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排序方式: 共有609条查询结果,搜索用时 281 毫秒
31.
Ane H. Medeiros Fabiana B. Mingossi Renata O. Dias Flávia P. Franco Renato Vicentini Marcia O. Mello Daniel S. Moura Marcio C. Silva-Filho 《International journal of molecular sciences》2016,17(9)
Sugarcane’s (Saccharum spp.) response to Diatraea saccharalis (F.) (Lepidoptera: (Crambidae) herbivory was investigated using a macroarray spotted with 248 sugarcane Expressed Sequence Tags (ESTs) encoding serine peptidase inhibitors, serine peptidases. and Clp protease system subunits. Our results showed that after nine hours of herbivory, 13 sugarcane genes were upregulated and nine were downregulated. Among the upregulated genes, nine were similar to serine peptidase inhibitors and four were similar to Bowman-Birk Inhibitors (BBIs). Phylogenetic analysis revealed that these sequences belong to a phylogenetic group of sugarcane BBIs that are potentially involved in plant defense against insect predation. The remaining four upregulated genes included serine peptidases and one homolog to the Arabidopsis AAA+ chaperone subunit ClpD, which is a member of the Clp protease system. Among the downregulated genes, five were homologous to serine peptidases and four were homologous to Arabidopsis Clp subunits (three homologous to Clp AAA+ chaperones and one to a ClpP-related ClpR subunit). Although the roles of serine peptidase inhibitors in plant defenses against herbivory have been extensively investigated, the roles of plant serine peptidases and the Clp protease system represent a new and underexplored field of study. The up- and downregulated D. saccharalis genes presented in this study may be candidate genes for the further investigation of the sugarcane response to herbivory. 相似文献
32.
C. F. Assumpção I. L. Nunes T. A. Mendonça A. Jablonski S. H. Flôres A. de O. Rios 《Journal of the American Oil Chemists' Society》2014,91(12):2035-2042
Samples of virgin and refined organic grape seed oil were studied for their physicochemical quality, oxidative stability, and the bioactive compounds they contained. All of the samples were within the limits established by the Codex Alimentarius with regard to their quality parameters. Lutein, zeaxanthin, β‐carotene, α‐tocopherol, and catechin were the bioactive compounds analyzed, and the virgin oil afforded more significant results. No measurable amounts of zeaxanthin and β‐carotene were observed in the refined oil, most likely due to the refining process that was carried out at high temperatures. The oxidative stability index decreased with increasing temperature, whereas the air flow had no effect on the stability index. The optimal parameters for the oxidative stability are 80 °C and a flow rate of 15 L h?1, and the virgin oil sample showed the best oxidative stability, possibly because it was not subjected to any treatment after extraction. The results from this study suggest that it would be preferable to consume virgin instead of refined grape oil because it is a better source of bioactive compounds and has a higher stability when heated. 相似文献
33.
Environmentally Friendly Determination of Quality Parameters of Biodiesel/Diesel Blends Using Fourier Transform Infrared Spectra 下载免费PDF全文
Carla Felippi Chiella Ruschel Chun Te Huang Dimitrios Samios Marco Flôres Ferrão Carlos Itsuo Yamamoto Rubia Carla Barato Plocharski 《Journal of the American Oil Chemists' Society》2015,92(3):309-315
Multivariate calibration models based on data from mid‐infrared spectroscopy of biodiesel/diesel blends were obtained. The blends were prepared from diesel oil and esters of soybean oil, waste cooking oil, and hydrogenated vegetable oil in proportions ranging from 0 to 100 % biodiesel. The results showed that the multivariate regression models with interval partial least squares (iPLS), backward interval partial least squares (biPLS), and synergy interval partial least squares (siPLS) were able to determine the fractions of the infrared spectrum that contain the relevant information for estimating the values of physicochemical properties, flash point, specific gravity, and cetane number, which are used in quality control of the blends. In the best models, the values of determination coefficients were greater than 0.9500, proving their efficiency as an alternative to traditional analytical methods. 相似文献
34.
