High temperature metal hydrides for energy systems Part A: Numerical model validation and calibration

Metal hydrides have become more and more significant both as hydrogen storage devices and as basic elements in energy conversion systems. Magnesium hydride (MgH₂) shows very interesting characteristics – i.e. high enthalpy of reaction and hydrogen gravimetric density – making it capable of being employed in the field of energy production. So there is interest in investigating the behaviour of this kind of hydride, placed in an energy system. In order to examine MgH₂ in depth, its main kinetic parameters must be found and this can be accomplished by means of the calibration of a model previously realised by author Marco Gambini in his 1989–1994 works.In the light of this, an assessment of the activation energies (E_a = 72,200 kJ/kmol, E_d = 89,000 kJ/kmol) and kinetic constants (k_0a = 15,000 s^?1, k_0d = 198,500 s^?1) in both absorption and desorption phase of magnesium hydride has been provided. Thanks to these values, the behaviour of MgH₂ can be modelled, making the performance of a magnesium hydride-based energy system estimable.     

Energy demand in solar home systems: the case of the communities in Ribeira Valley in the state of São Paulo,Brazil

An account is given of research on energy demand with solar home systems (SHSs) and the analysis of results of a field survey of 18 families located in 4 communities in the Ribeira Valley, on the southern coast of the State of São Paulo, Brazil. These families' energy consumption was measured over a one‐year period and, in order to do so, equipment that could determine the daily energy requirements in Ampere hour units was developed. The measurement instrument was coupled to existing (SHSs) in these communities and the data collection involved direct user participation. Data collection was done by hand and was intended to provide an interrelationship among the system, the user, and the researcher. The data provided social and cultural information related to the energy use in addition to essentially technical data. Through this methodology it was confirmed that energy demand is related to a number of factors which were not predicted before the survey. It was also confirmed that the people's behavior is reflected in the operation of the photovoltaic system as a whole. The results show that 55% of the SHSs researched showed consumption below 3 kW h/month. Copyright © 2001 John Wiley & Sons, Ltd.     

Cellular and Molecular Mechanism of Pulmonary Fibrosis Post-COVID-19: Focus on Galectin-1, -3, -8, -9

Pulmonary fibrosis is a consequence of the pathological accumulation of extracellular matrix (ECM), which finally leads to lung scarring. Although the pulmonary fibrogenesis is almost known, the last two years of the COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its post effects added new particularities which need to be explored. Many questions remain about how pulmonary fibrotic changes occur within the lungs of COVID-19 patients, and whether the changes will persist long term or are capable of resolving. This review brings together existing knowledge on both COVID-19 and pulmonary fibrosis, starting with the main key players in promoting pulmonary fibrosis, such as alveolar and endothelial cells, fibroblasts, lipofibroblasts, and macrophages. Further, we provide an overview of the main molecular mechanisms driving the fibrotic process in connection with Galactin-1, -3, -8, and -9, together with the currently approved and newly proposed clinical therapeutic solutions given for the treatment of fibrosis, based on their inhibition. The work underlines the particular pathways and processes that may be implicated in pulmonary fibrosis pathogenesis post-SARS-CoV-2 viral infection. The recent data suggest that galectin-1, -3, -8, and -9 could become valuable biomarkers for the diagnosis and prognosis of lung fibrosis post-COVID-19 and promising molecular targets for the development of new and original therapeutic tools to treat the disease.     

Friendships of older men and women: Exchange patterns and satisfaction.

Investigated the relation between perceived equity of exchanges and friendship satisfaction for 58 female and 58 male 64–91 yr old individuals. Attempts were made to determine whether (a) older men and women differ in the extent to which they view themselves as being involved in equitable vs inequitable friendships, (b) the individuals who perceive themselves to be in equitable friendships report greater satisfaction with the relationship than older persons who perceive themselves to be in nonequitable friendships, and (c) there are gender differences in the relation between equity and friendship satisfaction. Ss were interviewed concerning their relationship with their best friend and 1 other friend in their support network. Perceived equity was a significant predictor of friendship satisfaction only in the case of the other friend. In addition, results show that men were involved in more equitable friendships than were women. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of Surface Morphology on the Wear and Corrosion Resistance of Post-Treated Nitrided and Nitrocarburized 42CrMo4 Steel

