•NPs formed in a plasma-plume during laser irradiation of metals (Al, Ti, Ag) were studied.•In situ SAXS and ex situ TEM, XRD and Raman spectra were measured.•NPs size decreased when increasing the ...O2 fraction in a controlled O2+N2 atmosphere.•The oxidation of metal NPs in the plasma restricts the increase of the size of the NPs.
The influence of a reactive atmosphere on the formation of nanoparticles (NPs) in the plasma plume generated by nanosecond pulsed laser irradiation of metal targets (Ti, Al, Ag) was probed in situ using Small Angle X-ray Scattering (SAXS). Air and different O2–N2 gas mixtures were used as reactive gas within atmospheric pressure. SAXS results showed the formation of NPs in the plasma-plume with a mean radius varying in the 2–5nm range. A decrease of the NPs size with increasing the O2 percentage in the O2–N2 gas mixture was also showed. Ex situ observations by transmission electron microscopy and structural characterizations by X-ray diffraction and Raman spectroscopy were also performed for powders collected in experiments done using air as ambient gas. The stability of the different metal oxides is discussed as being a key parameter influencing the formation of NPs in the plasma-plume.
Patient education constitutes a relevant strategy to improve pain management. In the field of therapeutic patient education (TPE), we aimed 1) to assess pain impact in cancer patients, 2) to identify ...patients' educative needs in pain management, and 3) to refine research criteria for its future evaluation.
Pain intensity, relief and interference were assessed in 75 cancer patients with unbalanced background pain. Self-assessment questionnaire evaluated i) patients' pain management and ii) their knowledge and needs in TPE.
Most patients experienced pain for more than 6 months and 41.6% reported adequate pain relief. Understanding pain and pain management were major patients' preferences (>58%). Most patients declared they knew their pain treatments, but fewer than half of them were able to name them. However, education concerning pain treatment was considered as essential in <30% of patients. Almost all patients (97.1%) stated pain education as beneficial, with a preference for individualized sessions (41.2%). In addition, the assessment criteria for its future evaluation were refined.
Targeted population mainly concerned patients with persistent pain. Only half of patients reported pain relief despite antalgics. Patient education was declared as beneficial for almost all participants.
Tailoring a pain TPE on patients' needs has the potential to help them to optimally manage their pain daily.
Laser ablation of metallic targets in gas atmospheres gives rise to the formation of nanoparticle (NP) powders when high laser irradiances (i.e., > 1 GW/cm² for aluminium targets) are used. The ...properties of the NPs so formed vary as a function of the laser irradiation parameters and the pressure and composition of the ambient gas. Here, we studied the composition and structure of NPs formed by laser ablation of Al targets with a nanosecond Nd:YAG laser emitting at 1064 nm. The laser irradiance was 2.5 GW/cm
2
. N
2
–O
2
gas mixtures containing different amounts of nitrogen (100–80 vol% N
2
) were used as ambient gas at atmospheric pressure. The influence of the ambient gas composition on the morphology and the structure of the NPs was studied ex-situ by scanning and transmission electron microscopy, X-ray diffraction and micro-Raman spectroscopy. Their composition of light elements was determined by ion beam analysis. It was shown that together with metallic aluminium, different amounts of aluminium nitride and aluminium oxynitride were formed in the NPs as a function of the nitrogen concentration in the ambient gas. Below 95 vol% N
2
, the concentration of nitride phases decreases strongly. However, the formation of aluminium oxide (Al
2
O
3
) was not observed, whereas it was detected in NPs formed in air. A discussion of these results that takes into account the dynamics of the plasma plume is proposed.
Rate coefficient of the cyanide anion (CN
−) with cyanoacetylene (HC
3N) reaction, has been studied in gas phase at room temperature using a Flowing Afterglow Langmuir Probe – Mass Spectrometer ...(FALP–MS) apparatus. The rate constant for the CN
−
+
HC
3N reaction is
k
=
4.8
×
10
−9
cm
3/s with an uncertainty of 30%.
