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81.
Gougeon RD Soulard M Miehé-Brendlé J Chézeau JM Le Dred R Jeandet P Marchal R 《Journal of agricultural and food chemistry》2003,51(14):4096-4100
Two natural calcium-rich bentonites used for the removal of wine proteins, originating from Greece and Turkey, were studied by X-ray diffraction, thermal analysis, and solid state NMR, before and after activation by solid Na(2)CO(3). Exchange of Ca(2+) by Na(+) mainly occurs for cations located at the edge of layers and only weakly for interlayer cations. This Na(2)CO(3) activation process leads to an increased efficiency in the adsorption process of bovine serum albumin (BSA) used as a model protein for both bentonites. A direct correlation is observed between the extent of Ca(2+)/Na(+) exchange, the strength of adsorption of BSA, and the extent of unfolding of BSA backbone. 相似文献
82.
Darriet P Pons M Henry R Dumont O Findeling V Cartolaro P Calonnec A Dubourdieu D 《Journal of agricultural and food chemistry》2002,50(11):3277-3282
Powdery mildew due to the fungus Uncinula necator is an important disease for the vineyard. The development of the fungus at the surface of the berries leads to the occurrence of a very characteristic and sometimes intense mushroom-type odor cited as an important default for grapes quality. Gas chromatography/olfactometry, gas chromatography, and multidimensional gas chromatogaphy/mass spectrometry techniques were used to investigate the most important odorants of grapes diseased by powdery mildew. Among 22 odorants detected, strongly odorant compounds were identified or tentatively identified in purified extracts obtained from grapes diseased by powdery mildew. Aroma extraction dilution analysis (AEDA) analysis revealed that 1-octen-3-one (mushroom odor), (Z)-1,5-octadien-3-one (geranium-leaf odor), and an unidentified odorous zone (fishy-mushroom like odor) were the most potent volatiles of the diseased grapes. In the presence of nonproliferating Saccharomyces cerevisiae yeast cells, and consequently during alcoholic fermentation, the enzymatic reduction of 1-octen-3-one and (Z)-1,5-octadien-3-one to much less odorant compounds, namely 3-octanone and (Z)-5-octen-3-one, was shown. Those results explain to some extent the disappearance of the fungal aroma specific to powdery mildew grapes during alcoholic fermentation. 相似文献
83.
M. Sajjad Mirza Samina Mehnaz Philippe Normand Claire Prigent-Combaret Yvan Moënne-Loccoz René Bally Kauser A. Malik 《Biology and Fertility of Soils》2006,43(2):163-170
Nitrogen-fixing plant growth-promoting rhizobacteria (PGPR) from the genus Pseudomonas have received little attention so far. In the present study, a nitrogen-fixing phytohormone-producing bacterial isolate from kallar grass (strain K1) was identified as Pseudomonas sp. by rrs (16S ribosomal RNA gene) sequence analysis. rrs identity level was high with an uncharacterized marine bacterium (99%), Pseudomonas sp. PCP2 (98%), uncultured bacteria (98%), and Pseudomonas alcaligenes (97%). Partial nifH gene amplified from strain K1 showed 93% and 91% sequence similarities to those of Azotobacter chroococcum and Pseudomonas stutzeri, respectively. The effect of Pseudomonas strain K1 on rice varieties Super Basmati and Basmati 385 was compared with those of three non-Pseudomonas nitrogen-fixing PGPR (Azospirillum brasilense strain Wb3, Azospirillum lipoferum strain N4 and Zoogloea strain Ky1) used as single-strain inoculants. Pseudomonas sp. K1 was detected in the rhizosphere of inoculated plants by enrichment culture in nitrogen-free growth medium, which was followed by observation under the microscope as well as by PCR using a rrs-specific primer. For both rice varieties, an increase in shoot biomass and/or grain yield over that of noninoculated control plants was recorded in each inoculated treatment. The effect of Pseudomonas strain K1 on grain yield was comparable to those of A. brasilense Wb3 and Zoogloea sp. Ky1 for both rice varieties. These results show that nitrogen-fixing pseudomonads deserve attention as potential PGPR inoculants for rice. 相似文献
84.
