Thermodynamic studies on Cu(I) and Ag(I) phosphino complexes with potential anti-tumor activity

Some thermodynamic studies on the formation equilibria of new copper(I) and silver(I) complexes with the hydrophilic phosphine PTA (1,3,5-7-triazaphosphaadamantane) are presented. With the aim of finding new metal-based compounds with potential antitumor activity, some new copper(I) and silver(I) complexes of PTA phosphine were recently prepared. These compounds show a good cytotoxicity in-vitro against several human tumor cell lines, and their biological activity was related to the ability of copper to bind biologically important substates, after dissociation of one or more phosphines during the in-vitro tests. With the aim of clarifying the relationship occurring between the structure, the stability and the in-vitro cytotoxic activity of these compounds, several thermodynamic studies were undertaken, in order to study the formation equilibria of the copper(I)-, silver(I)-PTA complexes in aqueous solution, in conditions similar to those of biological testing. Experiments were carried out by means of potentiometric, spectrophotometric and microcalorimetric techniques, and results were corroborated by ESI mass spectrometry and DFT calculation

Cu(i) and Ag(i) complex formation with the hydrophilic phosphine 1,3,5-triaza-7-phosphadamantane in different ionic media. How to estimate the effect of a complexing medium

The complexes of Cu(i) and Ag(i) with 1,3,5-triaza-7-phosphadamantane (PTA) are currently studied for their potential clinical use as anticancer agents, given the cytotoxicity they exhibited in vitro towards a panel of several human tumor cell lines. These metallodrugs are prepared in the form of [M(PTA)4]+ (M = Cu+, Ag+) compounds and dissolved in physiological solution for their administration. However, the nature of the species involved in the cytotoxic activity of the compounds is often unknown. In the present work, the thermodynamics of formation of the complexes of Cu(i) and Ag(i) with PTA in aqueous solution is investigated by means of potentiometric, spectrophotometric and microcalorimetric methods. The results show that both metal(i) ions form up to four successive complexes with PTA. The formation of Ag(i) complexes is studied at 298.15 K in 0.1 M NaNO3 whereas the formation of the Cu(i) one is studied in 1 M NaCl, where Cu(i) is stabilized by the formation of three successive chloro-complexes. Therefore, for this latter system, conditional stability constants and thermodynamic data are obtained. To estimate the affinity of Cu(i) for PTA in the absence of chloride, Density Functional Theory (DFT) calculations have been done to obtain the stoichiometry and the relative stability of the possible Cu/PTA/Cl species. Results indicate that one chloride ion is involved in the formation of the first two complexes of Cu(i) ([CuCl(PTA)] and [CuCl(PTA)2]) whereas it is absent in the successive ones ([Cu(PTA)3]+ and [Cu(PTA)4]+). The combination of DFT results and thermodynamic experimental data has been used to estimate the stability constants of the four [Cu(PTA)n]+ (n = 1-4) complexes in an ideal non-complexing medium. The calculated stability constants are higher than the corresponding conditional values and show that PTA prefers Cu(i) to the Ag(i) ion. The approach used here to estimate the hidden role of chloride on the conditional stability constants of Cu(i) complexes may be applied to any Cu(i)/ligand system, provided that the stoichiometry of the species in NaCl solution is known. The speciation for the two systems shows that the [M(PTA)4]+ (M = Cu+, Ag+) complexes present in the metallodrugs are dissociated into lower stoichiometry species when diluted to the micromolar concentration range, typical of the in vitro biological testing. Accordingly, [Cu(PTA)2]+, [Cu(PTA)3]+ and [Ag(PTA)2]+ are predicted to be the species actually involved in the cytotoxic activity of these compounds. \ua9 2017 The Royal Society of Chemistry

Multimodal Phase-Based X-Ray Microtomography with Nonmicrofocal Laboratory Sources

We present an alternative laboratory implementation of x-ray phase-contrast tomography through a beam-tracking approach. A nonmicrofocal rotating anode source is combined with a high-resolution detector and an absorbing mask to obtain attenuation, phase, and ultra-small-angle scattering tomograms of different specimens. A theoretical model is also presented which justifies the implementation of beam tracking with polychromatic sources and provides quantitative values of attenuation and phase, under the assumption of low sample attenuation. The method is tested on a variety of samples featuring both large and small x-ray attenuation, phase, and scattering signals. The complementarity of the contrast channels can enable subtle distinctions between materials and tissue types, which appear indistinguishable to conventional tomography scanners

Accretion-induced prompt black hole formation in asymmetric neutron star mergers, dynamical ejecta and kilonova signals

We present new numerical relativity results of neutron star mergers with chirp mass $1.188M_\odot$ and mass ratios $q=1.67$ and $q=1.8$ using finite-temperature equations of state (EOS), approximate neutrino transport and a subgrid model for magnetohydrodynamics-induced turbulent viscosity. The EOS are compatible with nuclear and astrophysical constraints and include a new microphysical model derived from ab-initio calculations based on the Brueckner-Hartree-Fock approach. We report for the first time evidence for accretion-induced prompt collapse in high-mass-ratio mergers, in which the tidal disruption of the companion and its accretion onto the primary star determine prompt black hole formation. As a result of the tidal disruption, an accretion disc of neutron-rich and cold matter forms with baryon masses ${\sim}0.15M_\odot$, and it is significantly heavier than the remnant discs in equal-masses prompt collapse mergers. Massive dynamical ejecta of order ${\sim}0.01M_\odot$ also originate from the tidal disruption. They are neutron rich and expand from the orbital plane with a crescent-like geometry. Consequently, bright, red and temporally extended kilonova emission is predicted from these mergers. Our results show that prompt black hole mergers can power bright electromagnetic counterparts for high-mass-ratio binaries, and that the binary mass ratio can be in principle constrained from multimessenger observations.Comment: 20 pages, 21 figures, 4 table

