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Curcumin,a dietary polyphenol, is a natural spice with preventiveand therapeutic potential for neurodegenerative diseases such as Alzheimer’sand Parkinson’s diseases. Curcumin possesses a spectrum ofantioxidant, anti-inflammatory, anticarcinogenic, and antimutagenicproperties. Because of this broad spectrum of pharmacological activity,it has been suggested that, like cholesterol, curcumin exerts itseffect on a rather basic biological level, such as on lipid bilayersof biomembranes. The effect of curcumin on translational mobilityof lipids in biomembranes has not yet been studied. In this work,we used 1H NMR diffusometry to explore lateral diffusionin planar-oriented bilayers of dimyristoylphosphatidylcholine (DMPC)and dioleoylphosphatidylcholine (DOPC) at curcumin concentrationsof up to 40 mol % and in the temperature range of 298–333 K.The presence of curcumin at much lower concentrations (∼7 mol%) leads to a decrease in the lateral diffusion coefficient of DOPCby a factor of 1.3 at lower temperatures and by a factor of 1.14 athigher temperatures. For DMPC, the diffusion coefficient decreasesby a factor of 1.5 at lower temperatures and by a factor of 1.2 athigher temperatures. Further increasing the curcumin concentrationhas no effect. Comparison with cholesterol showed that curcumin andcholesterol influence lateral diffusion of lipids differently. Theeffect of curcumin is determined by its solubility in lipid bilayers,which is as low as 10 mol % that is much less than that of cholesteroĺs66 mol %. [ABSTRACT FROM AUTHOR]

Abstract  Application of solid electrolytes as undergate layers accelerates the response of a sensor at room temperature as compared with ordinary hydrogen sensors manufactured on the basis of the metal-insulator-semiconductor (MIS) structures with a palladium gate. The proton-conducting solid electrolytes under study include NAFION, zirconium hydrophosphate, and etherified polyvinyl alcohol (PVA) with heteropolyacids and phenoldisulfonic acid, which can be deposited under the platinum gate. Sensors based on the MIS structures with these solid electrolytes show a high sensitivity toward hydrogen (∼120 mV per concentration decade). The response time τ0.63 of a freshly manufactured sensor with a layer of zirconium hydrophosphate amounts to about 2 min. The maximum mechanical stability, especially at relative humidities in excess of 80% is intrinsic to sensors containing layers of PVA with heteropolyacids. The response time of such sensors is nearly 10 min. [ABSTRACT FROM AUTHOR]

A macroscopic model of the magnetoresistance effect in limited anisotropic semiconductors is built. This model allows us to solve the problem of measurement of physical magnetoresistance components of crystals and films. Based on a unified mathematical model the method is worked out enabling us to measure tensor components of the specific electrical resistance and the relative magnetoresistance of anisotropic semiconductors simultaneously. [ABSTRACT FROM AUTHOR]

We describe theoretically the grounded method of measuring the conductivity of anisotropic layered semiconductor materials. The suggested method implies the use of a four-probe testing device with a linear arrangement of probes. The final expressions for identifying the electrical conductivity are presented in the form of a series of analytic functions. The suggested method is experimentally verified, and practical recommendations of how to apply it are also provided. [ABSTRACT FROM AUTHOR]

Abstract  Separation of iron(III) and palladium(III) in recovery from binary hydrochloric solutions with liquid membranes containing diphenylthiocarbamide in 1,2-dichloroethane was studied under galvanostatic electrodialysis conditions. The effect of the current density, process duration, and compositions of the receiving solution and liquid membrane on the iron(III) recovery rate was examined. [ABSTRACT FROM AUTHOR]

The synthesis of the core motif ofbranched poly(adenosine diphosphateribose) (poly(ADPr)) is described, and structural analysis reassertedthe proposed stereochemistry for branching. For the synthesis, a ribosetrisaccharide was first constructed with only α-O-glycosidic linkages. Finally, the adenine nucleobase was introducedvia a Vorbrüggen-type glycosylation reaction. The orthogonalityof the selected protecting groups was demonstrated, allowing for theconstruction of branched poly(ADPr) oligomers in the near future. [ABSTRACT FROM AUTHOR]

Weused nuclear magnetic resonance (NMR) spectroscopy and dynamiclight scattering (DLS) techniques to study the structural and dynamicproperties of micellar solutions of nonionic surfactants of a homologousseries of oxyethylated isononylphenolsC9H19C6H4O(C2H4O)nH, where n= 6, 8, 9, 10, or 12ina wide range of temperatures, including cloud points. The radii ofthe micelles and aggregates, as well as their compositions at differentconcentrations of surfactant, were determined. Using aqueous phenolsolutions as a model, we studied the process of cloud point extractionwith oxyethylated isononylphenols. [ABSTRACT FROM AUTHOR]

A method to ribosylate adenosine on the 2′ hydroxyl function in an α-selective fashion and in good yield is presented. Protective groups chosen for the acceptor and donor used in this glycosylation not only direct α-selectivity but also allow the construction of a fully orthogonally protected building block for the future assembly of oligo-ADP-ribosylated peptides and proteins. [ABSTRACT FROM AUTHOR]

The conjugation of a ribonucleic acid 16-mer with the cationic amphiphilic peptide penetratin and an anionic hyaluronan tetrasaccharide by means of Cu-free “click” chemistry is reported. The alkyne-functionalized 16-mer was prepared by automated solid-phase synthesis, using a newly developed strained cyclooctyne phosphoramidite in the final coupling. Cycloaddition of the alkyne functionalized RNA to the azide containing biomolecules led to a clean conversion into the corresponding nucleic acid conjugates. [ABSTRACT FROM AUTHOR]

A one-pot procedure for the preparation of phosphoramidates, phosphorothioates, pyrophosphates, phosphodiesters, and phosphofluoridates has been devised using di( p-methoxybenzyl)- N, N-diisopropylphosphoramidite as the common phosphitylating reagent. [ABSTRACT FROM AUTHOR]