Valutazioni tecniche ed economiche sull'uso degli inseguitori solari

I processi di antropizzazione connessi allo sviluppo del settore energia hanno determinato delle “impronte” sul nostro pianeta ormai indelebili. Non resta che provare a ridurre i consumi energetici e affidare la produzione dell’energia ad un mix equilibrato di fonti. In questo contesto, con particolare riferimento alla produzione dell’energia elettrica, lo sfruttamento della risorsa solare ha assunto un ruolo di primo ordine. Gran parte delle attività di ricerca e sviluppo del settore si è concentrata sulle tecniche e sulle metodologie innovative di conversione della fonte in energia elettrica. Accanto a queste, a parità di tecnologia di conversione adottata, altre attività di ricerca e sviluppo sono state indirizzate alla ottimizzazione della produzione di energia elettrica mediante “concentrazione” della radiazione solare nel punto di collocazione del dispositivo di conversione ovvero mediante opportuna variazione dell’orientamento del dispositivo rispetto alla direzione della radiazione stessa. Tali attività di ricerca e sviluppo, intraprese dalla comunità scientifica e dal mondo imprenditoriale, certamente favoriranno un migliore sfruttamento della fonte solare e avranno ricadute in tempi diversi. Questo articolo concentra la sua attenzione su gli inseguitori solari, dispositivi di semplice applicazione basati su tecnologie consolidate, la cui diffusa applicazione potrebbe portare, in breve termine, ad un rilevante incremento di producibilità degli impianti fotovoltaici. In particolare, dopo una disamina delle caratteristiche degli inseguitori solari vengono presentati alcuni dati sull’incremento della producibilità degli impianti e alcune considerazioni di ordine tecnico ed economico circa la corretta valutazione della convenienza economica dell’uso di tali dispositivi, che sta alla base dell’effettivo sviluppo del relativo mercato

Radiation hardening of Rare-Earth doped fiber amplifiers

We investigated the radiation hardening of optical fiber amplifiers operating in space environments. Through a real-time analysis in active configuration, we evaluated the role of Ce in the improvement of the amplifier performance against ionizing radiations. Ce-codoping is an efficient hardening solution, acting both in the limitation of defects in the host glass matrix of RE-doped optical fibers and in the stabilization of lasing properties of the Er3+-ions. On the one hand, in the nearinfrared region, radiation induced attenuation measurements show the absence of radiation induced P-related defect species in host glass matrix of the Ce-codoped active fibers; on the other hand, in the Ce-free fiber, the higher lifetime variation shows stronger local modifications around the Er3+-ions with the absence of Ce

Human Red Blood Cells as Oxygen Carriers to Improve Ex-Situ Liver Perfusion in a Rat Model

Ex-situ machine perfusion (MP) has been increasingly used to enhance liver quality in different settings. Small animal models can help to implement this procedure. As most normothermic MP (NMP) models employ sub-physiological levels of oxygen delivery (DO2), the aim of this study was to investigate the effectiveness and safety of different DO2, using human red blood cells (RBCs) as oxygen carriers on metabolic recovery in a rat model of NMP. Four experimental groups (n = 5 each) consisted of (1) native (untreated/control), (2) liver static cold storage (SCS) 30 min without NMP, (3) SCS followed by 120 min of NMP with Dulbecco-Modified-Eagle-Medium as perfusate (DMEM), and (4) similar to group 3, but perfusion fluid was added with human RBCs (hematocrit 15%) (BLOOD). Compared to DMEM, the BLOOD group showed increased liver DO2 (p = 0.008) and oxygen consumption ( V O \u2d9 2) (p < 0.001); lactate clearance (p < 0.001), potassium (p < 0.001), and glucose (p = 0.029) uptake were enhanced. ATP levels were likewise higher in BLOOD relative to DMEM (p = 0.031). V O \u2d9 2 and DO2 were highly correlated (p < 0.001). Consistently, the main metabolic parameters were directly correlated with DO2 and V O \u2d9 2. No human RBC related damage was detected. In conclusion, an optimized DO2 significantly reduces hypoxic damage-related effects occurring during NMP. Human RBCs can be safely used as oxygen carriers

Radiation hardening techniques for rare-earth based optical fibers and amplifiers

Er/Yb doped fibers and amplifiers have been shown to be very radiation sensitive, limiting their integration in space. We present an approach including successive hardening techniques to enhance their radiation tolerance. The efficiency of our approach is demonstrated by comparing the radiation responses of optical amplifiers made with same lengths of different rare-earth doped fibers and exposed to gamma-rays. Previous studies indicated that such amplifiers suffered significant degradation for doses exceeding 10 krad. Applying our techniques significantly enhances the amplifier radiation resistance, resulting in a very limited degradation up to 50 krad. Our optimization techniques concern the fiber composition, some possible pre-treatments and the interest of simulation tools used to harden by design the amplifiers. We showed that adding cerium inside the fiber phosphosilicate-based core strongly decreases the fiber radiation sensitivity compared to the standard fiber. For both fibers, a pre-treatment with hydrogen permits to enhance again the fiber resistance. Furthermore, simulations tools can also be used to improve the tolerance of the fiber amplifier by helping identifying the best amplifier configuration for operation in the radiative environment

