13 research outputs found
Intracavity Frequency Doubling and Difference Frequency Mixing for Pulsed ns Ti:Sapphire Laser Systems at On-Line Radioactive Ion Beam Facilities
Intra-cavity second harmonic generation of a Titanium:sapphire (Ti:sa) laser system has been used to improve the conversion efficiency to the second harmonic. Over the course of several experiments performance data spanning the whole wavelength range of a Ti:sa has been collected, which may be used as a guideline for future experiments. An average output power of up to 3.7â
W was achieved, resulting in a conversion efficiency of >75% to the second harmonic. A wavelength coverage from 340â525â
nm has been demonstrated. To extend the wavelength range of the solid state laser system, difference frequency mixing has been applied to the intra-cavity doubled light and the fundamental output of a second Ti:sa laser. Up to 30â
mW of yellow light at the sodium D2 line at 589â
nm was generated. Based on numerical calculations this output power could still be improved by a factor of ten with simple changes in the experimental setup. Laser spectroscopy and measurement of the saturation behaviour has been carried out on an atomic beam of stable sodium
Reduced venous compliance: an important determinant for orthostatic intolerance in women with vasovagal syncope
Comparaison inter-laboratoires de profils dâoxylipines par lipidomique ciblĂ©e dans le cadre du projet OXYGENATE
Actuellement 20 Ă 25% de la population adulte mondiale prĂ©sente un syndrome cardiomĂ©tabolique. Ce syndrome est un exemple de maladie multifactorielle en lien avec lâalimentation et se caractĂ©rise par des troubles cardiovasculaires, mĂ©taboliques et inflammatoires. Ces troubles amĂšnent au dĂ©veloppement du diabĂšte de type II et des maladies cardiovasculaires. Cependant le diagnostic de ce syndrome nâest pas satisfaisant car pas assez intĂ©gratif et prĂ©coce pour permettre une prise en charge nutritionnelle.
Les oxylipines, mĂ©tabolites issus de lâoxygĂ©nation des acides gras polyinsaturĂ©s via diffĂ©rentes voies de biosynthĂšse, sont connues pour ĂȘtre des mĂ©diateurs lipidiques impliquĂ©s dans la rĂ©gulation de processus biologiques liĂ©s au syndrome cardiomĂ©tabolique et dont la biosynthĂšse est modulĂ©e par le statut cardiomĂ©tabolique et aussi par lâalimentation. DâoĂč lâhypothĂšse quâun profilage complet des oxylipines pourrait rĂ©vĂ©ler des perturbations prĂ©coces du statut cardiomĂ©tabolique et pourrait ĂȘtre un nouvel outil dâĂ©valuation de lâefficacitĂ© des prĂ©ventions et interventions nutritionnelles.
Le projet OXYGENATE a pour but dâidentifier et valider des oxylipines discriminant le statut cardiomĂ©tabolique et la qualitĂ© de lâalimentation. Pour cela, il est nĂ©cessaire dâavoir une mĂ©thode fiable de profilage quantitatif des oxylipines permettant dâobtenir des profils comparables entre diffĂ©rents laboratoires. Une comparaison inter-laboratoires de notre mĂ©thode a Ă©tĂ© rĂ©alisĂ©e afin dâestimer les variabilitĂ©s analytiques et dâidentifier les oxylipines critiques. Cinq laboratoires ont prĂ©parĂ© (en triplicat et sur 2 jours diffĂ©rents) et analysĂ© 7 plasmas prĂ©sentant des profils dâoxylipines trĂšs contrastĂ©s. Les variabilitĂ©s intra- et inter-jour ainsi que la part de variabilitĂ© attribuable Ă la prĂ©paration et Ă lâappareillage sont Ă©valuĂ©s.
Au-delĂ de lâintĂ©rĂȘt pour le projet, cette comparaison inter-laboratoires unique permettra dâharmoniser les profils dâoxylipines rĂ©alisĂ©s par lâensemble de la communautĂ© scientifique
The electron affinity of astatine
One of the most important properties influencing the chemical behavior of an element is the electron affinity (EA). Among the remaining elements with unknown EA is astatine, where one of its isotopes, 211At, is remarkably well suited for targeted radionuclide therapy of cancer. With the Atâ anion being involved in many aspects of current astatine labeling protocols, the knowledge of the electron affinity of this element is of prime importance. Here we report the measured value of the EA of astatine to be 2.41578(7)âeV. This result is compared to state-of-the-art relativistic quantum mechanical calculations that incorporate both the Breit and the quantum electrodynamics (QED) corrections and the electronâelectron correlation effects on the highest level that can be currently achieved for many-electron systems. The developed technique of laser-photodetachment spectroscopy of radioisotopes opens the path for future EA measurements of other radioelements such as polonium, and eventually super-heavy elements.peerReviewe
The aroma profile of wheat bread crumb influenced by yeast concentration and fermentation temperature
Ly-6C(hi) monocytes dominate hypercholesterolemia-associated monocytosis and give rise to macrophages in atheromata
Macrophage accumulation participates decisively in the development and exacerbation of atherosclerosis. Circulating monocytes, the precursors of macrophages, display heterogeneity in mice and humans, but their relative contribution to atherogenesis remains unknown. We report here that the Ly-6C(hi) monocyte subset increased dramatically in hypercholesterolemic apoEâdeficient mice consuming a high-fat diet, with the number of Ly-6C(hi) cells doubling in the blood every month. Ly-6C(hi) monocytes adhered to activated endothelium, infiltrated lesions, and became lesional macrophages. Hypercholesterolemia-associated monocytosis (HAM) developed from increased survival, continued cell proliferation, and impaired Ly-6C(hi) to Ly-6C(lo) conversion and subsided upon statin-induced cholesterol reduction. Conversely, the number of Ly-6C(lo) cells remained unaffected. Thus, we believe that Ly-6C(hi) monocytes represent a newly recognized component of the inflammatory response in experimental atherosclerosis
The electron affinity of astatine
One of the most important properties influencing the chemical behavior of an element is the electron affinity (EA). Among the remaining elements with unknown EA is astatine, where one of its isotopes, 211At, is remarkably well suited for targeted radionuclide therapy of cancer. With the Atâ anion being involved in many aspects of current astatine labeling protocols, the knowledge of the electron affinity of this element is of prime importance. Here we report the measured value of the EA of astatine to be 2.41578(7) eV. This result is compared to state-of-the-art relativistic quantum mechanical calculations that incorporate both the Breit and the quantum electrodynamics (QED) corrections and the electronâelectron correlation effects on the highest level that can be currently achieved for many-electron systems. The developed technique of laser-photodetachment spectroscopy of radioisotopes opens the path for future EA measurements of other radioelements such as polonium, and eventually super-heavy elements