BMP9-Induced Survival Effect in Liver Tumor Cells Requires p38MAPK Activation

The study of bone morphogenetic proteins (BMPs) role in tumorigenic processes, and specifically in the liver, has gathered importance in the last few years. Previous studies have shown that BMP9 is overexpressed in about 40% of hepatocellular carcinoma (HCC) patients. In vitro data have also shown evidence that BMP9 has a pro-tumorigenic action, not only by inducing epithelial to mesenchymal transition (EMT) and migration, but also by promoting proliferation and survival in liver cancer cells. However, the precise mechanisms driving these effects have not yet been established. In the present work, we deepened our studies into the intracellular mechanisms implicated in the BMP9 proliferative and pro-survival effect on liver tumor cells. In HepG2 cells, BMP9 induces both Smad and non-Smad signaling cascades, specifically PI3K/AKT and p38MAPK. However, only the p38MAPK pathway contributes to the BMP9 growth-promoting effect on these cells. Using genetic and pharmacological approaches, we demonstrate that p38MAPK activation, although dispensable for the BMP9 proliferative activity, is required for the BMP9 protective effect on serum withdrawal-induced apoptosis. These findings contribute to a better understanding of the signaling pathways involved in the BMP9 pro-tumorigenic role in liver tumor cells.     

Acidification of the electrolyte during the galvanic corrosion of AA7075: A numerical and experimental study

The electrochemical interactions between aluminum alloy 7075 and low-carbon steels under gelled electrolytes were studied. Such electrolytes provided the opportunity to investigate both thick and thin electrolyte systems. The electrolyte was chemically modified to visually track the acidic fronts during the anodic reaction and the subsequent hydrolysis process. Two mathematical models were validated for both thick and ultrathin electrolytes. The acidification of thick electrolytes was extended some millimeters beyond the aluminum alloy surface, whereas the acidic front was localized next to the metallic joint using ultrathin electrolytes. The combination of both numerical and experimental results allows proving (and explaining why) that the acidification process is more aggressive under dilute than under concentrated electrolytes.     

Spatio-temporal distribution of burned areas by ecoregions in Mexico and Central America

Fire activity in Mexico and Central America, and its associated emissions, has impacts across multiple scales. On the local-to-regional scale, fire activity impacts land use, productivity, and biodiversity. On the regional-to-global scale, fire activity impacts hydrological, biogeochemical, and atmospheric processes. A consistent, reliable, large-scale characterization of the spatial and temporal distribution of fire burned area is required to assess its environmental impacts and to support natural resources’ management. The spatial and temporal distributions of fire burned areas in ecoregions of Mexico and Central America are evaluated in this study for the period 2001–2014, using the satellite Moderate Resolution Imaging Spectroradiometer (MODIS) MCD45 Burned Area data set. The methodology combines the 500 m burned area product with a MODIS land cover product and a map of North American land cover to calculate the spatiotemporal variability of fire activity as a function of land-use type.

The total burned area over Mexico and Central America over the period 2001–2014 was found to be 614,243.5 km², but with significant interannual variability over the 14 years included in the study. Indeed, the minimum burned area over the period was 9892.25 km² in 2014 and the maximum was 37,669.50 km² in 2011, a fourfold increase. Burned areas were found to be concentrated in northern Mexico and on the Pacific coast, mainly from October to June. Agricultural burned areas accounted for 37% and 43% of total detected burns in Mexico and Central America, respectively. The largest extent of burned surface occurs in May for most land-cover types. The maximum density of burned areas occurred in the tropical dry forests ecoregion during the dry season. Both in Mexico and Central America, burned area anomalies have significant anti-correlation with precipitation anomalies.     

Photoacoustic Monitoring of Absorption Spectrum During the Dehydration Process of <Emphasis Type="Italic">pasilla</Emphasis> Chili Pepper

In this work, the optical absorption spectrum of peppers was monitored by phase-resolved photoacoustic spectroscopy during a dehydration process based on hot-air drying, yielding simultaneous information about changes in the exocarp and mesocarp. Our results show that between all of the dehydration processes of green Capsicum annuum L. variety pasilla peppers, only very small changes occur in the different phase angles, which has been correlated with the small changes in the exocarp thickness. The phase-resolved spectra of mesocarp show more clearly the evolution of the carotenoid compounds with respect to the optical absorption spectrum without phase resolving, due to the last spectrum having a band broadening in that region with more signals convolved. We have shown that not only do the ripened chili peppers produce new carotenoid compounds, but also we are probing that the dehydration process, beginning with the green stage, preserves the nutrimental content, similar to changes that occur in the natural ripening process.     

