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11.
Sleep deprivation (SD) modified the circadian rhythm of specific high affinity serotonin (5-HT) binding to rat brain membranes. In control rats a 24-hr rhythm was evident with a trough at 1000-1200 and a nadir at 0000. During the last 26 hr of a 49 hr SD period, trough and peak values were delayed by 4-6 hr. The 24-hr mean binding was significantly (P less than 0.001) different from that of controls. If sleep deprivation was followed by recovery sleep (RS), the normal rhythm of 5-HT binding was obtained already within 1 hr after SD. The effects of SD and RS were ascertained by plasma ACTH and corticosterone assay. No significant change in the hormone rhythms were observed through the mean plasma level of ACTH and corticosterone were enhanced to about 180 and 150%, respectively. Chronic treatment with the antidepressant imipramine resulted in a decrease of the 24-hr mean 5-HT binding by about 50% and a 2-hr delay of peak and trough values. Imipramine treatment decreased the peak value of 5-HT concentration at 1000 to about 65% and appears to abolish the rhythm of 5-HT concentration. 相似文献
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Jeannette Boguhn H. Kluth O. Steinhöfel Martina Peterhänsel M. Rodehutscord 《Archives of animal nutrition》2013,67(4):253-266
The aim of the present study was to determine equations that predict ME in total mixed rations (TMR) based on routine methods. The ME content of 30 TMR for dairy cows was determined based on digestible crude nutrients obtained with wether sheep. Concentrations in the TMR (in g/kg DM) varied between 118 and 234 for crude protein, 26 and 48 for crude lipid, 131 and 250 for crude fibre, 281 and 488 for NDF, and 173 and 304 for ADF. Gas production ranged from 40.7 to 54.1 ml/200 mg DM, and enzymatically degraded organic matter from 652 to 800 g/kg DM. Digestibility [%] ranged from 68.6 to 84.0 for organic matter, from 55.6 to 84.3 for crude lipid, from 55.0 to 77.8 for crude fibre, from 57.6 to 77.0 for NDF and from 53.1 to 79.6 for ADF. ME ranged from 9.6 to 11.9 MJ/kg DM, and NEL from 5.7 to 7.4 MJ/kg DM. ME content was highly correlated with the concentration of both crude fibre and enzymatically degradable organic matter as well as with organic matter digestibility. A multiple regression equation based on crude fibre and crude lipid predicted ME with a reasonable goodness of fit (r2 = 0.81; sy.x = 2.4%). The inclusion of other nutrients, of neutral and acid detergent fibre, neither of gas production did improve the goodness of fit. The best prediction was achieved with inclusion of enzymatically degraded organic matter (r2 = 0.90; sy.x = 1.7%). 相似文献
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Laura M. Suz Nadia Barsoum Sue Benham Hans‐Peter Dietrich Karl Dieter Fetzer Richard Fischer Paloma García Joachim Gehrman Ferdinand Kristöfel Miklós Manninger Stefan Neagu Manuel Nicolas Jan Oldenburger Stephan Raspe Gerardo Sánchez Hans Werner Schröck Alfred Schubert Kris Verheyen Arne Verstraeten Martin I. Bidartondo 《Molecular ecology》2014,23(22):5628-5644
Ectomycorrhizal fungi are major ecological players in temperate forests, but they are rarely used in measures of forest condition because large‐scale, high‐resolution, standardized and replicated belowground data are scarce. We carried out an analysis of ectomycorrhizas at 22 intensively monitored long‐term oak plots, across nine European countries, covering complex natural and anthropogenic environmental gradients. We found that at large scales, mycorrhizal richness and evenness declined with decreasing soil pH and root density, and with increasing atmospheric nitrogen deposition. Shifts in mycorrhizas with different functional traits were detected; mycorrhizas with structures specialized for long‐distance transport related differently to most environmental variables than those without. The dominant oak‐specialist Lactarius quietus, with limited soil exploration abilities, responds positively to increasing nitrogen inputs and decreasing pH. In contrast, Tricholoma, Cortinarius and Piloderma species, with medium‐distance soil exploration abilities, show a consistently negative response. We also determined nitrogen critical loads for moderate (9.5–13.5 kg N/ha/year) and drastic (17 kg N/ha/year) changes in belowground mycorrhizal root communities in temperate oak forests. Overall, we generated the first baseline data for ectomycorrhizal fungi in the oak forests sampled, identified nitrogen pollution as one of their major drivers at large scales and revealed fungi that individually and/or in combination with others can be used as belowground indicators of environmental characteristics. 相似文献
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Quantification of rapid,transient increases in jasmonic acid in wounded plants using a monoclonal antibody 总被引:9,自引:0,他引:9