Maurilio Toscano de Lucena Mário Ribeiro de Melo Júnior Mariana Montenegro de Melo Lira Célia Maria Machado Barbosa de Castro Leonardo Aguiar Cavalcanti Mariana Arruda de Menezes Flávia Cristina Morone Pinto José Lamartine de Andrade Aguiar 《Journal of materials science. Materials in medicine》2015,26(2):82
The development of a skin substitute suitable for immediately performing the function of the lost dermis and epidermis could result in a positive impact on the treatment of patients with extensive skin lesions. A biopolymer film was applied to skin wounds to investigate the biocompatibility and cutaneous reaction and to test its activity as a mechanical barrier and conductor in the healing process. Forty Wistar rats of both sexes were used in the present study. Two excisions were performed in the dorsal part of the skin flaps. The polysaccharide film was applied over one of the incisions and other incision was washed with saline. The time spent for complete healing of both lesions was virtually the same in both groups, during 21 days of observation. The film remained attached to the bed of the exposed wound for an average period of 6 days. There were no statistically significant differences with regard to lesion measurement area at assessment times of 2nd, 7th and 14th postoperative days. At day 21, the scar area showed a significant difference (0.0229). After 40 days, all wounds were completely healed. No statistically significant differences were found between the histological parameters assessed in the experimental and control groups. The cellulosic polysaccharide film integrated well with the tissue showing high biocompatibility and low skin reactivity. 相似文献
35.
36.
Evelisy C. O. Nassor Raquel V. Mambrini Eduardo N. dos Santos Flávia C. C. Moura Maria Helena Araujo 《Journal of Inorganic and Organometallic Polymers and Materials》2018,28(6):2288-2296
In this work, supported ionic liquid (IL) phases catalysts were prepared based on Pd dispersed in IL phases supported on magnetic particles of nickel/molybdenum covered with carbon (NiMo/C). The magnetic support was prepared via CVD method at 800 °C. XRD analysis showed the phases of metallic nickel and molybdenum carbide. The presence of carbon in these materials was confirmed by TEM/EDS and thermogravimetric analysis (TG) analysis. Pd particles were dispersed in 1 and 2.5 wt% of the IL 1-butyl-3-methylimidazolium tetrafluoroborate (BMIm·BF4), which were immobilized on the support surface via impregnation method. TG analysis shows a weight loss between 300 and 420 °C attributed to the BMIm·BF4, confirming the existence of IL on the support surface. The prepared materials were investigated in hydrogenations reactions of 1,5-cyclooctadiene and nitrobenzene, and the influence of IL on the activity and selectivity of these catalysts were observed. These materials have great potential for catalysis applications, because they bring together the advantages of the IL in the catalyst surface and the facility of magnetic materials separation. 相似文献
37.
In this paper we propose a class of linearly implicit numerical schemes for a two-phase flow model, allowing for violation of the CFL-criterion for all waves. Based on the Weakly Implixit Mixture Flux (WIMF) approach [SIAM J. Sci. Comput., 26 (2005), pp. 1449–1484], we here develop an extension denoted as Strongly Implicit Mixture Flux (SIMF). Whereas the WIMF schemes are restricted by a weak CFL condition which relates time steps to the fluid velocity, the SIMF schemes are able to break the CFL conditions corresponding to both the sonic and advective velocities. The schemes possess some desirable features compared to current industrial pressure-based codes. They allow for sequential updating of the momentum and mass variables on a nonstaggered grid by solving two sparse linear systems. The schemes are conservative in all convective fluxes and consistency between the mass variables and pressure is formally maintained. Numerical experiments are presented to shed light on the inherent differences between the WIMF and SIMF families of schemes. In particular, we demonstrate that the WIMF scheme is able to give an exact resolution of a moving contact discontinuity. The SIMF schemes do not possess the “exact resolution” property of WIMF, however, the ability to take larger time steps can be exploited so that more efficient calculations can be made when accurate resolution of sharp fronts is not essential, e.g. to calculate steady state solutions. 相似文献
38.
