참다슬기 아가미 조직으로부터 heat shock protein 70 유전자를 분리 · 동정하였다. 참다슬기 HSP70 cDNA의 open reading frame (ORF)는 1,917 bp로 639개의 아미노산을 암호화하여 분자 량은 약 70 kDa으로 예측되었다. 생물정보학 배열분석에 의해 HSP 유전자 기능과 관여되어 있는 3가지 주요 signature motifs와 보존된 도메인을 확인하였다. 계통학적 분석을 통하여 참 다슬기 HSP70 유전자는 왕우렁이 Pomacea canaliculate와 같은 클러스트에 포함된다는 사실을 확인하였다. 수온 및 염분 변화에 따라, 참다슬기 HSP70 mRNA 유전자 레벨은 유의적으로 증 가하였으며(p < 0.05), 이는 외부자극요인을 파악할 있는 분자생물학적 마커로서 활용될 수 있 을 것으로 사료된다.

This study investigates the thermal shock property of a polycrystalline diamond compact (PDC) produced by a high-pressure, high-temperature (HPHT) sintering process. Three kinds of PDCs are manufactured by the HPHT sintering process using different particle sizes of the initial diamond powders: 8-16 μm (D50 = 4.3 μm), 10-20 μm (D50 = 6.92 μm), and 12-22 μm (D50 = 8.94 μm). The microstructure observation results for the manufactured PDCs reveal that elemental Co and W are present along the interface of the diamond particles. The fractions of Co and WC in the PDC increase as the initial particle size decreases. The manufactured PDCs are subjected to thermal shock tests at two temperatures of 780oC and 830oC. The results reveal that the PDC with a smaller particle size of diamond easily produces microscale thermal cracks. This is mainly because of the abundant presence of Co and WC phases along the diamond interface and the easy formation of Co-based (CoO, Co3O4) and W-based (WO2) oxides in the PDC using smaller diamond particles. The microstructural factors for controlling the thermal shock property of PDC material are also discussed.

We examined the effects of cadmium exposure and various temperature stress on the expression of Pardosa astrigera heat shock protein 70 (HSP70). To do this, P. astrigera HSP70 gene was cloned and its sequence determined. Female spiders collected from non-contaminated region were exposed to 40mM CdCl2 for 2, 4 and 6 weeks by dietary uptake. At the end of every 2, 4 and 6 weeks of exposure, a batch of 5 spiders was collected and total RNA was extracted from each batch of whole bodies. Female spiders were also exposed to different temperatures (20, 25, 30 and 35℃) for 3h and RNA extracted likewise. Transcription profiles of HSP70 in response to cadmium and temperature were determined by quantitative real-time PCR using 18S rRNA as reference gene for data normalization. HSP70 transcription gradually increased during 2,4 and 6 weeks of exposure to cadmium. In particular, the expression level at 6-week exposure was 3.4-fold higher than that of untreated control. In the temperature response, an increased expression of HSP70 was also observed as temperature increased up to 30℃ and then slightly decreased at 35℃. The expression level at 30℃ was 2.3-fold higher than that of 25℃. Taken together, HSP70 gene appears to be up-regulated by general stress factors including cadmium exposure and temperature increase.