The effects of Ce as a promoter on the activity and stability of Pt/Al2O3 and Pt/CeO2-Al2O3 catalysts for autothermal reforming and partial oxidation of methane (POM) were investigated. The ...Pt/CeO2-Al2O3 catalyst exhibited higher activity and stability than the Pt/Al2O3 catalyst. Analysis by in situ X-ray absorption spectroscopy under POM conditions reveals that Pt is reduced by heating the catalysts to about 730 K. The overall first-shell coordination numbers suggest changes in Pt cluster morphology with increasing temperature. Transmission electron microscopy showed strong Pt agglomeration with time on stream for the Pt/Al2O3 catalyst. The higher stability of the Pt/CeO2-Al2O3 catalyst was attributed to a combination of different properties: (i) hindrance of carbon deposition on the Pt surface for a reactor fed with low H2O/CH4 ratio; (ii) interaction of Ptsingle bondOsingle bondCe species in the presence of oxygen, inhibiting vapor and diffusion transport of PtO2 and mainly, (iii) thermal stability of the support, which prevents the loss of surface area, and consequently the sintering of the Pt. PUBLICATION ABSTRACT
Measurements of the isotopic composition of single-charged cosmic rays provide important insights in the propagation processes. However, the isotopic identification is challenging due to the one ...hundred times greater abundance of protons when compared to deuterons, the only stable isotope of hydrogen. Taking advantage of the precise measurements of the velocity and momentum in the Alpha Magnetic Spectrometer (AMS-02), a particle physics detector operating aboard the International Space Station since May 2011, we describe a parametric template fit method, which takes into account systematic uncertainties such as the fragmentation of particles inside AMS-02 and eventual differences between data and simulation through the use of nuisance parameters. With this method we are also able to assess the AMS-02 performance in terms of mass resolution, showing that it is able to separate the isotopes of hydrogen up to 10 GeV/n.
The present review of noncaloric sweeteners (NCSs) by the Asociación Mexicana de Gastroenterología was carried out to analyze and answer some of the most frequent questions and concerns about NCS ...consumption in patients with gastrointestinal disorders, through a thorough review of the medical literature. A group of gastroenterologists and experts on nutrition, toxicology, microbiology, and endocrinology reviewed and analyzed the published literature on the topic. The working group formulated conclusions, based on the scientific evidence published, to give an opinion with respect to NCS ingestion. Current evidence does not confirm the carcinogenic potential of NCSs. However, the studies analyzed showed that saccharin could have a proinflammatory effect and that polyols can cause gastrointestinal symptoms and manifestations, depending on the dose and type of compound. The ingestion of xylitol, erythritol, sucralose, aspartame, acesulfame K, and saccharin could increase the secretion of the gastrointestinal hormones that regulate intestinal motility, and stevia and its derivatives could have a favorable effect on the percentage of liver fat. Caution should be taken in recommending aspartame consumption in patients with chronic liver disease because it reduces the ratio of branched-chain amino acids to aromatic amino acids. In addition, NCS ingestion could modify the composition of the intestinal microbiota, having an effect on gastrointestinal symptoms and manifestations. It is important to continue conducting causality studies on humans to be able to establish recommendations on NSC consumption.
An increasing body of evidences has demonstrated the ability of the mature adipocyte to dedifferentiate into a population of proliferative-competent cells known as dedifferentiated fat (DFAT) cells. ...As early as the 1970s, in vitro studies showed that DFAT cells may be obtained by ceiling culture, which takes advantage of the buoyancy property of lipid-filled cells. It was documented that DFAT cells may acquire a phenotype similar to mesenchymal stem cells and yet may differentiate into multiple cell lineages, such as skeletal and smooth muscle cells, cardiomyocytes, osteoblasts, and adipocytes. Additionally, recent studies showed the ability of isolated mature adipocytes to dedifferentiate in vivo and the capacity of the progeny cells to redifferentiate into mature adipocytes, contributing to the increase of body fatness. These findings shed light on the potential for use of DFAT cells, not only for clinical purposes but also within the animal science field, because increasing intramuscular fat without excessive increase in other fat depots is a challenge in livestock production. Knowledge of the mechanisms underlying the dedifferentiation and redifferentiation of DFAT cells will allow the development of strategies for their use for clinical and animal science purposes. In this review, we highlight several aspects of DFAT cells, their potential for clinical purposes, and their contribution to adipose tissue mass in livestock.
