Morphological changes in the electrodes of phosphoric acid fuel cells operating under open circuit voltage conditions

This paper reports the experimental evidence for morphological changes that occur at the electrodes of phosphoric acid fuel cells (PAFC) under very severe (OCV) conditions. In addition, the dissolution of Pt-supported crystallites in H₃PO₄ is demonstrated by Transmission Electron Microscopy (TEM) confirming previous results already reported in the literature. Finally, the experimental data are discussed on the basis of an analysis of the reaction rates and models for the corrosion mechanism is postulated.     

The influence of Pt on the electrooxidation behaviour of carbon in phosphoric acid

The electrooxidation behaviour of Pt/C catalysts for phosphoric acid fuel cells (PAFC) has been investigated by potentiostatic tests in the potential range 0.6 ÷ 1.0 V (rhe). Results indicate that the corrosion rate increases with an increase in Pt content, and is most noticeable at 0.6 V. At higher potentials anodic dissolution of Pt takes place, thus no metal is available to catalyze the corrosion of carbon. It is concluded that a definite influence of the presence of the supported metal on the extent of carbon corrosion under practical conditions does exist, but the understanding of mechanisms involved in the Pt-promoted carbon corrosion requires further studies.     

Microglial Activation and Priming in Alzheimer’s Disease: State of the Art and Future Perspectives

Alzheimer’s Disease (AD) is the most common cause of dementia, having a remarkable social and healthcare burden worldwide. Amyloid β (Aβ) and protein Tau aggregates are disease hallmarks and key players in AD pathogenesis. However, it has been hypothesized that microglia can contribute to AD pathophysiology, as well. Microglia are CNS-resident immune cells belonging to the myeloid lineage of the innate arm of immunity. Under physiological conditions, microglia are in constant motion in order to carry on their housekeeping function, and they maintain an anti-inflammatory, quiescent state, with low expression of cytokines and no phagocytic activity. Upon various stimuli (debris, ATP, misfolded proteins, aggregates and pathogens), microglia acquire a phagocytic function and overexpress cytokine gene modules. This process is generally regarded as microglia activation and implies that the production of pro-inflammatory cytokines is counterbalanced by the synthesis and the release of anti-inflammatory molecules. This mechanism avoids excessive inflammatory response and inappropriate microglial activation, which causes tissue damage and brain homeostasis impairment. Once the pathogenic stimulus has been cleared, activated microglia return to the naïve, anti-inflammatory state. Upon repeated stimuli (as in the case of Aβ deposition in the early stage of AD), activated microglia shift toward a less protective, neurotoxic phenotype, known as “primed” microglia. The main characteristic of primed microglia is their lower capability to turn back toward the naïve, anti-inflammatory state, which makes these cells prone to chronic activation and favours chronic inflammation in the brain. Primed microglia have impaired defence capacity against injury and detrimental effects on the brain microenvironment. Additionally, priming has been associated with AD onset and progression and can represent a promising target for AD treatment strategies. Many factors (genetics, environmental factors, baseline inflammatory status of microglia, ageing) generate an aberrantly activated phenotype that undergoes priming easier and earlier than normally activated microglia do. Novel, promising targets for therapeutic strategies for AD have been sought in the field of microglia activation and, importantly, among those factors influencing the baseline status of these cells. The CX3CL1 pathway could be a valuable target treatment approach in AD, although preliminary findings from the studies in this field are controversial. The current review aims to summarize state of the art on the role of microglia dysfunction in AD pathogenesis and proposes biochemical pathways with possible targets for AD treatment.     

Identification of a Maturation Plasma Cell Index through a Highly Sensitive Droplet Digital PCR Assay Gene Expression Signature Validation in Newly Diagnosed Multiple Myeloma Patients

DNA microarrays and RNA-based sequencing approaches are considered important discovery tools in clinical medicine. However, cross-platform reproducibility studies undertaken so far have highlighted that microarrays are not able to accurately measure gene expression, particularly when they are expressed at low levels. Here, we consider the employment of a digital PCR assay (ddPCR) to validate a gene signature previously identified by gene expression profile. This signature included ten Hedgehog (HH) pathways’ genes able to stratify multiple myeloma (MM) patients according to their self-renewal status. Results show that the designed assay is able to validate gene expression data, both in a retrospective as well as in a prospective cohort. In addition, the plasma cells’ differentiation status determined by ddPCR was further confirmed by other techniques, such as flow cytometry, allowing the identification of patients with immature plasma cells’ phenotype (i.e., expressing CD19+/CD81+ markers) upregulating HH genes, as compared to others, whose plasma cells lose the expression of these markers and were more differentiated. To our knowledge, this is the first technical report of gene expression data validation by ddPCR instead of classical qPCR. This approach permitted the identification of a Maturation Index through the integration of molecular and phenotypic data, able to possibly define upfront the differentiation status of MM patients that would be clinically relevant in the future.     