A monoclonal antibody (MAB JAH1-8-B4) for the analysis of 3R, 7R-jasmonic acid and its methyl ester is described. An IgG1(kappa) immunoglobulin, MAB JAH1-8-B4, was used to set up a competitive enzymelinked immunoassay employing 3R, 7R-jasmonate coupled to alkaline phosphatase as tracer. The assay has a linearity range (logit/log) between 50 fmol and 50 pmol (approx. 10 pg-10 ng) of 3R, 7R-methyljasmonate, the assay standard. A procedure combining prepurification of plant extracts by solid-phase extraction, followed by high-performance liquid chromatography and quantitation has been worked out, which uses 4 g of fresh plant material and has a detection limit between 0.2 and 0.4 g of 3R, 7R-jasmonic acid (determined as its methyl ester) per kg of tissue, depending on the tissue. Internal standards of 3R, 7R-methyljasmonate, added to split samples during extraction as well as a second internal standard, 3R, 7R-methyljasmonate-[O-C3H3], added to all samples prior to methylation, served to correct for workup losses and for the monitoring of Chromatographie separations. Using this assay, it was found that levels of jasmonic acid rise immediately and transiently in the tissues analyzed as a consequence of wounding. These data provide further and direct evidence for the hypothesis that wound-induction of the plant defense reactions is mediated by endogenous jasmonates.Abbreviations DHJA
9,10-dihydrojasmonic acid
- ELISA
enzyme-linked immunosorbent assay
- GC-MS
gas chromatography-mass spectrometry
- HCy
hemocyanin
- HPLC
high-performance liquid chromatography
- JA
jasmonic acid
- MAB
monoclonal antibody
- ME
methyl ester
- PDA
12-oxo-phytodienoic acid
This work was supported by the Deutsche Forschungsgemeinschaft, Bonn, FRG, by the Fonds der Chemischen Industrie, Frankfurt, FRG (literature provision), and by the Ministerium fü Wissenschaft und Forschung des Landes Sachsen-Anhalt, Magdeburg, FRG. We thank Drs. M. H. Zenk and Z.-Q. Xia, Pharmazeutische Biologie, Universität München, FRG, for gifts of reference compounds. We are especially grateful to Dr. M. J. Müller from the same institute for GC-MS analyses. 相似文献
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H. -D. Knöfel E. Schwarzkopf P. Müller G. Sembdner 《Journal of Plant Growth Regulation》1984,3(1-4):127-140
Starting from the well-known conversion of exogenously applied free gibberellic acid (GA3) to its 3(O)-glucoside by intact immature fruits of runner beans (Phaseolus coccineus L.), a protein fraction has been prepared from this plant material possessing glucosylating activity towards GAs. This glucosyltransferase is located in the pericarp only and utilizes preferably UDP-glucose as a sugar donor. The product formed enzymically from GA3 and UDP-glucose could be identified by derivatization and comparison with the authentic compound to be GA3-3(O)-glucoside. Among 15 native or chemically modified GAs, the enzyme glucosylates only GA3 and to a lower extent GA7 and GA30, indicating a high enzyme specificity with regard to the A ring of gibberellins. The physiological significance of the enzymic GA3-3(O)-glucoside formation inPhaseolus coccineus is not clear, since this glucoside is not known to be endogenous in this plant. The enzyme preparation did not glucosylate substances of phenolic structure, such as hydroquinone, aesculetin, and quercetin. Glucosylation of GA3 was achieved also by enzyme preparations fromVigna sinensis and from cell suspension cultures ofDigitalis purpurea. A number of other plant materials showed no activity. 相似文献
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5'-Nucleotidase belongs to a large superfamily of distantly related dinuclear metallophosphatases including the Ser/Thr protein phosphatases and purple acid phosphatases. The protein undergoes a 96 degrees domain rotation between an open (inactive) and a closed (active) enzyme form. Complex structures of the closed form with the products adenosine and phosphate, and with the substrate analogue inhibitor alpha,beta-methylene ADP, have been determined at 2.1 A and 1.85 A resolution, respectively. In addition, a complex of the open form of 5'-nucleotidase with ATP was analyzed at a resolution of 1.7 A. These structures show that the adenosine group binds to a specific binding pocket of the C-terminal domain. The adenine ring is stacked between Phe429 and Phe498. The N-terminal domain provides the ligands to the dimetal cluster and the conserved His117, which together form the catalytic core structure. However, the three C-terminal arginine residues 375, 379 and 410, which are involved in substrate binding, may also play a role in transition-state stabilization. The beta-phosphate group of the inhibitor is terminally coordinated to the site 2 metal ion. The site 1 metal ion coordinates a water molecule which is in an ideal position for a nucleophilic attack on the phosphorus atom, assuming an in-line mechanism of phosphoryl transfer. Another water molecule bridges the two metal ions. 相似文献
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Boulet P Knöfel C Kuchta B Hornebecq V Llewellyn PL 《Journal of molecular modeling》2012,18(11):4819-4830
A theoretical investigation of the adsorption of CO(2) onto ZrO(2) is presented. Various cluster models were used to mimic different basic and acidic sites on the surface. The method used was the density functional theory with the generalized gradient approximation and including Grimme's empirical model in order to properly describe the weak interactions that may occur between the adsorbate and the surface. We found that the adsorption at sites exhibiting two adjacent unsaturated zirconium atoms led to either the exothermic dissociation of CO(2) or to a strongly physisorbed state. By contrast, on a single unsaturated zirconium, CO(2) was adsorbed in an apical manner. In this case, the molecule is highly polarized and the adsorption energy amounts to -64.6?kJ?mol(-1). Finally, the weakest adsorption of CO(2) occurred on the basic OH sites on the surface. 相似文献
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Laura Schneider Markus Berger Eckhard Schüler-Hainsch Sven Knöfel Klaus Ruhland Jörg Mosig Vanessa Bach Matthias Finkbeiner 《The International Journal of Life Cycle Assessment》2014,19(3):601-610