| 1. |
- Jung, Min-Sook, et al.
(författare)
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Bioavailability of indomethacin-saccharin cocrystals
- 2010
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Ingår i: Journal of Pharmacy and Pharmacology (JPP). - : Oxford University Press (OUP). - 0022-3573 .- 2042-7158. ; 62:11, s. 1560-1568
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Tidskriftsartikel (refereegranskat)abstract
- Pharmaceutical cocrystals are new solid forms with physicochemical properties that appear promising for drug product development. However, the in-vivo bioavailability of cocrystals has rarely been addressed. The cocrystal of indomethacin (IND), a Biopharmaceutical Classification System class II drug, with saccharin (SAC) has been shown to have higher solubility than IND at all pH. In this study, we aimed to evaluate the in-vitro dissolution and in-vivo bioavailability of IND-SAC cocrystals in comparison with IND in a physical mixture and the marketed product Indomee (R).MethodsScale-up of the cocrystals was undertaken using cooling batch crystallisation without seeding. The chemical and physical purity of the up-scaled material was verified using high-performance liquid chromatography, differential scanning calorimetry and powder X-ray diffraction. The IND-SAC cocrystals and IND plus SAC were mixed with lactose and the formulations were placed into gelatin capsules. In-vitro dissolution studies were then performed using the rotating basket dissolution method. The intrinsic dissolution rate of IND and IND-SAC cocrystals was also determined. Finally, a bioavailability study for the formulations was conducted in beagle dogs. The plasma samples were analysed using high-performance liquid chromatography and the pharmacokinetic data were analysed using standard methodologies.Key findingsThe bulk cocrystals (i.e. scaled-up material) were chemically and physically pure. The in-vitro dissolution rate of the cocrystals was higher than that of IND and similar to that of Indomee (R) at pH 7.4 and pH 1.2. The in-vivo bioavailability of the IND-SAC cocrystals in dogs was significantly higher (ANOVA, P < 0.05) than that of IND but not significantly different from Indomee (R) (ANOVA, P > 0.05).ConclusionsThe study indicates that the improved aqueous solubility of the cocrystals leads to improved bioavailability of IND. Thus, the cocrystals are a viable alternative solid form that can improve the dissolution rate and bioavailability of poorly soluble drugs.
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| 2. |
- Kim, Sung-Soo, et al.
(författare)
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Particle Swarm Optimization For Location Mobility Management
- 2012
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Ingår i: International Journal of Innovative Computing Information and Control. - : ICIC INTERNATIONAL. - 1349-4198 .- 1349-418X. ; 8:12, s. 8387-8398
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Tidskriftsartikel (refereegranskat)abstract
- In the generic mobile location problem for locating mobile terminals in a network, assignment of cells to either "reporting" or "non-reporting" cells is an NP-complete problem with known exponential complexity, also known as the reporting cell planning (RCP). The number of reporting cells as well as their locations must be carefully determined to balance the registration (location update) and search (paging) operations to minimize the cost of RCP. In this paper, we propose binary particle swarm optimization (BPSO) for optimal design of RCP. Our extensive set of experimental simulations demonstrates the effectiveness of BPSO; BPSO also proved to be a competitive approach in terms of quality of solution for the optimal design of several benchmark problems. Results also provide invaluable insights into the nature of this classical formidable problem and its effective solutions.
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| 3. |
- Bengtsson, Anders, et al.
(författare)
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Counterterms in Gravity in the Light-Front Formulation and a D=2 Conformal-like Summetry in Gravity
- 2013
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Ingår i: Journal of High Energy Physics (JHEP). - 1126-6708 .- 1029-8479. ; 2013:3
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- In this paper we discuss gravity in the light-front formulation (light-cone gauge) and show how possible counterterms arise. We find that Poincare invariance is not enough to find the three-point counterterms uniquely. Higher-spin fields can intrude and mimic three-point higher derivative gravity terms. To select the correct term we have to use the remaining reparametrization invariance that exists after the gauge choice. We finally sketch how the corresponding programme for N=8 Supergravity should work.
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| 4. |
- Kim, Sung-Soo, et al.
(författare)
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Extremal solutions of the S3 model and nilpotent orbits of G2(2)
- 2010
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Ingår i: Journal of High Energy Physics (JHEP). - : Springer. - 1126-6708 .- 1029-8479. ; :8
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Tidskriftsartikel (refereegranskat)abstract
- We study extremal black hole solutions of the S-3 model (obtained by setting S-T-U in the STU model) using group theoretical methods. Upon dimensional reduction over time, the S 3 model exhibits the pseudo-Riemannian coset structure G/(K) over tilde with G = G(2(2)) and (K) over tilde = SO0(2; 2). We study nilpotent (K) over tilde -orbits of G(2(2)) corresponding to non-rotating single-center extremal solutions. We find six such distinct (K) over tilde -orbits. Three of these orbits are supersymmetric, one is non-supersymmetric, and two are unphysical. We write general solutions and discuss examples in all four physical orbits. We show that all solutions in supersymmetric orbits when uplifted to five-dimensional minimal supergravity have single-center Gibbons-Hawking space as their four-dimensional Euclidean hyper-Kahler base space. We construct hitherto unknown extremal (supersymmetric as well as non-supersymmetric) pressureless black strings of minimal five-dimensional supergravity and briefly discuss their relation to black rings.
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| 5. |
- Kim, Sung-Soo, et al.
(författare)
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N=5 three-algebras and 5-graded Lie superalgebras
- 2011
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Ingår i: Journal of Mathematical Physics. - : American Institute of Physics (AIP). - 0022-2488 .- 1089-7658. ; 52:8
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Tidskriftsartikel (refereegranskat)abstract
- We discuss a generalization of N = 6 three-algebras to N = 5 three-algebras in connection to anti-Lie triple systems and basic Lie superalgebras of type II. We then show that the structure constants defined in anti-Lie triple systems agree with those of N = 5 superconformal theories in three dimensions.
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| 6. |
- Kim, Sung-Soo, et al.
(författare)
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Swarm Intelligent Approaches for Location Area Planning
- 2014
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Ingår i: Journal of Multiple-Valued Logic and Soft Computing. - : Old City Publishing. - 1542-3980 .- 1542-3999. ; 22:3, s. 287-306
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Tidskriftsartikel (refereegranskat)abstract
- Location Area Planning (LAP) problem is to partition the cellular mobile network into location areas. It is very important to determine which one cellular network the users are. One strategy used in location management is to partition the network into location areas, in such a way that the handoff and paging costs will be minimized. Finding the optimal number of location areas and the corresponding configuration of the partitioned network is a difficult combinatorial optimization problem. We make an attempt to solve the problem by the swarm intelligent algorithms, i.e. Artificial Bee Colony (ABC) and Particle Swarm Optimization (PSO). They help us to obtain the optimal number of location areas and the corresponding configuration of the partitioned network. We also illustrate our approaches using the small, medium, and large size benchmark problems.
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