First crystal-structure determination of chromites from an acapulcoite and ordinary chondrites

We report the first crystal structure determinations of chromites from an acapulcoite and from ordinary chondrites. Cell edges range from 8.3212 (3) to 8.3501 (1) \uc5, while the oxygen positional parameters are in the range 0.2624 (3) to 0.26298 (9). Their compositions show they are very close to the chromite end-member FeCr2O4 with limited Al and Mg content. Titanium oxide content exceeds 1%, whereas the amount of Fe3+ is negligible. Extraterrestrial chromite is readily distinguished from terrestrial analogues on the basis of cell edge and oxygen positional parameter. These distinctions will facilitate ongoing attempts to reconstruct the paleoflux of meteorites to Earth from resistant extraterrestrial spinel grains recovered from ancient sediments

The Sodium Channel B4-Subunits are Dysregulated in Temporal Lobe Epilepsy Drug-Resistant Patients

Temporal lobe epilepsy (TLE) is the most common type of partial epilepsy referred for surgery due to antiepileptic drug (AED) resistance. A common molecular target for many of these drugs is the voltage-gated sodium channel (VGSC). The VGSC consists of four domains of pore-forming α-subunits and two auxiliary β-subunits, several of which have been well studied in epileptic conditions. However, despite the β4-subunits’ role having been reported in some neurological conditions, there is little research investigating its potential significance in epilepsy. Therefore, the purpose of this work was to assess the role of SCN4β in epilepsy by using a combination of molecular and bioinformatics approaches. We first demonstrated that there was a reduction in the relative expression of SCN4B in the drug-resistant TLE patients compared to non-epileptic control specimens, both at the mRNA and protein levels. By analyzing a co-expression network in the neighborhood of SCN4B we then discovered a linkage between the expression of this gene and K+ channels activated by Ca2+, or K+ two-pore domain channels. Our approach also inferred several potential effector functions linked to variation in the expression of SCN4B. These observations support the hypothesis that SCN4B is a key factor in AED-resistant TLE, which could help direct both the drug selection of TLE treatments and the development of future AED

Pressure stability field of Mg-perovskite under deep mantle conditions: A topological approach based on Bader's analysis coupled with catastrophe theory

The pressure stability field of the Mg-perovskite phase was investigated by characterizing the evolution of the electron arrangement in the crystal. Ab initio calculations of the perovskite structures in the range 0\u2013185 GPa were performed at the HF/DFT (Hartree-Fock/Density Functional Theory) exchange\u2013correlation terms level. The electron densities, calculated throughout the ab-initio wave functions, were analysed by means of the Bader's theory, coupled with Thom's catastrophe theory. To the best of our knowledge the approach is used for the first time. The topological results show the occurrence of two topological anomalies at P~20 GPa and P~110 GPa which delineate the pressure range where Mg-perovskite is stable. The paper accomplishes the twofold objectives of providing a contribution in shading light into the behaviour of the dominant component of the Earth's lower mantle across the D\u2019\u2019 layer and of proposing a novel approach in predicting the stability of a compound at extreme conditions

Inflammatory bowel disease and patterns of volatile organic compounds in the exhaled breath of children: A case-control study using Ion Molecule Reaction-Mass Spectrometry

Inflammatory bowel diseases (IBD) profoundly affect quality of life and have been gradually increasing in incidence, prevalence and severity in many areas of the world, and in children in particular. Patients with suspected IBD require careful history and clinical examination, while definitive diagnosis relies on endoscopic and histological findings. The aim of the present study was to investigate whether the alveolar air of pediatric patients with IBD presents a specific volatile organic compounds' (VOCs) pattern when compared to controls. Patients 10-17 years of age, were divided into four groups: Crohn's disease (CD), ulcerative colitis (UC), controls with gastrointestinal symptomatology, and surgical controls with no evidence of gastrointestinal problems. Alveolar breath was analyzed by ion molecule reaction mass spectrometry. Four models were built starting from 81 molecules plus the age of subjects as independent variables, adopting a penalizing LASSO logistic regression approach: 1) IBDs vs. controls, finally based on 18 VOCs plus age (sensitivity = 95%, specificity = 69%, AUC = 0.925); 2) CD vs. UC, finally based on 13 VOCs plus age (sensitivity = 94%, specificity = 76%, AUC = 0.934); 3) IBDs vs. gastroenterological controls, finally based on 15 VOCs plus age (sensitivity = 94%, specificity = 65%, AUC = 0.918); 4) IBDs vs. controls, built starting from the 21 directly or indirectly calibrated molecules only, and finally based on 12 VOCs plus age (sensitivity = 94%, specificity = 71%, AUC = 0.888). The molecules identified by the models were carefully studied in relation to the concerned outcomes. This study, with the creation of models based on VOCs profiles, precise instrumentation and advanced statistical methods, can contribute to the development of new non-invasive, fast and relatively inexpensive diagnostic tools, with high sensitivity and specificity. It also represents a crucial step towards gaining further insights on the etiology of IBD through the analysis of specific molecules which are the expression of the particular metabolism that characterizes these patients

