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51.
Tatjana Souza Lima Keesen Larisse Virgolino da Silva Juliana da Câmara Rocha Luciana Nalone Andrade Tamires Cardoso Lima 《Natural product research》2019,33(17):2536-2540
Leishmaniasis belongs to a complex of zoonotic disease caused by protozoa of the genus Leishmania and is considered a major public health problem. Several essential oil chemical components have inhibitory effect against protozoa, including Leishmania donovani. Thus, the aim of this study was to evaluate for the first time the anti-Leishmania activity of two p-menthane monoterpene isomers (EPER-1: perillaldehyde 1,2-epoxide and EPER-2: perillaldehyde 8,9-epoxide) against L. donovani promastigotes as well as evaluating cytotoxic effect on mononuclear peripheral blood cells. Results of anti-Leishmania assay revealed that EPER-2 (IC50 = 3.8 μg.mL?1) was 16-fold more potent than its isomer EPER-1 (IC50 = 64.6 μg.mL?1). In contrast to PBMC cells, EPER-2 was not cytotoxic (IC50 > 400 μg.mL?1) when compared to positive control. These data suggest that the disposition of epoxide group into the p-menthane skeleton affects the anti-Leishmania activity, being that the presence of the exocyclic epoxide group considerably increased potency. Thus, it was possible to observe that the location of the epoxide group into the p-menthane skeleton resulted in different potencies. 相似文献
52.
In this paper, we show that bounded weak solutions of the Cauchy problem for general degenerate parabolic equations of the form
$$ u_{t} + \operatorname{div}f(x,t,u) = \operatorname{div}\bigl( |u|^{\alpha } \nabla u\bigr), \quad x \in \mathbb{R}^{n} , \ t > 0, $$where \(\alpha > 0 \) is constant, decrease to zero, under fairly broad conditions on the advection flux \(f\). Besides that, we derive a time decay rate for these solutions.
相似文献53.
Josepha Yohanna de Jesus Eliane Santos de Carvalho Dantas Mairim Russo Serafini Paula dos Passos Menezes Juliana Cordeiro Cardoso Ricardo Luiz Cavalcanti Albuquerque-Jr Jivaldo do Rosário Matos Juliana Ferreira de Oliveira Irwin Rose Alencar de Menezes Francilene Amaral da Silva Adriano Antunes de Souza Araújo 《Journal of Thermal Analysis and Calorimetry》2016,123(3):2003-2012
54.
Effect of Cold Atmospheric Pressure Plasma on Maize Seeds: Enhancement of Seedlings Growth and Surface Microorganisms Inactivation 总被引:1,自引:0,他引:1
Anna Zahoranová Lucia Hoppanová Juliana Šimončicová Zlata Tučeková Veronika Medvecká Daniela Hudecová Barbora Kaliňáková Dušan Kováčik Mirko Černák 《Plasma Chemistry and Plasma Processing》2018,38(5):969-988
Cold atmospheric pressure ambient air plasma generated by Diffuse Coplanar Surface Barrier Discharge (DCSBD) was investigated for inhibition of native microbiota and potentially dangerous pathogens (Aspergillus flavus, Alternaria alternata and Fusarium culmorum) on the maize surface. Moreover, the improvement of germination and growth parameters of maize seeds was evaluated. Maize (Zea mays L.; cv. Ronaldinio), one of the most important cultivated crops worldwide, was selected as the research material. Electrical measurements confirmed the high volume power density (80 W cm?3) of DCSBD plasma. Non-equilibrium plasma state evaluated using optical emission spectroscopy showed values of vibrational and rotational temperature (2700?±?300) K and (370?±?75) K, respectively. Changes on the plasma treated seeds surface were studied by water contact angle measurement, scanning electron microscope analysis and Fourier transform infrared spectroscopy. A complete devitalisation of native microbiota on the surface of seeds was observed after a short treatment time of 60 s (bacteria) and 180 s (filamentous fungi). The plasma treatment efficiency of artificially contaminated maize seeds was estimated as a reduction of 3.79 log (CFU/g) in F. culmorum after a 60-s plasma treatment, 4.21 log (CFU/g) in A. flavus and 3.22 log (CFU/g) in A. alternata after a 300-s plasma treatment. Moreover, the obtained results show an increase in wettability, resulting in a better water uptake and in an enhancement of growth parameters. The investigated DCSBD plasma source provides significant technical advantages and application potential for seed surface finishing without the use of hazardous chemicals. 相似文献
55.
Douglas Iafrate Castelhano Juliana de Almeida Carlos Henrique de Paiva Pinheiro Rodnei Bertazzoli Christiane de Arruda Rodrigues 《Journal of Solid State Electrochemistry》2018,22(8):2445-2455
Although TiO2 anatase phase has been widely chosen as the main photocatalyst, it presents high electron/hole recombination rate. However, today, what is sought is a semiconductor material with enhanced photocatalytic activity with higher photon to electron conversion efficiency by introduction of electrons trap dopants. In this paper, TiO2 nanotubes arrays obtained by anodization of Ti substrates were decorated with Ru via electrodeposition, and their photo-response was investigated. First, voltammetric experiments were performed to elucidate the route of Ru reduction on the TiO2 surface and to select the range of potentials for Ru deposition. The reduction potentials were used for controlling the amount of Ru distributed all over the surface. Although Ru was electrodeposited at potentials over the range from ??0.025 to ??0.188 V vs. Ag/AgCl, the deposition of 3.7 mC cm?2 at ??0.100 V for 30 min resulted in a tenfold greater photocurrent when compared to the recorded photocurrent for the undecorated TiO2 nanotubes array. Next, Ru-decorated TiO2 nanotubes with a length of 323?±?18 nm and inner and outer diameters of 91 and 104 nm, respectively, were characterized using SEM-WDS, SEM-FEG, XRD, and XPS. UV-Vis-NIR diffuse reflectance spectroscopy and photoluminescence (PL) measurements, which revealed a maximum PL emission at 445 nm, showed that for the array of Ru-decorated TiO2 nanotubes, the electron-hole recombination may be effectively inhibited by the presence of ruthenium electrodeposited, which can make this photocatalyst even more attractive for environmental applications. The performances of the TiO2 and Ru-decorated TiO2 catalysts were compared in heterogeneous photocatalysis experiments for color removal of an azo-dye, which presented a pseudo-first-order rate constant more than twofold greater for the Ru-decorated TiO2 catalysts. 相似文献
56.
