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101.
102.
Ann?M.?McCauley Clain?A.?JonesEmail author Perry?R.?Miller Macdonald?H.?Burgess Catherine?A.?Zabinski 《Nutrient Cycling in Agroecosystems》2012,92(3):305-314
Crop-fallow systems dominate many semi-arid agricultural regions despite fallow’s negative effects on soil and water quality.
Annual legumes grown as a fallow-replacement crop, and terminated prior to maturity, can reduce these negative effects without
substantially decreasing plant available water for the subsequent crop. Interest in growing legume green manures (LGMs) in
synthetically-fertilized systems is increasing in the northern Great Plains of North America, partly due to the N-fixing capabilities
of legumes; however, little is known about the effects of planting and termination time on N fixation amounts in the region.
A 2-year field study was initiated in southwest Montana to determine the effects of planting time (spring or summer) and termination
time (e.g. flower or pod) on the amount of N fixed by field pea (Pisum sativum cv. Arvika) and lentil (Lens
culinaris cv. Richlea). Two methods, 15N natural abundance and N difference, were used to quantify N fixation, with wheat or in-crop weeds as reference plants. In
2009, N fixed by spring-planted lentil was higher by pod than flower (P = 0.03). Termination time did not affect the amount of N fixed by spring-planted pea, despite more biomass by pod than flower.
In 2010, both spring-planted crops fixed more N by pod than flower (P < 0.01) and more N was fixed by spring-planted than summer-planted crops (P < 0.01). These results should prove useful to growers interested in selecting management practices that optimize N fixation
of LGMs. 相似文献
103.
Virginie N. Kapchie Lili T. Towa Catherine C. Hauck Patricia A. Murphy 《Journal of the American Oil Chemists' Society》2012,89(5):947-956
The aim of this study was to investigate soy protein recovery feasibility after lab- and pilot-plant scale oleosome isolation.
The proteins were isolated by isoelectric precipitation and by ultrafiltration. The functional properties of the recovered
proteins were compared to soy protein isolate produced in our laboratory. The residual lipid content in the aqueous supernatant
affected the protein recovery yields and purities. Ethanol precipitation and ultrafiltration resulted in the best protein
yields, which were 25 and 26% greater than protein yield obtained by isoelectric precipitation with distilled water dilution.
The protein content of the isoelectric precipitated pilot-plant supernatant was higher (98%) than the protein content of ethanol-precipitated
proteins (80%). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed similar peptide profiles for laboratory and
pilot-plant supernatants. Protein solubility curves between pH 3 and 8 were typical for soy protein isolate with higher solubilities
for proteins obtained from pilot-plant supernatant. The soy protein isolate and ethanol-precipitated protein had the highest
emulsification capacity on a dry-weight basis. These desirable functional properties of proteins recovered as co-products
after oleosome isolation suggest they are highly suitable for industrial application as food ingredients and their recovery
would contribute to the economics of the overall oleosome fractionation process. 相似文献
104.
Dr. Christine Brotschi Dr. Catherine Roch Dr. John Gatfield Dr. Alexander Treiber Dr. Jodi T. Williams Dr. Thierry Sifferlen Dr. Bibia Heidmann Dr. Francois Jenck Dr. Martin H. Bolli Dr. Christoph Boss 《ChemMedChem》2019,14(13):1257-1270
The orexin system plays an important role in the regulation of wakefulness. Suvorexant, a dual orexin receptor antagonist (DORA) is approved for the treatment of primary insomnia. Herein, we outline our optimization efforts toward a novel DORA. We started our investigation with rac-[3-(5-chloro-benzooxazol-2-ylamino)piperidin-1-yl]-(5-methyl-2-[1,2,3]triazol-2-ylphenyl)methanone ( 3 ), a structural hybrid of suvorexant and a piperidine-containing DORA. During the optimization, we resolved liabilities such as chemical instability, CYP3A4 inhibition, and low brain penetration potential. Furthermore, structural modification of the piperidine scaffold was essential to improve potency at the orexin 2 receptor. This work led to the identification of (5-methoxy-4-methyl-2-[1,2,3]triazol-2-ylphenyl)-{(S)-2-[5-(2-trifluoromethoxyphenyl)-[1,2,4]oxadiazol-3-yl]pyrrolidin-1-yl}methanone ( 51 ), a potent, brain-penetrating DORA with in vivo efficacy similar to that of suvorexant in rats. 相似文献
105.
Majid Shahzad Michel ChaussumierRémy Chieragatti Catherine MabruFarhad Rezai Aria 《Journal of Materials Processing Technology》2010,210(13):1821-1826
The objective of the present work is to show the influence of machining and anodizing processes on fatigue life of alloy 7010-T7451. Two different cutting conditions were employed to obtain two different initial surface roughnesses. Degreasing, pickling and anodizing were then carried out. In the as machined condition, surface roughness is clearly effective in reducing fatigue life in this material. As the surface roughness increases fatigue life decreases and this effect is found to be more pronounced in high cycle fatigue where major portion of fatigue life is consumed in nucleating the cracks. Effects of pre-treatments, like degreasing and pickling employed prior to anodizing, on fatigue life of the given alloy were also studied. Fatigue curves showed that pickling had negative impact on fatigue life of specimens while degreasing showed no change in fatigue life. The small decrease in fatigue life of anodized specimens as compare to pickled specimens is attributed to brittle nature and micro-cracking of the coating. Scanning electron microscopic (SEM) examination revealed multi-site crack initiation for the pickled and anodized specimens. SEM examination also showed that pickling process attacked the grain boundaries and the inclusions present on the surface resulting in pits formation. These pits are of primary concern with respect to accelerated fatigue crack nucleation and subsequent anodized coating formation. 相似文献
106.
