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71.
A. Roach    J. Dunlap    F. Harte 《Journal of food science》2009,74(2):N23-N29
ABSTRACT:  The association of triclosan (TCS), a widely used hydrophobic compound, to the bovine casein micelle is investigated in this study. The use of high-pressure homogenization (HPH) at 0, 100, 200, and 300 MPa was introduced as a method for the dissociation of casein micelles in a skim milk/ethanol solution (1: 1, v/v) in the presence of TCS at 20, 80, and 160 mg/L where ethanol evaporation served as the final step for TCS association to caseins. The majority of TCS (over 80%) was associated with the caseins regardless of initial TCS concentration or applied pressure. TCS association to caseins was enhanced by 30% with continued pressurization to 300 MPa. Micellar dissociation and reassociation was found to be an irreversible process as evidenced by microscopy images. Pressurization to 300 MPa resulted in the formation of an integrated protein network of casein proteins and noncovalently linked whey proteins where the solubility of TCS was enhanced up to 40 times its reported water solubility at the highest initial TCS level of 160 mg/L. Reformed micelles exhibited Newtonian flow behavior at all pressure levels. This study provides evidence for the solubility enhancing quality of TCS through the solvent-mediated pressure/shear-induced dissociation of casein proteins.  相似文献   
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A total of 102 male and 146 female offspring of Sprague-Dawley rats injected daily from Day 16 through Day 20 of gestation with either 2 mg of testosterone propionate (TP) in .1 ml of sesame oil or oil alone were tested for sexual receptivity following injections of 3.3 μg of estradiol benzoate (EB) and .5 mg of progesterone (P) beginning at 40, 80, or 120 days of age. At each age, neonatally gonadectomized males and females from TP-injected litters exhibited less receptivity than corresponding oil-injected controls. Prenatally androgenized females were similar to neonatally castrated oil-injected males at all ages. Ovarian implants from birth to 35 days of age significantly increased receptivity in neonatally castrated males and androgenized females. Increasing the age at which testing was initiated systematically reduced receptivity in all groups. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
73.
The excellent properties exhibited by monolayer graphene have spurred the development of exfoliation techniques using bulk graphite to produce large quantities of pristine monolayer sheets. Development of simple chemistry to exfoliate and intercalate graphite and graphite mimics in large quantities is required for numerous applications. To determine the macroscopic behavior of restacked, exfoliated bulk materials, a systematic approach is presented using a simple, redox‐liquid sonication process along to obtain large quantities of 2D and 3D hexagonally layered graphite, molybdenum disulfide, and boron nitride, which are subsequently characterized to observe chemical and structural changes. For MoS2 sonicated with the antioxidant sodium bisulfite, results from Raman spectroscopy, X‐ray diffraction, and electron microscopy indicate the presence of distorted phases from different polymorphs, and apparent nanotube structures in the bulk, restacked powder. Furthermore, using thermograviemtric analysis, the antioxidant enhances the resistance to oxidative degradation of MoS2, upon thermal treatment up to 900 °C. The addition of the ionic antioxidant decreased dispersion stability in non‐polar solvent, suggesting decreased compatibility with non‐polar systems. Using simple chemical methods, the ability to generate tailored multidimensional layered materials with unique macroscopic properties is critical for numerous applications, including electrical devices, reinforced polymer composites, lithium–ion capacitors, and chemical sensing.  相似文献   
74.
An investigation of grounding-related problems in AC/DC substations is reported. The investigation is based on analytical studies and published experimental results. The following grounding related problems have been investigated: (1) ground potential rise in converter stations and DC grounds and its effect on safety; (2) touch, step, and transfer voltages in and around DC converter stations and DC grounds; and (3) effects on soil thermal stability during monopolar operation. Several conclusions have been reached, and the findings of the investigation are summarized in a proposed procedure for the safety assessment of DC grounding systems  相似文献   
75.
Tests for experiments with matched groups or repeated measures designs use error terms that involve the correlation between the measures as well as the variance of the data. The larger the correlation between the measures, the smaller the error and the larger the test statistic. If an effect size is computed from the test statistic without taking the correlation between the measures into account, effect size will be overestimated. Procedures for computing effect size appropriately from matched groups or repeated measures designs are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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A study of the influence of processing conditions and structure on engineering mechanical properties was conducted in bulk isotactic polypropylene. The influence of one processing parameter, undercooling, defined so as to account for both pressure and temperature effects, was particularly studied. Improved mechanical properties were found with increased undercooling. At low undercoolings, brittle failure without yield occurred, presumably the result of a sparsity of intercrystalline links under these conditions. As undercooling was increased, failure occurred after yielding as failure stress elevated dramatically, apparently because of greater link density. A modest improvement in yield stress with increased undercooling was attributed to the increasingly crosshatched lamellar structure produced at higher undercoolings, a structural trend confirmed by electron microscopy. Spherulite size, varied by altering melt history (melt temperature and time at melt temperature) at constant undercooling, was found to have no effect on engineering yield stress. This result indicates that apparent yield stress–spherulite size effects found by several earlier investigators were probably caused by structural variations other than spherulite size.  相似文献   
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P. W. Sheehan (see record 1974-10335-001) is erroneous in claiming to identify an artifact in T. X. Barber's (1969) model for hypnosis. While Sheehan shows empirically that the group differences in Barber's Ss do make a difference in suggestibility scores, this is a variable of constraint in terms of instructions, not an artifact. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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