Nuclear magnetic resonance in contemporary art: the case of “Moon Surface” by Turcato

Nuclear Magnetic Resonance (NMR) methodologies were applied to characterize the constitutive materials and the state of degradation of a contemporary painting. The investigation was mandatory to plan a suitable restoration. Noninvasive, portable NMR allowed the detection of degraded regions of the painting based on the measurement of longitudinal relaxation time. A few samples were investigated by high resolution solid state NMR and NMR in solution, which allowed us to identify the polyurethane constituting the artefact, to investigate the microstructure in detail, and to assess that the degradation process mostly affected the ethylene units used to cap the polypropylene oxide polymeric chain. As a matter of fact, a shortening of longitudinal relaxation time was accompanied by a degradation of ethylene units. The degradation of the inorganic loading was investigated by ²⁷Al MAS, which evidenced the absence of penta-coordinated aluminum in degraded samples.     

On balanced Hermitian structures on Lie groups

We present several methods for the construction of balanced Hermitian structures on Lie groups. In our methods a partial differential equation is involved so that the resulting structures are in general non homogeneous. In particular, we prove that for 3-step nilpotent Lie groups G of dimension 6, any left-invariant complex structure on G admits a balanced Hermitian metric. Starting from normal almost contact structures, we construct balanced metrics on 6-dimensional manifolds, generalizing warped products. Finally, explicit balanced Hermitian structures are also given on solvable Lie groups defined as semidirect products ${\mathbb{R}^k \ltimes \mathbb{R}^{2n-k}}$ .     

Detection of picramic acid and picramate in henné products by NMR Spectroscopy

Painting and body art are increasing their utilisation as well as their cultural impact, since piercing and tattoos are expanding social phenomena, involving many young people. However, the utilised materials often enter the market with insufficient control and several cases of skin damages are reported. Safety of the utilised products must be ensured by adequate quality controls which must be easily made, rapid, low cost, clear and persuasive. The method here reported, regards the analysis on the possible presence of picramic acid in the ethyl acetate extracts of commercial henné powders by NMR Spectroscopy. In the proton spectrum, three sets of peaks could be detected, corresponding to the three classes of makers resonances: hennosides, typical markers of Lawsonia inermis, the henné plant; picramic acid or picramate; fatty acids. In particular, the set of signals corresponding to hennosides can be used as markers of the utilisation of the correct raw material of henné.     

Combined Treatment with PI3K Inhibitors BYL-719 and CAL-101 Is a Promising Antiproliferative Strategy in Human Rhabdomyosarcoma Cells

Rhabdomyosarcoma (RMS) is a highly malignant and metastatic pediatric cancer arising from skeletal muscle myogenic progenitors. Recent studies have shown an important role for AKT signaling in RMS progression. Aberrant activation of the PI3K/AKT axis is one of the most frequent events occurring in human cancers and serves to disconnect the control of cell growth, survival, and metabolism from exogenous growth stimuli. In the study reported here, a panel of five compounds targeting the catalytic subunits of the four class I PI3K isoforms (p110α, BYL-719 inhibitor; p110β, TGX-221 inhibitor; p110γ, {"type":"entrez-protein","attrs":{"text":"CZC24832","term_id":"994587862","term_text":"CZC24832"}}CZC24832; p110δ, CAL-101 inhibitor) and the dual p110α/p110δ, AZD8835 inhibitor, were tested on the RMS cell lines RD, A204, and SJCRH30. Cytotoxicity, cell cycle, apoptosis, and the activation of downstream targets were analyzed. Of the individual inhibitors, BYL-719 demonstrated the most anti-tumorgenic properties. BYL-719 treatment resulted in G1/G0 phase cell cycle arrest and apoptosis. When combined with CAL-101, BYL-719 decreased cell viability and induced apoptosis in a synergistic manner, equaling or surpassing results achieved with AZD8835. In conclusion, our findings indicate that BYL-719, either alone or in combination with the p110δ inhibitor, CAL-101, could represent an efficient treatment for human rhabdomyosarcoma presenting with aberrant upregulation of the PI3K signaling pathway.     

Molecular-cluster studies of defects in silicon lattices

Summary Ab initio HF-SCF-LCAO calculations have been performed on Si _n H _2n+n (n=1 to 5) by means of four different basis sets. Total energies, first ionization potentials, minimum-energy geometries and torsional barriers of rotation around the Si−Si bond have been computed in order to test the accuracy of the basis sets used.

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Riassunto Sono stati eseguiti calcoliab initio HF-LCAO-SCF su composti della famiglia dei silani lineari (Si _n H _2n+2 ,n=1, ..., 5) mediate quatro differenti insiemi di funzioni di base. Sono state calcolate energie totali, primi potenziali di ionizzazione, geometrie al minimo di energia e barriere torsionali attorno al legame Si−Si per poter verificare l'accuratezza degl'insiemi di funzioni di base usati.

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Резюме Сначала проводятся вычисления HF-SCF-LCAO в семействе соединений Si _n H _2n+1 (n от 1 до 5), используя четыре различных базисных системы. С целью проверки точнсти использованных базисных систем систем бычислены полные знергии, первые потенциалы ионизации, геометрии с минимльной энергией и барьеры врашения вокруг связи Si−Si.

     

Production of hollow cylindrical plasmas for laser guiding in acceleration experiments

One of the major tasks for the progress of laser acceleration of electrons in plasmas is the guiding of focused pulses along path lengths much larger than the depth of focus. We have tested experimentally the production of hollow plasmas in gas to be used as guiding medium. We induced optical breakdown in Helium with a nanosecond laser pulse similar to the Amplified Spontaneous Emission (ASE) pedestal of a powerful ultrashort laser pulse. The plasma produced in this way was carefully characterized by high resolution interferometry. Plasma channels several millimeters in length whose density, depth and width match the requirements for an efficient guiding have been obtained. Channels with a variety of parameters can be created according to the well-known dynamics of the plasmas produced by optical breakdown. PACS 42.82.Et; 52.50.Jm; 41.75.Jv