인체 트롬보포이에틴(hTPO)은 megakaryopoiesis 과정에 주요한 역할을 하는 사이토카인이다. 따라서 이러한 트롬보포이에틴을 유선조직에서 직접적으로 발현시키기 위하여 소 베타 카제인 프로모터, 인체 트롬보포이에틴 cDNA 및 네오유전자로 구성된 발현벡터를 구축하였다. 소 귀조직 세포로부터 유도된 섬유아세포에 lipoffctamine을 이용하여 발현벡터(pBT-L n대)의 삽입을 유도하였다. G4l8 저항성을 지닌 세포의 콜로니 형성을 유도하기 위하여 2주 이상 배양을 실시하였다. 형질전환 콜로니는 PCR에 의해 동정하였으며, 이들 콜로니를 핵치환 전까지 계속적으로 증식을 유도하였다. 형질전환 세포에 의해 재구성된 난자는 전기적인 융합과 calcium ionophore와 6-DMAP를 이용한 활성화를 실시하였으며, 체외에서 7일간 배양을 실시하였다. 총 35개의 콜로니를 PCR에 의해 분석한 결과, 이 중 29(82.9%)개가 형질전환된 콜로니였다. 형질전환된 세포로 재구성된 난자의 난할율 및 배반포로의 발달율은 65.1%와 23.8%로 나타났다. 형질전환된 세포로 재구성된 난자로부터 발달한 29개의 배반포 중 27개가 형질전환으로 확인되었다. 따라서 이러한 결과들은 형질전환 소 수정란을 형질전환된 세포를 이용한 체세포 복제 기법을 통해 효과적으로 생산할 수 있다는 것을 제시하고있다.

Embryos derived from pig oocytes matured in mSOF are able to develop to blastocysts after IVF. Experiment 1 evaluated the effects of two maturation media (TCM-199 vs mSOF) on maturation rate, fertilization parameters, including penetration, polyspermy, male pronuclear formation, and the mean number of sperm penetrated per oocyte. Experiment 2 and Experiments 3 examined the effects of two maturation media on zona pellucida solubility and cortical granule distribution by transmissible electron microscopy, respectively. Experiment 4 assessed the effects of two maturation media on the in vitro embryo cleavage rate and development to blastocyst. Lastly, experiment 5 examined the cell number of blastocyst. An effect of media (P<0.05) was detected for mSOF on the mean number of sperm per oocyte. In TCM group, zona digestion time (196.515.5 vs 131.620.1 before IVF, 397.530.3s vs 185.316.4s after IVF, p<0.05) was higher in TCM-199 group. No significant effects of media was observed on cortical granule distribution between two groups by TEM. An effect (P<0.05) was observed on embryo development to blastocyst (16% vs 8%) but not on cleavage rates. No significant effects of media was observed on total cell number of blastocyst. We found that the high mean number of sperm penetrated per oocyte and the weaker zona pellucida on the basis of the digestion time was shown in pig oocytes matured in mSOF, however, porcine oocyte maturation with supplemented synthetic oviduct fluid medium (mSOF) resulted in blastocyst cell numbers comparable to those observed with Tissue Culture Medium 199.

Powder forging with a back pressure was investigated for production of automobile and compressor parts made of a rapidly solidified Al-Si alloy powder. Disk-shaped green compacts made of a rapidly solidified Al-Si alloy powder were hot forged, and hubs were formed by loading back pressure on their top. The influences of the back pressure and die temperatures on forgeabiliy and properties of parts made of a rapidly solidified Al-Si alloy powder were examined. This method was also applied to the production of a scroll part. The results of these studies are summarized as follows : 1. A back pressure on the hub top is very effective for consolidation and preventing crack formation in the hub. 2. When a back pressure tess than 98 MPa is applied, the forging pressure increases by the same amount of the applied back pressure. With more than 98 MPa, the forging pressure increases further due to an increased friction at the hub side. 3. Die temperatures higher than approximately 670k are needed in order to consolidate well the hub top without cracks.

