321 research outputs found
Thermessaite-(NH4), (NH4)2AlF3(SO4), a new fumarole mineral from la Fossa crater at Vulcano, Aeolian Islands, Italy
Thermessaite-(NH4), ideally (NH4)2AlF3(SO4), is a new mineral found as a medium- to high-temperature (about 250-300°C) fumarole encrustation at the rim of La Fossa crater, Vulcano, Aeolian Islands, Italy. The mineral deposited as aggregates of micrometer-sized sharp prismatic crystals on the surface of a pyroclastic breccia in association with thermessaite, sulfur, arcanite, mascagnite, and intermediate members of the arcanite-mascagnite series. The new mineral is colorless to white, transparent, non-fluorescent, has a vitreous luster, and a white streak. The calculated density is 2.185 g/cm3. Thermessaite-(NH4) is orthorhombic, space group Pbcn, with a = 11.3005(3) Å, b = 8.6125(3) Å, c = 6.8501(2) Å, V = 666.69(4) Å3, Z = 4. The eight strongest reflections in the X-ray powder-diffraction data [d in Å (I) (hkl)] are: 5.65 (100) (200), 4.84 (89) (111), 6.85 (74) (110), 3.06 (56) (112), 3.06 (53) (221), 3.08 (47) (311), 2.68 (28) (022), 2.78 (26) (130). The average chemical composition, determined by quantitative SEM-EDS (N by difference), is (wt%): K2O 3.38, Al2O325.35, SO336.58, F 26.12, (NH4)2O 22.47, O = F -11.00, total 102.90. The empirical chemical formula, calculated on the basis of 7 anions pfu, is [(NH4)1.85K0.15]Σ2.00Al106F2.94-S0.98O3.06. The crystal structure, determined from single-crystal X-ray diffraction data [R(F) = 0.0367], is characterized by corner-sharing AlF4O2octahedra which form [001] octahedral chains by sharing two trans fluoride atoms [Al-F2 = 1.8394(6) Å]. Non-bridging Al-F1 distances are shorter [1.756(1) Å]. The two trans oxygen atoms [Al-O = 1.920(2) Å] are from SO4tetrahedra. NH4+ions occur in layers parallel to (100) which alternate regularly with (100) layers containing ribbons of corner-sharing AlF4O2octahedra and associated SO4 groups. The NH4+ions are surrounded by five oxygen atoms and by four fluorine atoms. The mineral is named as the (NH4)-analogue of thermessaite, K2AlF3(SO4), and corresponds to an anthropogenic phase found in the burning Anna I coal dump of the Anna mine, Aachen, Germany. Both mineral and mineral name have been approved by the IMA-CNMNC commission (IMA 2011-077)
Characterisation of the Ionian-Lucanian coastal plain aquifer
This paper deals with a Southern Italy area, 40 km by 10 km wide, located where four river valleys anastomose themselves in the coastal plain. The geological and hydrogeological features of the study area and the chemical-physical groundwater characterisation have been inferred from the data analysis of 1130 boreholes. Some aquifers, connected among them, constituted by soils of different geological origin -marine terraces deposits, river valley alluvial deposits and alluvial and coastal deposits - have been considered. The coastal plain aquifer is the most interesting for practical utilisation. Groundwater flow is mainly unconfined in the marine terraces and in the river valleys while it becomes mostly confined in the coastal plain aquifer. An upper clayey layer overlies the sandy coastal aquifer characterised by a mean hydraulic conductivity value equal to 2.3 10-4 m/s. The bottom is a silty-clayey bed which lies under the sea level. Being the direct natural recharge extremely low, the recharge of this coastal aquifer is mainly guaranteed by the discharge from upward aquifers and from the river leakage. The new acquired knowledge permits to delineate scenarios useful for an optimization of the groundwater resources tapping and for pursuing the safeguard of them
L'uso dei traccianti nello studio delle acque sotterranee ed esperienze relative alla Puglia
Si descrivono alcune tecniche di studio basate sull’impiego di traccianti, con particolare riferimento alle esperienze maturate dalla comunità scientifica studiando le quattro unità idrogeologiche pugliesi, prevalentemente costituite da acquiferi rocciosi di natura carbonatica. La sintetica descrizione delle procedure utilizzate è integrata dall'analisi dei principali risultati conseguite in alcune esperienze. Le metodologie di studio basate sull'uso dei traccianti si sono dimostrate utili al fine di caratterizzare l’età delle acque sotterranee e la mobilità delle stesse, le modalità di circolazione idrica sotterranea e il moto degli inquinanti. In