On the role of surface functional groups in Pt carbon interaction

The interaction between platinum crystallites and surface functional groups of carbon in a homologously prepared series of Pt/C catalysts for phosphoric acid fuel cell (PAFC) applications has been studied by X-ray photoelectron spectroscopy (XPS) and potentiometric titration techniques. It has been found that the platinum surface area depends on the amount of oxygenated groups on the carbon support. In addition, relationships between the platinum electroactive surface area and the acid-base nature of support functionalities have been found. The carbon support functional groups have been shown to affect the electronic nature of the platinum states.     

Spectrophotometric Qualification of Italian Pasta Produced by Traditional or Industrial Production Parameters

Wheat durum pasta represents one of the most typical Italian food products. Many factories realize different class products regarding the use of organic wheat or not and the application of traditional or industrial production parameters. Being not subordinate to regulations, these classifications are only indicative of the real processes representing different quantitative levels for the same class. Aim of this study is to set up a rapid and nondestructive method to distinguish between different declared production parameters of pasta brands (spaghetti) such as industrial (high temperature, short-time drying, Teflon drawn) and traditional (low temperature, long-time drying, bronze drawn) processes and the use of organic wheat or not. A hyperspectral system operating within visible and near-infrared spectra was used to acquire images of spaghetti bundles (of two different years). Hyperspectral information was statistically analyzed by multivariate provisional soft independent modeling of class analogy (SIMCA). The results report a percentage of correct classification equal to 75.3 % for the first year and to 73.9 % for the second year. For both sampling years, all the traditional brands are the most distant from the origin (i.e., full industrial model). The Spearman's cross-correlation test performed on the SIMCA distances indicates a statistically significant correlation between the 2 years of analysis confirming the system repeatability. The results demonstrate that the differentiation of pasta does not depend only on the raw material (i.e., organic and not) but also on the times and types of processing (i.e., short- and long-time drying, bronze or Teflon wire drawing).     

Bibliometric analysis and mapping of publications on brewing science from 1940 to 2018

Over the last 80 years, malting and brewing has evolved through increased scientific understanding, driven by numerous factors including efficiency improvement, cost reduction, quality enhancement, risk minimisation, brand marketing and image enhancement. The aim of this work was to review the historical trends in global brewing research in order to identify current opportunities and emerging trends, as well as uncover future key drivers. A bibliometric analysis was performed with English language peer reviewed literature from the Scopus database together with mapping using the VOSviewer clustering software. The bibliometric results were structured to identify which affiliations, authors, and journals have been involved in brewing research, as well as the average number of citations per paper. The bibliometric mapping yielded ‘research term maps’, where the words occurring more frequently in the research papers were grouped in coloured clusters by area of interest, and their relationships indicated. The year maps revealed which average terms tended to emerge in chronological order. The estimated average citation number per paper was about nine. Countries, including Spain, Czech Republic, Italy and Belgium displayed higher average citation scores than the world average. In the period 1940-79, brewing publications were mainly process oriented whereas between 2008-18, there was a shift in focus to the consumer (health and social responsibility) and to environmental sustainability. © 2020 The Institute of Brewing & Distilling     

Preparation and characterization of thin film ZnCuTe semiconductors

Thin film p-ZnCuTe semiconductors were synthesized by electrodeposition. The deposition mechanism was investigated by cyclic voltammetry; formation of the ternary compound, having the cubic structure of ZnTe, was obtained upon annealing at 400°C, as confirmed by X-ray diffraction. A direct energy gap of 1.7 eV was determined by optical absorption experiments. Measurements of the Hall effect and Van der Pauw conductivity showed an increase of carrier concentration and a decrease of sheet resistance for ZnCuTe with respect to zinc telluride.     

AC‐Impedance Investigation of Different MEA Configurations for Passive‐Mode DMFC Mini‐Stack Applications

Membrane‐electrode assemblies (MEAs) characterised by different hydrophobic–hydrophilic properties were investigated in a passive Direct methanol fuel cell (DMFC) monopolar mini‐stack at room temperature. These properties were modulated by varying the amount of Nafion or replacing the ionomer in the catalytic layer with polytetrafluoroethylene (PTFE). Impedance spectroscopy provided valuable information with respect to the limiting processes occurring during fuel cell operation. Methanol crossover, especially in the presence of high methanol concentration, played a major role in determining the overall performance. The development of a methanol impermeable membrane appears crucial for increasing the performance of DMFC devices for portable applications.