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291.
Veronique Nelis Arnout Declerck Lien Vermeir Mathieu Balcaen Koen Dewettinck Paul Van der Meeren 《Magnetic resonance in chemistry : MRC》2019,57(9):707-718
Water-in-oil-in-water (W/O/W) double emulsions are a promising technology for encapsulation applications of water soluble compounds with respect to functional food systems. Yet molecular transport through the oil phase is a well-known problem for liquid oil-based double emulsions. The influence of network crystallization in the oil phase of W/O/W globules was evaluated by NMR and laser light scattering experiments on both a liquid oil-based double emulsion and a solid fat-based double emulsion. Water transport was assessed by low-resolution NMR diffusometry and by an osmotically induced swelling or shrinking experiment, whereas manganese ion permeation was followed by means of T2-relaxometry. The solid fat-based W/O/W globules contained a crystal network with about 80% solid fat. This W/O/W emulsion showed a reduced molecular water exchange and a slower manganese ion influx in the considered time frame, whereas its globule size remained stable under the applied osmotic gradients. The reduced permeability of the oil phase is assumed to be caused by the increased tortuosity of the diffusive path imposed by the crystal network. This solid network also provided mechanical strength to the W/O/W globules to counteract the applied osmotic forces. 相似文献
292.
Tan Phat Nguyen Tien Dung Le Phan Nhat Minh Bui Trong Dat Nguyen Kim Tuyen Pham Thi My Lien Do 《Natural product research》2016,30(21):2389-2395
From the fruit of Pandanus tectorius Parkinson ex Du Roi, one new dihydrofurocoumarin, named pandanusin A (1) and 15 known compounds, including one furanocoumarin (2), two coumarins (3, 4), four lignans (5–8), one neolignan (9), two flavonoids (10, 11), three phenolics (12–14), one monoglyceride (15) and one monosaccharide (16) were isolated by various chromatography methods. Among them, compounds (3–5) were obtained from the Pandanus genus for the first time and compounds (9–14, 16) were reported from this species for the first time. Their structures were elucidated by HR–ESI–MS, NMR 1D and 2D experiments and comparison with previous reported data. The α-glucosidase inhibitory activity of all compounds was measured. The isolated compounds (1–12, 14) showed better α-glucosidase inhibitory activity (IC50 = 42.2, 36.5, 84.7, 73.2, 40.8, 26.7, 76.5, 33.8, 68.1, 14.4, 22.1, 81.5, 43.8 μM, respectively) than the standard drug acarbose (IC50 = 214.5 μM). 相似文献
293.
In this paper, inverse nodal problems for Sturm–Liouville equations with boundary conditions polynomially dependent on the spectral parameter were studied. The authors showed that some uniqueness theorems on the potential function hold by the Weyl function, respectively. 相似文献
294.
For a graph G, let be the maximum number of vertices of G that can be colored whenever each vertex of G is given t permissible colors. Albertson, Grossman, and Haas conjectured that if G is s‐choosable and , then . In this article, we consider the online version of this conjecture. Let be the maximum number of vertices of G that can be colored online whenever each vertex of G is given t permissible colors online. An analog of the above conjecture is the following: if G is online s‐choosable and then . This article generalizes some results concerning partial list coloring to online partial list coloring. We prove that for any positive integers , . As a consequence, if s is a multiple of t, then . We also prove that if G is online s‐choosable and , then and for any , . 相似文献
295.
C. H. Lien 《Journal of Optimization Theory and Applications》2005,126(1):137-156
In this paper, guaranteed-cost observer-based controls for a class of uncertain neutral time-delay systems are considered. The asymptotic stabilization for the uncertain neutral systems is guaranteed with an observer-based feedback control. The linear matrix inequality (LMI) approach is used to design the observer-based feedback control system. Two classes of observer-based controls are proposed and their guaranteed costs are given. The control and observer gains are given from the LMI feasible solutions. A convex optimization problem with LMIs is formulated to design the optimal guaranteed-cost observer-based controls which minimize the guaranteed cost of the system considered. A numerical example is given to illustrate the results.The research reported here was supported by the National Science Council of Taiwan, ROC under Grant NSC 93-2213-E-214-020 相似文献
296.
The paper investigates the robust control for uncertain Takagi–Sugeno (T–S) fuzzy systems with time-varying state and input delays. Delay-dependent stabilization criterion is proposed to guarantee the asymptotic stabilization of fuzzy systems with parametric uncertainties. The result of [Lee HJ, Park JB, Joo YH. Robust control for uncertain Takagi–Sugeno fuzzy systems with time-varying input delay. ASME J Dyn Syst Meas Control 2005;127:302–6] is extended to uncertain fuzzy systems with time-varying state and input delays. Simulations show that significant improvement over the previous results can be obtained. 相似文献
297.