Rapid differentiation of astrocytes from human embryonic stem cells.

Astrocytes are abundant cells in the brain and have vital roles in various brain functions that include biochemical support of endothelial cells, supplying nutrients to the nervous tissue, maintaining the extracellular ion balance, etc. In developing nervous tissue, the differentiation of astrocytes occurs later compared to neurons. It takes more time and more techniques to obtain mature and pure astrocytes in vitro.

Survey on organochlorine pesticides, PCDD/Fs, dioxin-like PCBs and HCB in sediments from the Han river, Korea.

The contamination status of twelve persistent organic pollutants (POPs) on the Stockholm convention in the surface sediments of Han river, which is one of the largest river in the South Korea were investigated. Five organochlorine pesticides (OCPs) such as aldrin, dieldrin, endrin, mirex, and SigmaCHLs (alpha-chlordane, gamma-chlordane, cis-nonachlor, trans-nonachlor, and heptachlor) were not detected in all sediment samples. The overall concentrations of DDTs, HCB, dioxin-like PCBs (DL-PCBs) and PCDD/Fs were in the range of 1.

Emission and sputtering characteristics of Ne-Ar mixed gas glow discharge plasmas.

The emission characteristics of several Cu lines emitted from a Ne-Ar mixed gas glow discharge plasma were investigated. The addition of small amounts of Ar to a Ne plasma increases the sputtering rate of a Cu sample because Ar ions, which work as the impinging ions for cathode sputtering, are predominantly produced through Penning ionization collisions between Ne metastables and Ar atoms. Ar addition also elevates the number density of electrons in the plasma.

Development of soft plasma ionization (SPI) source for analysis of organic compounds.

We present a newly designed soft plasma ionization (SPI) source developed for mass spectrometric study of organic compounds in this study. The SPI cell having a relatively small size consists of a hollow anode and a hollow mesh cathode. The voltage-current characteristic depending on the pressure was investigated, indicating that it has similar characteristics to conventional hollow cathode glow discharges.