31 research outputs found
LCROSS (Lunar Crater Observation and Sensing Satellite) Observation Campaign: Strategies, Implementation, and Lessons Learned
Fabrication of Pores in a Silicon Carbide Wafer by Electrochemical Etching with a Glassy-Carbon Needle Electrode
An electrochemical method for making
pores in a silicon carbide (SiC) wafer, in which a glassy-carbon (GC)
needle electrode was used for processing, is described. By bringing
the GC electrode into contact with SiC at its tip end in 20 mol dm<sup>–3</sup> HF solution and applying an anodic potential of or
higher than 4 V vs Ag/AgCl to it, SiC was etched at the SiC/GC contact
area, leading to pore formation in SiC. The diameter of the pore was
almost the same as the diameter of the tip of the GC electrode (about
130 μm). By addition of sulfuric acid to the HF solution, the
rate of pore formation was increased. As a result, the depth of pores
formed after processing for 5 h at 10 V vs Ag/AgCl was increased from
15.3 μm to about 33 μm by addition of sulfuric acid at
a concentration of 3.0 mol dm<sup>–3</sup>
Pore Formation in a p‑Type Silicon Wafer Using a Platinum Needle Electrode with Application of Square-Wave Potential Pulses in HF Solution
By bringing an anodically biased needle electrode into
contact with n-type Si at its tip in a solution containing hydrofluoric
acid, Si is etched at the interface with the needle electrode and
a pore is formed. However, in the case of p-type Si, although pores
can be formed, Si is likely to be corroded and covered with a microporous
Si layer. This is due to injection of holes from the needle electrode
into the bulk of p-type Si, which shifts its potential to a level
more positive than the potential needed for corrosion and formation
of a microporous Si layer. However, by applying square-wave potential
pulses to a Pt needle electrode, these undesirable changes are prevented
because holes injected into the bulk of Si during the period of anodic
potential are annihilated with electrons injected into Si during the
period of cathodic potential. Even under such conditions, holes supplied
to the place near the Si/metal interface are used for etching p-type
Si, leading to formation of a pore at the place where the Pt needle
electrode was in contact
Fabrication of Pores in a Silicon Carbide Wafer by Electrochemical Etching with a Glassy-Carbon Needle Electrode
An electrochemical method for making
pores in a silicon carbide (SiC) wafer, in which a glassy-carbon (GC)
needle electrode was used for processing, is described. By bringing
the GC electrode into contact with SiC at its tip end in 20 mol dm<sup>–3</sup> HF solution and applying an anodic potential of or
higher than 4 V vs Ag/AgCl to it, SiC was etched at the SiC/GC contact
area, leading to pore formation in SiC. The diameter of the pore was
almost the same as the diameter of the tip of the GC electrode (about
130 μm). By addition of sulfuric acid to the HF solution, the
rate of pore formation was increased. As a result, the depth of pores
formed after processing for 5 h at 10 V vs Ag/AgCl was increased from
15.3 μm to about 33 μm by addition of sulfuric acid at
a concentration of 3.0 mol dm<sup>–3</sup>
Fixed Charge Control of Silylated Surface for Stiction-Free Drying with Surface Energy Reduction Process
The Impact of Reduced Dose of Posttransplant Cyclophosphamide in HLA-Haploidentical Peripheral Blood Stem Cell Transplantation
Fetal growth retardation and lack of hypotaurine in ezrin knockout mice.
Ezrin is a membrane-associated cytoplasmic protein that serves to link cell-membrane proteins with the actin-based cytoskeleton, and also plays a role in regulation of the functional activities of some transmembrane proteins. It is expressed in placental trophoblasts. We hypothesized that placental ezrin is involved in the supply of nutrients from mother to fetus, thereby influencing fetal growth. The aim of this study was firstly to clarify the effect of ezrin on fetal growth and secondly to determine whether knockout of ezrin is associated with decreased concentrations of serum and placental nutrients. Ezrin knockout mice (Ez(-/-)) were confirmed to exhibit fetal growth retardation. Metabolome analysis of fetal serum and placental extract of ezrin knockout mice by means of capillary electrophoresis-time-of-flight mass spectrometry revealed a markedly decreased concentration of hypotaurine, a precursor of taurine. However, placental levels of cysteine and cysteine sulfinic acid (precursors of hypotaurine) and taurine were not affected. Lack of hypotaurine in Ez(-/-) mice was confirmed by liquid chromatography with tandem mass spectrometry. Administration of hypotaurine to heterogenous dams significantly decreased the placenta-to-maternal plasma ratio of hypotaurine in wild-type fetuses but only slightly decreased it in ezrin knockout fetuses, indicating that the uptake of hypotaurine from mother to placenta is saturable and that disruption of ezrin impairs the uptake of hypotaurine by placental trophoblasts. These results indicate that ezrin is required for uptake of hypotaurine from maternal serum by placental trophoblasts, and plays an important role in fetal growth