Computer-aided planning for zygomatic bone reconstruction in maxillofacial traumatology

An optimal planning procedure has been proposed to define the target position of the zygomatic bone following a fracture of the mid-face skeleton. The protocol has been successfully tested on healthy subjects, and ensures the global symmetry of the face could be obtained after the reconstruction surgery. Now that the planning procedure is available, the next step of this project will be to develop an intra-operative guiding system to help the surgeon to follow the planning. This procedure will mainly rely on the intra-operative registration of the zygomatic bone fragment, and the design of specific surgical ancillaries for cranio-maxillofacial surgery

Biomechanics applied to computer-aided diagnosis: examples of orbital and maxillofacial surgeries

This paper introduces the methodology proposed by our group to model the biological soft tissues deformations and to couple these models with Computer-Assisted Surgical (CAS) applications. After designing CAS protocols that mainly focused on bony structures, the Computer Aided Medical Imaging group of Laboratory TIMC (CNRS, France) now tries to take into account the behaviour of soft tissues in the CAS context. For this, a methodology, originally published under the name of the Mesh-Matching method, has been proposed to elaborate patient specific models. Starting from an elaborate manually-built "generic" Finite Element (FE) model of a given anatomical structure, models adapted to the geometries of each new patient ("patient specific" FE models) are automatically generated through a non-linear elastic registration algorithm. This paper presents the general methodology of the Mesh-Matching method and illustrates this process with two clinical applications, namely the orbital and the maxillofacial computer-assisted surgeries

A highly active well-defined rhenium heterogeneous catalyst for olefin metathesis prepared via surface organometallic chemistry.

International audienc

A highly active well-defined rhenium heterogeneous catalyst for olefin metathesis prepared via surface organometallic chemistry.

International audienc

Characterization of surface organometallic complexes using high resolution 2D solid-state NMR spectroscopy. Application to the full characterization of a silica supported metal carbyne: (triple bond)SiO-Mo((triple bond)C-Bu-t)(CH(2)-Bu-t)(2).

International audienc

Perhydrocarbyl Re-VII complexes: Comparison of molecular and surface complexes

The molecular complex [Re(equivalent toC(t)Bu)(=(CHBu)-Bu-t)((CH2Bu)-Bu-t)2] (1) reacts with a silica partially dehydroxylated at 700 degreesC to give syn-2, [(equivalent toSiO)Re(equivalent toC(t)Bu)(=(CHBu)-Bu-t)((CH2Bu)-Bu-t)], as a single isomer according to mass-balance analysis, IR, and solid-state NMR spectroscopy. 1 D and 2D solid-state NMR.(HETCOR and long-range HETCOR) on a C-13-labeled-2 has allowed us to observe the chemical shifts of all carbons (including those that are not labeled) and ascertain their assignments. Moreover, EXAFS data are consistent with the presence of two carbons at a relatively short distance (1.79 Angstrom), which cannot be cleconvoluted, but which are consistent with the presence of alkylidene and alkylidyne carbons along with two other first neighbors at a longer distance (2.01 Angstrom), the alkyl carbon and the 0 atom by which the Re is attached to the surface. Moreover, the data also suggest the presence of a siloxane bridge of the silica surface at 2.4 Angstrom in the coordination sphere of the Re center. Thermal and photochemical treatment allow us to observe the anti isomer, which was also fully characterized by 1D and 2D solid-state NMR. This behavior parallels the reactivity of molecular Re complexes, and their respective H-1 and C-13 chemical shifts match those of the corresponding molecular analogues syn- and anti-2m and n. Finally, the grafting of 1 onto silica involves the reaction of both the alkyl and the alkylidene ligand with an equiprobability, leaving the alkylidyne as a spectator ligand. Noteworthy is the formation of 2 [(equivalent toSiO)Re(equivalent toC(t)Bu)(=(CHBu)-Bu-t)((CH2Bu)-Bu-t)], rather than the corresponding trisneopentyl-neopentylidyne Re complex, monografted on silica, [(equivalent toSiO)Re(equivalent toC(t)Bu)((CH2Bu)-Bu-t)(3)], which would have been expected from the reactivity of I with various molecular Bronsted acids and which also suggests that a proximal siloxane bridge forces the alpha-H abstraction process, leading to syn-2a

Direct observation of reaction intermediates for a well defined heterogeneous alkene metathesis catalyst

Grafting of [W(≡NAr)(=CHtBu)(2,5-Me2NC4H2)2] on a silica partially dehydroxylated at 700°C (SiO2- (700)) generates the corresponding monosiloxy complex [(≡SiO)W(≡NAr)(=CHtBu)(2,5-Me2NC4H2)] as the major species (≈90%) along with [(≡SiO)W(≡NAr)(CH2tBu)(2,5-Me2NC4H2)2], according to mass balance analysis, IR, and NMR studies. This heterogeneous catalyst displays good activity and stability in the metathesis of propene. Very importantly, solid state NMR spectroscopy allows observation of the propagating alkylidene as well as stable metallacyclobutane intermediates. These species have the same reactivity as the initial surface complex [(≡SiO)W(≡NAr)(=CHtBu)(2,5-Me2NC4H2)], which shows that they are the key intermediates of alkene metathesis