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排序方式: 共有339条查询结果,搜索用时 15 毫秒
101.
Renata leite Tavares Maria Helena Araújo de Vasconcelos Maria Letícia da Veiga Dutra Aline Barbosa DOliveira Marcos dos Santos Lima Mirian Graciela da Silva Stiebbe Salvadori Ramon de Alencar Pereira Adriano Francisco Alves Yuri Mangueira do Nascimento Josean Fechine Tavares Omar Guzman-Quevedo Jailane de Souza Aquino 《Molecules (Basel, Switzerland)》2020,25(23)
This study evaluated the effect of Mucuna pruriens (MP) administration on neuroinflammation and behavioral and murinometric parameters in obese rats. Proximate composition, oligosaccharide and phenolic compound profile of MP were determined. Wistar adult male rats were randomized into healthy (HG) and obese group (OG). The HG consumed a control chow diet while OG consumed a cafeteria diet for eight weeks. Then, they were subdivided into: Healthy (HG); Healthy with MP administration (HGMP); Obese (OG); Obese with MP administration (OGMP), with the consumption of the respective diets remaining for another eight weeks, in addition to gavage with MP extract to supplemented groups (750 mg/kg weight). MP presented a composition rich in proteins and phenolic compounds, especially catechin, in addition to 1-kestose and levodopa. Supplementation reduced food intake, body weight, and thoracic and abdominal circumferences in obese rats. MP showed anxiolytic and antidepressant effects and reduced morphological damage and expression of interleukin 6 in the hippocampus of obese rats. MP treatment showed satietogenic, slimming, anxiolytic and antidepressant effects, besides to minimizing hippocampal neuroinflammation in obese rats. Our results demonstrated the potential anti-obesity of MP which are probably related to the high content of bioactive compounds present in this plant extract. 相似文献
102.
Murilo P. Santos Maria G. F. Torraga Natlia B. Barbosa Denise T. Tavares Reinaldo Giudici 《大分子反应工程》2020,14(3)
The styrene and vinyl neodecanoate copolymerization system shows a strong tendency to form two separate homopolymers. In order to improve the feeding strategies and hence the copolymer uniformity, it is necessary to know the reactivity ratios between these monomers. The error‐in‐variables‐method (EVM) is the most recommended mathematical procedure for estimating these parameters. Experiments on free‐radical copolymerization in solution in sealed ampoules are carried out to provide data for the conversion (via gravimetry) and fractional monomer compositions (via Fourier transform mid‐infrared (mid‐FT‐IR) spectroscopy). These data allow estimation of the reactivity ratios. EVM appropriately takes into account the experimental errors in the data and allows determination of the reactivity ratio values by the Mayo–Lewis model (r1 = 28.60 and r2 = 1.23). The convergence and robustness of the method decrease considerably with a larger discrepancy between the reactivity values. 相似文献
103.
Gisele A. B. Canuto Emerson A. Castilho-Martins Marina F. M. Tavares Luis Rivas Coral Barbas Ángeles López-Gonzálvez 《Analytical and bioanalytical chemistry》2014,406(14):3459-3476
Miltefosine (MT) (hexadecylphosphocholine) was implemented to cope with resistance against antimonials, the classical treatment in Leishmaniasis. Given the scarcity of anti- Leishmania (L) drugs and the increasing appearance of resistance, there is an obvious need for understanding the mechanism of action and development of such resistance. Metabolomics is an increasingly popular tool in the life sciences due to it being a relatively fast and accurate technique that can be applied either with a particular focus or in a global manner to reveal new knowledge about biological systems. Three analytical platforms, gas chromatography (GC), liquid chromatography (LC) and capillary electrophoresis (CE) have been coupled to mass spectrometry (MS) to obtain a broad picture of metabolic changes in the parasite. Impairment of the polyamine metabolism from arginine (Arg) to trypanothione in susceptible parasites treated with MT was in some way expected, considering the reactive oxygen species (ROS) production described for MT. Importantly, in resistant parasites an increase in the levels of amino acids was the most outstanding feature, probably related to the adaptation of the resistant strain for its survival inside the parasitophorous vacuole. Online Abstract Figure
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104.
Luana B. S. Nascimento Marcos V. Leal‐Costa Marcela A. S. Coutinho Nattacha dos S. Moreira Celso L. S. Lage Nancy dos S. Barbi Sônia S. Costa Eliana S. Tavares 《Photochemistry and photobiology》2013,89(2):391-399
Antioxidant compounds protect plants against oxidative stress caused by environmental conditions. Different light qualities, such as UV‐A radiation and blue light, have shown positive effects on the production of phenols in plants. Kalanchoe pinnata (Lamarck) Persoon (Crassulaceae) is used for treating wounds and inflammations. Some of these beneficial effects are attributed to the antioxidant activity of plant components. We investigated the effects of blue light and UV‐A radiation supplementation on the total phenol content, antioxidant activity and chromatographic profile of aqueous extracts from leaves of K. pinnata. Monoclonal plants were grown under white light, white plus blue light and white plus UV‐A radiation. Supplemental blue light improved the antioxidant activity and changed the phenolic profile of the extracts. Analysis by HPLC of supplemental blue‐light plant extracts revealed a higher proportion of the major flavonoid quercetin 3‐O‐α‐l ‐arabinopyranosyl (1→2) α‐l ‐rhamnopyranoside, as well as the presence of a wide variety of other phenolic substances. These findings may explain the higher antioxidant activity observed for this extract. Blue light is proposed as a supplemental light source in the cultivation of K. pinnata, to improve its antioxidant activity. 相似文献
105.
