The 1:1 dependency between incorporated Na and H in samples doped with only Na suggests that all sodium is coupled to hydrogen in the range of Na-content investigated in this
study. In contrast, crystals doped with Fe and Na contain very different amounts of hydrogen, which is interpreted to be caused by several interacting mechanisms: in one mechanism the hydrous defect is replaced by an anhydrous aegirine compound, in another one the aegirine compound is replaced by the combination of a hydrous Fe-associated defect and an anhydrous Na-associated defect. The Fe-related hydrous defects could also be destroyed by a third mechanism, which allows the incorporation of ferric iron without being coupled to monovalent cations. The band at 3428 cm(-1) can be assigned to a Na-related OH-defect. Bands at 3360 and 3443 cm(-1) showing very similar behaviour Dactolisib may S63845 both be related to M-site vacancies, and the band at 3443 cm(-1) seems to be caused by replacement of two coordinating Mg by a ferric iron and a proton. For the 3651 cm(-1) peak no distinct assignment can be proposed. The results of this study show that different hydrous defects may transform into anhydrous defects, reducing hydrogen solubility in the crystal structure. Thus, water
content in clinopyroxene is not a simple function of the total amount of mono- and trivalent cations. In natural clinopyroxene crystals Selleck CP456773 from upper-mantle peridotites, which are Na- and Fe-bearing, neither the Na-associated band at 3428 cm(-1) nor the Fe-associated band at 3443 cm(-1) is observed. This fact suggests that other mechanisms, e.g. interactions between hydrous defects and other cations, most probably Al, could have influence on OH incorporation in natural clinopyroxenes.”
“After spinal cord injury (SCI), the
disruption of blood-spinal cord barrier by activation of the endothelin (ET) system is a critical event leading to leukocyte infiltration, inflammatory response and oxidative stress, contributing to neurological disability. In the present study, we showed that blockade of ET receptor A (ETAR) and/or ET receptor B (ETBR) prevented early inflammatory responses directly via the inhibition of neutrophil and monocyte diapedesis and inflammatory mediator production following traumatic SCI in mice. Long-term neurological improvement, based on a series of tests of locomotor performance, occurred only in the spinal cord-injured mice following blockade of ETAR and ETBR. We also examined the post-traumatic changes of the micro-environment within the injured spinal cord of mice following blockade of ET receptors. Oxidative stress reflects an imbalance between malondialdehyde and superoxide dismutase in spinal cord-injured mice treated with vehicle, whereas blockade of ETAR and ETBR reversed the oxidation state imbalance.