A renewable energy and hydrogen storage system for residential electricity supply

Because of the intermittent behavior of renewable sources, efficient, reliable and clean energy storage technologies are needed to achieve a more stable and secure energy supply. In this context, hydrogen technologies play a key role because they can store large amount of energy for long time. In this study, a hydrogen-based electrical energy storage system, integrated with a solar power plant, is designed and analyzed from the energy perspective. The system consists of a photovoltaic power plant, an alkaline electrolysis unit, metal hydride tanks for hydrogen storage, a Li-ion battery unit and a polymer electrolyte membrane fuel cell module. The system is conceived for supplying a residential user. A numerical model is developed for sizing the system’s components and for evaluating their behaviors in terms of produced/stored electricity and hydrogen production. In this purpose, a sensitivity analysis varying PV plant size as well as the Li-ion battery capacity is performed for achieving the best compromise in terms of energy supply among all the considered power sources

Identification et caractérisation du signal Sonic Hedgehog pour la maintenance et la réparation du cerveau

Dans le cerveau de souris adulte, la signalisation Sonic Hedgehog (Shh) régule le maintien des cellules souches et progénitrices, la connectivité neuronale et gliale ainsi que la réparation cérébrale. Cependant, les sources de Shh restent peu caractérisées. En utilisant des techniques d'hybridation in situ (RNAscope), j'ai découvert l'expression de Shh dans de plus grandes populations de neurones dans le cerveau de souris adultes que ce qui avait été initialement rapporté. En plus des neurones GABAergiques dans le pallidum ventral et des neurones cholinergiques dans les noyaux moteurs, des transcrits de Shh sont observés dans les neurones dopaminergiques du mésencéphale et dans les neurones nitrinergiques nNOS de différentes régions cérébrales (Russo et al., soumis). De plus, dans les noyaux hypothalamiques, nous avons détecté une distribution étendue des ARNm des récepteurs de Shh, Ptc et Smo, ainsi que des facteurs de transcription Gli1-3, dans les astrocytes. Nous avons montré qu'une activation de la signalisation Shh dans les astrocytes Glast+ via la suppression de Ptc, réduit l'adiposité, améliore la tolérance au glucose, prévient la résistance à l'insuline liée à l'âge et la prise de poids. Ainsi, la signalisation Shh dans les astrocytes joue un rôle central dans la lutte contre les défauts métaboliques liés à l'obésité et représente une nouvelle cible pour des stratégies potentielles de traitement de l'obésité (Tirou, Russo et al., 2021). J'ai également détecté des ARNm de Shh dans une population d'oligodendrocytes (OLs) exprimant les ARNm d'Olig2 et Sox10 dans presque toutes les régions cérébrales. En utilisant l'anticorps monoclonal Shh-C9C5, j'ai rapporté l'expression de Shh dans une sous-population d'OLs matures CC1+ qui n'expriment pas PDGFRα, un marqueur des cellules progénitrices d'OLs (OPCs). Ces données suggèrent qu'une population d'OLs matures constitue une nouvelle source de Shh dans des conditions physiologiques (Tirou, Russo et al., 2020). J'ai montré que l'expression de Shh-C9C5 augmente dans le cerveau de souris après la naissance, parallèlement à la protéine basique de la myéline (MBP). En utilisant des culture primaires d'OLs corticaux de rongeurs, j'ai montré que les ARNm et les protéines de Shh sont exprimés à des temps de division précoces et sont régulés à la hausse pendant la maturation des OLs, précédant la MBP, tandis que les cellules myélinisantes coexpriment Shh-C9C5 et MBP. En utilisant un modèle murin de démyélinisation focale par la LPC, j'ai montré une induction rapide à la fois des ARNm et du peptide de Shh dans les OPCs PDGFRα+ situées dans le corps calleux (cc) lors de la remyélinisation. En invalidant l'expression de Shh, j'ai montré une diminution de l'expression de la MBP et de la PLP à 10 et 20 jours après la lésion (jpl), suggérant un rôle de Shh dans la maturation des OLs et de la production de myéline. Ces données suggèrent que la modulation de Shh par les OLs constitue une nouvelle cible pharmacologique pour la remyélinisation (Russo et al., manuscrit en préparation). Trouver des thérapies régénératives novatrices pour les maladies démyélinisantes est crucial en raison du manque de médicaments efficaces. Ainsi, j'ai démontré kes propriétés pro-myélinisantes du GSA-10, un agoniste non canonique du récepteur Smo, in vitro sur la lignée cellulaire