Experimental approach to interaction physics challenges of the shock ignition scheme using short pulse lasers.

An experimental program was designed to study the most important issues of laser-plasma interaction physics in the context of the shock ignition scheme. In the new experiments presented in this Letter, a combination of kilojoule and short laser pulses was used to study the laser-plasma coupling at high laser intensities for a large range of electron densities and plasma profiles. We find that the backscatter is dominated by stimulated Brillouin scattering with stimulated Raman scattering staying at a limited level. This is in agreement with past experiments using long pulses but laser intensities limited to 2×10(15) W/cm2, or short pulses with intensities up to 5×10(16) W/cm2 as well as with 2D particle-in-cell simulations.

Anisotropic photon migration in human skeletal muscle.

It is demonstrated in the short head of the human biceps brachii of 16 healthy subjects (12 males and 4 females) that near infrared photon migration is anisotropic. The probability for a photon to travel along the direction of the muscle fibres is higher (approximately 0.4) than that of travelling along a perpendicular axis (approximately 0.3) while in the adipose tissue the probability is the same (approximately 0.33) in all directions. Considering that the muscle fibre orientation is different depending on the type of muscle considered, and that inside a given skeletal muscle the orientation may change, the present findings in part might explain the intrasubject variability observed in the physiological parameters measured by near infrared spectroscopy techniques. In other words, the observed regional differences might not only be physiological differences but also optical artefacts.

Kinetics of plasma cytokine levels in children hyposensitized with wasp venom.

Specific immunotherapy shifts immune responses towards a Th0/Th1 response. Production of chemokines is also decreased early after the initiation of rush venom immunotherapy. We aimed to investigate in vivo whether cytokine plasma levels reflect the shift towards a Th0-Th1 pattern of immune response as seen in vitro in lymphocytes from patients undergoing venom immunotherapy. Therefore, we studied plasma levels of various cytokines before (day 1), during (day 2), and after (day 4) rush immunotherapy in nine wasp-allergic children. The levels of interleukin-5 and IFN-gamma were below the detection threshold. No variations were observed in levels of interleukin-4, interleukin-10, and TNF-alpha. In contrast, mean levels of RANTES transiently increased at day 2, and decreased below the pretreatment levels at day 4. Those alterations were significant in five children with high levels of RANTES at day 1, and reporting severe anaphylaxis. In the four other children, the levels of RANTES were not significantly increased at day 4. These results suggest that RANTES plasma levels are positively correlated with the severity of the reaction to hymenoptera venom, and that a significant decrease in the levels of RANTES occurs only in children with high pretreatment levels. However, the kinetics of RANTES plasma levels correlated neither with the results of allergological tests, nor with the outcome of venom immunotherapy.

Factors associated with increased serum levels of cardiac troponins T and I in chronic haemodialysis patients: Chronic Haemodialysis And New Cardiac Markers Evaluation (CHANCE) study.

BACKGROUND: Serum concentrations of the cardiac troponins (cTn) T and I, specific markers of myocardial injury, are frequently elevated in haemodialysis patients. The clinical relevance of this is unclear. The aim of this study was to investigate factors associated with increased serum levels of cTn in haemodialysis patients. METHODS: We included in this cross-sectional study 258 chronic haemodialysis patients (150 men, age 60+/-15 years) without acute coronary symptoms. Clinical data, echocardiographic hypertrophy, biochemical status, and haemodialysis regimen were evaluated for each patient. Pre-dialysis serum cTnT (Elecsys, Roche), cTnI (Stratus and RXL, Dade-Berhing), and CK-MB (Stratus, Dade-Berhing) concentrations were determined. Logistic regression was the principal method of analysis. RESULTS: Pre-dialysis levels of cTnT >0.1 ng/ml (n=48, 18.6% of patients) were associated with age (P<0.001), diabetes (P<0.005), history of ischaemic heart disease (P<0.05), and left ventricular hypertrophy (P<0.05). In multivariate analysis, age odds ratio ((OR) 1.04), diabetes (OR 4.9), and indexed left ventricular mass (OR 1.01) were found to be independently associated with cTnT concentration above the threshold. Only six patients had cTnI-Stratus levels >0.6 ng/ml. cTnI-RXL levels >0.3 ng/ml (n=13, 5.0%) were associated with age (P=0.05) and hypercholesterolaemia (P<0.05). Only age (OR 1.06) remained associated in multivariate analysis. CONCLUSION: Elevated baseline serum levels of cardiac troponins were associated with cardiovascular risk factors, history of ischaemic heart disease and left ventricular hypertrophy in asymptomatic chronic haemodialysis patients.

Electrophoresis of gliadins in long acrylamide gels: method and nomenclature.

Gliadins, defined as wheat kernel storage proteins soluble in 70% ethanol, possess an electrophoretic diversity permitting us to identify different varieties. Because of genetic proximity, however, it sometimes proves impossible to distinguish between different varieties using standard methods. An electrophoresis method, utilizing a discontinuous buffer system with aluminum lactate and potassium lactate in the gel and sodium lactate in the electrode vessels, is described for two types of gels 18 cm and 32 cm in length. The number of bands is higher than with standard methods, and is significantly increased with long gels, facilitating the distinction between varieties. A nomenclature for the new bands is presented for several widely different cultivars.

[Prevention of hyperkalemia and muscular fasciculations induced by suxamethonium]. / Prophylaxie de l'hyperkaliémie et des fasciculations musculaires induites par le suxaméthonium.

Suxamethonium has not yet been replaced to ease endotracheal intubation despite its many undesirable side effects. Hyperkalemia and muscle pain are two such side effects; they are not reliably prevented by giving, before suxamethonium, a small dose of a non depolarizing muscle relaxant, although it does decrease muscle fasciculations. The purpose of this study was to compare with a control group three different pretreatments of these undesirable effects of suxamethonium: 1) hyperventilation, 2) calcium chloride which are accepted means of lowering the serum potassium, and 3) magnesium sulfate which has been reported in a non-controlled study to decrease muscle fasciculations. The study was performed in 40 patients (10 per group) in whom changes of plasma potassium and calcium levels were determined and muscle fasciculations measured by an objective method. Serum electrolyte variations and the quantity and duration of muscle fasciculations were similar in all groups. None of the pretreatments administered had any adverse effect on the neuromuscular block induced by suxamethonium.