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排序方式: 共有317条查询结果,搜索用时 15 毫秒
51.
Azin Rekowski Monika A. Wimmer Bernd Hitzmann Bernhard Hermannseder Heike Hahn Christian Zrb 《植物养料与土壤学杂志》2020,183(2):260-270
Background: Nitrogen losses is an economic problem for wheat production and a high risk to the environment. Therefore, improved N fertilizer management is a key to increasing the N efficiency and minimizing N losses. To increase N efficiency, enhanced fertilizers such as urea combined with urease inhibitor can be used. Aims: The aim of present study was to evaluate the effects of different N forms on grain storage protein subunits in winter wheat and to examine whether the observed changes correlate with parameters of baking quality. Methods: The investigation was performed over two consecutive years at two locations in Germany. Protein subunits were analyzed by SDS‐PAGE. Results: Protein concentrations were similarly increased after fertilization with ammonium nitrate and urea + urease inhibitor. Analysis of the individual storage protein fractions indicated that both fertilizers specifically enhanced ω‐gliadins and HMW glutenins, but the effect was more pronounced in the ammonium nitrate treatment. Application of urea + urease inhibitor had greater influence on the protein composition and resulted in higher specific baking volume as well as the best fresh keeping ability, in comparison with urea treatment. Conclusion: Considering that the urea + urease inhibitor treatment resulted in almost comparable improvements of NUE and baking quality, with the additional benefit of reduced N losses in combination with easy handling, urea + urease inhibitor can be recommended as a viable alternative to both urea alone and ammonium nitrate treatments. This opens up an opportunity for the reduction of N loss in wheat production when use of urea is preferred. 相似文献
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54.
Alan Akers Eberhard Ammermann Ernst Buschmann Norbert Gtz Walter Himmele Gisela Lorenz Ernst-Heinrich Pommer Costin Rentzea Franz Rhl Hardo Siegel Bernhard Zipperer Hubert Sauter Matthias Zipplies 《Pest management science》1991,31(4):521-538
In spite of considerable efforts by many workers, there has been a lack of progress in the area of amine fungicides since fenpropimorph. Random synthesis of a large variety of different amine compounds, as well as intelligent structural modification of the lead structure fenpropimorph (well over 15 000 amines have been screened at BASF alone) have not led to a new market product so far. Further work has been focused on the reported mode of action of fenpropimorph, notably on the inhibition of the sterol Δ14-reductase. Although some doubt has to be cast on the hypothesis that fenpropimorph behaves as a sterol mimic, the concept of ‘high energy intermediate’ inhibitors has been employed successfully. Rational drug design of azasterol mimics has led to a number of very potent inhibitors of the sterol Δ14-reductase which also displayed high fungicidal activity in the greenhouse. Although many of these compounds are more powerful reductase inhibitors than fenpropimorph, under field conditions none showed significant advantages over this established fungicide. Most likely, fenpropimorph already exhibits the maximum fungicidal activity which can be attained by blocking the sterol Δ14-reductase. This would mean that, with the development of the ‘second generation’ amine fungicide fenpropimorph, this class of compounds has already virtually been optimized. 相似文献
55.
Ulrich Ammer Werner Kroth Karl E. Rehfuess Walter Schöpfer Peter Schütt Bernhard Ulrich Friedrich Georgi Rudolf Georgi 《European Journal of Forest Research》1986,105(1):445-445
Ohne Zusammenfassung 相似文献
56.
Microclimate in agroforestry systems in central Amazonia: does canopy closure matter to soil organisms? 总被引:7,自引:0,他引:7
Christopher Martius Hubert Höfer Marcos V.B. Garcia Jörg Römbke Bernhard Förster Werner Hanagarth 《Agroforestry Systems》2004,60(3):291-304
Microclimate was recorded and soil organisms were collected 1997-1999 in ecosystem stands of contrasting structure in central
Amazonia (a primary forest, a 12-year secondary forest, two different agroforestry systems, a rubber tree (Hevea brasiliensis) plantation, and a peach palm (Bactris gasipaes) monoculture with a densely closed canopy). The aim was to look at the effects of canopy closure on microclimate and soil
organisms. Monthly maxima temperature, average air and soil temperatures, and saturation deficit were highest in September
1997, and total annual rainfall in 1997 was 12-28% lower than in the other study years. The monthly average litter temperatures
were consistently 2-4 °C higher in the plantation sites than in the rainforest and the secondary forest, and temperatures
on single days (not the monthly averages) in the plantations were up to 10 °C higher than in the primary forest. The highest
average litter and soil temperatures and the highest temperature maxima were recorded in the agroforestry plantations. Canopy
closure strongly determined the litter temperatures in the sites. Soil macrofauna biomass was also strongly correlated to
canopy closure (linear regression, P = 0.05). We conclude that a well developed canopy effectively protects the soil macrofauna
from high temperature variation and drought stress. Therefore, optimizing these agroforestry systems for canopy closure may
contribute to a better management of the beneficial soil decomposer community.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
57.
