The relative kinetic stabilities of different 16-mer oligonucleotide duplexes were investigated by source collision-induced dissociation (CID) in a heated capillary electrospray ion source. They were compared with the relative stabilities in solution obtained by thermal denaturation monitored by UV spectrophotometry. The results clearly show that both hydrogen bonding and base stacking interact...

We developed a kinetic assay for calcium in serum and urine, based on the activation of porcine pancreatic alpha-amylase (EC 3.2.1.1) with 2-chloro-4-nitrophenyl-alpha-maltotrioside as substrate. The kinetic generation of 2-chloro-4-nitrophenol, monitored at 405 nm, was proportional to the concentration of calcium in serum and urine. The assay was developed and evaluated with the Cobas Bio cent...

An optoacoustic technique for solutions of strongly light-absorbing analytes at 0.1-0.01 mol l(-1) is proposed. The technique is based on the wide-band forward mode detection of temporal profiles of laser-generated ultrasonic pulses (optoacoustic signals). The leading edge of the signal repeats the distribution of the laser fluence in the medium, which makes it possible to determine its optical...

ARCONS, the Array Camera for Optical to Near-infrared Spectrophotometry, was recently commissioned at the coudé focus of the 200-inch Hale Telescope at the Palomar Observatory. At the heart of this unique instrument is a 1024-pixel Microwave Kinetic Inductance Detector (MKID), exploiting the Kinetic Inductance effect to measure the energy of the incoming photon to better than several percent. T...

On the basis of oxidoreductive rapid kinetic and titration experiments with purified cytochrome c oxidase (EC 1.9.3.1), monitored by electron paramagnetic resonance (EPR) at 13 degrees K and by spectrophotometry at 100 degrees K, a new assignment of EPR signals is proposed. The bulk of both the low-spin (g = 3.0; 2.2; 1.5) and highspin (g = 6; 2) signals is attributed to the component with the ...

Visible spectrophotometry is used to study the kinetic of ligand exchange in the system Cu(salpn)/H2salen with or without triethylamine (NEt3) and H2O in acetonitrile solvent at 25 ± 0.1°C and 0.01 M NaNO3 (H2salen and H2salpn are N,N'-ethylen-bis(salicylaldimine) and N,N'-propylen-bis(salicylaldimine), respectively). It is found that the reaction rate is first-order with respect to Cu(salpn). ...

Kinetic and thermodynamic studies were made on the effect of caffeine on the activity of adenosine deaminase in 50 mM sodium phosphate buffer, pH 7.5, using UV spectrophotometry and isothermal titration calorimetry (ITC). An uncompetitive inhibition was observed for caffeine. A graphical fitting method was used for determination of binding constant and enthalpy of inhibitor binding by using iso...

The kinetics and mechanism of the reaction between benzaldehyde 1, malononitrile 2 and dimedone 3 in a mixture of ethanol and water as solvents in the presence of fructose as a biodegradable catalyst has been studied by the spectroscopic method (UV-Vis spectrophotometry method). The influence of various parameters (temperature, solvent and concentration) was studied on the reaction by means of ...