost method is proposed to classify wine and whisky samples using a disposable voltammetric electronic tongue that was fabricated using gold and copper substrates and a pattern recognition technique (Principal Component Analysis). The proposed device was successfully used to discriminate between expensive and cheap whisky samples and to detect adulteration processes using only a copper electrode. For wines, the electronic tongue was composed of copper and gold working electrodes and was able to classify three different brands of wine and to make distinctions regarding the wine type, i.e., dry red, soft red, dry white and soft white brands. 相似文献