150 research outputs found
Interest of Pet Imaging in Multiple Myeloma
The interest of 18Fluoro-deoxyglucose (FDG) positron emission tomography (PET) imaging in the management of patients with multiple myeloma (MM) for the workup at diagnosis and for therapeutic evaluation has recently been demonstrated. FDG-PET is a powerful imaging tool for bone lesions detection at initial diagnosis with high sensitivity and specificity values. The independent pejorative prognostic value on progression-free survival (PFS) and overall survival (OS) of baseline PET-derived parameters (presence of extra-medullary disease (EMD), number of focal bone lesions (FLs), and maximum standardized uptake values [SUVmax]) has been reported in several large independent prospective studies. During therapeutic evaluation, FDG-PET is considered as the reference imaging technique, because it can be performed much earlier than MRI which lacks specificity. Persistence of significant FDG uptake after treatment, notably before maintenance therapy, is an independent pejorative prognostic factor, especially for patients with a complete biological response. So FDG-PET and medullary flow cytometry are complementary tools for detection of minimal residual disease before maintenance therapy. However, the definition of PET metabolic complete response should be standardized. In patients with smoldering multiple myeloma, the presence of at least one hyper-metabolic lytic lesions on FDG-PET may be considered as a criterion for initiating therapy. FDG-PET is also indicated for initial staging of a solitary plasmacytoma so as to not disregard other bone or extra-medullary localizations. Development of nuclear medicine offer new perspectives for MM imaging. Recent PET tracers are willing to overcome limitations of FDG. (11)C-Methionine, which uptake reflects the increased protein synthesis of malignant cells seems to correlate well with bone marrow infiltration. Lipid tracers, such as Choline or acetate, and some peptide tracers, such as (68) Ga-Pentixafor, that targets CXCR4 (chemokine receptor-4, which is often expressed with high density by myeloma cells), are other promising PET ligands. 18F-fludarabine and immuno-PET targeting CD138 and CD38 also showed promising results in preclinical models
Statistical mechanics of two-dimensional vortices and stellar systems
The formation of large-scale vortices is an intriguing phenomenon in
two-dimensional turbulence. Such organization is observed in large-scale
oceanic or atmospheric flows, and can be reproduced in laboratory experiments
and numerical simulations. A general explanation of this organization was first
proposed by Onsager (1949) by considering the statistical mechanics for a set
of point vortices in two-dimensional hydrodynamics. Similarly, the structure
and the organization of stellar systems (globular clusters, elliptical
galaxies,...) in astrophysics can be understood by developing a statistical
mechanics for a system of particles in gravitational interaction as initiated
by Chandrasekhar (1942). These statistical mechanics turn out to be relatively
similar and present the same difficulties due to the unshielded long-range
nature of the interaction. This analogy concerns not only the equilibrium
states, i.e. the formation of large-scale structures, but also the relaxation
towards equilibrium and the statistics of fluctuations. We will discuss these
analogies in detail and also point out the specificities of each system.Comment: Chapter of the forthcoming "Lecture Notes in Physics" volume:
``Dynamics and Thermodynamics of Systems with Long Range Interactions'', T.
Dauxois, S. Ruffo, E. Arimondo, M. Wilkens Eds., Lecture Notes in Physics
Vol. 602, Springer (2002
CĂ©lestin Freinet, la escritura en libertad y el periĂłdico escolar: un modelo de innovaciĂłn educativa en la primera mitad del siglo 20
L'Aventure documentaire : une alternative aux manuels scolaires /
Notes (part. bibliogr.) au bas des p
Inventaire provisoire des manuscrits de la bibliothĂšque nationale de France concernant l'histoire de la Marine (mars 2023)
Tiers Monde et environnement : le développement hypothéqué
Barré Rémi, Godet Michel. Tiers Monde et environnement : le développement hypothéqué. In: Tiers-Monde, tome 23, n°91, 1982. pp. 507-515
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