OL immortalisée Oli-neuM. De plus, j'ai démontré que le GSA-10 favorise le recrutement des OPCs et leur différenciation en OLs matures dans le cc à 5 jpl, ce qui en fait un nouvel agent potentiel pour la remyélinisation (Del Giovane, Russo et al., 2022).Mon travail établit un cadre pour de nouvelles études visant à comprendre les mécanismes impliqués dans le fonctionnement du cerveau et les pathologies associées. De plus, ces données suggèrent que des modulateurs de Shh pourraient favoriser le recrutement et la maturation des OPCs, facilitant ainsi la remyélinisation et la récupération fonctionnelle dans les maladies démyélinisantes.In the adult mouse brain, Sonic Hedgehog (Shh) signaling regulates stem and progenitor cell maintenance, neuronal and glial circuitry and brain repair. However, the sources of Shh remain poorly characterized.Using single-molecule fluorescent in situ hybridization, I discovered Shh expression in a wider population of adult mouse neurons than initially reported. Besides GABAergic neurons in the ventral pallidum and cholinergic neurons in the motor nuclei, Shh transcripts were observed in midbrain dopaminergic neurons and nNOS nitrergic neurons in different brain areas, such as the molecular layer of the cerebellum, cortical layers, the CA3 pyramidal cell layer of the hippocampus, and in hypothalamic nuclei. These data underline the importance of nNOS neurons in regulating Shh availability to brain cells (Russo et al., submitted).Furthermore, in hypothalamic nuclei, we detected a broad distribution of mRNA of Shh receptors Ptc and Smo, as well as Gli1-3 transcription factors, in astrocytes. Interestingly, we showed that activating Shh signaling in Glast+ astrocytes via Ptc deletion reduces adiposity, improves glucose tolerance and prevents age-related insulin resistance. We then studied the impact of Ptc deletion on metabolic dysfunctions induced by high-fat diet and showed that Ptc deletion also prevents weight gain, adipose tissue increase and hyperglycemia. Thus, Shh signaling in astrocytes appears to play a central role in countering the obesity related metabolic defects and represents a new target for potential strategies to treat obesity (Tirou, Russo et al., 2021).I also detected Shh mRNAs in a subset of oligodendrocytes (OLs) expressing Olig2 and Sox10 mRNAs across almost all brain areas. Interestingly, by using the Shh-C9C5 monoclonal antibody I reported a broad Shh expression in a subpopulation of CC1+ mature OLs that do not express PDGFRα, an OL progenitor cells (OPCs) marker. These data suggest a subset of mature OLs as a new source of Shh in physiological conditions (Tirou, Russo et al., 2020).Importantly, I showed that Shh-C9C5 expression increases in the postnatal mouse brain, in parallel with the Myelin Basic Protein (MBP). Using primary culture of cortical rodent OLs, I revealed that both Shh mRNA and protein are expressed at earlier division time points (day in vitro 1, DIV1) and are upregulated during OLs maturation, preceding MBP, while myelinating cells are co-expressing Shh-C9C5 and MBP at DIV3 and DIV6. Interestingly, by using the LPC focal demyelination mouse model, I unraveled a rapid induction of both Shh mRNA and peptide in PDGFRα+ OPCs located into the corpus callosum (cc) during remyelination. Moreover, by invalidating Shh expression, I showed a decrease in MBP and myelin proteolipid protein (PLP) expression at 10 and 20 days post lesion (dpl), suggesting a role of Shh in guiding OLs maturation and myelin production. These data suggest the increase of Shh production by OLs as a new pharmacological target for remyelination (Russo et al, in prep).Finding innovative regenerative therapies for demyelinating diseases is crucial due to the lack of effective drugs. Thus, I investigated the effect of GSA-10, a non-canonical Smo receptor agonist (Manetti et al., 2016) in vitro on the immortalized OL cell line Oli-neuM. We showed that GSA-10 increases MBP expression and enhances cells engagement on polystyrene microfibers. Furthermore, I demonstrated that GSA-10 promotes OPCs recruitment and their differentiation into mature OLs into the cc at 5 dpl, representing a potential new agent for remyelination (Del Giovane et al., 2022).My work provides the most robust central map of Shh-expressing cells to date and suggests a framework for new studies aimed at understanding new mechanisms implicated in brain maintenance and disease. Moreover, these data provide insight in using Shh modulators to promote OPC recruitment and maturation, facilitating remyelination and functional recovery in demyelinating diseases

