4,213 research outputs found
Untersuchungen zum Gehalt an ME und praecaecal verdaulichen Aminosäuren aus einem Gemisch thermisch behandelter Körnerleguminosen (LEGUMI-therm®) beim Broiler
The objective of this study was to assess the effect of heating a mixture of grain legumes based on sweet lupins, faba beans, and peas (1:1:1, toasted “LEGUMItherm ®”; untreated: “LEGUMI-mix”) on the content of metabolisable energy (ME) and precaecal digestible (pc) amino acids for broilers. The mean of amino acid digestibility of LEGUMI-mix and LEGUMI-therm was 88 and 87 %. The ME content of the mixture ranged between 11.9 (LEGUMI-therm) and 12.1 MJ/kg DM (LEGUMI-mix). Both parameters were unaffected by heating
Nanoscale density fluctuations in swift heavy ion irradiated amorphous SiO2
We report on the observation of nanoscale density fluctuations in 2 μm thick amorphous SiO₂ layers irradiated with 185 MeV Au ions. At high fluences, in excess of approximately 5 × 10¹² ions/cm², where the surface is completely covered by ion tracks, synchrotron small angle x-ray scattering measurements reveal the existence of a steady state of density fluctuations. In agreement with molecular dynamics simulations, this steady state is consistent with an ion track “annihilation” process, where high-density regions generated in the periphery of new tracks fill in low-density regions located at the center of existing tracks.The authors acknowledge the Australian Research
Council and the Australian Synchrotron Research Program
for financial support and thank the staff at the ANU Heavy
Ion facility for their continued technical assistance. O.P.,
F.D., and K.N. acknowledge financial support from the
Academy of Finland under its Centre of Excellence program
as well as the OPNA project, and grants of computer
capacity from CSC
Nanopatterning of epitaxial CoSi₂ using oxidation in a local stress field and fabrication of nanometer metal-oxide-semiconductor field-effect transistors
A patterning method for the generation of epitaxialCoSi₂nanostructures was developed based on anisotropic diffusion of Co∕Si atoms in a stress field during rapid thermal oxidation (RTO). The stress field is generated along the edge of a mask consisting of a thin SiO₂ layer and a Si₃N₄ layer. During RTO of the masked silicide structure, a well-defined separation of the silicide layer forms along the edge of the mask. The technique was used to make 50-nm channel-length metal-oxide-semiconductor field-effect transistors(MOSFETs). These highly uniform gaps define the channel region of the fabricated device. Two types of MOSFETs have been fabricated: symmetric transistor structures, using the separated silicide layers as Schottky source and drain, and asymmetric transistors, with n+ source and Schottky drain. The asymmetric transistors were fabricated by an ion implantation into the unprotected CoSi₂ layer and a subsequent out diffusion to form the n+ source. The detailed fabrication process as well as the I–V characteristics of both the symmetric and asymmetric transistor structures will be presented
Konzept zur verfahrenstechnischen Auslegung einer 1000 Jahrestonnen PUREX-Referenzanlage mit Basisdaten fuer eine Spaltstoffflusskontrolle
On the mechanism of the shape elongation of embedded nanoparticles
The mechanism of the shape elongation of metal nanoparticles (NPs) in silica, which is induced under swift heavy ion irradiation, is discussed with comparing the two candidates: (i) the synergy between the ion hammering and the transient melting of NPs by the inelastic thermal spike and (ii) the thermal pressure and flow model. We show that three experimental results are inconsistent with (i). The latter is supported by two-temperature molecular dynamics simulations, which simulate not only the atomic motions but also the local electron temperatures. A remarkable correlation was observed between the temporal evolution of the silica density around the ion trajectory and that of the aspect ratio of the NP later than similar to 1 ps after the ion impact, while no correlation was observed earlier than similar to 1 ps, even under the assumption of the instantaneous energy deposition.Peer reviewe
UV light-blocking contact lenses protect against short-term UVB-induced limbal stem cell niche damage and inflammation
