Positive solutions for a system of difference equations with coupled multi-point boundary conditions

We investigate the existence and nonexistence of positive solutions for a system of nonlinear second-order difference equations with parameters subject to coupled multi-point boundary conditions.     

Positive solutions for systems of nonlinear second‐order multipoint boundary value problems

We study the existence of positive solutions for systems of second‐order nonlinear ordinary differential equations, subject to multipoint boundary conditions. Copyright © 2013 John Wiley & Sons, Ltd.     

Synthesis and <Emphasis Type="Italic">in vitro</Emphasis> evaluation of new diphenyl ether derivatives as serotonin transporter ligands

For the development of new ligands as potential imaging agents for the serotonin transporter (SERT), a series of diphenyl ether derivatives have been synthesized, characterized, and evaluated for their in vitro binding affinities to the SERT. Among the above compounds, 2-(2-((dimethylamino)methyl)-4-fluorophenoxy)-5-bromobenzenamine (15) and 2-(2-((dimethylamino)methyl)-4-fluorophenoxy)-5-iodobenzene amine (16) show high binding affinities for the SERT with K _i values of 0.28 and 0.20 nmol·L⁻¹, respectively. They can be further labeled with carbon-11, fluorine-18, iodine-123 or bromine-76, and evaluated as useful imaging agents for the SERT. Moreover, the study of the structure-activity relationship (SAR) provides some useful information for the future design of new ligands. Supported by the National Natural Science Foundation of China (Grant No. 20471011)     

Bioactivities and chemical constituents of a Vietnamese medicinal plant Che Vang, Jasminum subtriplinerve Blume (Oleaceae)

Five crude extracts were made from leaves and stems of Jasminum subtriplinerve Blume (Oleaceae) and investigated for antimicrobial, antioxidant and cytotoxic activities. The extractions were done with petroleum ether, ethyl acetate, ethanol, methanol or water. All extracts exhibited anti-bacterial activity except the water fraction. On the other hand, all extracts exhibit antioxidant activity except the petroleum ether fraction using the DPPH radical scavenging assay. Only the petroleum ether fraction showed a cytotoxicity activity against tested cell-lines, Hep-G2 and RD with IC(50) values of 19.2 and 20 microg mL(-1), respectively. From the petroleum ether and ethyl acetate extracts, two triterpenes namely 3beta-acetyl-oleanolic acid and lup-20-en-3beta-ol and a sterol, stigmast-5-en-3beta-ol were isolated. The structure of those compounds were elucidated by spectrometric methods IR, MS, 1D-NMR, 2D-NMR and simulated ACD/NMR spectra. The data presented here indicate that J. subtriplinerve do contain compounds with interesting biological activity.     

Variational approaches to p-Laplacian discrete problems of Kirchhoff-type

Critical point results for Kirchhoff-type discrete boundary value problems are exploited in order to prove that a suitable class possesses at least one solution under an asymptotical behaviour of the potential of the nonlinear term at zero, and also possesses infinitely many solutions under some hypotheses on the behaviour of the potential of the nonlinear term at infinity. Some recent results are extended and improved. Some examples are presented to demonstrate the applications of our main results.