Quantitative wave function analysis for excited states of transition metal complexes

The character of an electronically excited state is one of the most important descriptors employed to discuss the photophysics and photochemistry of transition metal complexes. In transition metal complexes, the interaction between the metal and the different ligands gives rise to a rich variety of excited states, including metal-centered, intra-ligand, metal-to-ligand charge transfer, ligand-to-metal charge transfer, and ligand-to-ligand charge transfer states. Most often, these excited states are identified by considering the most important wave function excitation coefficients and inspecting visually the involved orbitals. This procedure is tedious, subjective, and imprecise. Instead, automatic and quantitative techniques for excited-state characterization are desirable. In this contribution we review the concept of charge transfer numbers---as implemented in the TheoDORE package---and show its wide applicability to characterize the excited states of transition metal complexes. Charge transfer numbers are a formal way to analyze an excited state in terms of electron transitions between groups of atoms based only on the well-defined transition density matrix. Its advantages are many: it can be fully automatized for many excited states, is objective and reproducible, and provides quantitative data useful for the discussion of trends or patterns. We also introduce a formalism for spin-orbit-mixed states and a method for statistical analysis of charge transfer numbers. The potential of this technique is demonstrated for a number of prototypical transition metal complexes containing Ir, Ru, and Re. Topics discussed include orbital delocalization between metal and carbonyl ligands, nonradiative decay through metal-centered states, effect of spin-orbit couplings on state character, and comparison among results obtained from different electronic structure methods.Comment: 47 pages, 19 figures, including supporting information (7 pages, 1 figure

Functional correlates of optic flow motion processing in Parkinson’s disease

The visual input created by the relative motion between an individual and the environment, also called optic flow, influences the sense of self-motion, postural orientation, veering of gait, and visuospatial cognition. An optic flow network comprising visual motion areas V6, V3A, and MT+, as well as visuo-vestibular areas including posterior insula vestibular cortex (PIVC) and cingulate sulcus visual area (CSv), has been described as uniquely selective for parsing egomotion depth cues in humans. Individuals with Parkinson’s disease (PD) have known behavioral deficits in optic flow perception and visuospatial cognition compared to age- and education-matched control adults (MC). The present study used functional magnetic resonance imaging (fMRI) to investigate neural correlates related to impaired optic flow perception in PD. We conducted fMRI on 40 non-demented participants (23 PD and 17 MC) during passive viewing of simulated optic flow motion and random motion. We hypothesized that compared to the MC group, PD participants would show abnormal neural activity in regions comprising this optic flow network. MC participants showed robust activation across all regions in the optic flow network, consistent with studies in young adults, suggesting intact optic flow perception at the neural level in healthy aging. PD participants showed diminished activity compared to MC particularly within visual motion area MT+ and the visuo-vestibular region CSv. Further, activation in visuo-vestibular region CSv was associated with disease severity. These findings suggest that behavioral reports of impaired optic flow perception and visuospatial performance may be a result of impaired neural processing within visual motion and visuo-vestibular regions in PD.Published versio

Cooccurrence de violence conjugale et de maltraitance envers les enfants : points de vue des intervenants de la protection de la jeunesse