particolare, le misure relative al contenuto in radon delle acque di falda hanno evidenziato che negli acquiferi pugliesi a maggiori concentrazioni di radon nelle acque sotterranee corrisponde una maggiore mobilità delle stesse. I traccianti radioattivi utili per lo studio delle correnti verticali sono risultati lo iodio-131 ed il bromo-82, mentre tra i traccianti stabili è stato utilizzato il cloruro di cadmio in soluzione alcolica, anche se, di recente, l’impiego dello ioduro di potassio come tracciante ha mostrato anch’esso buoni risultati. La misura della direzione dei deflussi sotterranei in un pozzo singolo ha consentito di accertare sia l’inversione della direzione di deflusso delle acque dolci di falda in prossimità della costa, a causa delle oscillazioni del livello del mare, sia la direzione del moto delle acque di mare di invasione continentale, che in condizioni di alta marea è orientato verso il continente e che si inverte con la bassa marea
Characterisation of Ionian-Lucanian coastal aquifer and seawater intrusion hazard
e paper deals with the seawater intrusion hazard along the Ionian coastal plain (Southern Italy), between the mouths of Sinni and Bradano Rivers. Subjected to intense agricultural activities, the good-quality of the tapped groundwater is seriously important for the economic growth of this coastal area. The stratigraphical and hydrogeological set-up of the area as the geochemical features of the groundwater arise from the data analysis of 1130 boreholes, widespread over the whole area and from 1.3 up to 423 meters deep. The contribution of seawater intrusion to salinization processes of the studied groundwater system is characterised. As pointed out by chemical-physical data, this phenomenon involves the studied coastal plain for a width of 1-1.5 km on average and it is less evident moving inwards where the altitude of the clayey bottom of the aquifer becomes progressively higher than the sea level. A preliminary seawater hazard map has been carried out through piezometric and aquifer geometrical data
Membrane Microvesicles as Actors in the Establishment of a Favorable Prostatic Tumoral Niche: A Role for Activated Fibroblasts and CX3CL1-CX3CR1 Axis
Tumor microenvironment is enriched in plasma membrane microvesicles (MV) shed from all cell types that constitute the tumor mass, reflecting the antigenic profile of the cells they originate from. Fibroblasts and tumor cells mutually communicate within tumor microenvironment. Recent evidences suggest that tumor-derived MVs (TMV) exert a broad array of biological functions in cell-to-cell communication. To elucidate their role in cancer-to-fibroblast cell communication, TMV obtained from two prostate carcinoma cell lines with high and weak metastatic potential (PC3 and LnCaP, respectively) have been characterized. TMV exhibit matrix metalloproteinases (MMP) and extracellular MMP inducer at their surface, suggesting a role in extracellular matrix degradation. Moreover, TMV not only induce the activation of fibroblasts assessed through extracellular signal-regulated kinase 1/2 phosphorylation and MMP-9 up-regulation, increase motility and resistance to apoptosis but also promote MV shedding from activated fibroblasts able in turn to increase migration and invasion of highly metastatic PC3 cells but not LnCaP cells. PC3 cell chemotaxis seems, at least partially, dependent on membrane-bound CX3CL1/fractalkine ligand for chemokine receptor CX3CR1. The present results highlight a mechanism of mutual communication attributable not only to soluble factors but also to determinants harbored by MV, possibly contributing to the constitution of a favorable niche for cancer development. [Cancer Res 2009;69(3):785–93
New Insights into the Evolution and Gene Structure of the Mitochondrial Carrier Family Unveiled by Analyzing the Frequent and Conserved Intron Positions
