Imaging in the time of NFD/NSF: do we have to change our routines concerning renal insufficiency?

To date there are potential chronology-based but not conclusive reasons to believe that at least some of the gadolinium complexes play a causative role in the pathophysiology of nephrogenic systemic fibrosis (NSF) or nephrogenic fibrosing dermopathy (NFD). Still, the exact pathogenesis and the risk for patients is unclear beside the obvious connection to moderate to severe renal insufficiency. So far, MR imaging with Gd-enhancement was regarded as the safest imaging modality in these patients—the recent development creates tremendous uncertainty in the MR-community. Nevertheless, one should remember that, despite the over 200 cases of NSF and about 100 with proven involvement of Gd3+, the vast majority of over 200 million patients exposed to gadolinium since the 1980s have tolerated these agents well. Importantly, NSF is a rare disease and does not appear to occur in patients without renal impairment. Many patients and researchers have undergone MR investigations with Gd exposure in the past. For those, it is essential to know about the safety of the agents at normal renal function. We can hope that pharmacoepidemiological and preclinical studies will allow us to better understand the pathophysiology and role of the various MR contrast agents in the near future

Mobility, turnover and storage of pollutants in soils, sediments and waters : achievements and results of the EU project AquaTerra : a review.

AquaTerra is one of the first environmental projects within the 6th Framework program by the European Commission. It began in June 2004 with a multidisciplinary team of 45 partner organizations from 13 EU countries, Switzerland, Serbia, Romania and Montenegro. Results from sampling and modeling in 4 large river basins (Ebro, Danube, Elbe and Meuse) and one catchment of the Brévilles Spring in France led to new evaluations of diffuse and hotspot input of persistent organic and metal pollutants including dynamics of pesticides and polycyclic aromatic hydrocarbons, as well as metal turnover and accumulation. While degradation of selected organic compounds could be demonstrated under controlled conditions in the laboratory, turnover of most persistent pollutants in the field seems to range from decades to centuries. First investigations of long-term cumulative and degradation effects, particularly in the context of climate change, have shown that it is also necessary to consider the predictions of more than one climate model when trying to assess future impacts. This is largely controlled by uncertainties in climate model responses. It is becoming evident, however, that changes to the climate will have important impacts on the diffusion and degradation of pollutants in space and time that are just at the start of their exploration

Nature of empty states in superconducting CaC6 and related Li-Ca ternary graphite intercalation compounds using polarized x-ray absorption near-edge structure at the Ca K edge

International audienceThe angular dependence of the x-ray absorption near-edge structure (XANES) was recorded at the calcium K edge in three graphite intercalated compounds: CaC6, Li3.1Ca2.1C6 (phase !), and Li0.4Ca2.7C6 (phase "). The polarized XANES spectra provide experimental pictures of the Ca px,y and pz empty states of these three materials. In the case of CaC6, first-principles calculations based on density functional theory were performed, including XANES modeling and projected density-of-state simulations. A good agreement is obtained between theoretical and experimental polarized spectra. This enables us to assign the main XANES peaks in terms of orbital hybridization. The thorough analysis of the CaC6 polarized XANES spectra is used to interpret the spectral differences observed between the three compounds. The absence of pre-edge for all these phases indicates that Ca atoms are in locally centrosymmetric sites. The presence of Li in the graphitic interlayer drastically reduces the anisotropy of the Ca p empty states, as compared to CaC6. Structural and electronic information is extracted from the spectra of the " and ! phases, leading to substantial results, in absence of fully determined crystallographic structures