313 research outputs found

    Domain size effects on the dynamics of a charge density wave in 1T-TaS2

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    Recent experiments have shown that the high temperature incommensurate (I) charge density wave (CDW) phase of 1T-TaS2 can be photoinduced from the lower temperature, nearly commensurate (NC) CDW state. Here we report a time-resolved x-ray diffraction study of the growth process of the photoinduced I-CDW domains. The layered nature of the material results in a marked anisotropy in the size of the photoinduced domains of the I-phase. These are found to grow self-similarly, their shape remaining unchanged throughout the growth process. The photoinduced dynamics of the newly formed I-CDW phase was probed at various stages of the growth process using a double pump scheme, where a first pump creates I-CDW domains and a second pump excites the newly formed I-CDW state. We observe larger magnitudes of the coherently excited I-CDW amplitude mode in smaller domains, which suggests that the incommensurate lattice distortion is less stable for smaller domain sizes.Comment: 8 pages, 8 figure

    Green tea and pomegranate extract administered during critical moments of the production cycle improves blood antiradical activity and alters cecal microbial ecology of broiler chickens

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    Phytobiotics are usually tested in feed and throughout the production cycle. However, it could be beneficial to evaluate their effects when administered only during critical moments, such as changes in feeding phases. The aim of the trial was to investigate the effect of a commercial plant extract (PE; IQV-10-P01, InQpharm Animal Health, Kuala Lumpur, Malaysia) on growth performance, blood antiradical activity and cecal microbiome when administered in drinking water to broiler chickens during the post-hatching phase and at each change of diet. In the experiment, 480 1-day-old male broiler chicks were assigned to two groups in a 50-day trial. Broilers received drinking water (C) or drinking water plus PE (T) at a rate of 2 mL/L on days 0 to 4, 10\u201311 and 20\u2013 21. PE did not affect performance and water intake, while total antiradical activity was improved (p < 0.05). A greater abundance of lactic acid bacteria (false discovery rate (FDR) < 0.05) was found in the T group and the result was confirmed at a lower taxonomic level with higher Lactobacillaceae abundance (FDR < 0.05). Our findings suggest that PE administration during critical moments of the production cycle of broiler chickens may exert beneficial effects at a systemic level and on gut microbial ecology

    Ultrafast relaxation dynamics of the antiferrodistortive phase in Ca doped SrTiO3

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    The ultrafast dynamics of the octahedral rotation in Ca:SrTiO3 is studied by time resolved x-ray diffraction after photo excitation over the band gap. By monitoring the diffraction intensity of a superlattice reflection that is directly related to the structural order parameter of the soft-mode driven antiferrodistortive phase in Ca:SrTiO3, we observe a ultrafast relaxation on a 0.2 ps timescale of the rotation of the oxygen octahedron, which is found to be independent of the initial temperaure despite large changes in the corresponding soft-mode frequency. A further, much smaller reduction on a slower picosecond timescale is attributed to thermal effects. Time-dependent density-functional-theory calculations show that the fast response can be ascribed to an ultrafast displacive modification of the soft-mode potential towards the normal state, induced by holes created in the oxygen 2p states

    Feed particle size evaluation: conventional approach versus digital holography based image analysis

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    The aim of this study was to evaluate the application of image analysis approach based on digital holography in defining particle size in comparison with the sieve shaker method (sieving method) as reference method. For this purpose ground corn meal was analyzed by a sieve shaker Retsch VS 1000 and by image analysis approach based on digital holography. Particle size from digital holography were compared with results obtained by screen (sieving) analysis for each of size classes by a cumulative distribution plot. Comparison between particle size values obtained by sieving method and image analysis indicated that values were comparable in term of particle size information, introducing a potential application for digital holography and image analysis in feed industry

    Effects of nucleotides administration on growth performance and immune response of post-weaning piglets

