Search results for "EMT"
showing 10 items of 413 documents
Spatiotemporal properties of nanoshell plasmonic response for strong-field experiments
2015
International audience; Field enhancement behavior of a SiO 2 /Au nanoshell is studied in the framework of strong-field physics. Localized plasmonic fields induce local electric field enhancement with the potential to lead to the strong-field regime without the use of costly amplified lasers. In this framework, electrons are tunnel ionized from the nanoshell and accelerated by the local field being spatially inhomogeneous in terms of spectral and polarization properties. These processes are happening within a single laser shot, and thermal effects are therefore neglected. We show that the localized response to ultrashort femtosecond pulses can be investigated by extending Mie theory to mult…
Strong-field molecular ionization: determination of ionization probabilities calibrated with field-free alignment
2006
International audience; We report an original optical method providing the probability of molecular ionization induced by femtosecond laser pulses. The approach consists of exploiting molecular alignment in order to extract reliable information about ionization. The cross defocusing technique implemented for this purpose reveals a sensitivity with respect to post-pulse alignment, as well as to free electron density induced by the ultra-short laser pulse. The analysis of the resulting signal gives thus access to absolute single-ionization probabilities calibrated through the degree of alignment provided that free electrons are mainly produced from single-ionization. The relevance of the meth…
Pre-Emptive Treatment with Cidofovir for Cytomegalovirus Antigenemia in Autologous Bone Marrow Recipient and CLL Patients on Therapy with Alemtuzumab.
2006
Abstract Cytomegalovirus (CMV) is an important cause of morbidity and mortality in patients who have undergone severe immunosuppressive therapy. Ganciclovir continues to be the first choice for pre-emptive therapy, but it needs multiple intravenous daily administration for three weeks and may cause myelosuppression. Cidofovir is a non myelotoxic nucleotide analogue effective against CMV; its favourable pharmacokinetic profile allows a once-a-week dosing. We reviewed a database on 110 consecutive Autologous Stem Cell Transplant (ASCT) and that of 15 Chronic Lymphocytic Leukemia (CLL) patients treated with alemtuzumab. All patients were virologically monitored by quantification of pp65 antige…
Femtosecond time resolved coherent anti-Stokes Raman spectroscopy: Experiment and modelization of speed memory effects on H2-N2 mixtures in the colli…
2005
194317; With the aim of temperature diagnostic, femtosecond time-resolved CARS (coherent anti-Stokes Raman spectroscopy) is applied to probe H2 in H2-N2 mixtures. In a first part, a Lorentzian profile is used to model the femtosecond CARS response. A difference between the experimental broadening and the expected one is observed in the collision regime. The observed broadening increases strongly in an inhomogeneous way with respect to the perturber concentration. This is of considerable importance for temperature measurements. In a second part, we show that in the collision regime, this inhomogeneous broadening is due to the speed dependence of the collisional parameters and the memory effe…
Hepatitis B Virus Reactivation and Alemtuzumab Therapy.
2004
Abstract Reactivation of hepatitis B virus infection in subjects receiving cytotoxic treatment for haematological malignancies occurs in 21–53% of chronic HBsAg carriers and in an unknown number of HBsAg negative subjects harbouring occult HBV infection. Immunotherapy with alemtuzumab, a humanized monoclonal antibody against CD52 on lymphoid cells, produces deep immunosuppression. We describe two subjects with chronic lymphocytic leukaemia and occult HBV infection who developed a virological and biochemical flare of hepatitis B following immunotherapy with alemtuzumab. One of them developed a full blown hepatitis with seroreversion from anti-HBs to HBsAg after four weeks of alemtuzumab. Lam…
High rate concentration measurement of molecular gas mixtures using a spatial detection technique
2010
International audience; Concentration measurement in molecular gas mixtures using a snapshot spatial imaging technique is reported. The approach consists of measuring the birefringence of the molecular sample when field-free alignment takes place, each molecular component producing a signal with an amplitude depending on the molecular density. The concentration measurement is obtained on a single-shot basis by probing the time-varying birefringence through femtosecond time-resolved optical polarigraphy (FTOP). The relevance of the method is assessed in air.
Fotballklubbers forankring og betydning i det norske samfunn : en casestudie av Viking fotballklubb
2008
Masteroppgave i idrettsvitenskap- Universitetet i Agder 2008 Fotballklubbers lokale forankring og betydning vil ses nærmere på gjennom teoretisk refleksjon og empirisk observasjon der Viking FK er case. Teorien som anvendes er Luhmanns systemteori og det som danner det empiriske materialet er dokumenter og kvalitative intervjuer. Ifølge Luhmann (2000a) er sosiale fenomen, som eksemplifisert ved Viking FK i denne avhandlingen, sosiale system som danner seg selv gjennom å skille seg fra omverden. Skille mellom systemet selv og dets omverden danner en unik betraktning av seg selv som noe forskjellig fra omverden. Det utgjør systemets realitetsforståelse, dets mening som uttrykkes gjennom forve…
Experimental investigation of the kink effect and the low frequency noise properties in pseudomorphic HEMT’s
2005
The kink effect in low-noise pseudomorphic (AlGaAs/InGaAs) HEMT's has been examined in detail by investigating the steady-state and pulsed I-V characteristics, the behavior of the output conductance dispersion and the performance of the gate leakage current to understand its origin. No clear evidence of impact ionization occurrence in the InGaAs channel at kink bias conditions (V-DS.kink = 1.5 V) has been found, thus suggesting that the predominant mechanism should be attributed to trap-related phenomena. A significant rise of the gate current has been found at very high drain voltages (far from V-DS.kink) associated with low drain current values which is probably due to impact ionization o…
Smēķēšanas un perivaskulāro taukaudu savstarpējā mijiedarbība asinsvadu veselībā
2021
Darba mērķis bija novērtēt cigarešu smēķēšanas un perivaskulāro taukaudu ietekmi uz kopējās miega artērijas sieniņas IMT. Pētījumā piedalījās 9 personas vecuma 18-25 gadiem ar atšķirīgu smēķēšanas statusu. Veica antropometriskos mērus ķermeņa svara raksturojumam; ar ultrasonogrāfiju noteica PVAT daudzumu, mērot kopējās miega artērijas EMT; kā arī IMT, ko izmanto aterosklerozes agrīnā diagnosticēšanā. Nelielā pētījuma dalībnieku skaita dēļ, rezultāti tika salīdzināti ar citu zinātnisko pētījumu datiem, kas iegūti ar līdzīgām metodēm. No literatūras analīzes izriet, ka PVAT akumulācija var rosināt artēriju sieniņu sabiezināšanos, savukārt smēķēšana mijiedarbojas ar endotēlija funkciju. Smēķēt…
Concentration measurements in molecular gas mixtures with a two-pump pulse femtosecond polarization spectroscopy technique
2001
0021-9606; Recently, we have demonstrated the ability of the Raman-induced polarization spectroscopy (RIPS) technique to accurately determine concentration or polarizability anisotropy ratio in low-pressure binary molecular mixtures [E. Hertz, B. Lavorel, O. Faucher, and R. Chaux, J. Chem. Phys. 113, 6629 (2000)]. It has been also pointed out that macroscopic interference, occurring when two revivals associated to different molecules time overlap, can be used to achieve measurements with picosecond time resolution. The applicability of the technique is intrinsically limited to a concentration range where the signals of both molecules are of the same magnitude. In this paper, a two-pump puls…