The activity and mechanism of uranium oxide catalysts for the oxidative destruction of volatile organic compounds 总被引:8,自引:0,他引:8
Stuart H. Taylor Catherine S. Heneghan Graham J. Hutchings Ian D. Hudson 《Catalysis Today》2000,59(3-4):249-259
Uranium oxide based catalysts have been investigated for the oxidative destruction of volatile organic compounds (VOCs) to carbon oxides and water. The catalysts have been tested for the destruction of a range of organic compounds at space velocities up to 70 000 h−1. Destruction efficiencies greater than 99% can be achieved over the appropriate uranium based catalyst in the temperature range 300–450°C. Volatile organic compounds investigated include benzene, butylacetate, cyclohexanone, toluene, methanol, acetylene, butane, chlorobutane and chlorobenzene. The catalysts are thermally stable, destroy low concentrations and mixtures of VOCs and lifetime studies indicate that deactivation during oxidation of chlorinated VOCs did not occur. A temporal analysis of products (TAPs) reactor is used to investigate the mechanism of oxidation of VOCs by uranium oxide catalysts. Studies indicated that VOCs were oxidised directly to carbon oxides on the catalyst surface. A combination of TAP pulse experiments with oxygen present and absent in the gas phase has indicated that the lattice oxygen from the catalyst is responsible for the total oxidation activity. This has been confirmed by studies using isotopically labelled oxygen which indicates that the catalyst operates by a redox mechanism. 相似文献
107.
Philippe Allongue Catherine Henry de Villeneuve Sylvie Morin Rabah Boukherroub Danial D. M. Wayner 《Electrochimica acta》2000,45(28):4591
The reasons why ideally flat H–Si(111) surface can be prepared by NH4F etching are investigated from correlation between AFM observations and experimental conditions used for etching. It is shown that pitting may be completely suppressed if a one side polished wafer is immersed in an oxygen free solution. An analytical electrochemical study of the (111) and rough face of the same n-Si wafer is presented to yield insight into observations. 相似文献
108.
Jonathon E. Beves Edwin C. Constable Catherine E. Housecroft Markus Neuburger Silvia Schaffner 《Inorganic chemistry communications》2009,12(9):898-901
The synthesis and characterization of three new bis(2,2′:6′,2′-terpyridine) (tpy) ligands containing different hydrazone spacers between the metal-binding domains are described. Treatment of 1,4-benzenedicarbaldehyde bis(2,2′:6′,2′′-terpyridin-4′-ylhydrazone) (1) with [(tpy)RuCl3] in the presence of N-ethylmorpholine results in the formation of [(tpy)Ru(μ-1)Ru(tpy)]4+. Single crystal X-ray diffraction data for [(tpy)Ru(μ-1)Ru(tpy)][PF6]4·8MeCN confirm the ability of the hydrazone-based ligand to bridge two ruthenium(II) centres, providing proof-of-principle for the application of this class of flexible ligand in the design of coordination polymers. 相似文献
109.
Sharon Rose Aarons Catherine R. O’Connor Hossein M. Hosseini Cameron J. P. Gourley 《Nutrient Cycling in Agroecosystems》2009,84(1):81-92
In grazing systems dung is an important source of nutrients which can increase soil fertility and contribute to nutrient cycling
through increased pasture production. Changes in soil chemical and biological properties and pasture production were measured
below and around dung pads created in the field. Almost 65% of the total dung P remained after 45 days and about two-thirds
of the pad fresh weight had disappeared in that time, indicating that physical degradation is the mechanism of incorporation
of dung P. All the pads bar one were completely degraded by 112 days. At this time, soil pH and EC increased under dung pads
as did Olsen extractable inorganic phosphorus (Pi) and total phosphorus (Pt), with these changes observed at 0–5 and 5–10 cm
depths. Bicarbonate extractable soil organic phosphorus (Po) was not affected by dung and the observed differences in soil
Po:Pi ratios were largely influenced by the substantial addition of inorganic P from dung. Dung increased the P buffering
capacity of the 0–5 cm soil samples collected at the end of the experiment, potentially contributing to the increased extractable
soil P measured under the pads. Dung also changed soil properties in 0–10 cm samples with increases in soil pH, EC, Colwell
P and Colwell K recorded even long after the dung had completely disappeared. Microbial biomass carbon increased under dung
pads in the 0–10 cm soil samples in the first 45 days after pads were applied. Total herbage production and ryegrass biomass
increased significantly under and around the pads by 112 days after dung was applied. The botanical composition changed significantly
with increased ryegrass contents observed, but only under the dung pads. This experiment demonstrated that increases in pasture
around dung pads in the field are not solely due to animal rejection. 相似文献
110.
Behavioral responses of males from three New York races of European corn borer,Ostrinia nubilalis (Hübner), to various suspected sexpheromone-response antagonists were investigated with a flight tunnel protocol. Males from a bivoltine (Z) race and from a univoltine (Z) race utilizing a natural pheromone blend of 982 (Z)-(E)-11-tetradecenyl acetates and males from a bivoltine (E) race utilizing a 199 (Z)-(E)-11-tetradecenyl acetate ratio were flown to their natural blends and to blends containing 1 % of one of the following additional compounds: Z9–12OAc,E9–12OAc,Z9–14OAc, andE9–14OAc. In each race, the added components lowered significantly the number of individuals completing the behavioral sequence. The only exception was bivoltineE males flown to a blend withE9–12OAc added. The number completing the sequence in this case was statistically not significantly lower than the number that completed the sequence to the standard blend. In all three races, theZ9–14OAc produced the most dramatic reduction in completed flights, and in the univoltineZ race, this added component was significantly more effective in reducing completed flights than any other added component. The response to the Z9–14OAc is understandable given recently published findings of an electrophysiological study of single sensilla in the European corn borer. 相似文献