120 research outputs found
Cluster size distributions in gas jets for different nozzle geometries
Cluster size distributions were investigated in case of different nozzle
geometries in argon and xenon using Rayleigh scattering diagnostics. Different
nozzle geometries result in different behaviour, therefore both spatial- and
temporal cluster size distributions were studied to obtain a well-characterized
cluster target. It is shown that the generally used Hagena scaling can result
in a significant deviation from the observed data and the behaviour cannot be
described by a single material condensation parameter. The results along with
the nanoplasma model applied to the data of previous high harmonic generation
experiments allow the independent measurement of cluster size and cluster
density.Comment: 7 pages, 6 figure
Microthrombotic renal involvement in an SLE patient with concomitant catastrophic antiphospholipid syndrome: the beneficial effect of rituximab treatment
LBK
Intense circularly polarized attosecond pulse generation from relativistic laser plasmas using few-cycle laser pulses
Effect of genotypic, meteorological and agronomic factors on the gluten index of winter durum wheat
The determination of the gluten index is a widely used method for analysing the gluten strength of bread wheat and spring durum wheat genotypes. The present work was carried out to study the effect of the genotype, meteorological factors (temperature, precipitation and number of days with Tmax ≥ 30 °C) and agronomic treatments (N fertilisation and plant protection) on the gluten index of winter durum wheat varieties and breeding lines. The results indicated that the gluten index had little dependence on the environment, being determined to the greatest extent by the genotype. Compared with varieties having weak gluten, those with a strong gluten matrix responded less sensitively to changes in environmental conditions. Among the meteorological factors, high temperature at the end of the grain-filling period caused the greatest reduction in the mean gluten index of three varieties (R 2 = 0.462), while the fertiliser was found to be a significant factor affecting the gluten strength of winter durum wheat varieties. Using selection based on the gluten index, the gluten strength of winter durum wheat lines can be improved sufficiently to make them competitive with high quality spring varieties
Effect of additional water supply during grain filling on protein composition and epitope characteristics of winter oats
Pure oats in gluten-free diets (GFD) represent important nutritional benefits for people suffering from celiac disease (CD). However, oat cultivars do not contain the typical CD-related wheat gliadin analog polypeptides. Emerging evidence suggests that oat cultivars containing gluten-like epitopes in avenin sequences may pose potential health risks for celiac patients in rare cases, depending on the individual’s susceptibility. Consequently, it is necessary to screen oats in terms of protein and epitope composition, to be able to select safe varieties for gluten-free applications. The overall aim of our study is to investigate the variation of oat protein composition directly related to health-related and techno-functional properties and to examine how the protein compositional parameters change due to irrigation during the grain-filling period as compared to the natural rain-fed grown, in a large winter oat population of different geographic origin.
Elements of an oat sample population representing 164 winter oat varieties from 8 countries and the protein composition of resulting samples have been characterized. Size distribution of the total protein extracts has been analyzed by SE-HPLC, while the 70% ethanol extracted proteins were analyzed by RP-HPLC. Protein extracts are separated into 3 main groups of fractions on the SE-HPLC column; polymeric, avenin, and non-avenin monomeric protein groups, representing 59.17–80.87%, 12.89–31.03%, and 3.40–9.41% of total protein content, respectively. The ratio of polymeric to monomeric proteins varied between 1.71 and 6.07. 91 RP-HPLC-separated peaks have been differentiated from the ethanol extractable proteins of the entire population.
The various parameters identified a lot of variation, confirming the significance of genotypic variation. In addition, it was also established that the additional water supply during grain filling significantly affected the various quantitative parameters of protein content, but not its qualitative structure. This environmental effect, however, was strongly genotype-dependent. Winter oat genotypes with low levels of epitope content were identified and it was proven that these characteristics were independent of the environmental factor of water availability. These genotypes are appropriate for initiating a specific breeding program to yield oat cultivars suitable for CD patients
Propagation-enhanced generation of intense high-harmonic continua in the 100-eV spectral region
The study of core electron dynamics through nonlinear spectroscopy requires intense isolated attosecond extreme ultraviolet or even X-ray pulses. A robust way to produce these pulses is high-harmonic generation (HHG) in a gas medium. However, the energy upscaling of the process depends on a very demanding next-generation laser technology that provides multi-terawatt (TW) laser pulses with few-optical-cycle duration and controlled electric field. Here, we revisit the HHG process driven by 16-TW sub-two-cycle laser pulses to reach high intensity in the 100-eV spectral region and beyond. We show that the combination of above barrier-suppression intensity with a long generation medium significantly enhances the isolation of attosecond pulses compared to lower intensities and/or shorter media and this way reduces the pulse duration as well as field-stability requirements on the laser driver. This novel regime facilitates the real-time observation of electron dynamics at the attosecond timescale in atoms, molecules, and solids
Cold hardening protects cereals from oxidative stress and necrotrophic fungal pathogenesis
The effects of cold hardening of cereals on their
cross-tolerance to treatments leading to oxidative stress
were investigated. Long-term exposure to low non-freezing
temperatures provided partial protection to wheat and
barley plants from the damage caused by paraquat and
hydrogen peroxide treatments. It also conferred resistance
in two barley cultivars to the necrotic symptoms and
growth of the fungal phytopathogen
Pyrenophora
teres
f.
teres
. Pathogen-induced oxidative burst was also reduced
in cold hardened plants. The possible roles of host-derived
redox factors and other signaling components in the
observed forms of cereal cross-tolerance are discussed
Spectral interferometry with waveform-dependent relativistic high-order harmonics from plasma surfaces
The interaction of ultra-intense laser pulses with matter opened the way to generate the shortest light pulses available nowadays in the attosecond regime. Ionized solid surfaces, also called plasma mirrors, are promising tools to enhance the potential of attosecond sources in terms of photon energy, photon number and duration especially at relativistic laser intensities. Although the production of isolated attosecond pulses and the understanding of the underlying interactions represent a fundamental step towards the realization of such sources, these are challenging and have not yet been demonstrated. Here, we present laser-waveform-dependent high-order harmonic radiation in the extreme ultraviolet spectral range supporting well-isolated attosecond pulses, and utilize spectral interferometry to understand its relativistic generation mechanism. This unique interpretation of the measured spectra provides access to unrevealed temporal and spatial properties such as spectral phase difference between attosecond pulses and field-driven plasma surface motion during the process
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