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91.
Effective means for controlled delivery of nutrients and nutraceuticals are needed. Whey protein-based gels, as a model system and as a potential delivery system, exhibit pH-dependent swelling when placed in aqueous solutions. Understanding the physics that govern gel swelling is thus important when designing gel-based delivery platforms. The extent of swelling over time was monitored gravimetrically. In addition to gravimetric measurements, magnetic resonance imaging (MRI) a real-time noninvasive imaging technique that quantified changes in geometry and water content of these gels was utilized. Heat-set whey protein gels were prepared at pH 7 and swelling was monitored in aqueous solutions with pH values of 2.5, 7, and 10. Changes in dimension over time, as characterized by the number of voxels in an image, were correlated to gravimetric measurements. Excellent correlations between mass uptake and volume change (R(2)= 0.99) were obtained for the gels in aqueous solutions at pH 7 and 10, but not for gels in the aqueous solution at pH 2.5. To provide insight into the mechanisms for water uptake, nuclear magnetic resonance (NMR) relaxation times were measured in independent experiments. The relaxation spectrum for the spin-spin relaxation time (T(2)) showed the presence of 3 proton pools for pH 7 and 10 trials and 4 proton pools for pH 2.5 trials. Results demonstrate that MRI and NMR relaxation measurements provided information about swelling in whey protein gels that can constitute a new means for investigating and developing effective delivery systems for foods.  相似文献   
92.
Exploring the effects of cations in whey protein-based gels (WPG) is of importance when these gels are used for controlled release applications in food systems. The objective of this study was to evaluate both water uptake and cation release from heat-set WPGs. Magnetic Resonance Imaging and NMR relaxometry were employed to study the uptake and release. A non-paramagnetic (Ca+2) and a paramagnetic cation (Mn+2) were incorporated into the WPG as model divalent cations. Cylindrical pieces of WPGs with manganese were immersed in water (pH 2.40, 7.00, 10.40) or in EDTA solution whereas WPGs with calcium were immersed in water at pH 2.40. Water uptake by the gels was influenced by both ionic environment and pH. The release of Mn+2 from WPG was enhanced by the presence of EDTA. Relaxation spectra of Mn+2-loaded gels were significantly influenced by pH of the suspending fluid and by the presence of EDTA. Results of relaxometry experiments, obtained with Ca+2-loaded gels immersed in water at pH 2.40, indicated a strong correlation (R2 > 0.99) between relative areas of the proton pools and the amount of calcium released to the medium. Results support the use of MRI and NMR to monitor cation release and water uptake in WPG, non-destructively.  相似文献   
93.
The effect of radio-frequency (RF) or low-frequency (LF) bias voltage on the for- mation of amorphous hydrogenated carbon (a-C:H) films was studied on silicon substrates with a low methane (CH4) concentration (2-10 vol.%) in CH4+Ar mixtures. The bias substrate was applied either by RF (13.56 MHz) or by LF (150 kHz) power supply. The highest hardness values (~18-22 GPa) with lower hydrogen content in the fihns (~20 at.%) deposited at 10 vol.% CH4, was achieved by using the RF bias, However, the films deposited using the LF bias, under similar RF plasma generation power and CH4 concentration (50 W and 10 vol.%, respectively), displayed lower hardness (~6-12 GPa) with high hydrogen content (~40 at.%). The structures analyzed by Fourier Transform Infrared (FTIR) and Raman scattering measurements provide an indication of trans-polyacetylene structure formation. However, its excessive formation in the films deposited by the LF bias method is consistent with its higher bonded hydrogen concentration and low level of hardness, as compared to the film prepared by the RF bias method. It was found that the effect of RF bias on the film structure and properties is stronger than the effect of the low-frequency (LF) bias under identical radio-frequency (RF) powered electrode and identical PECVD (plasma enhanced chemical vapor deposition) system configuration.  相似文献   
94.
A method to calculate the shape of the gas/liquid interface in a rectangular cavity is presented. This article is an expansion of investigations carried out in the 1960s, where the direction of the body force was assumed to be parallel to the side walls of the cavity. In the present work this assumption is eliminated, thus introducing the tilt angle as an additional variable affecting the interface shape. The shape of the interface for several values of Bond number, contact angle, and tilt angle is calculated. A critical Bond number below which the interface shape does not change is identified. The implications to liquid-phase processing in micromachining and microelectronics fabrication are discussed.  相似文献   
95.
