Synthesis, structural, spectroscopic, and electrochemical characterization of high oxidation state diruthenium complexes containing four identical unsymmetrical bridging ligands

Six Ru2(6+) derivatives of the form Ru2(L)4(C[triple bond]CC6H5)(2), where L = 2-Fap, 2,3-F(2)ap, 2,4-F(2)ap, 2,5-F(2)ap, 3,4-F(2)ap, or 2,4,6-F(3)ap, are synthesized and characterized as to their electrochemical, spectroscopic, and/or structural properties. These compounds are synthesized from a reaction between LiC[triple bond]CC6H5 and Ru2(L)4Cl. Two of the investigated complexes exist in a (4,0) isomeric form while four adopt a (3,1) geometric conformation. These two series of geometric isomers are compared with previously characterized (4,0) Ru2(ap)4(C[triple bond]CC6H5)(2), (4,0) Ru2(F5ap)4(C[triple bond]CC6H5)(2), and (3,1) Ru2(F5ap)4(C[triple bond]CC6H5)(2). The overall data on the nine compounds thus provide an opportunity to systematically examine how the electrochemical and structural properties of these Ru2(6+) complexes vary with respect to isomer type and electronic properties of the bridging ligands.     

Simultaneous and ultrasensitive detection of multiple microRNAs by single-molecule fluorescence imaging

Cell status changes are typically accompanied by the simultaneous changes of multiple microRNA (miRNA) levels. Thus, simultaneous and ultrasensitive detection of multiple miRNA biomarkers shows great promise in early cancer diagnosis. Herein, a facile single-molecule fluorescence imaging assay was proposed for the simultaneous and ultrasensitive detection of multiple miRNAs using only one capture anti-DNA/RNA antibody (S9.6 antibody). Two complementary DNAs (cDNAs) designed to hybridize with miRNA-21 and miRNA-122 were labelled with Cy3 (cDNA1) and Cy5 (cDNA2) dyes at their 5′-ends, respectively. After hybridization, both miRNA-21/cDNA1 and miRNA-122/cDNA2 complexes were captured by S9.6 antibodies pre-modified on a coverslip surface. Subsequently, the Cy3 and Cy5 dyes on the coverslip surface were imaged by the single-molecule fluorescence setup. The amount of miRNA-21 and miRNA-122 was quantified by counting the image spots from the Cy3 and Cy5 dye molecules in the green and red channels, respectively. The proposed assay displayed high specificity and sensitivity for singlet miRNA detection both with a detection limit of 5 fM and for multiple miRNA detection both with a detection limit of 20 fM. Moreover, it was also demonstrated that the assay could be used to detect multiple miRNAs simultaneously in human hepatocellular cancer cells (HepG2 cells). The proposed assay provides a novel biosensing platform for the ultrasensitive and simple detection of multiple miRNA expressions and shows great prospects for early cancer diagnosis.

A single-molecule assay for multiple microRNA detection.     

Gastrointestinal motility enhancing effect of ginger and its active constituents

The effect of ginger root (Zingiberis Rhizoma) on gastrointestinal motility was examined based on its ability to enhance charcoal meal transport in mice. Oral administrations of the acetone extract of ginger (which contains volatile oils and bitter substances) at 75 mg/kg, [6]-shogaol at 2.5 mg/kg, or a [6]-, [8]- or [10]-gingerol at 5 mg/kg enhanced the transport of a charcoal meal. The effects of these substances were similar to or slightly weaker than those of metoclopramide and donperidone.     

STRUCTURE CHARACTERIZATION AND CATALYTICACTIVITY TEST OF Ni(II) COMPLEXES CONTAINING2-(DIPHENYLPHOSPHINOAMINO) PYRIDINE(PAP)

IntroductionIn1962,N.V.Kutepow'SgroupfirstusedcomplexesofFe,CoandNiascatalyststocatalyzecarboXylationofethanoltopreparepropanoicacidanditsderivants.Thereactionpressurewashighandtheyieldwaslow.LateronPaulalsandhiscolleagueusedabC13andiodineascatalyst,which…     

核糖核酸酶A在DAB-环乙烷溶液中的活性和构象

The activity and conformation of ribonuclerse A (RNaseA) solubilized in cyclohexane via dodecylammonium butyrate(DAB) reverse micelles were investigated. The activity of RNaseA was studied using the cytidine 2’,3’ -phosphate as the substrate, and it was found that kcat increases significantly with respect to that in water attended by an increased Km•FT-IR spectra of RNaseA in reverse micellar solution were investigated as a function of w0(= [H2O]/ [DAB]), and it was noted that the structure of RNaseA became losser in reverse micelles campared to that in aqueous solution. The relation between activity and conformation was discussed.     

Separation of Dyes from Aqueous Solutions by Paper Adsorption

Separation of the dyes methyl violet, methylene blue, and congo red from aqueous solutions by paper capillary permeation adsorption method was studied using paper. Nearly 100% of the investigated dyes could be separated under the optimum conditions. The effect of pH on the separation efficiency was studied in particular. At pH 5–9, 1.3–11, and 7–11, the maximum separation was achieved for methyl violet, methylene blue and congo red, respectively. The effects of dye concentration and some foreign ions on the separatability were examined. Moreover, the selective separation of some dyes was attempted by elution with chemical reagents.     

Reversed stereoselectivity in iodohydroxylation of allenyl sulfides. An efficient synthesis of (Z)-3-organosulfur-2-iodo-2-propenols

[reaction: see text] It is observed that the iodohydroxylation of 1,2-allenyl sulfides with I(2) and water in aqueous acetone showed Z-selectivity, which is opposite to that of the iodohydroxylation of 1,2-allenyl sulfoxides.     

Heterolytic cleavage of a beta-phosphatoxyalkyl radical resulting in phosphate migration or radical cation formation as a function of solvent polarity

[formula: see text] The 2-(diethylphosphatoxy)-2-(p-methoxyphenyl)-1,1-dimethylethyl radical (1) reacted to give the benzylic radical product from phosphate migration or a radical cation (or a mixture of the two) as a function of solvent. Smooth acceleration in rates of reactions of 1 in solvents of increasing polarity and consistent entropies of activation indicate that radical 1 reacts by common mechanism irrespective of the final products formed, specifically by initial heterolysis to a radical cation-phosphate anion pair.     

Kinetics of zinc and cadmium dissociation of metallothionein in the presence of chelating agents

The dissociation kinetics of metal ions from native metallothionein (Cd₅Zn₂-MT) of rat liver has been studied in the presence of external ligands including amino acids, peptide and polyamino polycarboxylic acids at 25°C. The study shows that the solution pH affects the metal dissociation process. Different ligands present different multiphasic kinetics. The possible mechanism of metal dissociation from metallothionein has been proposed.