Institution
University of Rennes
Education•Rennes, France•
About: University of Rennes is a education organization based out in Rennes, France. It is known for research contribution in the topics: Population & Crystal structure. The organization has 18404 authors who have published 40374 publications receiving 995327 citations.
Topics: Population, Crystal structure, Ruthenium, Catalysis, Antenna (radio)
Papers published on a yearly basis
Papers
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TL;DR: The two approaches to induce noncentrosymmetry at the macroscopic level, either by supramolecular organization or by the all optical poling procedure are shown.
Abstract: Coordination compounds are of particular interest for the design of new chromophores with large nonlinear optical (NLO) susceptibilities. They offer a wide range of metals with different oxidation states and ligands, which can give rise to tunable electronic properties. Metal ions are excellent templates to build 2D and 3D octupolar NLO-phores. Their associations with functionalized bipyridyl ligands give rise to octahedral and tetrahedral metal complexes with large first-order hyperpolarizabilities. The ability to functionalize these octupoles allows their incorporation into macromolecular architectures such as polymers and metallodendrimers, We also show in this Account two approaches to induce noncentrosymmetry at the macroscopic level, either by supramolecular organization or by the all optical poling procedure.
263 citations
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TL;DR: A unique synergistic growth mechanism is elucidated by the combination of light and electron microscopy, synchrotron X-ray diffuse scattering and Raman spectroscopy, which results in the synthesis of unprecedented double-walled silica nanotubes with monodisperse diameters that self-organize into highly ordered centimetre-sized fibres.
Abstract: Diatoms, shells, bones and teeth are exquisite examples of well-defined structures, arranged from nanometre to macroscopic length scale, produced by natural biomineralization using organic templates to control the growth of the inorganic phase. Although strategies mimicking Nature have partially succeeded in synthesizing human-designed bio-inorganic composite materials, our limited understanding of fundamental mechanisms has so far kept the level of hierarchical complexity found in biological organisms out of the chemists' reach. In this letter, we report on the synthesis of unprecedented double-walled silica nanotubes with monodisperse diameters that self-organize into highly ordered centimetre-sized fibres. A unique synergistic growth mechanism is elucidated by the combination of light and electron microscopy, synchrotron X-ray diffuse scattering and Raman spectroscopy. Following this growth mechanism, macroscopic bundles of nanotubules result from the kinetic cross-coupling of two molecular processes: a dynamical supramolecular self-assembly and a stabilizing silica mineralization. The feedback actions between the template growth and the inorganic deposition are driven by a mutual electrostatic neutralization. This 'dynamical template' concept can be further generalized as a rational preparation scheme for materials with well-defined multiscale architectures and also as a fundamental mechanism for growth processes in biological systems.
263 citations
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TL;DR: In this paper, Fourier transform infrared (FTIR) spectra were used to predict the organic matter composition in peat samples at various stages of peatland regeneration from five European countries.
Abstract: Vegetational changes during the restoration of cutover peatlands leave a legacy in terms of the organic matter quality of the newly formed peat. Current efforts to restore peatlands at a large scale therefore require low cost and high throughput techniques to monitor the evolution of organic matter. In this study, we assessed the merits of using Fourier transform infrared (FTIR) spectra to predict the organic matter composition in peat samples at various stages of peatland regeneration from five European countries. Using predictive partial least squares (PLS) analyses, we were able to reconstruct peat C:N ratio and carbohydrate signatures with reasonable accuracy, but not the micromorphological composition of vegetation remains. Despite utilising different size fractions, both carbohydrate (
263 citations
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TL;DR: In this paper, the authors show that differences between species in adaptations to various dispersal vectors, in combination with changes in the availability of these vectors, contribute significantly to explaining losses in plant diversity in Northwest Europe in the 20th century.
Abstract: The ongoing decline of many plant species in Northwest Europe indicates that traditional conservation measures to improve the habitat quality, although useful, are not enough to halt diversity losses. Using recent databases, we show for the first time that differences between species in adaptations to various dispersal vectors, in combination with changes in the availability of these vectors, contribute significantly to explaining losses in plant diversity in Northwest Europe in the 20th century. Species with water- or fur-assisted dispersal are over-represented among declining species, while others (wind- or bird-assisted dispersal) are under-represented. Our analysis indicates that the 'colonization deficit' due to a degraded dispersal infrastructure is no less important in explaining plant diversity losses than the more commonly accepted effect of eutrophication and associated niche-based processes. Our findings call for measures that aim to restore the dispersal infrastructure across entire regions and that go beyond current conservation practices.
261 citations
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TL;DR: Increasing age emerges as a major determinant of the clinical characteristics of infective endocarditis, and lower rates of surgical treatment and high mortality are the most prominent features of elderly patients with IE.
Abstract: Results: Elderly patients reported more frequently a hospitalization or an invasive procedure before IE onset. Diabetes mellitus and genitourinary and gastrointestinal cancer were the major predisposing conditions. Blood culture yield was higher among elderly patients with IE. The leading causative organism was Staphylococcus aureus, with a higher rate of methicillin resistance.Streptococcusbovis and enterococci were also significantly more prevalent. The clinical presentation of elderly patients with IE was remarkable for lower rates of embolism, immune-mediated phenomena, or septic complications. At both echocardiography and surgery, fewer vegetations and more abscesses were found, and the gain in the diagnostic yield of transesophageal echocardiography was significantly larger. Significantly fewer elderly patients underwent cardiac surgery (38.9% vs 53.5%; P.001). Elderly patients with IE showed a higher rate of in-hospital death (24.9% vs 12.8%; P.001), and age older than 65 years was an independent predictor of mortality. Conclusions: In this large prospective study, increasing age emerges as a major determinant of the clinical characteristics of IE. Lower rates of surgical treatment and high mortality are the most prominent features of elderly patients with IE. Efforts should be made to prevent health care–associated acquisition and improve outcomes in this major subgroup of patients with IE.
261 citations
Authors
Showing all 18470 results
Name | H-index | Papers | Citations |
---|---|---|---|
Philippe Froguel | 166 | 820 | 118816 |
Bart Staels | 152 | 824 | 86638 |
Yi Yang | 143 | 2456 | 92268 |
Geoffrey Burnstock | 141 | 1488 | 99525 |
Shahrokh F. Shariat | 118 | 1637 | 58900 |
Lutz Ackermann | 116 | 669 | 45066 |
Douglas R. MacFarlane | 110 | 864 | 54236 |
Elliott H. Lieb | 107 | 512 | 57920 |
Fu-Yuan Wu | 107 | 367 | 42039 |
Didier Sornette | 104 | 1295 | 44157 |
Stefan Hild | 103 | 452 | 68228 |
Pierre I. Karakiewicz | 101 | 1207 | 40072 |
Philippe Dubois | 101 | 1098 | 48086 |
François Bondu | 100 | 440 | 69284 |
Jean-Michel Savéant | 98 | 517 | 33518 |