Artemisia douglasiana leaf has been shown to be efficacious complementary herbal treatment for chronic bladder infection in a paraplegic youth. The leaf oil has been analyzed by GC-MS and the major components found to be camphor (29%), artemisia ketone (26%), artemisia alcohol (13%), alpha-thujone (10%), 1,8-cineole (8%), and hexanal (5%). The leaf oil and the major components have been tested for antimicrobial activity against Bacillus cereus, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, and Aspergillus niger. The essential oil shows limited antimicrobial activity in vitro, so it is unclear if the oil exerts a direct antimicrobial effect in vivo, or plays some role in stimulation of host defenses. 相似文献
58.
Marschang RE Gleiser CB Papp T Pfitzner AJ Böhm R Roth BN 《Veterinary microbiology》2006,117(2-4):258-266
Herpesviruses are an important cause of epidemic disease in tortoises. There are at least two serologically distinct herpesviruses capable of infecting tortoises. Methods for the diagnosis of herpesvirus infections in tortoises include virus isolation and a number of different PCRs. We have compared 11 virus isolates collected from various species in different countries over several years using sequences from three different viral genes. During this study we used four different PCR protocols described for the diagnosis of herpesvirus infections in tortoises. The protocols used included two based on portions of the DNA polymerase gene, one targeting the UL5 homologue, and one targeting the UL39 homologue. Comparison of the methods showed that the tortoise herpesvirus-specific protocols were all serotype specific. Sequences of the obtained amplicons were compared with one another and with sequences of herpesviruses available in GenBank. The sequence alignments showed that the tortoise herpesviruses were most closely related to members of the subfamily Alphaherpesvirinae. They also showed that the tortoise isolates could be clearly divided into two genogroups. 相似文献
59.
Koglin A Mofid MR Löhr F Schäfer B Rogov VV Blum MM Mittag T Marahiel MA Bernhard F Dötsch V 《Science (New York, N.Y.)》2006,312(5771):273-276
Protein dynamics plays an important role in protein function. Many functionally important motions occur on the microsecond and low millisecond time scale and can be characterized by nuclear magnetic resonance relaxation experiments. We describe the different states of a peptidyl carrier protein (PCP) that play a crucial role in its function as a peptide shuttle in the nonribosomal peptide synthetases of the tyrocidine A system. Both apo-PCP (without the bound 4'-phosphopantetheine cofactor) and holo-PCP exist in two different stable conformations. We show that one of the apo conformations and one of the holo conformations are identical, whereas the two remaining conformations are only detectable by nuclear magnetic resonance spectroscopy in either the apo or holo form. We further demonstrate that this conformational diversity is an essential prerequisite for the directed movement of the 4'-PP cofactor and its interaction with externally acting proteins such as thioesterases and 4'-PP transferase. 相似文献
60.
Yano J Kern J Sauer K Latimer MJ Pushkar Y Biesiadka J Loll B Saenger W Messinger J Zouni A Yachandra VK 《Science (New York, N.Y.)》2006,314(5800):821-825
The oxidation of water to dioxygen is catalyzed within photosystem II (PSII) by a Mn(4)Ca cluster, the structure of which remains elusive. Polarized extended x-ray absorption fine structure (EXAFS) measurements on PSII single crystals constrain the Mn(4)Ca cluster geometry to a set of three similar high-resolution structures. Combining polarized EXAFS and x-ray diffraction data, the cluster was placed within PSII, taking into account the overall trend of the electron density of the metal site and the putative ligands. The structure of the cluster from the present study is unlike either the 3.0 or 3.5 angstrom-resolution x-ray structures or other previously proposed models. 相似文献