Trace Elements in Chromian Spinels from Four Siberian Kimberlites

We analysed the major, minor and trace elements chemistry of forty-two Cr-spinels from four Siberian kimberlites. They showed a wide range in Mg# (Mg/(Mg + Fe2+); 0.42–0.78) and Cr# (Cr/(Cr + Al); 0.32–0.92) and a common trend of increasing Cr# with decreasing Mg#. The major element classification schemes suggested that there were spinels deriving from a peridotitic source (Xen) and spinels crystallised from kimberlitic melts (Chr). Laser-Ablation Inductively Coupled Plasma Mass Spectrometry on both groups showed that the trace elements with the highest abundance were Mn (985–3390 ppm), Ni (531–3162 ppm), V (694–2510 ppm) and Zn (475–2230 ppm). Testing the effectiveness of trace elements in determining the source for Cr-spinels, we found out that Cr-spinels crystallised directly from a kimberlitic melt usually showed higher Mn, Ni, Sc and V concentrations with respect to those of peridotitic origin. In addition, using the available partitioning models, we found that the correlations between major elements and Ni, Co, Sc and Ga in the Xen group could be explained by subsolidus equilibration between spinel, olivine and clinopyroxene at 800–1000 °C, thus supporting a peridotitic source for this group. Finally, we calculated the composition of the possible melts in equilibrium with the Cr-spinels of the Chr group, using a selected set of partition coefficients. Calculated abundances of Cu, Ga and Zr were comparable to those of the kimberlite, while V was never close to the kimberlite composition. This simulation highlighted the need for new data on the trace elements partition coefficients between kimberlitic melts and Cr-spinel

Early differentiating osteoclast interactions with a well suitable bone-like composite

Osteoclasts, as well as preosteoclasts, show different adhesion features in relationship to the substrate on which cells are grown, i.e. the formation of either podosomes belt or sealing zones. Podosomes belt forms on non bone substrates, i.e. when cells interact with glass coverslips or culture plates, whereas sealing zones form when cells grow on bone-like substrates. Podosomes belt corresponds to numerous F-actin columns arranged at the cell periphery, whereas the sealing zone could be defined as a unique large band of actin [1]. In the study of bone resorption mechanisms, the employ of bone slices is not perfectly suitable to investigate actin rearrangement due to cell-extracellular matrix (ECM) interaction, since it doesn’t allow to obtain high quality preparations to be examined both by light and electronmicroscopy (TEM and SEM). In particular, TEM preparation requires demineralization which could influence the chemical properties of either bone slices or bone-like composites. Moreover, the use of bone slices as scaffold, although extensive, doesn’t allow ultrastructural details that are necessary in the study of mineral resorption by monocytes or preosteoclasts [2,3]. The aim of the present study was to set up an experimental model for the study of cell-ECM interaction between either monocytes or early differentiating osteoclasts and a mineralized ECM. RAW 264.7 cells (a monocyte-macrophage cell line that can differentiate in osteoclasts) were cultured on a composite constituted by calcium phosphate and type I collagen to investigate actin polymerization and podosome formation. This bone-like composite doesn’t present the mechanical bone properties, but it is constituted by the main bone components and exhibits the advantage that collagen glues the mineral phase in clusters that can be either added to cell cultures or applied on coverslips, as well as to the culture medium. Light and fluorescence microscopy, as well as TEM and SEM techniques were employed. Results showed that the use of this bone-like composite allowed to obtain useful morphological information about the resorption activity of RAW 264.7 cell line differentiating towards the osteoclastic phenotype

Diamond-inclusion system recording old deep lithosphere conditions at Udachnaya (Siberia)

Diamonds and their inclusions are unique fragments of deep Earth, which provide rare samples from inaccessible portions of our planet. Inclusion-free diamonds cannot provide information on depth of formation, which could be crucial to understand how the carbon cycle operated in the past. Inclusions in diamonds, which remain uncorrupted over geological times, may instead provide direct records of deep Earth’s evolution. Here, we applied elastic geothermobarometry to a diamond-magnesiochromite (mchr) host-inclusion pair from the Udachnaya kimberlite (Siberia, Russia), one of the most important sources of natural diamonds. By combining X-ray diffraction and Fourier-transform infrared spectroscopy data with a new elastic model, we obtained entrapment conditions, Ptrap = 6.5(2) GPa and Ttrap = 1125(32)–1140(33) °C, for the mchr inclusion. These conditions fall on a ca. 35 mW/m2 geotherm and are colder than the great majority of mantle xenoliths from similar depth in the same kimberlite. Our results indicate that cold cratonic conditions persisted for billions of years to at least 200 km in the local lithosphere. The composition of the mchr also indicates that at this depth the lithosphere was, at least locally, ultra-depleted at the time of diamond formation, as opposed to the melt-metasomatized, enriched composition of most xenoliths

Il Museo di Mineralogia e Petrografia del Dipartimento di Matematica e Geoscienze dell’Università degli Studi di Trieste. Dalla conservazione alla diffusione della cultura scientifica

Il Museo di Mineralogia e Petrografia del Dipartimento di Matematica e Geoscienze, oltre a costituire un importante strumento di apprendimento per gli studenti universitari dei Corsi di Studio in Scienze Geologiche, Scienze e Tecnologie per l’Ambiente e la Natura e Ingegneria, è un valido supporto per la diffusione della cultura scientifica in ambito delle Scienze della Terra. Per quest’ultima funzione il Museo predispone mostre temporanee e partecipa alle manifestazioni organizzate nel Campus di S. Giovanni in collaborazione con altre realtà museali del Comprensorio. Inoltre, presso il Museo vengono svolte visite guidate per le scolaresche di ogni ordine e grado, in modo da stimolare la curiosità e possibilmente fornire un orientamento per i futuri studi universitari.The Museum of Mineralogy and Petrology of the Department of Mathematics and Geosciences, is not only an important instrument for the students of Geological Sciences, Sciences and Technologies for the Environment and Nature, and Engineering, but also a valid support for the diffusion of scientific knowledge in Earth Sciences. For this purpose, the Museum organizes temporary exhibitions and contributes to the organization of events in the St. Giovanni campus, in collaboration with other museums existing in the same campus. Moreover, the Museum hosts guided visit to scholarships (primary to high school) in order to stimulate their curiosity and interest and possibly to introduce them to Earth Sciences as a future university career