Radiation-damage investigation of a DNA 16-mer.

In macromolecular crystallography, a great deal of effort has been invested in understanding radiation-damage progression. While the sensitivity of protein crystals has been well characterized, crystals of DNA and of DNA-protein complexes have not thus far been studied as thoroughly. Here, a systematic investigation of radiation damage to a crystal of a DNA 16-mer diffracting to 1.

Calibration of rotation axes for multi-axis goniometers in macromolecular crystallography.

The installation of multi-axis goniometers such as the ESRF/EMBL miniKappa goniometer system has allowed the increased use of sample reorientation in macromolecular crystallography. Old and newly appearing data collection methods require precision and accuracy in crystal reorientation. The proper use of such multi-axis systems has necessitated the development of rapid and easy to perform methods for establishing and evaluating device calibration.

Water-induced changes in the charge-transport dynamics of titanate nanowires.

The temperature dependence of dielectric processes in humid titanate nanowires was investigated via broadband dielectric spectroscopy under quasi-isosteric conditions in the temperature range of 150-350 K. It was found that the dynamic parameters obtained from low-temperature measurements cannot describe the dielectric behavior of the system above 273 K, implying changes in the dynamics of the corresponding dielectric processes. The calculated activation energies and pre-exponential factors counterintuitively increase linearly with the amount of adsorbed water, and a compensation effect was also found to apply to all contributions in the TiONW spectra.

Water types and their relaxation behavior in partially rehydrated CaFe-mixed binary oxide obtained from CaFe-layered double hydroxide in the 155-298 K temperature range.

Heat-treated CaFe-layered double hydroxide samples were equilibrated under conditions of various relative humidities (11%, 43% and 75%). Measurements by FT-IR and dielectric relaxation spectroscopies revealed that partial to full reconstruction of the layered structure took place. Water types taking part in the reconstruction process were identified via dielectric relaxation measurements either at 298 K or on the flash-cooled (to 155 K) samples.

Superoxide dismutase mimicking Cu(II)-mixed amino acid complexes covalently grafted onto silica gel--an FT-IR study.

Our recent work concerning the synthesis, characterisation and testing of bioinspired electron transfer catalysts is described in this contribution. The catalysts were various Cu(II) complexes having mixed C- or N-protected amino acids (L-histidine and L-tyrosine) as ligands covalently grafted onto surface-modified silica gel. The resulting materials were structurally characterised by FT-IR spectroscopy, and their superoxide dismutase activities were tested.