The preparation of high conversion polymeric systems containing eugenol residues and their rheological characterization

Copolymeric systems bearing eugenol covalently linked to the macromolecular chains have been prepared and characterised in terms of thermal, rheological and in vitro behaviour. Eugenyl methacrylate (EgMA) and ethoxyeugenyl methacrylate (EEgMA) were polymerized and copolymerized with ethyl methacrylate (EMA) in a wide range of feed composition by bulk at high conversion. Glass transition temperature (T_g) increased with the content of EgMA in the copolymer whereas T_g decreased with the content of EEgMA. The presence of any of the eugenyl monomers in the copolymer increased the thermal stability of the materials. Rheological analysis showed that EMA-co-EgMA copolymers present a higher density of crosslinking or entanglements among the chains compared with EMA-co-EEgMA materials, and copolymers containing more than 40% EgMA exhibited a pseudo-solid like behaviour with G′ relatively independent of the frequency. The average molecular weight between cross-links (M_c) for the latter copolymers was in the order of 10⁴ Da. For EEgMA copolymers, tan δ was lower than unity and G′ showed a gradual and slight dependency with frequency over the whole range of composition. In vitro behaviour showed a higher hydrophilicity of the EEgMA containing copolymers manifested in higher water sorption values, lower water contact angle values and higher surface free energy due to an increase in polarity. All systems presented a good cytocompatibility with human fibroblasts assessed through direct and indirect assays.     

Effect of simulated gastrointestinal digestion on the antihypertensive properties of synthetic beta-lactoglobulin peptide sequences

In this study, the antihypertensive activity in spontaneously hypertensive rats of two peptides isolated from beta-lactoglobulin hydrolysates with thermolysin was evaluated. These peptides, with sequences LLF [beta-lg f(103-105)] and LQKW [beta-lg f(58-61)], showed potent in vitro ACE-inhibitory activity. Two hours after administration, both sequences caused a clear and significant decrease in the blood pressure of these rats. The impact of a simulated gastrointestinal digestion on ACE-inhibitory and antihypertensive activities of these peptides was also studied. The results showed that both fragments were susceptible to proteolytic degradation after incubation with pepsin and Corolase PP. In addition, their in vitro ACE-inhibitory activity decreased after the simulated digestion. It is likely that fragment LQK was the active end product of the gastrointestinal digestion of peptide LQKW. The fragment LL, observed after digestion of peptide LLF, probably exert its antihypertensive effect through a mechanism of action different than ACE-inhibition.     

Recycling of the Products Obtained in the Pyrolysis of Fibre-Glass Polyester SMC

An SMC (Sheeting Moulding Compound) of fibre-glass and orthophthalic polyester has been pyrolysed in a 3·5 dm³ autoclave for 30 min in a nitrogen atmosphere at 300, 400, 500, 600 and 700°C. Gas yields of 8–13 weight%, liquid yields of 9–16 weight% and solid residues of 72–82 weight% were obtained. The suitability of the pyrolysis process for recycling SMC is discussed. The characteristics, compositions and possible ways of reusing the liquid and gaseous fractions are presented. The solid pyrolysis residue has been recycled in another thermoset composite (Bulk Moulding Compound, BMC) and its mechanical properties have been compared with those of virgin BMC. The main conclusion is that pyrolysis can be an appropriate method for recycling thermoset polymeric composites such as SMC. The pyrolysis gas fraction can be sufficient to provide the energy requirements of the process plant. The pyrolysis liquids have high gross calorific values (36·8 MJ kg⁻¹) and are non-polluting liquid fuels; about 40 weight% of such liquids could be used as petrols, and the remaining 60% could be mixed with fuel oils. The solid pyrolysis residue can be recycled in BMC with no detrimental effect on the BMC mechanical properties. Concerning temperature, it has been concluded that 400–500°C are the most suitable temperatures for recycling SMC by pyrolysis. © 1997 SCI.