A perspective on DNA damage-induced potentiation of the pentose phosphate shunt and reductive stress in chemoresistance

Metabolic rearrangements and genome instability are two hallmarks of cancer. Recent evidence from our laboratory demonstrates that persistent DNA lesions hampering transcription may cause glucose rerouting through the pentose phosphate shunt and reductive stress. Here, we highlight the relevance of these findings for cancer and chemoresistance development

Body composition in Karate: a dual-energy X-ray absorptiometry study

Karate is a widely practiced combat sport. Karatekas' body composition has typically been obtained in small groups using skinfolds or bioelectric impedance. In this work, we assessed three-compartment body composition using the accurate dual-energy X-ray absorptiometry technique (QDR Horizon, Hologic) in a large sample (n = 58; 74% males) of black belt karatekas. Stature-adjusted body composition indices (fat mass index; fat-free mass index; bone mineral apparent density) were calculated. The Student's t-test was used for group-group analysis. Correlation was assessed using the Pearson's r. The ability of fat-free soft tissue mass to predict bone mineral content and areal bone mineral density was assessed with linear regression. Reference mean and quartile values for whole-body and regional body composition were obtained for the male athletes. The body composition indices were generally more favorable in the male than female karatekas. The bone mineral apparent density was similar in the males and females at all sites except the right leg. The fat-free soft tissue mass predicted the bone mineral content and areal bone mineral density with good accuracy (R-2 = 0.542-0.827; p < 0.001 for all models). The data presented in this paper are expected to be of use for karate coaches, physical trainers, and participants interested in assessing and monitoring athletes' body composition

Viscoelastic Characterization and Degradation Stability Investigation of Poly(butylene-adipate-co-terephthalate) - Calcium-Phosphate Glass Composites

In this work new biodegradable composite materials based on poly(butylene-adipate-co-terephthalate) (PBAT) reinforced with water-soluble calcium-phosphate glass (CPG) microparticles at different filler concentration (0, 4, 10, 20 and 40 wt%) were characterized by dynamic-mechanical analysis (DMA), aging and fragmentation tests. DMA results showed increasing storage modulus (E') values with the filler content, without a significant modification of the glass transition temperature (Tg), translating in a reinforcing effect of the filler particles with good interphase adhesion. The creep compliance decreased with the increase of the CPG content, confirming a greater resistance of the composites to deformation under constant stress. The stability to weathering agents and the degree of fragmentation in laboratory-scale composting conditions were also tested, obtaining a higher sensitivity to degradation of the PBAT-based composites with the increase of CPG content. Overall, the addition of CPG particles in a PBAT matrix produced stiffer composites, with modulation of the properties based on the filler content, enhancing at the same time their degradation rate, making them a promising and more sustainable alternative to traditional polymers

Sustainable hydrogen production via LiH hydrolysis for unmanned air vehicle (UAV) applications

In the current study, an experimental approach for the further understanding of the LiH hydrolysis reaction for hydrogen production is considered. The experimental work has been undertaken under small scale conditions by utilising fixed bed reactors. The hydrolysis reaction has been studied at several oven temperatures (150 °C, 300 °C and 500 °C). The favourable driving potentials for the hydrolysis reactions were identified by the utilisation of the Gibbs free energy analysis. The main outcome of the study is the deceleration of the reaction pace due to the formation of the by-product layers during the reaction. At the initial stage, due to the contact of steam with the unreacted and fresh LiH surface, the reaction proceeds on a fast pace, while the formation of the layers tends to decelerate the diffusion of steam into the core of material, forcing the production step to be slower. The hydrogen yield was found to be more than 90% of the theoretical value for all the reaction temperatures. Finally, a scenario of a hybrid-electric propulsion system for Unmanned Aerial Vehicles (UAVs) including Li-ion battery, Proton Membrane Fuel Cell (PEMFC) and an on-board hydrogen production system based on LiH hydrolysis is introduced and studied

Hydrogen storage properties of magnesium borohydride infiltrated in silica aerogel using solvated and pressure methods