This work reports on phase diagrams for mixtures of a complex salt formed by a cationic surfactant and an oppositely charged polyelectrolyte, hexadecyltrimethylammonium polymethacrylate, in binary mixtures with water and in ternary mixtures containing water and organic solvents of different polarity ('oils'): decanol, octanol, p-xylene and cyclohexane. The liquid crystalline structures formed were identified by small angle X-ray scattering measurements, which also provided information about changes in the size of the aggregates as a function of the system composition. These results are analysed in comparison with others previously reported [Bernardes et al., J. Phys. Chem. B 110 (2006) 10332-10340] for the analog complex formed with polyacrylate and, in general, reveal that the presence of an extra methylene group in the polymer chain does not produce significant changes in the complex phase diagrams nor in the structure of the liquid crystalline phases formed. Additionally, the obtained results confirm once more the approach used to analyze these kinds of systems formed by polymer and oppositely charged surfactant. 相似文献
57.
We wish to describe here the diastereoselective reaction between chiral N-Boc-α-amino aldehydes and achiral allyltrichlorostannanes leading to 1,2-syn-N-Boc-α-amino alcohols, which are treated with catalytic amounts of OsO4 in the presence of NaIO4 to provide the corresponding 4-N-Boc-amino-3-hydroxy ketones. 相似文献
58.
Richard Howley Matthew Mansi Janhavi Shinde Juliana Restrepo Bin Chen 《Photochemistry and photobiology》2023,99(2):787-792
As a tumor photodiagnostic agent, 5-aminolevulinic acid (ALA) is metabolized in the heme biosynthesis pathway to produce protoporphyrin IX (PpIX) with fluorescence. ALA-PpIX fluorescence was evaluated in human renal cell carcinoma (RCC) cell lines and non-tumor HK-2 cell lines. We found that extracellular PpIX level was correlated with ABCG2 activity, illustrating its importance as a PpIX efflux transporter. Extracellular PpIX was also related to the Km of ferrochelatase (FECH) that chelates PpIX with ferrous iron to form heme. The Vmax of FECH was higher in all RCC cell lines tested than in the HK-2 cell line. TCGA dataset analysis indicates a positive correlation between FECH expression and RCC patient survival. These findings suggest FECH as an important biomarker in RCC. Effects of iron chelator deferoxamine (DFO) on the enhancement of PpIX fluorescence were assessed. DFO increased intracellular PpIX in both tumor and non-tumor cells, resulting in no gain in tumor/non-tumor fluorescence ratios. DFO appeared to increase ALA-PpIX more at 1-h than at 4-h treatment. There was an inverse correlation between ALA-PpIX fluorescence and the enhancement effect of DFO. These results suggest that enhancement of ALA-PpIX by DFO may be limited by the availability of ferrous iron in mitochondria following ALA administration. 相似文献
59.
Gustavo Pierdominici-Sottile Marcelo A. Martí Juliana Palma 《Chemical physics letters》2008,456(4-6):243-246
We present the results of combined molecular dynamics and full-quantum calculations aimed at elucidating the role of residue Thr122 of the enzyme methylamine dehydrogenase. Calculations were performed on the native structure and the T122A mutant. We found that the presence of Thr122 has a deleterious effect on the proton transfer step that is proposed to determine the rate of the reaction. Besides, at the PM3 level, the substitution of Thr122 by Ala does not significantly modify the preference of the proton by atom OD2 of Asp76. Transmission coefficients obtained form MP2/6-31G(d,p)//PBE/DZP minimum energy paths show that proton tunneling is significant. 相似文献
60.
Juliana Aristéia de Lima 《European Polymer Journal》2008,44(4):1140-1148
In this work blends of poly(ethylene-co-vinyl alcohol) (EVOH) with different ethylene contents (27, 32, 38 and 44 mol%) and poly(methyl methacrylate) (PMMA) were prepared by mechanical mixing in the melted state. The miscibility and melting behavior as a function of blend composition and the ethylene content in EVOH copolymers were investigated by means of differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA). The morphology of the cryofractured surfaces was examined by scanning electron microscopy (SEM). DSC and DMTA data show that EVOH/PMMA blends are immiscible, independent of EVOH and blend composition. The SEM analysis in agreement with DMTA analysis indicates that the morphology of phases depends on the blend composition, with phase inversion occurring as the concentration of one or other polymer component increases. However, the copolymer composition apparently does not affect the domain size distribution for blends containing 20 wt% of EVOH or 20 wt% of PMMA. A better phase adhesion is observed mainly for blends with 50 wt% of each polymer component. 相似文献