23,815 research outputs found

    On the Toda Lattice Equation with Self-Consistent Sources

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    The Toda lattice hierarchy with self-consistent sources and their Lax representation are derived. We construct a forward Darboux transformation (FDT) with arbitrary functions of time and a generalized forward Darboux transformation (GFDT) for Toda lattice with self-consistent sources (TLSCS), which can serve as a non-auto-Backlund transformation between TLSCS with different degrees of sources. With the help of such DT, we can construct many type of solutions to TLSCS, such as rational solution, solitons, positons, negetons, and soliton-positons, soliton-negatons, positon-negatons etc., and study properties and interactions of these solutions.Comment: 20 page

    The Degasperis-Procesi equation with self-consistent sources

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    The Degasperis-Procesi equation with self-consistent sources(DPESCS) is derived. The Lax representation and the conservation laws for DPESCS are constructed. The peakon solution of DPESCS is obtained.Comment: 15 page

    In vivo effect of FK506 on human pancreatic islets

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    The purpose of this study was to evaluate the in vivo effect of FK506 on human pancreatic islets. Twenty-five nude mice were made diabetic by one intravenous injection of streptozotocin. Approximately 600 islets were administered in the renal subcapsular space 3-5 days following streptozotocin administration. One week after transplantation, the mice were divided in four groups. In group 1, the animals received 1 injection of 0.5 ml of diluent i.p. daily for one week. In groups 2, 3, and 4 the treatments were daily i.p. injection of 0.3, 1, and 3 mg/kg FK506, respectively. After treatment, the functional integrity of the transplanted human islets was tested by measuring the plasma glucose and human C-peptide response to intraperitoneal glucose injection in groups 1 and 4. IPGTT alone was assessed in groups 2 and 3. The results indicate that i.p. administration of FK506 for one week at a dose 0.3 mg/kg/day did not result in any significant alteration of glucose disappearance and C-peptide response to IPGTT. Higher doses of FK506 produced a significant delay in glucose disappearance in groups 3 and 4, and a significant inhibition of glucose-mediated C-peptide response in group 4. © 1991 by Williams and Wilkins

    Day-ahead Scheduling of Integrated Energy System Coupled with Liquid Air Energy Storage System

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    This paper implements scheduling optimization on an integrated energy system to utilize waste heat recovered from steel mills. The system includes liquid air energy storage system (LAES), thermal energy storage system (TES), photovoltaic (PV) power generation and thermal and electrical loads. Liquid air energy storage is used to act as electrical energy storage, and waste heat is utilized in the form of superheating the air entering the turbine to increase the round-trip efficiency of the liquid air energy storage system. Through the constructed Mixed-Integer Linear Programming (MILP) model to forecast the day-ahead scheduling scheme of the system components, scheduling results of 4 cases with different power demand are solved to discuss the impact on system cost with and without liquid air energy storage. The results show the utilization of LAES has a positive effect on reducing system costs However, the limitation of LAES' maximum output power and the constraint of thermal balance make the effect of LAES on reducing the total cost of the system limited

    In vitro Anti-Gastric Tumor Activities and Possible Mechanisms of Action of Paederosidic Acid from Paederia scandens (Lour) Merrill

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    Purpose: To evaluate the anti-tumor activity and explore the possible mechanisms of action of paederosidic acid isolated from Paederia scandens (Lour.) Merrill.Methods: Paederosidic acid (PA) was isolated from P. scandens and identified by spectroscopic methods. The cytotoxic effects of PA in gastric cancer cell lines (MGC-803, BGC-823, and SGC-7901 cells) were assayed using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT). Apoptosis of PA in SGC-7901 cells was evaluated by DAPI staining. To investigate the possible mechanisms of apoptosis, the effect of PA on C-caspase-3, C-caspase-9, Bcl-2 and Bax expressions in SGC-7901 cells were assayed by Western blot analysis.Results: PA exerted significant inhibitory effects on MGC-803, BGC-823, and SGC-7901 cells with 50 % inhibitory concentration (IC50) values of 42.2, 43.7, and 30.5 μM, respectively, and in a concentration-dependent manner. Subsequently, SGC-7901 cells were selected for further studies. After treatment with PA, obvious condensation of the nucleus was observed in fluorescence photomicrographs, which is a  characteristic of apoptosis. In addition, caspase-3, caspase-9 proteins and Bax were significantly  up-regulated (p < 0.05), whereas Bcl-2 was significantly down-regulated (p < 0.05) by PA in a concentration-dependent  manner.Conclusion: PA has significant anti-tumor activity on SGC-7901 cells in vitro, and the possible mechanism of action may be related to PA-induced apoptosis via mitochondria-mediated apoptosis pathway.Keywords: Paederosidic acid, Paederia scandens, Anti-tumor activity, Apoptosis, Gastric cance

    The Solutions of the NLS Equations with Self-Consistent Sources

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    We construct the generalized Darboux transformation with arbitrary functions in time tt for the AKNS equation with self-consistent sources (AKNSESCS) which, in contrast with the Darboux transformation for the AKNS equation, provides a non-auto-B\"{a}cklund transformation between two AKNSESCSs with different degrees of sources. The formula for N-times repeated generalized Darboux transformation is proposed. By reduction the generalized Darboux transformation with arbitrary functions in time tt for the Nonlinear Schr\"{o}dinger equation with self-consistent sources (NLSESCS) is obtained and enables us to find the dark soliton, bright soliton and positon solutions for NLS+^{+}ESCS and NLS^{-}ESCS. The properties of these solution are analyzed.Comment: 24 pages, 3 figures, to appear in Journal of Physics A: Mathematical and Genera
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