Cet article rend compte des résultats d’une étude exploratoire portant sur les pratiques d’intervention dans le domaine de la protection de la jeunesse concernant les situations où il y a violence conjugale et maltraitance envers les enfants. Plus précisément, l’étude permet de documenter les éléments pris en considération dans le dépistage et l’évaluation des situations de cooccurrence ainsi que les défis auxquels les intervenants sont confrontés dans ce type de cas. L’analyse qualitative du contenu de 43 entrevues montre que les intervenants reconnaissent l’existence des liens de cooccurrence entre les deux problématiques et l’importance d’en tenir compte dans l’intervention. La prise en compte de ces liens dans les pratiques d’intervention mises en oeuvre soulève toutefois des enjeux et des dilemmes importants concernant le dépistage et l’évaluation des situations ainsi que pour la création d’un lien de confiance et de collaboration avec les membres de la famille.This article shows the results of an exploratory study about intervention practices in youth protection in situations where conjugal violence and child maltreatment co-occur. More specifically, the study documents the elements taken into consideration to detect and assess the situations of cooccurrence as well as the stakes the social workers are confronted with in those cases. The qualitative analysis of 43 interviews shows that the social workers recognize the existence of the links of cooccurrence between both problems and the importance to take it into account in their interventions. However, the consideration of these links in the implemented practices raises stakes and an important dilemma concerning the detection and the evaluation of those situations as well as for the establishment of collaboration and trust with family members.Este artículo da cuenta de los resultados de un estudio exploratorio sobre las prácticas de intervención en el ámbito de la protección a la infancia en situaciones en que existe a la vez violencia conyugal y maltrato de menores. De manera más precisa, el estudio permite documentar los elementos que se toman en cuenta en la detección y evaluación de situaciones de coocurrencia, así como los desafíos a que se enfrentan los trabajadores sociales en este tipo de casos. El análisis cualitativo del contenido de 43 entrevistas muestra que los trabajadores sociales reconocen la existencia de relaciones de coocurrencia entre ambas problemáticas y la importancia de tomarlas en cuenta durante la intervención. La consideración de dichas relaciones constituye, sin embargo, un desafío en la práctica, pues plantea dilemas importantes respecto de la detección y la evaluación de esas situaciones, así como para el establecimiento de un clima de confianza y colaboración con los miembros de la familia concernida

Biochemical disorders induced by cytotoxic marine natural products in breast cancer cells as revealed by proton NMR spectroscopy-based metabolomics

International audienceMarine plants and animals are sources of a huge number of pharmacologically active compounds, some of which exhibit antineoplastic activity of clinical relevance. However the mechanism of action of marine natural products (MNPs) is poorly understood. In this study, proton NMR spectroscopy-based metabolomics was applied to unravel biochemical disorders induced in human MCF7 breast cancer cells by 3 lead candidate anticancer MNPs: ascididemin (Asc), lamellarin-D (Lam-D), and kahalalide F (KF). Asc, Lam-D, and KF provoked a severe decrease in DNA content in MCF7 cells after 24h treatment. Asc and Lam-D provoked apoptosis, whereas KF induced non-apoptotic cell death. Metabolite profiling revealed major biochemical disorders following treatment. The response of MCF7 tumor cells to Asc involved the accumulation of citrate (×17 the control level, <0.001), testifying enzyme blockade in citrate metabolism, and the accumulation of gluconate (×9.8, <0.005), a metabolite never reported at such concentration in tumor cells, probably testifying glycolysis shutdown. The response to Lam-D involved the accumulation of aspartate (×7.2, <0.05), glutamate (×14.7, <0.05), and lactate (×2.3, <0.05), probably in relation with the targeting of the malate-aspartate shuttle, as discussed. The response to KF involved increased lipid accumulation (polyunsaturated fatty acids ×9.8, <0.05), and phospholipid and acetate derivative alterations. Altogether, this study demonstrates the potential of proton NMR spectroscopy-based metabolomics to help uncover metabolic targets and elucidate the mechanism of cytotoxicity of candidate antineoplastic MNPs

Interstate Vibronic Coupling Constants Between Electronic Excited States for Complex Molecules

In the construction of diabatic vibronic Hamiltonians for quantum dynamics in the excited-state manifold of molecules, the coupling constants are often extracted solely from information on the excited-state energies. Here, a new protocol is applied to get access to the interstate vibronic coupling constants at the time-dependent density functional theory level through the overlap integrals between excited-state adiabatic auxiliary wavefunctions. We discuss the advantages of such method and its potential for future applications to address complex systems, in particular those where multiple electronic states are energetically closely lying and interact. As examples, we apply the protocol to the study of prototype rhenium carbonyl complexes [Re(CO)$_3$(N,N)(L)]$^{n+}$ for which non-adiabatic quantum dynamics within the linear vibronic coupling model and including spin-orbit coupling have been reported recently.Comment: 36 pages, 7 figures, 4 table