Scaeosopha속의 1종을 신종으로 기재, 발표한다. 이 속은 구북구지역에서 처음으로 기록된다. Scaeothyris Diakonoff은 Scaeosopha Meyrick의 synonym으로 정리한다.

An outline is given of our development of mosaic CCD cameras. Hardware and data reduction software of two operational cameras are described. Scientific objectives of wide-field imaging with the cameras are briefly described.

곤충계통분류연구센터와 러시아동물토양연구소에 소장된 표본을 중심으로 조사한 결과, 4종의 신종(Morophaga parabucephala sp. nov., Ceratuncus orientanus sp. nov., Gerontha ampliptera sp. nov., and G. namgaensis sp. nov.)을 발견, 기재발표한다. 또한 6종(Montescardia kurenzovi (Zagulajev), Morophagoides ussuriensis (Caradja), Gerontha borea Moriuti, Niditinea baryspilas (Meyrick), Monopis pavlovskii Zagulajev, and M. rusticella Hubner)이 한국 미기록종으로 보고되며, 4종은 극동러시아에서 처음 기록되는 종이다.

In order to evaluation of beneficial functions for organic farming, we have divided beneficial functions as 9 sub-functions such as flooding control, fostering water resources, purifying the air, mitigating summer climate, purifying water quality, decreasing soil erosion, accumulating soil carbon, conserving biodiversity, and preventing accidents from pesticides. And they were quantified by searching related repots and statistics, and surveying fields. Organic farming, especially organic paddy farming, showed that some functions like fostering water resources, accumulating soil carbon, conserving biodiversity, and preventing accidents from pesticides were higher than conventional paddy farming, while the others were almost similaι The foste꺼ng water resources function was evaluated as 4,297 ton ha-1 year-1 to increase about 3.6% comparing with that of conventional farming. New function for accumulating soil carbon at organic paddy fields has been assessed by 4.67 ton ha-1 in terms of long periods over 10 years. Considering area of organic paddy farming in Korea and value of carbon price， it was evaluated monetary value as 22.4 to 84.1 billion won using replaced method. It could be also evaluated that flooding control, fostering water resources, purifying the air, mitigating summer climate, purifying water quality, decreasing soil erosion, and preventing accidents from pesticides were 2,980, 123.4, 482.6, 87.5, 0.9, 55.6, and 284.1 billion won, respectively. Conserving biodiversity function would be very big at organic farming though it couldn ’l be evaluated as monetary value.

The development of humanized culture system of human embryonic stem cells (hESCs) hold promise for therapeutic applications. However, conventional culture system contain animal-derived components such as fetal bovine serum and mouse embryonic fibroblasts that bear a risk of transmitting non-human pathogens and incorporation of non-human immunogenic molecules to hESCs. In this study, we developed an efficient xeno-free hESCs culture system using humanized materials, the CELLstartTM, human foreskin feeder and xeno-free medium containing knockOutTM SR XenoFree (XF-medium) without animal-derived material. The hESCs were gradually adapted to the XF-medium; 25:75, 50:50, 75:25 and 100:0. Two karyotypically normal hESC lines, SNUhES4 and H1, were used for the experiments of xeno-free culture condition. The attachment rates at xeno-free culture system were 52.6±12.4%, 67.0±16.6%, 59.0±13.9%, 28.3±2.9% in SNUhES4, 79.3±5.4%, 53.8±20.9%, 69.4 ±6.4%, 59.8±12.6% in H1 and the spontaneous differentiation rates were 42.2±12.7%, 31.4±2.9%, 40.8±14.5%, 55.2±35.5% in SNUhES4, 35.6±8.5%, 36.4±13.5%, 48.4±7.8%, 80.1±6.0% in H1 in the first four passage. Although the attachment rates were low and the spontaneous differentiation rates were high compared to that of conventional system in the early passages using this humanized culture condition, hESCs in this culture condition were found to maintain hESC characterizations; morphology, expression of cell surface markers and stable karyotype. Our results indicate that simplified compositions of humanized culture system can be applicable to the further optimization for a xeno-free culture of hESCs without the loss of pluripotency and contamination from xenogenic sources.