Extended Peptide Nucleic Acid Nucleobases Based on Isoorotic Acid for the Recognition of A–U Base Pairs in Double-Stranded RNA

Peptide nucleic acids (PNA) with extended isoorotamide containing nucleobases ( I _o ) were designed for binding A–U base pairs in double-stranded RNA. Isothermal titration calorimetry and UV thermal melting experiments revealed improved affinity for A–U using the Io scaffold in PNA. PNAs having four sequential Io extended nucleobases maintained high binding affinity.     

Conducting moisture sensitive reactions under mechanochemical conditions

Dry organic solvents are used for various organic reactions that employ moisture sensitive reagents. The processes to dry these solvents are hazardous and costly. Setting up reactions in an open atmosphere while using moisture sensitive reagents has little to no effect on the rate or yield of the reaction under mechanochemical conditions. We believe this is partly due to the gaseous nature of the water vapor in the air compared to the dissolved water and oxygen in solution.     

Green synthesis of palladium nanoparticles using broth of Cinnamomum camphora leaf

The development of dependable, environmentally benign processes for the synthesis of nanoscale materials is an important aspect of nanotechnology. In the present study, we report one-pot biogenic fabrication of palladium nanoparticles by a simple procedure using broth of Cinnamomum camphora leaf without extra surfactant, capping agent, and/or template. The mean size of palladium nanoparticles, ranging from 3.2 to 6.0 nm, could be facilely controlled by merely varying the initial concentration of the palladium ions. The polyols components and the heterocyclic components were believed to be responsible for the reduction of palladium ions and the stabilization of palladium nanoparticles, respectively.     

Siacci’s resolution of the acceleration vector for a space curve

For motion of a material point along a space curve, a kinematical decomposition, discovered by Siacci, expresses the acceleration vector as the sum of two special oblique components in the osculating plane to the curve. A new proof of Siacci’s theorem is presented.     

Foreword

Foundations of Computational Mathematics -     

THE PREPARATION OF SULPHIDES AND POLYSULPHIDES FROM β-KETO-ESTERS AND 1,3-DIKETONES

Abstract

We have found that the treatment of certain β-keto-esters or 1,3-diketones with thionyl chloride gives either a sulphide or a sulphinyl chloride together with the chloro-compound depending on the structure of the active methylene compound. In certain cases cyclisation of sulphide provides a useful route to a 1,4-oxathiin.