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In vitro degradation of 10 mono‐ and sesquiterpenes of plant origin by caprine rumen micro‐organisms
Laurent‐Philippe Broudiscou Agnès Cornu Annie Rouzeau 《Journal of the science of food and agriculture》2007,87(9):1653-1658
The extent of disappearance of 10 mono‐ and sesquiterpenes in presence of mixed rumen micro‐organisms has been measured in 24‐h batch cultures. The molecules that were tested are frequently found in the plants consumed by ruminants in highland pastures (limonene, β‐myrcene, β‐ocimene, α‐pinene, sabinene, γ‐terpinene and thymol) or are potential markers of the diet (camphene, β‐caryophyllene and α‐copaene). All terpenes were tested at 2 µL mL?1, except α‐copaene and thymol, which were tested at 0.9 µL mL?1 and 2 mg mL?1, respectively. Camphene and thymol were not degraded to a significant extent. The disappearance of part of β‐caryophyllene, (?)‐limonene and γ‐terpinene could not be attributed to the direct action of rumen micro‐organisms but rather than to an effect of the extracellular medium. In contrast, a third group of one sesquiterpene (α‐copaene) and four monoterpenes (myrcene, β‐ocimene, α‐pinene and sabinene) was extensively degraded by rumen micro‐organisms, at rates of 1.6, 4.5, 3.5, 4.8 and 5.4 µmol mL?1 inoculum day?1, respectively. The preliminary exposure of rumen micro‐organisms to a specific blend of essential oils compounds, containing mainly thymol, guajacol and limonene, increased the extent of disappearance of γ‐terpinene only. Copyright © 2007 Society of Chemical Industry 相似文献
23.
Li J Li C Delmas A 《Journal of the Optical Society of America. A, Optics, image science, and vision》2007,24(7):1950-1954
An approximated formulation of the Fresnel function is put forward and is used in the approximate evaluation of the Fresnel diffraction integral. By comparing the approximate formulation with the experimental measurements and calculations in the fast Fourier transform (FFT) method of the diffraction integral, we demonstrate that the proposed method is sufficiently accurate for calculating the Fresnel diffraction. For the diffraction field calculation on a spatial surface, the calculation speed of this method is usually higher than that of the FFT method. 相似文献
24.
In this work we use cathodoluminescence (CL) at liquid helium temperature to investigate the boron incorporation in {111}-homoepitaxial diamond films, grown outside the visible plasma ball by the Microwave plasma-assisted chemical vapor deposition (MPCVD) technique. The boron concentration of this set of films covers the whole possible doping range divided into four parts: Low doping (5 × 1016 < [B] < 1.5 × 1019 cm? 3), high doping (1.5 × 1019 < [B] < 3 × 1020 cm? 3), heavy doping (3 × 1020 < [B] < 2 × 1021 cm? 3), and phase separation range ([B] > 2 × 1021 cm? 3). The phase separation occurs for very high boron concentrations, between the diamond phase (sp3 carbon) and the other components of the layer, namely sp2 carbon and boron. A part of them is accumulated outside the diamond lattice.This detailed cathodoluminescence investigation of {111}-homoepitaxial diamond films has led to determining the doping range of the films and following the evolution of their crystalline quality when the boron concentration increases. In addition, a comparison between {111} and {100} films in the same doping ranges has been undertaken. 相似文献
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Rapp D Potier P Jocteur-Monrozier L Richaume A 《Environmental science & technology》2006,40(20):6324-6329
This study is part of a European project focused on understanding the biotic and abiotic mechanisms involved in the retention and dissemination of transmissible spongiform encephalopathies (TSE) infectivity in soil in order to propose practical recommendations to limit environmental contamination. A 1-year field experiment was conducted with lamb carcasses buried in a pasture soil at three depths (25, 45, and 105 cm). Microbial community response to carcasses was monitored through the potential proteolytic activity and substrate induced respiration (SIR). Soil above carcasses and control soil exhibited low proteolytic capacity, whatever the depth of burial. Contrastingly, in soil beneath the carcasses, proteolysis was stimulated. Decomposing carcasses also stimulated SIR, i.e., microbial biomass, suggesting that proteolytic populations specifically developed on lixiviates from animal tissues. Decomposition of soft tissues occurred within 2 months at subsurface while it lasted at least 1 year at deeper depth where proteolytic activities were season-dependent. The ability of soil proteases to degrade the beta form of prion protein was shown in vitro and conditions of burial relevant to minimize the risk of prion protein dissemination are discussed. 相似文献
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Systems for distributed event processing have recently gained increasing attention in a broad range of application domains. This raises the demand for methods to adapt the system design to application-specific needs. Our approach considers (1) trade-offs regarding the hardware infrastructure and (2) trade-offs in the software design. For the underlying model we categorize events along the dimensions of temporal complexity and physical distribution. This yields a categorization of events that drives trade-offs in the infrastructure design. The presented model supports design decisions in dependence on application-specific event properties and design goals. 相似文献
29.
Tunnel junctions with multiferroic barriers 总被引:2,自引:0,他引:2
Gajek M Bibes M Fusil S Bouzehouane K Fontcuberta J Barthélémy A Fert A 《Nature materials》2007,6(4):296-302
Multiferroics are singular materials that can exhibit simultaneously electric and magnetic orders. Some are ferroelectric and ferromagnetic and provide the opportunity to encode information in electric polarization and magnetization to obtain four logic states. However, such materials are rare and schemes allowing a simple electrical readout of these states have not been demonstrated in the same device. Here, we show that films of La(0.1)Bi(0.9)MnO(3) (LBMO) are ferromagnetic and ferroelectric, and retain both ferroic properties down to a thickness of 2 nm. We have integrated such ultrathin multiferroic films as barriers in spin-filter-type tunnel junctions that exploit the magnetic and ferroelectric degrees of freedom of LBMO. Whereas ferromagnetism permits read operations reminiscent of magnetic random access memories (MRAM), the electrical switching evokes a ferroelectric RAM write operation. Significantly, our device does not require the destructive ferroelectric readout, and therefore represents an advance over the original four-state memory concept based on multiferroics. 相似文献
30.
Castagna Claudia; Absil Philippe; Foidart Agnès; Balthazart Jacques 《Canadian Metallurgical Quarterly》1998,112(1):233
The authors investigated the behavioral actions of vasotocin (VT) in castrated testosterone-treated male Japanese quail. The appetitive and consummatory components of sexual behavior as well as the occurrence frequency of crows were inhibited, in a dose-dependent manner, by injections of VT. The authors observed opposite effects after injection of the V1 receptor antagonist, dPTyr(Me)AVP. Lower doses of VT were more active after central than after systemic injection, and effects of systemic injections of VT were blocked by a central injection of dPTyr(Me)AVP. The behavioral inhibition was associated with a modified diuresis after systemic but not central injection. These results provide direct evidence that VT affects male sexual behavior in quail by a direct action on the brain independent of its peripheral action on diuresis. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献