Corrosion resistance of monolayer hexagonal boron nitride on copper.

Hexagonal boron nitride (hBN) is a layered material with high thermal and chemical stability ideal for ultrathin corrosion resistant coatings. Here, we report the corrosion resistance of Cu with hBN grown by chemical vapor deposition (CVD). Cyclic voltammetry measurements reveal that hBN layers inhibit Cu corrosion and oxygen reduction. We find that CVD grown hBN reduces the Cu corrosion rate by one order of magnitude compared to bare Cu, suggesting that this ultrathin layer can be employed as an atomically thin corrosion-inhibition coating.

beta-Spectrin São PauloII, a novel frameshift mutation of the beta-spectrin gene associated with hereditary spherocytosis and instability of the mutant mRNA.

Hereditary spherocytosis (HS) is a common inherited anemia characterized by the presence of spherocytic red cells. Defects in several membrane protein genes have been involved in the pathogenesis of HS. beta-Spectrin-related HS seems to be common. We report here a new mutation in the beta-spectrin gene coding region in a patient with hereditary spherocytosis. The patient presented acanthocytosis and spectrin deficiency and, at the DNA level, a novel frameshift mutation leading to HS, i.e., a C deletion at codon 1392 (beta-spectrin São PauloII), exon 20. The mRNA encoding beta-spectrin São PauloII was very unstable and the mutant protein was not detected in the membrane or in other cellular compartments. It is interesting to note that frameshift mutations of the beta-spectrin gene at the 3' end allow the insertion of the mutant protein in the red cell membrane, leading to a defect in the auto-association of the spectrin dimers and consequent elliptocytosis. On the other hand, beta-spectrin São PauloII protein was absent in the red cell membrane, leading to spectrin deficiency, HS and the presence of acanthocytes.

ß-Spectrin Säo PauloII, a novel frameshift mutation of the ß-spectrin gene associated with hereditary spherocytosis and instability of the mutant mRNA

Hereditary spherocytosis (HS) is a common inherited anemia characterized by the presence of spherocytic red cells. Defects in several membrane protein genes have been involved in the pathogenesis of HS. ß-Spectrin-related HS seems to be common. We report here a new mutation in the ß-spectrin gene coding region in a patient with hereditary spherocytosis. The patient presented acanthocytosis and spectrin deficiency and, at the DNA level, a novel frameshift mutation leading to HS, i.e., a C deletion at codon 1392 (ß-spectrin Säo PauloII), exon 20. The mRNA encoding ß-spectrin Säo PauloII was very unstable and the mutant protein was not detected in the membrane or in other cellular compartments. It is interesting to note that frameshift mutations of the ß-spectrin gene at the 3' end allow the insertion of the mutant protein in the red cell membrane, leading to a defect in the auto-association of the spectrin dimers and consequent elliptocytosis. On the other hand, ß-spectrin Säo PauloII protein was absent in the red cell membrane, leading to spectrin deficiency, HS and the presence of acanthocytes

Micropropagation of Melissa officinalis L. through proliferation of axillary shoots.

Multiple shoots were differentiated in cotyledonary nodes of 10 d old seedlings of Melissa officinalis, cultured on MS medium supplemented with BAP (0-4 mg/l). The production of shoots was further induced in subcultures of the original expiant, after the first harvest of shoots (stump), using similar conditions. The highest average number of shoots in the two inoculations was obtained with 2 mg/l of BAP: 24 axillary shoots per explant, 7 in the first inoculation and 17 in the second one. The maximum elongation of shoots was achieved with BAP at 0.2 mg/l, and higher concentrations of the hormone induced a decrease in their size. A range of BAP concentrations between 0.2-0.5 mg/l allowed the production of more shoots with a size suitable for rooting. Roots were induced in 30 d old shoots, transferred to MS medium individually supplemented with IBA or NAA (0-4 mg/l). Micropropagated plants were successfully transferred to soil.