UVB irradiation has been linked to pathogenesis of pterygium, a conjunctival tumor growing onto transparent cornea, the windscreen of the eye. Due to corneal anatomy, ambient UVB irradiation is amplified at the stem cell-containing nasal limbus. The aim of this study was to analyse the effect of a UV-blocking contact lens (UVBCL, senofilcon A, Class 1 UV blocker) on limbal epithelial cells and fibroblasts under UVB irradiation compared to a non-UVB-blocking contact lens. UVBCL prevented UVB-induced DNA damage (as assessed by cyclobutane pyrimidine dimer immunostaining) as well as a decrease in proliferation and scratch wound closure rate of both limbal epithelial and fibroblast cells. Similarly, UVBCL protected limbal epithelial cells from UVB-induced loss of their phenotype in terms of colony forming efficiency and stem cell marker expression (ABCB5, P63α, integrin β1) compared to controls. Moreover, with UVBCL pro-inflammatory cytokines such as TNFα and MCP1 remained unchanged. These data demonstrate the significance of UV-protection in preserving the limbal niche in response to at least short-term UVB. Our data support the use of UVBCL in protecting limbal niche cells, especially after limbal stem cell transplantation and in patients after pterygium surgery, to help prevent recurrences
Drug regulatory-compliant validation of a qPCR assay for bioanalysis studies of a cell therapy product with a special focus on matrix interferences in a wide range of organ tissues
Quantitative polymerase chain reaction (qPCR) has emerged as an important bioanalytical method for assessing the pharmacokinetics of human-cell-based medicinal products after xenotransplantation into immunodeficient mice. A particular challenge in bioanalytical qPCR studies is that the different tissues of the host organism can affect amplification efficiency and amplicon detection to varying degrees, and ignoring these matrix effects can easily cause a significant underestimation of the true number of target cells in a sample. Here, we describe the development and drug regulatory-compliant validation of a TaqMan qPCR assay for the quantification of mesenchymal stromal cells in the range of 125 to 20,000 cells/200 L lysate via the amplification of a human-specific, highly repetitive α-satellite DNA sequence of the chromosome 17 centromere region HSSATA17. An assessment of matrix effects in 14 different mouse tissues and blood revealed a wide range of spike recovery rates across the different tissue types, from 11 to 174%. Based on these observations, we propose performing systematic spike-and-recovery experiments during assay validation and correcting for the effects of the different tissue matrices on cell quantification in subsequent bioanalytical studies by multiplying the back-calculated cell number by tissue-specific factors derived from the inverse of the validated percent recovery rate
UV light-blocking contact lenses protect against short-term UVB-induced limbal stem cell niche damage and inflammation
UVB irradiation has been linked to pathogenesis of pterygium, a conjunctival tumor growing onto transparent cornea, the windscreen of the eye. Due to corneal anatomy, ambient UVB irradiation is amplified at the stem cell-containing nasal limbus. The aim of this study was to analyse the effect of a UV-blocking contact lens (UVBCL, senofilcon A, Class 1 UV blocker) on limbal epithelial cells and fibroblasts under UVB irradiation compared to a non-UVB-blocking contact lens. UVBCL prevented UVB-induced DNA damage (as assessed by cyclobutane pyrimidine dimer immunostaining) as well as a decrease in proliferation and scratch wound closure rate of both limbal epithelial and fibroblast cells. Similarly, UVBCL protected limbal epithelial cells from UVB-induced loss of their phenotype in terms of colony forming efficiency and stem cell marker expression (ABCB5, P63α, integrin β1) compared to controls. Moreover, with UVBCL pro-inflammatory cytokines such as TNFα and MCP1 remained unchanged. These data demonstrate the significance of UV-protection in preserving the limbal niche in response to at least short-term UVB. Our data support the use of UVBCL in protecting limbal niche cells, especially after limbal stem cell transplantation and in patients after pterygium surgery, to help prevent recurrences
Measurement of the strong coupling alpha_S from the three-jet rate in e+e- - annihilation using JADE data
We present a measurement of the strong coupling alpha_S using the three-jet
rate measured with the Durham algorithm in e+e- -annihilation using data of the
JADE experiment at centre-of-mass energies between 14 and 44 GeV. Recent
theoretical improvements provide predictions of the three-jet rate in e+e-
-annihilation at next-to-next-to-leading order. In this paper a measurement of
the three-jet rate is used to determine the strong coupling alpha_s from a
comparison to next-to-next-to-leading order predictions matched with
next-to-leading logarithmic approximations and yields a value for the strong
coupling alpha_S(MZ) = 0.1199+- 0.0010 (stat.) +- 0.0021 (exp.) +- 0.0054
(had.) +- 0.0007 (theo.) consistent with the world average.Comment: 27 pages, 8 figure
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