Stress-controlled decomposition routes in cubic AlCrN films assessed by in-situ high-temperature high-energy grazing incidence transmission X-ray diffraction.

The dependence of decomposition routes on intrinsic microstructure and stress in nanocrystalline transition metal nitrides is not yet fully understood. In this contribution, three Al0.7Cr0.3N thin films with residual stress magnitudes of -3510, -4660 and -5930 MPa in the as-deposited state were in-situ characterized in the range of 25-1100 °C using in-situ synchrotron high-temperature high-energy grazing-incidence-transmission X-ray diffraction and temperature evolutions of phases, coefficients of thermal expansion, structural defects, texture as well as residual, thermal and intrinsic stresses were evaluated. The multi-parameter experimental data indicate a complex intrinsic stress and phase changes governed by a microstructure recovery and phase transformations taking place above the deposition temperature. Though the decomposition temperatures of metastable cubic Al0.7Cr0.3N phase in the range of 698-914 °C are inversely proportional to the magnitudes of deposition temperatures, the decomposition process itself starts at the same stress level of ~-4300 MPa in all three films. This phenomenon indicates that the particular compressive stress level functions as an energy threshold at which the diffusion driven formation of hexagonal Al(Cr)N phase is initiated, provided sufficient temperature is applied. In summary, the unique synchrotron experimental setup indicated that residual stresses play a decisive role in the decomposition routes of nanocrystalline transition metal nitrides.

Circadian variation of cytosol glucocorticoid receptors in human polymorphonuclear leukocytes (PMN) and mononuclear cells (MN) in a normal population.

UNLABELLED: Glucocorticoid cytosol and whole cell receptors from human PMN's have been quantified, and compared to those of human MN leukocytes on the same blood sample. The normal cytosol PMN receptor density (N = 15) averaged 1,254 +/- 105 (SE) molecules bound/cell at 0900 h and increased significantly to 1,497 +/- 98 at 2,100 h (P less than 0.02). MN cell cytosol receptor density was 1,198 +/- 145 at 0900 h and increased significantly to 1,551 +/- 117 molecules bound/cell at 2,100 h (P less than 0.01). Corresponding whole cell receptor densities at 0900 h were 2,845 +/- 273 (PMN) and 3,547 +/- 290 (MN) and these did not change significantly at 2,100 h. CONCLUSIONS: Cytosol receptors in normal human PMN and MN cells increased significantly at 2,100 h from the 0900 h level while serum cortisol levels were dropping. Whole cell receptors in the same PMN and MN cell samples did not change significantly between 0900 and 2,100 h. The normal circadian variation in serum cortisol influences the distribution of the glucocorticoid receptor between the cytosol and the nucleus, but does not influence the amount of receptor available to the whole cell. This is the first time that an endogenous physiological variation of cortisol concentration has been utilized to demonstrate a corresponding change in receptor capacity in vivo.

Adrenal Size and function after irradiation with 131I-6 beta-Iodocholesterol in rabbits.

Administration of high doses of 131I-6 beta-iodocholesterol to rabbits is followed by marked size reduction of the adrenal glands with concomitant changes of the histological structure and with a decrease of serum cortisol. Stimulation of 131I-6 beta-iodocholesterol uptake into the adrenals by additional administration of ACTH had only a minor additional effect on adrenal weight. However, with further accumulation of labeled cholesterol in the adrenals the radioactivity was reduced in blood urine, and the ovaries.