The challenge of cardiomyopathies and heart failure in pregnancy

Purpose of review To discuss the risk preexisting or new onset cardiomyopathy/heart failure (CMP/heart failure) in pregnant woman, and recent insights regarding their management and therapy. Recent findings Recent data from the European Registry on Pregnancy and Heart disease of the European Society of Cardiology (ROPAC) suggest that, after an adequate prepregnancy evaluation in specialized centres, the vast majority of pregnancies are safe for both mother and foetus. A tailored approach is required according to cardiac phenotype (i.e. type of cardiomyopathy), clinical and functional status, and new potential treatments (i.e. bromocriptine in patients with peripartum cardiomyopathy). In clinical practice, prepregnancy cardiac evaluation is mandatory, including evaluation of the clinical status, standard ECG (and 24-48 h monitoring, whenever required), and imaging, to define the individual risk profile. In presence of severe symptoms (advanced New York Heart Association class), cardiac dysfunction (moderate-severe reduced ejection fraction), haemodynamic load (left ventricular outflow tract obstruction, pulmonary hypertension), pregnancy is contraindicated. A tailored monitoring is warranted in other cases (mild-moderate risk pregnancies). Likewise, in women who develop PPCM, a risk stratification and tailored monitoring and therapy should be achieved by an expert, multidisciplinary team, including cardiologists, gynaecologists, obstetricians, genetic counsellor, and psychologists

C9C5 positive mature oligodendrocytes are a source of Sonic Hedgehog in the mouse brain

International audienceIn the mature rodent brain, Sonic Hedgehog (Shh) signaling regulates stem and progenitor cell maintenance, neuronal and glial circuitry and brain repair. However, the sources and distribution of Shh mediating these effects are still poorly characterized. Here, we report in the adult mouse brain, a broad expression pattern of Shh recognized by the specific mono-clonal C9C5 antibody in a subset (11-12%) of CC1 + mature oligodendrocytes that do not express carbonic anhydrase II. These cells express also Olig2 and Sox10, two oligodendro-cyte lineage-specific markers, but not PDGFRα, a marker of oligodendrocyte progenitors. In agreement with oligodendroglial cells being a source of Shh in the adult mouse brain, we identify Shh transcripts by single molecule fluorescent in situ hybridization in a subset of cells expressing Olig2 and Sox10 mRNAs. These findings also reveal that Shh expression is more extensive than originally reported. The Shh-C9C5-associated signal labels the oligo-dendroglial cell body and decorates by intense puncta the processes. C9C5 + cells are distributed in a grid-like manner. They constitute small units that could deliver locally Shh to its receptor Patched expressed in GFAP + and S100β + astrocytes, and in HuC/D + neurons as shown in Ptc LacZ/+ reporter mice. Postnatally, C9C5 immunoreactivity overlaps the myelina-tion peak that occurs between P10 and P20 and is down regulated during ageing. Thus, our data suggest that C9C5 + CC1 + oligodendroglial cells are a source of Shh in the mouse post-natal brain

Spontaneous Food Fermentations and Potential Risks for Human Health

Fermented foods and beverages are a heterogeneous class of products with a relevant worldwide significance for human economy, nutrition and health for millennia. A huge diversity of microorganisms is associated with the enormous variety in terms of raw materials, fermentative behavior and obtained products. In this wide microbiodiversity it is possible that the presence of microbial pathogens and toxic by-products of microbial origin, including mycotoxins, ethyl carbamate and biogenic amines, are aspects liable to reduce the safety of the consumed product. Together with other approaches (e.g., use of preservatives, respect of specific physico-chemical parameters), starter cultures technology has been conceived to successfully dominate indigenous microflora and to drive fermentation to foresee the desired attributes of the matrix, assuring quality and safety. Recent trends indicate a general return to spontaneous food fermentation. In this review, we point out the potential risks for human health associated with uncontrolled (uninoculated) food fermentation and we discuss biotechnological approaches susceptible to conciliate fermented food safety, with instances of an enhanced contribution of microbes associated to spontaneous fermentation

Interactions among Relevant Non-<i>Saccharomyces</i>, <i>Saccharomyces,</i> and Lactic Acid Bacteria Species of the Wine Microbial Consortium: Towards Advances in Antagonistic Phenomena and Biocontrol Potential