The surface of alloyed carbon steel was subjected to thermochemical modification by nitrocarburizing and nitriding with or without postoxidation in order to improve its mechanical properties, corrosion, and wear resistance. Treated samples were characterized by testing their basic properties (compound layer thickness, nitriding, nitrocarburizing depth, and surface hardness) according to standards. Detailed estimation of the modified metal surface was performed by additional testing: X-ray diffraction, microstructure, surface roughness and topography, and wear and corrosion resistance. The surface layer obtained after nitrocarburizing treatment consists mainly of ε-Fe_2-3(N,C) and γ’-Fe₄(N,C); similarly, the nitrided surface is formed by ε-Fe_2-3N and γ’-Fe₄N iron nitrides. The surface layer after postoxidation contains additionally Fe₃O₄. The results obtained show that nitrocarburization, nitridation, and postoxidation result in better mechanical, wear, and corrosion resistance of 42CrMo4 steel, and postoxidized sample properties are influenced by surface morphology.     

Gliadin Peptide P31-43 Induces mTOR/NFkβ Activation and Reduces Autophagy: The Role of Lactobacillus paracasei CBA L74 Postbiotc

Celiac disease (CD) is an autoimmune disease characterized by an altered immune response stimulated by gliadin peptides that are not digested and cause damage to the intestinal mucosa. The aim of this study was to investigate whether the postbiotic Lactobacillus paracasei (LP) could prevent the action of gliadin peptides on mTOR, autophagy, and the inflammatory response. Most of the experiments performed were conducted on intestinal epithelial cells Caco-2 treated with a peptic-tryptic digest of gliadin (PTG) and P31-43. Furthermore, we pretreated the Caco-2 with the postbiotic LP before treatment with the previously described stimuli. In both cases, we evaluated the levels of pmTOR, p70S6k, and p4EBP-1 for the mTOR pathway, pNFkβ, and pERK for inflammation and LC 3 and p62 for autophagy. For autophagy, we also used immunofluorescence analysis. Using intestinal organoids derivate from celiac (CD) patients, we analyzed the effect of gliadin after postbiotic pretreatment with LP on inflammation marker NFkβ. Through these experiments, we showed that gliadin peptides are able to induce the increase of the inflammatory response in a more complex model of intestinal epithelial cells. LP postbiotic was able to induce autophagy in Caco-2 cells and prevent gliadin effects. In conclusion, postbiotic pretreatment with LP could be considered for in vivo clinical trials.     

Two-Dimensional Titanium Dioxide–Surfactant Photoactive Supramolecular Networks: Synthesis,Properties, and Applications for the Conversion of Light Energy

The desire to harness solar energy to address current global environmental problems led us to investigate two-dimensional (2D) core–shell hybrid photocatalysts in the form of a 2D-TiO₂–surfactant, mainly composed of fatty acids. The bulk products, prepared by two slightly different methods, consist of stacked host–guest hybrid sheets held together by van der Waals forces between alkyl carboxylate moieties, favoring the synergistic conjugation of the photophysical properties of the core and the hydrophobicity of the self-assembled surfactant monolayer of the shell. X-ray diffraction and the vibrational characteristics of the products revealed the influence of synthesis strategies on two types of supramolecular aggregates that differ in the core chemical structure, guest conformers of alkyl surfactant tails and type, and the bilayer and monolayer of the structure of nanocomposites. The singular ability of the TiO₂ core to anchor carboxylate leads to commensurate hybrids, in contrast to both layered clay and layered double-hydroxide-based ion exchangers which have been previously reported, making them potentially interesting for modeling the role of fatty acids and lipids in bio-systems. The optical properties and photocatalytic activity of the products, mainly in composites with smaller bandgap semiconductors, are qualitatively similar to those of nanostructured TiO₂ but improve their photoresponse due to bandgap shifts and the extreme aspect-ratio characteristics of two-dimensional TiO₂ confinement. These results could be seen as a proof-of-concept of the potential of these materials to create custom-designed 2D-TiO₂–surfactant supramolecular photocatalysts.     

Immune Response Modifications in the Genetic Forms of Parkinson’s Disease: What Do We Know?

Parkinson’s disease (PD) is a common neurodegenerative disease characterized by loss of dopaminergic neurons in the pars compacta of the midbrain substantia nigra. PD pathophysiology is complex, multifactorial, and not fully understood yet. Nonetheless, recent data show that immune system hyperactivation with concomitant production of pro-inflammatory cytokines, both in the central nervous system (CNS) and the periphery, is a signature of idiopathic PD. About 5% of PD patients present an early onset with a determined genetic cause, with either autosomal dominant or recessive inheritance. The involvement of immunity in the genetic forms of PD has been a matter of interest in several recent studies. In this review, we will summarize the main findings of this new and promising field of research