Analysis of variable coefficient advection-diffusion problems via complex variable reproducing kernel particle method

The complex variable reproducing kernel particle method （CVRKPM） of solving two-dimensional variable coefficient advection-diffusion problems is presented in this paper. The advantage of the CVRKPM is that the shape function of a two-dimensional problem is formed with a one-dimensional basis function. The Galerkin weak form is employed to obtain the discretized system equation, and the penalty method is used to apply the essential boundary conditions. Then the corresponding formulae of the CVRKPM for two-dimensional variable coefficient advection-diffusion problems are obtained. Two numerical examples are given to show that the method in this paper has greater accuracy and computational efficiency than the conventional meshless method such as reproducing the kernel particle method （RKPM） and the element- free Galerkin （EFG） method.     

Synthesis, characterization and catalytic activity of magnesium and zinc aminophenoxide complexes: catalysts for ring-opening polymerization of L-lactide

A series of novel magnesium and zinc aminophenoxide complexes were successfully synthesized and one zinc complex was characterized by X-ray crystallography. They were also investigated as initiators for the ring opening polymerization of L-lactide. The complexes are effective in forming polylactides with good conversions. The nature and steric bulk of the ligands coordinated to the central metal ions enormously influenced the polymer properties. Among all the complexes, the zinc aminophenoxide complexes as initiators produced polymers with good molecular weight control and relatively narrow PDIs.     

Modeling the effects of social impact on epidemic spreading in complex networks

We investigate by mean-field analysis and extensive simulations the effects of social impact on epidemic spreading in various typical networks with two types of nodes: active nodes and passive nodes, of which the behavior patterns are modeled according to the social impact theory. In this study, nodes are not only the media to spread the virus, but also disseminate their opinions on the virus—whether there is a need for certain self-protection measures to be taken to reduce the risk of being infected. Our results indicate that the interaction between epidemic spreading and opinion dynamics can have significant influences on the spreading of infectious diseases and related applications, such as the implementation of prevention and control measures against the infectious diseases.     

Phytochemical and cytotoxic investigations of Alpinia mutica rhizomes

The methanol and fractionated extracts (hexane, ethyl acetate and water) of Alpinia mutica (Zingiberaceae) rhizomes were investigated for their cytotoxic effect against six human carcinoma cell lines, namely KB, MCF7, A549, Caski, HCT116, HT29 and non-human fibroblast cell line (MRC 5) using an in vitro cytotoxicity assay. The ethyl acetate extract possessed high inhibitory effect against KB, MCF7 and Caski cells (IC?? values of 9.4, 19.7 and 19.8 μg/mL, respectively). Flavokawin B (1), 5,6-dehydrokawain (2), pinostrobin chalcone (3) and alpinetin (4), isolated from the active ethyl acetate extract were also evaluated for their cytotoxic activity. Of these, pinostrobin chalcone (3) and alpinetin (4) were isolated from this plant for the first time. Pinostrobin chalcone (3) displayed very remarkable cytotoxic activity against the tested human cancer cells, such as KB, MCF7 and Caski cells (IC?? values of 6.2, 7.3 and 7.7 μg/mL, respectively). This is the first report of the cytotoxic activity of Alpinia mutica.     

Electrokinetically-controlled RNA-DNA hybridization assay for foodborne pathogens

Chitosan microspheres were prepared by an emulsion crosslinking method using glutaraldehyde as the cross-linker. Two auxins were dissolved in ethyl benzoate and encapsulated into the microspheres. The best encapsulation efficiency for naphthalene-1-acetic acid and indole-3-acetic acid, respectively, are 68% and 56% and depends on the selection of the appropriate extent of crosslinker, crosslinking time, and the ratio of the oil/water phase. The microspheres were characterized by FTIR spectroscopy. Differential scanning calorimetry was applied to study the thermal stabilities, and scanning electron microscopy to investigate the morphology of the loaded microspheres. In-vitro release studies performed in buffered aqueous methanol at pH 7.4 indicated that the cumulative release rate of the auxins from the particles reaches a maximum (60%) after about 120?h. The release rate in water is higher than the one in methanol. Based on data for the correlation coefficient it is concluded that the drug release is controlled by a diffusion mechanism that follows a super Case-II transport scheme.