Fábio de Souza Dias Aline Klassen Marina Franco Maggi Tavares Jorge Maurício David 《Chromatographia》2013,76(9-10):559-563
Six phenolic compounds were separated and determined by capillary zone electrophoresis in red wine from Brazil’s region Vale do São Francisco with total analysis time of 12 min. The limit of detections varied from 1.59 to 2.24 mg L?1. The relative standard deviations (for n = 6) varied from 0.28 to 3.50 %. The red wine samples analyzed were bought in the local market and the phenolic compound recoveries were in the range of 98–101 %. The concentrations of gallic acid in the samples of wines varied from 16.0 to 42.0 mg L?1, caffeic acid (3.16–5.18 mg L?1), syringic acid (5.73–13.0 mg L?1), kaempferol (2.32–4.33 mg L?1), quercetin (1.68–4.03 mg L?1), myricetin (7.52–25.1 mg L?1). The concentrations found agree with data reported in the literature. 相似文献
106.
Paula F. dos Santos Marcelo C. Duarte Denise Aline C. Bezerra Maria de F. Agra José M. Barbosa Filho Marcelo S. da Silva Josean F. Tavares 《Helvetica chimica acta》2013,96(6):1085-1092
The phytochemical investigation of Xylopia langsdorffiana A.St.‐Hil. & Tul . led to the isolation of eight diterpenes, i.e., of the four new compounds (5β,7β,8α,9β,10α,12α)‐atisane‐7,16‐diol 7‐acetate ( 1 ), named xylodiol 7‐acetate, (5β,8α,9β,10α,12α)‐16‐hydroxyatisan‐7‐one ( 2 ), named xylopinone, (3α,12Z)‐3‐hydroxy‐ent‐labda‐8(20),12,14‐trien‐18‐oic acid ( 3 ), named labdorffianic acid A, and 8,20‐epoxy‐13‐hydroxy‐ent‐labd‐14‐en‐18‐oic acid ( 4 ), named labdorffianic acid B, and of the four known compounds 5 – 8 , i.e., ent‐kauran‐16‐ol, ent‐kaur‐16‐en‐19‐oic acid, ent‐kaur‐16‐en‐19‐ol, and ent‐trachyloban‐18‐oic acid. The structures were established by IR, HR‐ESI‐MS, and NMR data analysis with the aid of 2D techniques. 相似文献
107.
A. Dias Tavares Jr. C. E. Fellows C. A. Massone 《Applied physics. B, Lasers and optics》1985,38(4):259-262
An analysis of a modified electrode geometry for pulsed gas-laser excitation circuits, generating shorter excitation pulses than those normally obtained, is reported. Results from an atmospheric N2 laser obtained with this electrode geometry are compared with others available in the literature.Paper partially presented at the XIII Intern. Quantum Electronics Conf., Los Angeles, CA, USA (1984) 相似文献
108.
109.
Miguel Ramos Hugo Tavares 《Calculus of Variations and Partial Differential Equations》2008,31(1):1-25
We consider a system of the form , in an open domain of , with Dirichlet conditions at the boundary (if any). We suppose that f and g are power-type non-linearities, having superlinear and subcritical growth at infinity. We prove the existence of positive
solutions and which concentrate, as , at a prescribed finite number of local minimum points of V(x), possibly degenerate. 相似文献
110.
Ana Cláudia M. Oliveira Marluce S. Santos Luma M. S. Brandão R. M. Navarro Yerga J. L. G. Fierro Manuela S. Leite Eliane B. Cavalcantia Renan Tavares Figueiredo 《Chemical Papers》2017,71(6):1129-1141
This work reports the reforming of bio-ethanol on chitosan–TiO2 hybrid photocatalysts at ambient temperature. The influence of chitosan composition on the photocatalytic performance of chitosan–TiO2 hybrid was studied. The hybrids were characterized by CHN elemental analysis, nitrogen adsorption–desorption isotherms, thermogravimetric analysis, diffuse reflectance spectroscopy, X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The results showed that the preparation variables used for the incorporation of chitosan on TiO2 promoted changes in the morphology, superficial area, crystal size and porosity of the photocatalyst, affecting the band gap of this semiconductor and consequently the reactivity of the chitosan–TiO2 hybrids. The catalysts were evaluated for hydrogen production from ethanol under visible light. It was demonstrated that the calcination temperature of 623 K and a chitosan content of 20% were the most appropriate preparation conditions and the resulting product displays a pore size of 1.9 nm, crystal size of 11.3 nm, BET area of 178 m2 g?1 and band gap of 2.92 eV. The calcination temperature of 623 K and incorporation of 20% of chitosan obtained the same results in the conversion rate of hydrogen in comparison to the pure TiO2 P25. 相似文献