Valorization of traditional Italian walnut (Juglans regia L.) production: genetic, nutritional and sensory characterization of locally grown varieties in the Trentino region

15openYesJuglans regia (L.) is cultivated worldwide for its nutrient-rich nuts. In Italy, despite the growing demand, walnut cultivation has gone through a strong decline in recent decades, which led to Italy being among the top five net importing countries. To promote the development of local high-quality Italian walnut production, we devised a multidisciplinary project to highlight the distinctive traits of three varieties grown in the mountainous region Trentino (northeast of Italy): the heirloom ‘Bleggiana’, a second local accession called local Franquette and the French cultivar ‘Lara’, recently introduced in the local production to increase yield. The genetic characterization confirmed the uniqueness of ‘Bleggiana’ and revealed local Franquette as a newly described autochthonous variety, thus named ‘Blegette’. The metabolic profiles highlighted a valuable nutritional composition of the local varieties, richer in polyphenols and with a lower ω-6/ω-3 ratio than the commercial ‘Lara’. ‘Blegette’ obtained the highest preference scores from consumers for both the visual aspect and tasting; however, the volatile organic compound profiles did not discriminate among the characterized cultivars. The described local varieties represent an interesting reservoir of walnut genetic diversity and quality properties, which deserve future investigation on agronomically useful traits (e.g., local adaptation and water usage) for a high-quality and sustainable production.Di Pierro, Erica A.; Franceschi, Pietro; Endrizzi, Isabella; Farneti, Brian; Poles, Lara; Masuero, Domenico; Khomenko, Iuliia; Trenti, Francesco; Marrano, Annarita; Vrhovsek, Urska; Gasperi, Flavia; Biasioli, Franco; Guella, Graziano; Bianco, Luca; Troggio, MichelaDi Pierro, E.A.; Franceschi, P.; Endrizzi, I.; Farneti, B.; Poles, L.; Masuero, D.; Khomenko, I.; Trenti, F.; Marrano, A.; Vrhovsek, U.; Gasperi, F.; Biasioli, F.; Guella, G.; Bianco, L.; Troggio, M

X-ray dark-field tomography using edge-illumination

X-ray dark-field imaging is used to visualize the ultra-small angle x-ray scattering signal that originates from sub-resolution density fluctuations within the sample microstructure. Dark-field tomography using the edge-illumination x-ray imaging system is presented as a tool for measuring this scattering signal in a sample in three dimensions. Its applicability to different fields is shown through example images of a multi-material phantom, a tissue-engineered esophagus, a pouch cell battery and a short-fiber reinforced composite material. The multichannel contrast available in edge-illumination helps with material identification, with high contrast at boundaries enhancing dark-field reconstructions

Thermodynamic studies on Cu(I) and Ag(I) phosphino complexes with potential anti-tumor activity

Some thermodynamic studies on the formation equilibria of new copper(I) and silver(I) complexes with the hydrophilic phosphine PTA (1,3,5-7-triazaphosphaadamantane) are presented. With the aim of finding new metal-based compounds with potential antitumor activity, some new copper(I) and silver(I) complexes of PTA phosphine were recently prepared. These compounds show a good cytotoxicity in-vitro against several human tumor cell lines, and their biological activity was related to the ability of copper to bind biologically important substates, after dissociation of one or more phosphines during the in-vitro tests. With the aim of clarifying the relationship occurring between the structure, the stability and the in-vitro cytotoxic activity of these compounds, several thermodynamic studies were undertaken, in order to study the formation equilibria of the copper(I)-, silver(I)-PTA complexes in aqueous solution, in conditions similar to those of biological testing. Experiments were carried out by means of potentiometric, spectrophotometric and microcalorimetric techniques, and results were corroborated by ESI mass spectrometry and DFT calculationsNel presente lavoro è riportato uno studio riguardante gli equilibri termodinamici di formazione di alcuni coplessi di rame (I) e argento (I) con la fosfina idrofilica PTA (1,3,5-7-triazaphosphaadamantane). Nell’ambito della ricerca di nuovi composti metallici con potenziale attività antitumorale sono stati di recente preparati alcuni complessi rame(I) e argento(I) con la fosfina PTA. I composti hanno esibito una buona citotossicità in vitro nei confronti di diverse linee cellulari tumorali umane, e la chiave della loro attività biologica è stata attribuita alla capacità del rame di coordinare di siti biologicamente rilevanti, a seguito della dissociazione di una o più fosfine, nel corso dei test in vitro. Allo scopo di chiarire le relazioni tra struttura, stabilità e citotossicità in vitro di questi composti, sono stati condotti alcuni studi termodinamici, il cui fine era lo studio degli equilibri formazione del complessi di rame(I) – e argento(I) con PTA in soluzione acquosa, in condizioni simili a quelle dei test biologici. Gli esperimenti sono stati svolti mediante l’uso di tecniche potenziometriche, spettrofotometriche e microcalorimetriche, ed i risultati sono stati confermati mediante spettrometria di massa ESI e calcoli DF

Derivati di Au(III) con dipeptidi funzionalizzati come agenti antitumorali

Sono state sintetizzati derivati peptidici ditiocarbammici di Au(III) come potenziali agenti antitumorali. Tali composti sono stati caratterizzati dal punto di vista chimico e della stabilità in ambiente fisiologico. Sono riportati studi preliminari di citotossicità in vitro su cellule tumorali umane