Sunlight induced cycloaddition and host-guest property of self-assembled organometallic macrocycles based on a versatile building block

Organometallic rectangle 1 which undergoes [2+2] cycloaddition upon irradiation with sunlight and organometallic prism 3 which displayed interesting host-guest property were self-assembled based on a versatile building block.     

SnSe2 quantum dot sensitized solar cells prepared employing molecular metal chalcogenide as precursors

A kind of molecular metal chalcogenide, (N(2)H(4))(3)(N(2)H(5))(4)Sn(2)Se(6) complex, was synthesized in the hydrazine solution and employed as the precursors for SnSe(2) deposition on TiO(2) nanocrystalline porous films. A power conversion efficiency of 0.12% under AM 1.5, 1 sun was obtained for the SnSe(2) sensitized TiO(2) solar cells.     

Butylated hydroxytoluene analogs: synthesis and evaluation of their multipotent antioxidant activities

A computer-aided predictions of antioxidant activities were performed with the Prediction Activity Spectra of Substances (PASS) program. Antioxidant activity of compounds 1, 3, 4 and 5 were studied using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and lipid peroxidation assays to verify the predictions obtained by the PASS program. Compounds 3 and 5 showed more inhibition of DPPH stable free radical at 10?? M than the well-known standard antioxidant, butylated hydroxytoluene (BHT). Compound 5 exhibited promising in vitro inhibition of Fe2?-induced lipid peroxidation of the essential egg yolk as a lipid-rich medium (83.99%, IC?? 16.07 ± 3.51 μM/mL) compared to α-tocopherol (α-TOH, 84.6%, IC?? 5.6 ± 1.09 μM/mL). The parameters for drug-likeness of these BHT analogues were also evaluated according to the Lipinski’s “rule-of-five” (RO5). All the BHT analogues were found to violate one of the Lipinski’s parameters (LogP > 5), even though they have been found to be soluble in protic solvents. The predictive polar surface area (PSA) and absorption percent (% ABS) data allow us to conclude that they could have a good capacity for penetrating cell membranes. Therefore, one can propose these new multipotent antioxidants (MPAOs) as potential antioxidants for tackling oxidative stress and lipid peroxidation processes.     

Rational Design of a Palladium-Catalyzed C(sp) -C(sp) Cross-Coupling Reaction Inspired by Kinetic Studies

Less is More: A highly selective Pd-catalyzed C(sp) -C(sp) cross-coupling reaction between terminal alkynes and 1-bromoacetylenes has been developed. Catalyst loading is low (only 0.0001-0.01?mol?% of Pd is required) and provides products with high selectivities and good to excellent yields under mild conditions. TBAB=tetrabutylammonium bromide, TON=turnover number.     

An integrated chip for immunofluorescence and its application to analyze lysosomal storage disorders

Immunofluorescence (IF) is a common method to observe protein distribution and localization at the single-cell level through wide-field fluorescence or confocal microscopy. Conventional protocol for IF staining of cells typically requires a large amount of reagents, especially antibodies, and noticeable investment in both labor and time. Microfluidic technologies provide a cost-effective alternative: it can evaluate and optimize experimental conditions, and perform automatic and high-throughput IF staining on-chip. We employed this method to analyze lysosomal storage disorders (LSDs) based on the expression and morphological distribution of LAMP1 and LC3 in starving cells. With pneumatic valves integrated on-chip, the parallel staining process can be completed within a few hours. The total consumption of each antibody solution for the whole experiment is merely 0.3 μL. This device provides a promising tool for automated high-throughput molecular imaging at cell level that can be applied for diagnostic analysis.