Prefigurative performance in the age of political deception

The most notable forms of activism in recent years, prefigurative interventions and occupations, are comparable to theatrical performance by embodying, situating and interacting hypothetical scenarios. The mutual points of political performance lies in open-ended, horizontal performance practices such as site-sensitive interventions, tactical media, applied theatre and cognate modes of interactive performance. Whilst several examples of such overlapping performance phenomena are given and justified in the article, the political disciplines also face mutual challenges from hegemonic politics and thus share a need to adapt their performative effects into sustainable social movements

The Effect of Prior Exposures on the Notched Fatigue Behavior of Disk Superalloy ME3

Environmental attack has the potential to limit turbine disk durability, particularly in next generation engines which will run hotter; there is a need to understand better oxidation at potential service conditions and develop models that link microstructure to fatigue response. More efficient gas turbine engine designs will require higher operating temperatures. Turbine disks are regarded as critical flight safety components; a failure is a serious hazard. Low cycle fatigue is an important design criteria for turbine disks. Powder metallurgy alloys, like ME3, have led to major improvements in temperature performance through refractory additions (e.g. Mo,W) at the expense of environmental resistance (Al, Cr). Service conditions for aerospace disks can produce major cycle periods extending from minutes to hours and days with total service times exceeding 1,000 hours in aerospace applications. Some of the effects of service can be captured by extended exposures at elevated temperature prior to LCF testing. Some details of the work presented here have been published

Heteroleptic diimine copper(i) complexes with large extinction coefficients: synthesis, quantum chemistry calculations and physico-chemical properties.

International audience: Using the HETPHEN approach, five new heteroleptic copper(i) complexes composed of a push-pull 4,4'-styryl-6,6'-dimethyl-2,2'-bipyridine ligand and a bulky bis[(2-diphenylphosphino)phenyl]-ether (DPEphos) or a bis2,9-mesityl phenanthroline (Mes2Phen) were prepared and characterized by electronic absorption spectroscopy, electrochemistry, and TD-DFT calculations. These complexes exhibit very intense absorption bands in the visible region with extinction coefficient in the range of 5-7 × 10(4) M(-1) cm(-1). The analysis of the position, intensity and band shape indicates a strong contribution from an intra-ligand charge-transfer transition centered on the styrylbipyridine ligand along with MLCT transitions. These new complexes experimentally demonstrate that good light harvesting properties with bis-diimine copper(i) complexes are a reality if one chooses suitable ligands in the coordination sphere. This constitutes a milestone towards using bis-diimine copper(i) complexes for solar energy conversion (artificial photosynthesis and solar cells)

Economic Burden of Surgical Site Infections at a European University Hospital

Objective. To quantify the economic burden of in-hospital surgical site infections (SSIs) at a European university hospital. Design. Matched case-control study nested in a prospective observational cohort study. Setting. Basel University Hospital in Switzerland, where an average of 28,000 surgical procedures are performed per year. Methods. All in-hospital occurrences of SSI associated with surgeries performed between January 1, 2000, and December 31, 2001, by the visceral, vascular, and traumatology divisions at Basel University Hospital were prospectively recorded. Each case patient was matched to a control patient by age, procedure code, and National Nosocomial Infection Surveillance System risk index. The case-control pairs were analyzed for differences in cost of hospital care and in provision of specialized care. Results. A total of 6,283 procedures were performed:187 SSIs were detected in inpatients, 168 of whom were successfully matched with a control patient. For case patients, the mean additional hospital cost was SwF19,638 (95% confidence interval [CI], SwF8,492-SwF30,784); the mean additional postoperative length of hospital stay was 16.8 days (95% CI, 13-20.6 days); and the mean additional in-hospital duration of antibiotic therapy was 7.4 days (95% CI, 5.1-9.6 days). Differences were primarily attributable to organ space SSIs (n = 76). Conclusions. Ina European university hospital setting, SSIs are costly and constitute a heavy and potentially preventable burden on both patients and healthcare provider