The value of the multidisciplinary team in metastatic renal cell carcinoma: paving the way for precision medicine in toxicities management

The new landscape of treatments for metastatic clear cell renal carcinoma (mRCC) is constantly expanding, but it is associated with the emergence of novel toxicities, adding to up to those observed in the tyrosine-kinase inhibitor (TKI) era. Indeed, the introduction of immune checkpoint inhibitors (ICIs) alone or in combination has been associated with the development of immune-related adverse events (irAEs) involving multiple-organ systems which, even if rarely, had led to fatal outcomes. Moreover, due to the relatively recent addition of ICIs to the previously available treatments, the potential additive adverse effects of these combinations are still unknown. A prompt recognition and management of these toxicities currently represents a fundamental issue in oncology, since it correlates with the outcome of cancer patients. Even if clinical guidelines provide indications for the management of irAEs, no specific protocol to evaluate the individual risk of developing an adverse event during therapy is currently available. A multidisciplinary approach addressing appropriate interventions aimed at reducing the risk of any insidious, severe, and/or dose-limiting toxicity might represent the most efficacious strategy to timely prevent and manage severe irAEs, allowing indirectly to improve both patients' cancer-specific survival and quality of life. In this review, we reported a five-case series of toxicity events that occurred at our center during treatment for mRCC followed by the remarks of physicians from different specialties, pinpointing the relevant role of an integrated and extended multidisciplinary team in a modern model of mRCC patient management

Fenomeno Caulerpa 2010-2013. Rapporto sull'evoluzione delle specie aliene nel Canale di Sicilia

Gli studi effettuati da ARPA-Sicilia, ISPRA e CNR-IAMC hanno perseguito l’obiettivo principale di monitorare e valutare l’impatto della diffusione delle alghe indagate, attraverso l’analisi dell’evoluzione spazio-temporale del fenomeno e la caratterizzazione eco-tossicologica delle aree di pesca maggiormente interessate dalla presenza delle caulerpe. In particolare Le ricerche di ARPA-Sicilia sono state mirate a: - Definire le aree di studio principalmente interessate dal fenomeno di diffusione delle due alghe aliene; - Caratterizzare da un punto di vista ambientale le aree oggetto d’indagine; - Valutare le pressioni antropiche che insistono lungo le coste delle aree indagate; - Stimare l’influenza che le pressioni antropiche possono esercitare sulla diffusione della Caulerpa; - Indagare l’andamento spazio-temporale della distribuzione di Caulerpa in specifiche aree di indagine. Gli studi condotti da ISPRA hanno puntato a: - Valutare possibili interferenze dell’alga con le attività di pesca, l’intasamento delle reti e la riduzione della pescabilità dell’attrezzo; - Rilevare l’eventuale diversità tra aree con insediamento e prive di insediamento; - Avviare l’introduzione di buone pratiche per evitare che la pesca possa rappresentare un ulteriore vettore di invasioni secondarie attraverso disseminazione dei frammenti e propaguli dell’alga; - Definire comportamenti alieutici nel tempo utili alla mitigazione del potenziale impatto della pesca sulle risorse nelle aree colpite; - Istituire in tutta l’area di studio e, in particolare, nell’arcipelago delle Pelagie, un “Osservatorio delle Specie Aliene” per svolgere attività di monitoraggio sulla diffusione delle specie aliene, al fine di formulare proposte gestionali mirate alla salvaguardia degli ecosistemi e delle attività economiche di pesca. Le indagini realizzate dal CNR-IAMC hanno avuto come obiettivi principali: - Confrontare le caratteristiche dei popolamenti bentonici associati a praterie di Posidonia oceanica della Sicilia meridionale interessate dall’invasione di Caulerpa taxifolia var. distichophylla con quelle di popolamenti associati a posidonieti di località limitrofe non colpite dal fenomeno; - Confrontare la struttura trofica della comunità bentonica associata a matte di Posidonia oceanica in località invase e non invase da alghe aliene del genere Caulerpa della Sicilia meridionale; - Valutare gli effetti dell’invasione di Caulerpa racemosa var. cylindracea sulla struttura e sulla funzione di popolamenti macrobentonici sessili di fondo duro dell’infralitorale

Uncoupling the functions of CALM in VAMP sorting and clathrin-coated pit formation.