Behavior-state matching and synchrony in interactions were assessed in 48 depressed and nondepressed mother–infant dyads when the infants were 3 months old. Attentive/affective behavior states were coded for the infants and mothers on a negative to positive scale. The depressed mothers and their infants matched negative behavior states more often and positive behavior states less often than did the nondepressed dyads. The total percentage of time spent in matching behavior states was less for the depressed than for the nondepressed dyads. Cross-spectral analyses of the mothers' and the infants' behavior-state time series suggested only a trend for greater coherence or synchrony in the interactions of the nondepressed dyads. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
96.
Foreword.     
Two years ago, the editors reasoned that the diverse and fundamental character of religious experience would promote an equally varied special issue devoted to the topic of psychotherapy and religion. We have not been disappointed. The papers composing this issue vary greatly in terms of literary style, research methodology, theoretical persuasion, and religious topics. There remains a need to clarify the extent to which religious issues or material that emerge during therapy need to be dealt with via "new" techniques (involving major modifications of classical techniques and ideologies) or via the classical methodologies, informed, perhaps, by expanded insights and perspectives. This issue is meant to be both current and historically representative. These two goals have not always been in agreement. The day of monolithic theories, presumed to address all matters of religious and psychotherapeutic importance, has passed, but not without leaving trails along which the present studies follow. Contemporary religious pluralism is more closely matched with the varied beliefs and problems of those seeking psychotherapy. This change has entailed a growing refinement in the psychological study of therapy and religious practice; it also implies a more astute and psychologically informed understanding of both the healthy and pathological aspects of religious experience. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
97.
Israel Aircraft Industries has recently been conducting a novel six-month intensive course to retrain practicing engineers to become software engineers working on embedded computer systems. The first course was concluded in January 1982 and the second course began in November 1982. This paper describes the objectives, educational philosophy, course content, and practical experience of the first course. It also describes how the second course was modified as a result of the lessons learned from the successes and failures of the first course.  相似文献   
98.
It is known that under a wide variety of assumptions a database decomposition is lossless if and only if the database scheme has a lossless join. Biskup, Dayal and Bernstein (1979) have shown that when the given dependencies are functional, the database scheme has a lossless join if and only if one of the relation schemes is a key for the universal scheme. In this note we supply an alternative proof of that characterization. The proof uses tools from the theory of embedded join dependencies and the theory of tuple and equality generating dependencies, but is, nevertheless, much simpler than the previously published proof.  相似文献   
99.
The title compounds 2,2-ethano-1-methylene and 1,1-ethano-2-methylene-1,2,3,4-tetrahydronaphthalene ( 13 and 14 respectively) were synthesized by the Wittig reaction from the corresponding ethano-tetralones ( 16 ) and ( 19 ) which were, in turn, prepared from the respective α- and β-tetralones ( 15 ) and ( 18 ). It is shown that the reaction of ( 13 ) with TCNE at 0° yields the corresponding [2 + 2] cycloaddition adduct ( 20 ), isomerizing thermally to the formal [2 + 5] cycloaddition adduct ( 21 ). Compound ( 13 ) reacts with N-tosylisocyanate (TIC) and with N-phenylsulfonylisocyanate (PSI) to a 4:1-isomeric mixture of (Z)- and (E)-acryloamides ( 24 ) and ( 26 ), respectively. The reaction of ( 14 ) with TCNE at 0° leads to the [2 + 5] cycloadduct ( 30 ), while with (TIC) and (PSI) the corresponding tricyclic adducts ( 28a ) and ( 28b ) result. Bromination of ( 16 ) with NBS yielded the respective 4-bromo-2,2-ethano-1-tetralone ( 31 ) which gave, upon dehydrobromination with the aid of DBU, the naphtho-dihydrofurane derivative ( 34 ). The latter was formed most likely via facile cyclopropylketone upon dihydrofurane rearrangement of an initially formed 2,2-ethano-1-oxo-1,2-dihydronaphthalene ( 32 ) which was desired for the formation of ( 33 ). Structures of all new compounds were assigned on basis of analytical and spectroscopic data (IR, UV, mass spectra, 1H-NMR).  相似文献   
100.
Telecommunication Systems - We are on the entry of the exponential advancement of the internet-of-things (IoT) due to the quick development of internet-connected smart-objects. As the number of...  相似文献   
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