A combined study of small-angle and wide-angle X-ray scattering (SAXS/WAXS) of the melting of a nylon-6 sample by localized microwave radiation has shown that this method can reveal the presence of ...bubbles forming and disappearing rapidly in real time in the interior of the sample due to its thermal decomposition.
Small Angle X-ray Scattering has been used to characterize nanoparticles generated by electrical arcing between metallic (AgSnO2) electrodes. The particles are found to have diameters between 30 and ...40 nm and display smooth surfaces suggesting that they are either in liquid form or have solidified from the liquid state. Particles collected around the electrodes were analyzed by Transmission Electron Microscopy and were seen to be much larger than those seen in the SAXS measurement, to be spherical in form and composed of silver metal with irregular tin oxide particles deposited on their surface. Mixed metal nanoparticles can have important practical applications and the use of mixed sintered electrodes may be a direct method for their production.
HiPER laser architecture principles Garrec, B J Le; Hernandez-Gomez, C; Winstone, T ...
Journal of physics. Conference series,
08/2010, Volume:
244, Issue:
3
Journal Article
Peer reviewed
Open access
The HiPER project 1 is in a preliminary phase and a risk assessment is being conducted for a generic HiPER beamline concept – this is based on an anticipated requirement for a single beamline (or ...focal spot unit) drawn from the best available knowledge we have to date of the fusion physics requirement. For the moment the general architecture is to first order independent of the specific beamline implementation (i.e compression phase or ignition phase) as the fundamental requirements are very similar. In this paper we are describing the laser beamline as a bundle of unit beams (or beamlets) and we are explaining that optical zooming is quite possible especially in the case of shock ignition.
Controversy exists regarding the treatment of infants with symptomatic nasolacrimal duct obstruction. One philosophy advocates "early" nasolacrimal duct probing, generally in the office - a ...relatively common approach in France, while others prefer to wait until the age of 12 months to offer a procedure under general anesthesia. The goal of this study is to report results of immediate office probing for congenital nasolacrimal duct obstruction (CNLDO) under age 1 year in terms of efficacy and cost.
A retrospective study was performed on 329 patients (443 eyes) treated by probing for CNLDO under the age of 12 months age. A single probing was performed at the first visit in the office under topical anesthesia without sedation. In order to determine the factors associated with failure of probing, univariate analysis was performed using the Student t-test, Pearson's, homogeneity Chi(2) or Fisher's exact tests. For cost evaluation, hypothetical estimates of spontaneous resolution month by month were used according to data in the literature, along with health insurance reimbursement data.
The ages of the patients ranged from 2 to 11 months (mean 7.0 ± SD 2.3). The overall success rate for cure by immediate office probing was 76.7%. Unilateral CNLDO had an 80.4% success rate whereas bilateral CNLDO had a 73.2% success rate for each eye (P=0.09). Discharge during probing was associated with failed probing (P=0.02). The cost for the spontaneous resolution strategy was 1.56 times higher than for the immediate probing strategy. A strategy which would apply the spontaneous resolution strategy for children ≤ 5 months and the probing strategy to children>5 months would be the most cost-effective.
Immediate office probing between the ages of 5 to 12 months is a safe, effective method to relieve CNLDO and is the most cost-effective.
LMJ is a 240 high power laser beam facility for achieving laser matter interaction experiments, high energy density science, including the demonstration of fusion ignition through Inertial ...Confinement. The Laser Integration Line (LIL) facility is currently a 4-beam prototype for LMJ. In order to achieve precisely specified energies over a wide range of energies, power, temporal shapes and pulse lengths, a computational model has been developed and optimised on every LIL shot. This optimisation is based on the best fit possible between the predicted performances and the measured ones. It is therefore possible to predict the characteristics of a given shot in the 4- beam LIL configuration.
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