A practical solid-phase synthesis of deoxynucleic guanidine (DNG), a positively charged DNA backbone analogue, is reported. The nucleoside coupling step in the solid-phase synthesis of DNG involves the attack of a terminal 3′-amine upon an electronically activated 5′-carbodiimide to create a protected guanidinium internucleoside linkage. The activated carbodiimide is synthesized in situ by the ...

Abstract In this study, a solid phase extraction method was successfully applied in the preconcentration and determination of trace levels Cu(II) Cd(II) ions Phanerochaete chrysosporium (white rot fungus) modified bentonite used as adsorbent. After biosorption ions, metal concentrations samples were determined by atomic absorption spectrophotometry. pH, adsorbent amount, eluent type, sample vol...

nano-cus powders were synthesized with chemical solution method. xrd and sem and spectrophotometry were used for characterization of the cus powders. xrd analysis indicated that tetragonal cus was the main phase with particle size of 16.2nm and little cu2s phase was present. scanning electron microscopy (sem) analysis revealed that powder was plate like and had very little aspect ratio in morph...

An analytical method was developed for enantiomeric determination of amphetamine and methamphetamine in human urine. The enantiomers were isolated from urine by solid-phase extraction, and diastereomers were formed by derivatization with the chiral Marfey's reagent (1-fluoro-2,4-dinitrophenyl-5-l-aniline amide). The diastereomers were separated by reversed-phase high-performance liquid chromato...

The present work involves numerical simulation of a steady, incompressible forcedconvection fluid flow through a matrix of porous media between two parallel plates at constanttemperature. A Darcy model for the momentum equation was employed. The mathematical model forenergy transport was based on single phase equation model which assumes local thermal equilibriumbetween fluid and solid phases. ...