Singlet-triplet gaps in large multireference systems: spin-flip-driven alternatives for bioinorganic modelling

The proper description of low-spin states of open-shell systems, which are commonly encountered in the field of bioinorganic chemistry, rigorously requires using multireference ab initio methodologies. Such approaches are unfortunately very CPU-time consuming as dynamic correlation effects also have to be taken into account. The broken-symmetry unrestricted (spin-polarized) density functional theory (DFT) technique has been widely employed up to now to bypass that drawback, but despite a number of relative successes in the determination of singlet-triplet gaps, this framework cannot be considered as entirely satisfactory. In this contribution, we investigate some alternative ways relying on the spin-flip time-dependent DFT approach [Y. Shao et al. J. Chem. Phys. 118, 4807 (2003)]. Taking a few well-documented copper-dioxygen adducts as examples, we show that spin-flip (SF)-DFT computed singlet-triplet gaps compare very favorably to either experimental results or large-scale CASMP2 computations. Moreover, it is shown that this approach can be used to optimize geometries at a DFT level including some multireference effects. Finally, a clear-cut added value of the SF-DFT computations is drawn: if pure ab initio data are required, then the electronic excitations revealed by SF-DFT can be considered in designing dramatically reduced zeroth-order variational spaces to be used in subsequent multireference configuration interaction or multireference perturbation treatments

QUBIC: the Q&U Bolometric Interferometer for Cosmology

The primordial B-mode polarisation of the Cosmic Microwave Background is the imprints of the gravitational wave background generated by inflation. Observing the B-mode is up to now the most direct way to constrain the physics of the primordial Universe, especially inflation. To detect these B-modes, high sensitivity is required as well as an exquisite control of systematics effects. To comply with these requirements, we propose a new instrument called QUBIC (Q and U Bolometric Interferometer for Cosmology) based on bolometric interferometry. The control of systematics is obtained with a close-packed interferometer while bolometers cooled to very low temperature allow for high sensitivity. We present the architecture of this new instrument, the status of the project and the self-calibration technique which allows accurate measurement of the instrumental systematic effects

Novel Sulfated Polysaccharides Disrupt Cathelicidins, Inhibit RAGE and Reduce Cutaneous Inflammation in a Mouse Model of Rosacea

Rosacea is a common disfiguring skin disease of primarily Caucasians characterized by central erythema of the face, with telangiectatic blood vessels, papules and pustules, and can produce skin thickening, especially on the nose of men, creating rhinophyma. Rosacea can also produce dry, itchy eyes with irritation of the lids, keratitis and corneal scarring. The cause of rosacea has been proposed as over-production of the cationic cathelicidin peptide LL-37.We tested a new class of non-anticoagulant sulfated anionic polysaccharides, semi-synthetic glycosaminoglycan ethers (SAGEs) on key elements of the pathogenic pathway leading to rosacea. SAGEs were anti-inflammatory at ng/ml, including inhibition of polymorphonuclear leukocyte (PMN) proteases, P-selectin, and interaction of the receptor for advanced glycation end-products (RAGE) with four representative ligands. SAGEs bound LL-37 and inhibited interleukin-8 production induced by LL-37 in cultured human keratinocytes. When mixed with LL-37 before injection, SAGEs prevented the erythema and PMN infiltration produced by direct intradermal injection of LL-37 into mouse skin. Topical application of a 1% (w/w) SAGE emollient to overlying injected skin also reduced erythema and PMN infiltration from intradermal LL-37.Anionic polysaccharides, exemplified by SAGEs, offer potential as novel mechanism-based therapies for rosacea and by extension other LL-37-mediated and RAGE-ligand driven skin diseases

Action Based Approach to Archaeological Reconstruction Projects: Case of the Karnak Temple in Egypt

The proposed paper deals with a numerical approach that could better assist the archaeologist in the archaeological reconstruction projects. The goal of our research is to explore and study the use of computerized tools in archaeological reconstruction projects of monumental architecture in order to propose new ways in which such technology can be used

Importance of backdonation in [M–(CO)]p+ complexes isoelectronic to [Au–(CO)]+

International audienc

Trends in ns2np0 [M(CO)]q+ complexes: From germanium to element 114 (Uuq)

International audienc

Enforcing hemidirectionality in Pb(II) complexes: The importance of anionic ligands

International audienc

Pulse shape analysis for the location of the /spl gamma/-interactions in AGATA

A new method to determine the positions and energies of the /spl gamma/-interactions in a segmented HPGe crystal of the AGATA detector is presented. The procedure is able to decompose multi-hit events, even if hits occur in the same segment. We tested the method with simulated signals; noise and the finite bandwidth of the preamplifier have been considered

Lead Substitution in Synaptotagmin: A Case Study

International audienc

Computer Modeling as a Means of Reflexion in Archaeology. a New Epigraphic and Architectural Approach Applied to a Monument Registered on the World Heritage List.

Purpose of this paper is to present the first promising results of an ongoing research program that is part of a larger multi-year project carried out by the Computer Aided Design Research Group (GRCAO) of the Universitè de Montrèal, in order to define new methods of archaeological restitution using computer-aided means. This novel approach involves a redefinition of surveying techniques, data processing and knowledge-based thinking in disciplines such as epigraphy and architecture. As its chosen field of investigation, the GRCAO is using the Egyptian temple of Karnak, a monument on the UNESCO World Heritage list that is of considerable historical importance. This impressive archaeological site serves as an excellent case study and testing ground for the project, since it underwent tremendous and complex architectural transformations in the course of its two thousand year-long history