Using a formulation described previously with Kollicoat MAE 30 D as the film-forming agent, the effect of variations in plasticizer type and quantity and talc concentration on the preparation and processing of spray-coating suspensions and the properties of isolated films and film-coated caffeine tablets prepared using them was investigated. In the preparation and processing of spray-coating suspensions, the plasticizers polyethylene glycol (PEG) 400, PEG1500, and TEC (triethyl citrate) tended to coagulate at all concentrations investigated, while Cremophor RH 40 coagulated above 10% (expressed as a percentage of the mass of the film-forming agent used). Analogous preparations using propylene glycol (PG), PEG6000, and Lutrol F 68, on the other hand, were found to be stable at all concentrations. The instability was not caused by the Kollicoat MAE 30 D polymer dispersion as such, but by interactions between the finely dispersed pigments and other formulation ingredients. Equivalent nonpigmented preparations are stable and do not coagulate. With all the plasticizers investigated, the minimum film-forming temperature (MFT) fell, albeit to differing degrees, as the amount of plasticizer increased. Similarly, the tensile strength of isolated films declined as plasticizer concentration increased, while the reverse was true as regards their elongation at break. Whereas neither the subsequent disintegration time nor the rate of release of active ingredient at pH 6.8 was significantly affected by the various plasticizer additives, the different film-coated tablet formulations with a core containing a powerful disintegrant exhibited varying degrees of permeability to simulated gastric fluid. With PEG6000, permeability increased as the plasticizer concentration increased, while Lutrol F 68 provided an optimum barrier at 20%, and PG provided a good barrier between 10% and 30%. No gastroresistance was obtained with TEC at 10%. Only the best plasticizer formulations were used in the trials with different talc concentrations, namely, those formulations with 20% PEG6000, 20% Lutrol F 68, 20% PG, and 10% PG. When talc was added, the MFT rose, reaching its maximum at 13% talc (as a proportion of the film-forming agent). In the test for gastroresistance, film-coated caffeine tablets without talc absorbed distinctly more acid than those containing talc. Above 27% talc, the acid resistance improved only insignificantly. On the other hand, during this test, only a maximum of 3% of the active ingredient was released into the gastric juice. Of the variants investigated, the formulation with 20% PG and 27% talc performed best. 相似文献
39.
Hegedus C Flóra-Nagy E Martos R Juhász A Fülöp I Pomaházi S Nagy IP Tóth Z Márton I Keszthelyi G 《Computer methods and programs in biomedicine》2000,63(2):77-84
The aim of this study was to examine the accuracy of the computerized 3D surface analyzing and volume measuring method in dentistry. Two different types of test objects were used in the first part of the measurements. Each sample of the two groups was cross-sectioned using a hard tissue microtome. The sections were photographed on both sides and were projected on a graphical tablet and analyzed using a computer program. The measured and calculated parameters were compared. In the second part, 200 microm thick horizontal sections were prepared from 11 human incisor roots using the hard tissue microtome. This way, five sections were prepared from the apical 2 mm of each root. The effects of section thickness and number were modeled by decreasing the inclusion rate of the obtained number of sections from 10 to 2 and its influence on the calculated results was determined. This method was suitable for the approximation and analysis of 3D parameters. The results indicated that using 200-300 microm section thickness, the measured values were approximately 8-21% lower than the real parameters. 相似文献
40.
A total of 97 samples (48 summer and 49 winter) of food waste from private households were investigated for Penicillium and for mycotoxins. Twenty-five Penicillium species were isolated and Penicillium crustosum, Penicillium brevicompactum, Penicillium chrysogenum, Penicillium expansum, Penicillium roqueforti, Penicillium spinulosum, Penicillium viridicatum, Penicillium commune, Penicillium citrinum and Penicillium solitum were, in decreasing order, the most frequently identified species. Mycotoxins produced by several of these species, including mycophenolic acid, roquefortine C, penitrems A-F and thomitrems A and E, were detected. Of the 48 summer samples, 36 were severely infected and contained more than 10(5) colony forming units (CFU) Penicillium/g sample. The levels of mycotoxins in these samples were in the range 75-19000 microg/kg mycophenolic acid, 40-920 microg/kg roquefortine C, 35-7500 microg/kg penitrem A, 20-2100 microg/kg thomitrem A and 20-3300 microg/kg thomitrem E. Of the 49 winter samples, only one was found to contain mycophenolic acid (4800 microg/kg) and roquefortine C (190 microg/kg), and this sample was severely infected with P. roqueforti. Thirty samples of food waste collected from the food manufacturing industry were also investigated. The number of Penicillium in these samples was between 10(5) and 10(6) colony forming units (CFU)/g sample. Seven of these samples contained mycophenolic acid ranging from 50 to 600 microg/kg and three of these samples also contained roquefortine C in the range 100-250 microg/kg. 相似文献