The aim of this work was to develop solid lipid nanoparticles (SLN) containing copaiba oil with and without allantoin (NCOA, NCO, respectively) and to evaluate their antifungal activity. Nanoparticle ...suspensions were prepared using a high homogenisation technique and characterised by dynamic light scattering, laser diffraction, nanoparticle tracking analysis, multiple light scattering analysis, high-pressure liquid chromatography, pH and rheology. The antifungal activities of the formulations were tested in vitro against the emergent yeasts Candida krusei and Candida parapsilosis, and the fungal pathogens of human skin Trichophyton rubrum and Microsporum canis. The dynamic light scattering analysis showed z-average diameters (intensity) between 118.63 ± 8.89 nm for the nanoparticles with both copaiba oil and allantoin and 126.06 ± 9.84nm for the nanoparticles with just copaiba oil. The D4,3 determined by laser diffraction showed similar results of 123 ± 1.73 nm for the nanoparticles with copaiba oil and allantoin and 130 ± 3.6 nm for the nanoparticles with copaiba oil alone. Nanoparticle tracking analysis demonstrated that both suspensions had monomodal profiles and consequently, the nanoparticle populations were homogeneous. This analysis also corroborated the results of dynamic light scattering and laser diffraction, exhibiting a smaller mean diameter for the nanoparticles with copaiba oil and allantoin (143 nm) than for the nanoparticles with copaiba oil (204 nm). The physicochemical properties indicated that the dispersions were stable overtime. Rheology evidenced Newtonian behaviour for both suspensions. Antifungal susceptibility showed a MIC90 of 125 μg/mL (nanoparticles with copaiba oil) and 7.8 μg/mL (nanoparticles with copaiba oil and allantoin) against C. parapsilosis. The nanoparticles with copaiba oil and the nanoparticles with copaiba oil and allantoin presented a MIC90 of 500 μg/mL and 250 μg/mL, respectively, against C. krusei. The MIC90 values were 500 μg/mL (nanoparticles with copaiba oil) and 1.95 μg/mL (nanoparticles with copaiba oil and allantoin) against T. rubrum. Against M. canis, the nanoparticles with copaiba oil and allantoin had a MIC9 of 1.95 μg/mL. In conclusion, nanoencapsulation improved the antifungal activity of copaiba oil, which was enhanced by the presence of allantoin. The MICs obtained are comparable to those of commercial products and can represent promising therapeutics for cutaneous infections caused by yeasts and dermatophytes.
An increasing body of evidences has demonstrated the ability of the mature adipocyte to dedifferentiate into a population of proliferative-competent cells known as dedifferentiated fat (DFAT) cells. ...As early as the 1970s, in vitro studies showed that DFAT cells may be obtained by ceiling culture, which takes advantage of the buoyancy property of lipid-filled cells. It was documented that DFAT cells may acquire a phenotype similar to mesenchymal stem cells and yet may differentiate into multiple cell lineages, such as skeletal and smooth muscle cells, cardiomyocytes, osteoblasts, and adipocytes. Additionally, recent studies showed the ability of isolated mature adipocytes to dedifferentiate in vivo and the capacity of the progeny cells to redifferentiate into mature adipocytes, contributing to the increase of body fatness. These findings shed light on the potential for use of DFAT cells, not only for clinical purposes but also within the animal science field, because increasing intramuscular fat without excessive increase in other fat depots is a challenge in livestock production. Knowledge of the mechanisms underlying the dedifferentiation and redifferentiation of DFAT cells will allow the development of strategies for their use for clinical and animal science purposes. In this review, we highlight several aspects of DFAT cells, their potential for clinical purposes, and their contribution to adipose tissue mass in livestock.
Leaf Water Potential (LWP) is an indicator widely used to understand water relations in a coffee tree. Monitoring water potential is a challenge for remote sensing using low-cost multispectral ...cameras, with images taken by remotely piloted aircraft. The objective of this work was to evaluate the potential of a low-cost camera to discriminate different water treatments in the coffee tree. In addition, the accuracy of models to estimate LWP in the coffee crop was evaluated. The results showed that the NDVI (Normalized Difference Vegetation Index) vegetation index was able to discriminate 61.6 % more plots in a drought regime than the Near-InfraRed (NIR) band in the rainfall regime. For LWP, the architecture that presented the best performance in the detection of water stress was for the first flight (SMOreg algorithm using as predictor variables all bands, Red, Green, and NIR, and the NDVI vegetation index) with RMSE value of 0.1880 and RMSE% of 34.18. For the second flight (Random Tree algorithm, using as predictor variables all bands and NDVI) with RMSE (0.0520) and RMSE% (32.00) values.
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