Mitochondrial carriers (MCs) belong to a eukaryotic protein family of transporters that in higher organisms is called the solute carrier family 25 (SLC25). All MCs have characteristic triplicated sequence repeats forming a 3-fold symmetrical structure of a six-transmembrane α-helix bundle with a centrally located substrate-binding site. Biochemical characterization has shown that MCs altogether transport a wide variety of substrates but can be divided into subfamilies, each transporting a few specific substrates. We have investigated the intron positions in the human MC genes and their orthologs of highly diversified organisms. The results demonstrate that several intron positions are present in numerous MC sequences at the same specific points, of which some are 3-fold symmetry related. Many of these frequent intron positions are also conserved in subfamilies or in groups of subfamilies transporting similar substrates. The analyses of the frequent and conserved intron positions in MCs suggest phylogenetic relationships not only between close but also distant homologs as well as a possible involvement of the intron positions in the evolution of the substrate specificity diversification of the MC family members
Anti-Ro and anti-La autoantibodies induce TNF-α production by human salivary gland cells: an in vitro study
Obiettivo: Lo scopo di questo studio e stato valutare la produzione di TNF-α, induttore della via estrinseca del processo apoptotico, in seguito al trattamento con gli autoanticorpi anti-Ro ed anti-La isolati da pazienti con sindrome di Sjogren primaria in un modello sperimentale rappresentato dalla linea cellulare di ghiandole salivari umane, A- 253. E stata, inoltre, valutata la presenza sulla superficie di tali cellule di recettori specifici per tale induttore, TNFR1 e TNFR2. Materiali e metodi: Gli autoanticorpi anti-La ed anti-Ro sono stati purificati su una colonna cromatografia ad alta affinita. Le metodiche utilizzate per la valutazione della produzione di TNF-α e lo studio dei recettori di superficie sono state immunofluorescenza, RT-PCR e saggi immunoenzimatici. Risultati: I nostri risultati hanno dimostrato che le cellule A-253 esprimono in superficie i recettori TNFR1 e TNFR2 e che gli autoanticorpi anti-Ro e anti-La sono in grado di indurre la produzione di TNF-α nelle stesse cellule. Conclusioni: Il trattamento con gli autoanticorpi anti-Ro ed anti-La induce la produzione di TNF-α in cellule di ghiandole salivari umane e questo potrebbe spiegare la attivazione della via estrinseca della apoptosi
Editorial: Rising stars in neuropsychology 2021
In the kaleidoscope of neuropsychological research, the Rising stars in neuropsychology 2021 Research Topic converges on pivotal studies exploring Adult Attention-Deficit/Hyperactivity Disorder (ADHD), the role of predictive processing in linguistics, and the variants of Primary Progressive Aphasia (PPA). In this editorial, we delve into these studies while weaving connections with executive functioning, neurodegenerative diseases, and the nuanced framework of neurocognitive models.No financial support was received for the research, authorship, and/or publication of this article
Caratterizzazione idrogeologica della piana di Metaponto, qualità e rischi di degrado delle acque sotterranee
The study area falls within the Ionian coastal plain (Southern Italy), bounded on the West by the Sinni River and on the East by Bradano River. It covers 40 km along the coast and 6 km inland. The geological and hydrogeological features of the study area and the chemical-physical groundwater characterisation have been inferred from the data analysis of 1130 boreholes. Some aquifers, connected among them, constituted by soils of different geological origin, exist in the area also if the coastal plain aquifer is the most interesting for practical utilisation. Groundwater flow is mainly unconfined inland, where the aquifer is constituted by terraced deposits and confined in the alluvial coastal plain. An upper clayey layer overlies the sandy coastal aquifer characterised by a mean hydraulic conductivity value equal to 2.3 10-4 m/s. Being the direct natural recharge extremely low, the recharge of this coastal aquifer is mainly guaranteed by the discharge from upward aquifers and from the river leakage. The bottom of the aquifer is a silty-clayey bed which lies under the sea level permitting so the seawater intrusion. This phenomenon involves the studied coastal plain for a width of 1-1.5 km on average and it is less evident moving inwards where the altitude of the clayey bottom of the aquifer becomes progressively higher than the sea level. Other chemical-physical data, studied to determine the quality of the waters, showed that the pollution of the groundwater is considered a grave environmental problem for the studied area
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