In this work, the polymorphic α-magnesium borohydride form was infiltrated by wet impregnation using tetrahydrofuran (THF) as solvent and subcritical carbon dioxide as innovative drying process. Pressure infiltration at high temperature was also tested as another promising method for confinement. After infiltration, onset decomposition temperature was reduced from 280 °C into 220 °C using high pressure infiltration and down to 100 °C using wet impregnation followed by CO2 drying. Faster kinetics were obtained in both cases due the possible particle size reduction in the precipitation process of the complex hydride and the presence of silica, which could behave as an additive. It is the first time that this complex borohydride is 6.1 wt% H2 reversible performing the rehydrogenation at moderate conditions of 390 °C and 120 bar H2 using silica as support. Different values were obtained after infiltration method due to the different intermediates that were obtained after the first dehydrogenation

Solid state hydrogen storage in alanates and alanate-based compounds: A review

The safest way to store hydrogen is in solid form, physically entrapped in molecular form in highly porous materials, or chemically bound in atomic form in hydrides. Among the different families of these compounds, alkaline and alkaline earth metals alumino-hydrides (alanates) have been regarded as promising storing media and have been extensively studied since 1997, when Bogdanovic and Schwickardi reported that Ti-doped sodium alanate could be reversibly dehydrogenated under moderate conditions. In this review, the preparative methods; the crystal structure; the physico-chemical and hydrogen absorption-desorption properties of the alanates of Li, Na, K, Ca, Mg, Y, Eu, and Sr; and of some of the most interesting multi-cation alanates will be summarized and discussed. The most promising alanate-based reactive hydride composite (RHC) systems developed in the last few years will also be described and commented on concerning their hydrogen absorption and desorption performance

Novel PBAT-Based Biocomposites Reinforced with Bioresorbable Phosphate Glass Microparticles

Biocomposites based on poly(butylene adipate terephthalate) (PBAT) and reinforced with micro-particles of inorganic biodegradable phosphate glass (PG) at 2, 10, and 40 wt% are prepared and characterized from a mechanical and morphological point of view. Scanning electron microscope (SEM) images show a good dispersion of the PG micro-grains, even at high concentrations, in the PBAT matrix, resulting in homogeneous composites. Tensile and dynamic-mechanical tests, respectively, indicate that Young's and storage moduli increase with PG concentration. The reinforcement of PBAT aims at modifying and tailoring the mechanical and viscoelastic properties of the material to expand its application field especially in the food and agricultural packaging sector, thanks to the similarity of PBAT performance with polyethylene

Intermolecular interactions of substituted benzenes on multi-walled carbon nanotubes grafted on HPLC silica microspheres and interaction study through artificial neural networks

Purified multi-walled carbon nanotubes (MWCNTs) grafted onto silica microspheres by gamma-radiation were applied as a HPLC stationary phase for investigating the intermolecular interactions between MWCNTs and substituted benzenes. The synthetic route, simple and not requiring CNTs derivatization, involved no alteration of the nanotube original morphology and physical–chemical properties. The affinity of a set of substituted benzenes for the MWCNTs was studied by correlating the capacity factor (k′) of each probe to its physico-chemical characteristics (calculated by Density Functional Theory). The correlation was found through a theoretical approach based on feedforward neural networks. This strategy was adopted because today these calculations are easily affordable for small molecules (like the analytes), and many critical parameters needed are not known. This might increase the applicability of the proposed method to other cases of study. Moreover, it was seen that the normal linear fit does not provide a good model. The interaction on the MWCNT phase was compared to that of an octadecyl (C18) reversed phase, under the same elution conditions. Results from trained neural networks indicated that the main role in the interactions between the analytes and the stationary phases is due to dipole moment, polarizability and LUMO energy. As expected for the C18 stationary phase correlation, is due to dipole moment and polarizability, while for the MWCNT stationary phase primarily to LUMO energy followed by polarizability, evidence for a specific interaction between MWCNTs and analytes. The CNT-based hybrid material proved to be not only a chromatographic phase but also a useful tool to investigate the MWCNT-molecular interactions with variously substituted benzenes