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    The aim of this study was to assess the effect of nucleotides administration on growth perform- ance and immune response in post-weaning piglets. Twenty-eight male weaned piglets, homo- geneous for age and weight were randomly allocated to two experimental treatments. Treated group (T) was daily orally administered 0.8g/head of a mixture of nucleotides suspended in 2.1 mL water solution; while control group (C) received 2.1 mL saline solution. Body weight (BW) and average daily gain (ADG) were individually recorded weekly, while feed intake (FI), and gain:feed (G:F) were recorded and calculated on pen basis. Faecal score was evaluated every seven days. On day 0, 9, 18 and 27 blood samples were collected to determine IgA, IgG and haptoglobin concentration. At day 28 all piglets were sacrificed, and tissue samples of ileal Peyer\u2019s patches were collected for the evaluation of IL1a, IL1b, IL6, IL10, TNFa, TLR2, TLR4 and PPARc gene expression. Nucleotides supplementation significantly increased BW (17.37 vs. 19.00kg/pig; p 1\u20444 <.01), ADG (.351 vs. .400kg/d; p < .01), and FI (3.96 vs. 4.39kg/d; p < .01), but not G:F (.61 vs. .64; p 1\u20444 .29). Faecal consistency was not different between the experimental groups and no occurrence of diarrhoea was reported. IgA and IgG content in blood was not influenced by the treatment, as well as gene expression of inflammatory cytokines in Peyer\u2019s patches. The present trial shows that nucleotide administration is able to improve growth per- formance of post-weaning piglets, with no effects on inflammatory response and the expression of immune-related genes

    Low n-6/n-3 Gestation and Lactation Diets Influence Early Performance, Muscle and Adipose Polyunsaturated Fatty Acid Content and Deposition, and Relative Abundance of Proteins in Suckling Piglets

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    Elevated omega-6 (n-6) and omega-3 (n-3) polyunsaturated fatty acids (PUFAs) ratios in swine diets can potentially impose a higher risk of inflammatory and metabolic diseases in swine. A low ratio between the two omega PUFAs has beneficial effects on sows' and piglets' production performance and immunity status. At present, there are few studies on how sow nutrition directly affects the protein and fat deposition in suckling piglets. Two groups of sows were fed diets with high or low n-6/n-3 polyunsaturated ratios of 13:1 (SOY) and 4:1 (LIN), respectively, during gestation and lactation. Longissimus dorsi muscle and adipose tissue from newborn piglets, nourished only with sow's milk, were subjected to fatty acid profiling by gas chromatography-mass spectrometry (GC-MS) and to proteomics assays based on nano-liquid chromatography coupled to high-resolution tandem mass spectrometry (nLC-HRMS). Fatty acid profiles on both muscle and adipose tissues resembled the magnitude of the differences between fatty acid across diets. Proteomic analysis revealed overabundance of 4 muscle and 11 adipose tissue proteins in SOY compared to LIN in both piglet tissues. The detected overabundance of haptoglobin, an acute-phase protein, and the stimulation of protein-coding genes and proteins related to the innate immune response and acute inflammatory response could be associated with the pro-inflammatory role of n-6 PUFAs

    Watching the birth of a charge density wave order: diffraction study on nanometer-and picosecond-scales

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    Femtosecond time-resolved X-ray diffraction is used to study a photo-induced phase transition between two charge density wave (CDW) states in 1T-TaS2_2, namely the nearly commensurate (NC) and the incommensurate (I) CDW states. Structural modulations associated with the NC-CDW order are found to disappear within 400 fs. The photo-induced I-CDW phase then develops through a nucleation/growth process which ends 100 ps after laser excitation. We demonstrate that the newly formed I-CDW phase is fragmented into several nanometric domains that are growing through a coarsening process. The coarsening dynamics is found to follow the universal Lifshitz-Allen-Cahn growth law, which describes the ordering kinetics in systems exhibiting a non-conservative order parameter.Comment: 6 pages, 5 figure

    Animal dietary exposure : overview of current approaches used at EFSA

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    At EFSA, animal dietary exposure estimates are undertaken by several Panels/Units to assess the risk of feed contaminants, pesticide residues, genetically modified feed and feed additives. Guidance documents describing methodologies for animal dietary exposure assessment are available both at EFSA and international levels. Although appropriate within pertinent regulatory frameworks, the methodologies used to assess animal dietary exposure vary across risk assessment areas. There are different approaches ranging from quick worst-case estimations to more refined methods assessing actual exposure, resulting from the use of a heterogeneous selection of animal populations and default values to estimate feed intake. Furthermore, current feed classification systems in place at international and national levels contain a large and heterogeneous number of feed materials, which may benefit from further harmonisation efforts. This technical report presents an overview of the current approaches in place at EFSA to assess the exposure to chemicals in feed. The possibility for a greater harmonisation of feed classification and terminology is also addressed by comparing the structure of the EU catalogue of feed materials and the Harmonised OECD tables of feedstuffs derived from field crops with the EFSA FoodEx2 system
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