The topic of microbial interactions is of notable relevance in oenology, being connected with their impact on microbial biodiversity and wine quality. The interactions among different couples of microorganisms, in particular yeasts and lactic acid bacteria representative of the must/wine microbial consortium, have been tested in this study. This interaction’s screening has been implemented by means of plate assays, using culture medium, grape juice, and wine agar as substrates. Different antagonistic phenomena have been detected, belonging to the following interaction categories: yeast-yeast, yeast-bacteria, bacteria-yeast, and bacteria-bacteria. In general, the inhibitory activity has been observed in all three media agar used as substrates, resulting in more frequent on culture medium, followed by grape juice and, finally, wine. Specifically, the work is one of the first reports demonstrating the reciprocal interactions between non-Saccharomyces yeasts (NSY) and malolactic bacteria. The findings shed new light on the co-inoculation of the yeast starter culture with malolactic bacteria, as well as the biocontrol potential of Lactic Acid Bacteria (LAB) strains. Highlighted microbial interactions are relevant for the management of alcoholic fermentation, malolactic fermentation, and the development of distinctive aroma profiles, control of spoilage yeasts, and the selection of tailored mixed starter cultures. In addition, the plate assay method could be a fast, cheap, and suitable method to exclude negative interactions among Saccharomyces spp., NSY, and malolactic bacteria during trials from regional spontaneous fermentations with the aim to select tailored mixed starter cultures

A Metagenomic-Based Approach for the Characterization of Bacterial Diversity Associated with Spontaneous Malolactic Fermentations in Wine

This study reports the first application of a next generation sequencing (NGS) analysis. The analysis was designed to monitor the effect of the management of microbial resources associated with alcoholic fermentation on spontaneous malolactic consortium. Together with the analysis of 16S rRNA genes from the metagenome, we monitored the principal parameters linked to MLF (e.g., malic and lactic acid concentration, pH). We encompass seven dissimilar concrete practices to manage microorganisms associated with alcoholic fermentation: Un-inoculated must (UM), pied-de-cuve (PdC), Saccharomyces cerevisiae (SC), S. cerevisiae and Torulaspora delbrueckii co-inoculated and sequentially inoculated, as well as S. cerevisiae and Metschnikowia pulcherrima co-inoculated and sequentially inoculated. Surprisingly, each experimental modes led to different taxonomic composition of the bacterial communities of the malolactic consortia, in terms of prokaryotic phyla and genera. Our findings indicated that, uncontrolled AF (UM, PdC) led to heterogeneous consortia associated with MLF (with a relevant presence of the genera Acetobacter and Gluconobacter), when compared with controlled AF (SC) (showing a clear dominance of the genus Oenococcus). Effectively, the SC trial malic acid was completely degraded in about two weeks after the end of AF, while, on the contrary, malic acid decarboxylation remained uncomplete after 7 weeks in the case of UM and PdC. In addition, for the first time, we demonstrated that both (i) the inoculation of different non-Saccharomyces (T. delbrueckii and M. pulcherrima) and, (ii) the inoculation time of the non-Saccharomyces with respect to S. cerevisiae resources (co-inoculated and sequentially inoculated) influence the composition of the connected MLF consortia, modulating MLF performance. Finally, we demonstrated the first findings of delayed and inhibited MLF when M. pulcherrima, and T. delbrueckii were inoculated, respectively. In addition, as a further control test, we also assessed the effect of the inoculation with Oenococcus oeni and Lactobacillus plantarum at the end of alcoholic fermentation, as MLF starter cultures. Our study suggests the potential interest in the application of NGS analysis, to monitor the effect of alcoholic fermentation on the spontaneous malolactic consortium, in relation to wine

A renewable energy and hydrogen storage system for residential electricity supply

Because of the intermittent behavior of renewable sources, efficient, reliable and clean energy storage technologies are needed to achieve a more stable and secure energy supply. In this context, hydrogen technologies play a key role because they can store large amount of energy for long time. In this study, a hydrogen-based electrical energy storage system, integrated with a solar power plant, is designed and analyzed from the energy perspective. The system consists of a photovoltaic power plant, an alkaline electrolysis unit, metal hydride tanks for hydrogen storage, a Li-ion battery unit and a polymer electrolyte membrane fuel cell module. The system is conceived for supplying a residential user. A numerical model is developed for sizing the system’s components and for evaluating their behaviors in terms of produced/stored electricity and hydrogen production. In this purpose, a sensitivity analysis varying PV plant size as well as the Li-ion battery capacity is performed for achieving the best compromise in terms of energy supply among all the considered power sources