Membrane depolarization stimuli (high potassium concentration and veratridine) increased neuropeptide V (NPY) mRNA abundance time-dependently, without a change in~-actin mRNA level, in NG1O8-15 and PC12 cells. Although the induction by veratridine was blocked completely by tetrodotoxin, the induction by potassium was suppressed minimally. Voltage-dependent Ca channel blockers and calmodulin antagonists inhibited the increases by both depolarization stimuli completely, suggesting involvement of Ca2Vcalmodulin-dependent kinases (CaM kinases). Transient assay using chioramphenicol acetyltransferase reporter genes containing the rat NPY gene promoter indicated that membrane depolarization and Ca entry stimulate transcription of the NPY gene. The depolarization-induced transactivation was also blocked by CaM kinase inhibitors. The 200-bp 5'upstream region (-344/-145) was localized as a calmodulin-responsive element (CaMRE), which confers depolarization-induced transactivation. It is interesting that this CaMRE did not contain the canonical Ca-responsive elements such as CRE, SRE, NF-AT, or the C/EBP~3binding site and was separated from a 64-bp cyclic AMP! phorbol 1 2-myristate 13-acetate-responsive element (-1441-81). These findings suggested that membrane depolarization regulates the NPY gene transcription positively through the unique CaMRE by activation of CaM kinases following Ca entry through L-type Ca channels.
Ferritic/martensitic steel was chosen as a primary candidate structural material for China Initiative Accelerator Driven System (CiADS) which started in 2015. A new kind of tempered martensitic steel, Steel of Institute of Modern Physics (SIMP), was designed to meet the requirements of the special operating environment. Structural materials suffer from liquid Pb‐Bi corrosion and liquid metal wetting at 450°C. Liquid metal wetting can seriously affect the mechanical properties of structural materials due to the decrease in surface energy and transition from martensitic laths to ferritic grains. Creep‐to‐rupture of SIMP steel was explored in stagnant liquid Pb‐Bi eutectic at 450°C. The possible reasons for creep‐to‐rupture are discussed. The results of the present study provide a new insight into challenges related to the application of SIMP steel in CiADS.
SiC-based components are sometimes susceptible to aqueous dissolution in LWR coolant environments. To address this issue, ~10 μm thick Cr coatings was deposited on reaction-bonded silicon carbide (RBSC) plates by magnetron sputtering. Corrosion behavior of Cr-coated SiC and -uncoated SiC coupons was studied by immersing in autoclave (345°C and 16.5 MPa). The weight loss of the Cr coated SiC coupons (3.02% after the 93-days) in the autoclave tests was effectively reduced due to their Cr-coated surfaces, in contrast to the uncoated ones (20.4% after the 78-days). Moreover, microstructural and compositional evolutions were examined by using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman spectroscopy. It was revealed that a continuous and dense Cr2O3 layer formed on the surface after the hydrothermal corrosion, which can suppress the in-diffusion of corrosive medium.
The corrosion behavior of iron with vacancies in a liquid lead-bismuth eutectic environment is simulated by molecular dynamics with embedded-atom model potential at 700-1073 K. The vacancy is substituted into Fe crystal with the percentage of 0%, 0.2%, 0.4%, 1.0%, and 2.0% to investigate the effect of the
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.