Two Cu(I) complexes based on semicarbazone ligand: synthesis,crystal structure,Hirshfeld surface and anticancer activity evaluation against human cell lines

Structural Chemistry - Two novel Cu(I) complexes with the 2-acetylpyridine-N(4)-phenyl semicarbazone (HL) ligand, [CuCl (HL)(PPh3)]∙CH3CN (1) and [CuBr (HL)(PPh3)] (2), were investigated by...     

Prospects for high-energy P−P beams: Study of hadronic jets and possible intermediate bosons

Predictions for large p_T hadronic jets in high-energy proton-antiproton collisions, produced by strong interactions alone or through intermediate boson production and decay, and strong interactions, are calculated and compared. Two alternative models are considered for the strong interactions between partons: the phenomenological model of quark-scattering and lowest order QCD. In the last case, gluons are also taken into account as partons, with different choices of the gluon distribution inside the proton. The differential cross-sections for two-jet productions are given in the more interesting regions of the phase-space, as well as the predictions for the mean charge of the jets. Possible signatures for the detection of the W are stressed. In particular, W's could show up only for jets with p_T near its maximum value. Our conclusions are mostly independent of the weak interaction model: the Weinberg-Salam one is considered for definiteness but alternative models are also discussed. The mean charge of the hadronic jets arising from either the weak or the strong interactions could be a rather distinctive tool in the search for the W. However, if gluons are present, their interactions could preponderate in the jet production mechanism and obstruct the search for intermediate bosons in the hadronic channels.     

Automating a 96-well microtiter plate assay for identification of AGEs inhibitors or inducers: application to the screening of a small natural compounds library

Advanced glycation end-products (AGEs) are involved in the pathogenesis of numerous affections such as diabetes and neurological diseases. AGEs are also implied in various changes in tissues and organs. Therefore, compounds able to break them or inhibit their formation may be considered as potential drugs, dietary supplements, or bioactive additives. In this study, we have developed a rapid and reliable (Z′ factor calculation) anti-AGEs activity screening based on the overall fluorescence of AGEs. This method was successfully evaluated on known AGEs inhibitors and on a small library of natural compounds, yielding coherent results when compared with literature data.     

Supramolecular architectures and crystal structures of gold(III) compounds with semicarbazones

The synthesis and crystal structures of two novel semicarbazones and four gold(III) compound derivatives of these semicarbazones are presented. A pattern in the formation of the semicarbazones shows the association of Cl^– ions held together by intra- and intermolecular forces. [AuCl₄]^? and [AuBr₄]^? anions are co-crystallised with these semicarbazone ligands, and the packing architectures revealed by a single-crystal X-ray diffraction analysis showed the different influences of the anions and the association of these chemical species by intermolecular forces on the crystal packing. Crystal engineering led to gold(III) compounds that are stabilised by relevant hydrogen bonding networks, which demonstrated their importance to the supramolecular organisation of the studied compounds. Interestingly, Cl???Br interactions are observed and contribute to the formation of the supramolecular structures. Elemental analysis data and spectroscopic properties in the solid state and solution are also described.     

Dehydrogenation of ammonia borane aided by hydrophobic ionic liquids

The beneficial effect on the dehydrogenation of ammonia borane due to mixing with hydrophobic ionic liquids (ILs) is investigated by means of detailed combined TG–DTA and IR measurements. Desorption of several mixtures of ammonia borane with hydrophobic ILs having bis(trifluoromethanesulfonyl)-imide or trifluorosulfonyl-imide anions was studied in both isothermal and non-isothermal conditions. The addition of hydrophobic liquids lowers the dehydrogenation temperatures and allows the observation of the decomposition process without any induction time even at temperatures below 90 °C. The IR data of the products of the decomposition confirm that ILs do not react with AB but provide an highly polar medium which promotes the decomposition reaction. Furthermore, the proposed method to enhance hydrogen release from ammonia borane provides the possibility of working in air avoiding any protective atmosphere.     

Overwinter changes to near-surface bulk density, penetration resistance and infiltration rates in compacted soil

Previous studies at Yakima Training Center (YTC), in Washington State, suggest freeze-thaw (FT) cycles can ameliorate soil compacted by tracked military vehicles [J. Terramechanics 38 (2001) 133]. However, we know little about the short-term effects of soil freezing over a single winter. We measured bulk density (BD), soil penetration resistance (SPR), and steady-state runoff rates in soil newly tracked by an Abrams tank and in uncompacted soil, before and after a single winter at YTC. We similarly measured BD, SPR and saturated hydraulic conductivity (k_fs) in simulated tank tracks at another site near Lind Washington. Average BD was significantly greater in tank ruts at YTC and in simulated tracks at the Lind site than in uncompacted soil soon after tracking and did not change significantly during the winter of 1997–1998. Measurements of SPR were strongly influenced by soil moisture. When soil was moist or tracks were newly formed, SPR was significantly higher in tank ruts than in uncompacted soil from the surface to a depth of about 10–15 cm. The greatest average SPR in compacted soil was observed between 4 and 6 cm depth. We observed less difference in SPR between tank ruts and uncompacted soil near-surface at YTC as the time after trafficking increased. We observed highest SPR ratios (compacted rut:undisturbed) in fresh tracks near the surface, with lower ratios associated with increasing track age or soil depth, indicating that some recovery had occurred at YTC near-surface. However, we did not observe a similar over-winter change in SPR profiles at the Lind site. Rainfall simulator data from YTC showed higher steady-state runoff rates in tank ruts than over uncompacted soil both before and after winter. However, more time was required to reach steady-state flow in tank ruts and the proportion of runoff was slightly lower in May 1998 than in August 1997. At the Lind site, k_fs was lower in newly compacted soil than in one-year old compacted soil or uncompacted soil. Our data suggest that indices of water infiltration such as steady-state runoff rates or k_fs, are more sensitive indicators of soil recovery after compaction than are BD or SPR.     

Composition of prehistoric rock-painting pigments from Egypt (Gilf Kébir area)

The composition of rock-painting pigments from Egypt (Gilf Kebia area) has been analyzed by means of molecular spectroscopy such as Fourier transform infrared and micro-Raman spectroscopy and scanning electron microscopy coupled to an energy dispersive X-ray spectrometer and X-ray fluorescence analysis. Red and yellow pigments were recognized as red and yellow ochre with additional rutile.