CALM (clathrin assembly lymphoid myeloid leukemia protein) is a cargo-selective adaptor for the post-Golgi R-SNAREs VAMPs 2, 3, and 8, and it also regulates the size of clathrin-coated pits and vesicles at the plasma membrane. The present study has two objectives: to determine whether CALM can sort additional VAMPs, and to investigate whether VAMP sorting contributes to CALM-dependent vesicle size regulation. Using a flow cytometry-based endocytosis efficiency assay, we demonstrate that CALM is also able to sort VAMPs 4 and 7, even though they have sorting signals for other clathrin adaptors. CALM homologues are present in nearly every eukaryote, suggesting that the CALM family may have evolved as adaptors for retrieving all post-Golgi VAMPs from the plasma membrane. Using a knockdown/rescue system, we show that wild-type CALM restores normal VAMP sorting in CALM-depleted cells, but that two non-VAMP-binding mutants do not. However, when we assayed the effect of CALM depletion on coated pit morphology, using a fluorescence microscopy-based assay, we found that the two mutants were as effective as wild-type CALM. Thus, we can uncouple the sorting function of CALM from its structural role

Alternative splicing of the human gene SYBL1 modulates protein domain architecture of longin VAMP7/TI-VAMP, showing both non-SNARE and synaptobrevin-like isoforms

<p>Abstract</p> <p>Background</p> <p>The control of intracellular vesicle trafficking is an ideal target to weigh the role of alternative splicing in shaping genomes to make cells. Alternative splicing has been reported for several Soluble <it>N</it>-ethylmaleimide-sensitive factor Attachment protein REceptors of the vesicle (v-SNAREs) or of the target membrane (t-SNARES), which are crucial to intracellular membrane fusion and protein and lipid traffic in Eukaryotes. However, splicing has not yet been investigated in Longins, i.e. the most widespread v-SNAREs. Longins are essential in Eukaryotes and prototyped by VAMP7, Sec22b and Ykt6, sharing a conserved N-terminal Longin domain which regulates membrane fusion and subcellular targeting. Human VAMP7/TI-VAMP, encoded by gene SYBL1, is involved in multiple cell pathways, including control of neurite outgrowth.</p> <p>Results</p> <p>Alternative splicing of SYBL1 by exon skipping events results in the production of a number of VAMP7 isoforms. In-frame or frameshift coding sequence modifications modulate domain architecture of VAMP7 isoforms, which can lack whole domains or domain fragments and show variant or extra domains. Intriguingly, two main types of VAMP7 isoforms either share the inhibitory Longin domain and lack the fusion-promoting SNARE motif, or vice versa. Expression analysis in different tissues and cell lines, quantitative real time RT-PCR and confocal microscopy analysis of fluorescent protein-tagged isoforms demonstrate that VAMP7 variants have different tissue specificities and subcellular localizations. Moreover, design and use of isoform-specific antibodies provided preliminary evidence for the existence of splice variants at the protein level.</p> <p>Conclusions</p> <p>Previous evidence on VAMP7 suggests inhibitory functions for the Longin domain and fusion/growth promoting activity for the Δ-longin molecule. Thus, non-SNARE isoforms with Longin domain and non-longin SNARE isoforms might have somehow opposite regulatory functions. When considering splice variants as "natural mutants", evidence on modulation of subcellular localization by variation in domain combination can shed further light on targeting determinants. Although further work will be needed to characterize identified variants, our data might open the route to unravel novel molecular partners and mechanisms, accounting for the multiplicity of functions carried out by the different members of the Longin proteins family.</p

The binding of Varp to VAMP7 traps VAMP7 in a closed, fusogenically inactive conformation.

SNAREs provide energy and specificity to membrane fusion events. Fusogenic trans-SNARE complexes are assembled from glutamine-contributing SNAREs (Q-SNAREs) embedded in one membrane and an arginine-contributing SNARE (R-SNARE) embedded in the other. Regulation of membrane fusion events is crucial for intracellular trafficking. We identify the endosomal protein Varp as an R-SNARE-binding regulator of SNARE complex formation. Varp colocalizes with and binds to VAMP7, an R-SNARE that is involved in both endocytic and secretory pathways. We present the structure of the second ankyrin repeat domain of mammalian Varp in complex with the cytosolic portion of VAMP7. The VAMP7-SNARE motif is trapped between Varp and the VAMP7 longin domain, and hence Varp kinetically inhibits the ability of VAMP7 to form SNARE complexes. This inhibition will be increased when Varp can also bind to other proteins present on the same membrane as VAMP7, such as Rab32-GTP

Subtle Alterations in PCNA-Partner Interactions Severely Impair DNA Replication and Repair

Dynamic switching of PCNA-partner interactions is essential for normal DNA replication and repair in yeast