Ultracold Li + Li₂ collisions: Bosonic and fermionic cases

We have carried out quantum dynamical calculations of vibrational quenching in Li Li2 collisions for both bosonic 7Li and fermionic 6Li. These are the first ever such calculations involving fermionic atoms. We find that for the low initial vibrational states considered here (v 3), the quenching rates are not suppressed for fermionic atoms. This contrasts with the situation found experimentally for molecules formed via Feshbach resonances in very high vibrational states

Mathematical modeling of serotonin compartmentation in normal human platelets

Projet PROMATHThe movement of radiolabelled 5-hydroxytryptamine (5-HT, serotonin) and its by-products between the extracellular medium, the thrombin-releasable (vesicular) compartment and the non-thrombin-releasable compartment(s) has been investigated in normal human platelets. Using the data obtained, identification of the kinetic constants for movement between the various compartments was possible. For carrying out the a priori identifiability analysis, a recent extension of similarity transformation approach to nonlinear compartmental models was used. Then numerical identification was performed by implementing and achieving efficient methods coming from optimal control theory. Under our experimental conditions, the main results achieved are the following : the vesicular compartment corresponds to the platelet storage 5-HT compartment - instead of the pools I and II proposed previously only a single non-releseable thrombin-resistant pool could be detected and - the optimized model computed to suit the first set of experiments fits subsequent results obtained under similar experimental conditions

Field-linked States of Ultracold Polar Molecules

We explore the character of a novel set of ``field-linked'' states that were predicted in [A. V. Avdeenkov and J. L. Bohn, Phys. Rev. Lett. 90, 043006 (2003)]. These states exist at ultralow temperatures in the presence of an electrostatic field, and their properties are strongly dependent on the field's strength. We clarify the nature of these quasi-bound states by constructing their wave functions and determining their approximate quantum numbers. As the properties of field-linked states are strongly defined by anisotropic dipolar and Stark interactions, we construct adiabatic surfaces as functions of both the intermolecular distance and the angle that the intermolecular axis makes with the electric field. Within an adiabatic approximation we solve the 2-D Schrodinger equation to find bound states, whose energies correlate well with resonance features found in fully-converged multichannel scattering calculations

Update of EULAR recommendations for the treatment of systemic sclerosis

The aim was to update the 2009 European League against Rheumatism (EULAR) recommendations for the treatment of systemic sclerosis (SSc), with attention to new therapeutic questions. Update of the previous treatment recommendations was performed according to EULAR standard operating procedures. The task force consisted of 32 SSc clinical experts from Europe and the USA, 2 patients nominated by the pan-European patient association for SSc (Federation of European Scleroderma Associations (FESCA)), a clinical epidemiologist and 2 research fellows. All centres from the EULAR Scleroderma Trials and Research group were invited to submit and select clinical questions concerning SSc treatment using a Delphi approach. Accordingly, 46 clinical questions addressing 26 different interventions were selected for systematic literature review. The new recommendations were based on the available evidence and developed in a consensus meeting with clinical experts and patients. The procedure resulted in 16 recommendations being developed (instead of 14 in 2009) that address treatment of several SSc-related organ complications: Raynaud's phenomenon (RP), digital ulcers (DUs), pulmonary arterial hypertension (PAH), skin and lung disease, scleroderma renal crisis and gastrointestinal involvement. Compared with the 2009 recommendations, the 2016 recommendations include phosphodiesterase type 5 (PDE-5) inhibitors for the treatment of SSc-related RP and DUs, riociguat, new aspects for endothelin receptor antagonists, prostacyclin analogues and PDE-5 inhibitors for SSc-related PAH. New recommendations regarding the use of fluoxetine for SSc-related RP and haematopoietic stem cell transplantation for selected patients with rapidly progressive SSc were also added. In addition, several comments regarding other treatments addressed in clinical questions and suggestions for the SSc research agenda were formulated. These updated data-derived and consensus-derived recommendations will help rheumatologists to manage patients with SSc in an evidence-based way. These recommendations also give directions for future clinical research in SSc

Antiretroviral-naive and -treated HIV-1 patients can harbour more resistant viruses in CSF than in plasma

Objectives The neurological disorders in HIV-1-infected patients remain prevalent. The HIV-1 resistance in plasma and CSF was compared in patients with neurological disorders in a multicentre study. Methods Blood and CSF samples were collected at time of neurological disorders for 244 patients. The viral loads were >50 copies/mL in both compartments and bulk genotypic tests were realized. Results On 244 patients, 89 and 155 were antiretroviral (ARV) naive and ARV treated, respectively. In ARV-naive patients, detection of mutations in CSF and not in plasma were reported for the reverse transcriptase (RT) gene in 2/89 patients (2.2%) and for the protease gene in 1/89 patients (1.1%). In ARV-treated patients, 19/152 (12.5%) patients had HIV-1 mutations only in the CSF for the RT gene and 30/151 (19.8%) for the protease gene. Two mutations appeared statistically more prevalent in the CSF than in plasma: M41L (P = 0.0455) and T215Y (P = 0.0455). Conclusions In most cases, resistance mutations were present and similar in both studied compartments. However, in 3.4% of ARV-naive and 8.8% of ARV-treated patients, the virus was more resistant in CSF than in plasma. These results support the need for genotypic resistance testing when lumbar puncture is performe

Electron Collisional Excitation of C+2

International audienc

Molecular collision processes. II - Excitation of the fine-structure transition of C/+/ in collisions with H2

International audienc

Rate coefficients for the rotational excitation of CO by ortho- and para-H2

International audienc

On the validity of the distorted wave method in electron-atom collision theory

International audienc

Shear transformation in the layered compound KAlF4 : low temperature phase structure and transformation mechanism

The layered compound KA1F4 undergoes a structural phase transition in the vicinity of 250 K. Both phases have been studied by X-ray and electron diffraction and by profile refinement of the neutron powder diffraction patterns. The room temperature structure (tetragonal space group D5 4h — P 4/mbm — Z = 2 ; a = b = 5.045 Å, c = 6.159 A) derived from the T1A1F4 type is confirmed. We have determined the low temperature structure (monoclinic, P 2 1/m, Z = 4; am = 7.340 A, bm = 7.237 A, cm = 6.407 Å, β= 106.8° at 4 K) closely related to the KFeF4 structure. From structural argument it is shown that this first order transition is mainly characterized by a gliding of the successive sheets in the [100] direction. This can explain the 16° misorientation of twinned microcrystals resulting from the transition as shown by X-ray diffraction and by electron microscopy.Le composé lamellaire KAlF4 subit une transition de phase structurale au voisinage de 250 K. Les deux phases ont été étudiées par diffraction de rayons X, d'électrons et par affinement du profil des raies de diffraction de neutrons. La phase ambiante (groupe d'espace quadratique D54h — P 4/mbm — Z = 2; a = b = 5,045 A, c = 6,159 A) dérivée du type T1A1F4 a été confirmée. Nous avons déterminé la structure basse température (monoclinique, P 21/m, Z = 4; am = 7,340 Å, bm = 7,237 Å, c m = 6,407 Å, β = 106,8° à 4 K) qui est très voisine de la structure de KFeF4. Nous montrons par des arguments structuraux que cette transition de phase du premier ordre est principalement caractérisée par un glissement dans la direction [100] des feuillets successifs ce qui permet d'expliquer après transition la désorientation de 16° entre les microcristaux mâclés mise en évidence par diffraction de rayons X et par microscopie électronique