The rates of nucleation of liquid aerosols from the gaseous mixtures H2SO4 + H2O and HNO3 + H2O at 25°C for various relative humidities (10 to 100%) and various activities of acid vapor are calculated using the Flood-Neumann-Döring-Reiss-Doyle theory of binary homogeneous nucleation. The activities of acid vapor needed for nucleation are 25 to 300 times smaller for H2SO4 + H2O than for HNO3 + H2O. This is due to the much larger free energy of mixing in the liquid phase for H2SO4 + H2O. Conversion from activities to actual pressures leads to concentrations of HNO3 which are much too high to be found under normal atmospheric conditions. On the other hand, the concentrations of H2SO4 vapor needed to nucleate droplets in the H2SO4 + H2O system are in the range 4(10?5) to 1.3 (10?2) ppm, a concentration which can result from photo-oxidation of SO2 in the atmosphere. Calculations are made of the growth curves for H2SO4 + H2O droplets (radius vs composition) at various relative humidities from the critical size radius up to a 1000 Å radius, corresponding to nuclei large enough to serve as condensation centers for heterogeneous nucleation. The limitations of binary homogeneous nucleation theory at extremely low concentrations of one of the components are discussed and it is shown that this theory becomes inapplicable if the actual vapor pressure of one component is below 10?6 torr. 相似文献
85.
van Hullebusch Eric Auvray Franck Deluchat Véronique Chazal Philippe M. Baudu Michel 《Water, air, and soil pollution》2003,146(1-4):75-91
Lake Courtille was a polymictic eutrophic lake prone to large pH variations and sediment resuspension. Short term P release (96 hr) under laboratory resuspension conditions for two sedimentsample types, surface sediments which represent sediment accumulated over several years and trap sediments which representcurrent year sediment, was studied. The experiments were carriedout in oxic conditions at different pH values. According to phosphorus fractionation, Fe-bound-P, Al-bound-P and Organic-bound-P comprised the largest phosphorus pool (80% of Total Phosphorus). Phosphorus release was from the Fe-P, Al-P and organic fractions. These represent 35% of the total phosphorus content at pH 10. At circumneutral pH, in oxic conditions, a lower quantity of P was released (roughly 4% of total P sediment content) than at pH 10. The organic matter mineralization occurring at the end of summer can also influenceP release as illustrated by the difference in total phosphoruscontent between sediment samples of 2000 and of the last five years. This type of P release was observed in Lake Courtille. High soluble reactive phosphorus content was measured in the water column at the end of summer. Aluminium treatment was thus not efficient in preventing P release. Moreover, a higher alum dose was needed to reduce P content in the water column in order to decrease primary productivity and subsequent organic matter sedimentation. 相似文献
86.
Philippe Quevauviller 《Journal of Soils and Sediments》2001,1(3):175-180
Single and sequential extraction procedures are often used to study the environmental fate of trace elements from soils and
sediments. Although these schemes are quite popular, they are prone to various sources of errors, which require them to be
thoroughly controlled. Owing to their operationally-defined character, the only way to compare analytical data is to stick
closely to procedures that have been collaboratively studied and written in the form of an operating protocol. Groups of scientists
have hence developed ‘harmonised’ procedures that are used as a reference for fractionation studies. A higher level is the
formal standardisation of the procedures by official standardisation bodies, which also fulfils the need for achieving the
comparability of data obtained by different laboratories from different countries. This paper discusses aspects of harmonisation
(consensus obtained by groups of scientists) and standardisation (adoption of standards as mandated by an international organisation)
as applied to single and extraction schemes for trace element fractionation studies, including quality control aspects. 相似文献
87.
88.
89.
R Rott 《Zentralblatt für Veterin?rmedizin. Reihe B. Journal of veterinary medicine. Series B》1965,12(2):97-116 concl
90.
Jandrey KE Smarick SD Burkitt JM Labelle P Mohr FC Kittleson MD 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2005,19(4):602-605
A young adult, 28 kg, intact female Siberian husky-mixed breed dog was presented to the Veterinary Medical Teaching Hospital (VMTH) Emergency Service for evaluation of a dysrhythmia and an abnormal cardiac structure. The dog had been adopted from an animal shelter approximately 3 months before presentation. The dog occasionally showed exercise intolerance, and the owners suspected that she had impaired vision. Initial clinical signs appeared 2 days before presentation during strenuous activity—the dog uncharacteristically stopped and lay down while tachypneic. The dog produced dark liquid feces and was lethargic and anorexic overnight. 相似文献