Fe-Mn-Si계 합금의 형상기억능에 미치는 변형온도 및 training 효과

강후원,한재익,장우양,강조원 조선대학교 생명과학연구소 2000 生産技術硏究 Vol.22 No.1

The shape memory effect is resulted from the reverse motion of Shockley partial dislocations which change εmartensite back to austenite. In Fe-Mn-Si alloys, the shape memory effect is obtained by the reverse transformation of stress-induced E martensite during heating. The reversibility of the motion of partial dislocations will not lead to a complete recovery. There are many factors influencing the shape memory effect like as alloy composition, Neel temperature, transformation temperature, applied stress and strain, annealing and quenching temperature, deformation and recovery annealing temperature etc. In this paper, shape memory effect by training treatment(cold working- annealing) and deformation temperature between -20℃ and 200℃ with amount of strain was improved in Fe-l5Mn-5Cr-10Co-3Si alloys Training treatment suppresses slip deformation and lower the stress for induced εmartensite transformation through introducing the stacking faults which can act as nucleation embryo for εmartensite.

은행나무(Ginkgo biloba) 種子에서 雌性配偶體 組織의 미세구조

이규배 조선대학교 생명과학연구소 1997 생명과학 연구 Vol.5 No.-

The interface of the female gametophytic tissue and the cotyledons of embryo in Gink biloba L. seeds was studied at the anatomical and ultrastructural levels. Under the light microscope, the female gametophytic tissues were distinguished into three zones; ⅰ) the compressed zone near the cotyledons consisted of 5 to 10-layered cells; ⅱ) the vacuolated zone next to the compressed zone consisted of 3 to 5-layered cells; ⅲ) the amyloplast zone was adjacent to the vacuolated zone. In the vacuolate cells the plastids with starch grains were frequently surrounded by smooth endoplasmic reticulum, whereas this feature was not found in the compressed cells. The density of cytoplasm and mitocondrial matrix in the vacuolated cells was lower than that in the compressed cells. The internal membranes of mitochondria and plastids in the vacuolated cells were somewhat less developed than those in the compressed cells. The compressed cells contained a lot of pleomorphic unidentified inclusion with a dense matrix. This structure limited by a single membrane seemed to be originated from smooth endoplasmic reticulum. The compressed cells were gradually disorganized during the embryos had grown within seeds. It suggested that the nutrients derived from the gradual breakdown of the female gametophytic cells would be translocated to the embryos.

핵전이에 의한 Aspergillus oryzae var. oryzae와 Penicillium chrysogenum의 잡종에서 Alkaline protease 고생산균주의 개량

강희경,임채영,문명님,여명구,송규상,양영기 조선대학교 생명과학연구소 1997 생명과학 연구 Vol.5 No.-

A. oryzae var. oryzae와 P. chrysogenum간의 alkaline protease 우수 생성 좋간형질전환체를 획득하고 유전분석을 통하여 다음과 같은 결과를 얻었다. 핵전이를 위한 원형질체 형성 및 재생 조건에서는 Novozym 234의 농도 1%, 삼투안정제는 0.6M KCI 그리고 효소의 처리 시간은 189분으로 나타났다. 또한 핵전이에 의한 형질전화의 빈도는 1.3~3.8 x 10^(-4)으로 비교적 낮은 편이었다. 유전적 안정성, conidia의 크기, DNA 함량의 측정 그리고 핵염색 결과 형질전환체의 핵형은 aneuploid로 추정되었고, 형질전환체의 alkaline protease 활성은 모균주와 비교하여 1.1~2.2 배 증가하였다. Interspecific hybrids between Aspergillus oryzae var. oryzae and Penicillium chrysogenum(Tyr^(-)), hyperlipolytic enzyme-producing fungi, were obtained by nuclear transfer technique. Optical contitions for formation of intergeneric hybrids were investigated Maximum production of protoplasts were obtained by 1% Novozym 234 at 30! for 3 hours and the most effective osmotic stabilizers for the isolation of protoplasts were 0.6M KCI. Frequencies of hybrid formation by nuclear transfer were 1.3 10^(-3)∼2.8×10^(-3). From the observation of genetic stability, conidial size, DNA content, and nuclear stain, it was suggested that their karyotypes are aneuploid. The hybrids showed 1.1∼2.2 fold higher alkaline protease activities than parental strains, It was strong1y supported by results of this study that nuclear transfer technique is efficient in the formation of intergeneric hybrids fusion and is very useful for the improvement of strains.

Recombinant phage antibody system에서 ScFvB9 및 그 변이주의 유도 및 발현

양은주,장해춘 조선대학교 부설생명과학 연구소 1998 생명과학 연구 Vol.6 No.-

The recombinant phage antibody system(RPAS) is designed to clone antibody genes and express and detect functional antibodies. Recombinant single-chain fragment(ScFv) of the murine monoclonal antibody B9(MabB9) were generated by using a polymerase chain reaction (PCR) from the Fab fragment of MabB9. The recombinant ScFv fragment(variable heavy-linker-variable light) was cloned into the pCANTAB 5E phagemid vector and transformed into E. coli TG1 and E. coli HB2151, respectively. Each phage displayed ScFv and soluble andtibody protein were expressed and detected as functional antibodies by enzyme-linked immunosorbent assay(ELISA) and Western blotting analysis.

EXPRESSION OF FLAVONOID 3'AND 3'5'HYDROXYLASE GENES IN POTATOES (SOLANUM TUBEROSUM CV. JOPUNG)

Park, Yoonkyung,Cheong, Hyeonsook 조선대학교 부설생명과학 연구소 1999 생명과학 연구 Vol.7 No.-

The 3' (F3'OH) and 3'5' hydroxylase (F3'5'OH) genes play a major role in the synthesis of flavonoids. The F3'OH and F3'5'OH genes were introduced into potato genome by Agrobacterium-mediated transformation. Presence of the petunia F3'OH and F3'5'OH genes in these transgenic plants were confirmed by Southern analyses and 2 kb bands were detected in all of the putative transgenic potato plants. To investigate whether mRNA are expressed in transgenic potato plants F3'OH and F3'5'OH genes, Northern blot analyses were carried out using total RNA obtained from the transgenic plants. The hybridized bands were consistent with the expected size of F3'5'OH mRNA. These results suggested the expression of the F3'OH and F3'5'OH genes from the transgenic potatoes.

조간대 저서무척추동물 군집에 미치는 태안화력발전소 온배수의 영향

윤성명,정석훈,백경환,김시욱,정혜광,이정섭 조선대학교 부설생명과학 연구소 1999 생명과학 연구 Vol.7 No.-

태안화력발전소의 온배수 유출이 주변 해역 조간대의 저서무척추동물 군집에 미치는 영향을 파악하기 위한 조사가 1998년에 수행되었다. 현지조사는 발전소 주변 조간대의 배수구 정점과 대조정점인 취수구 정점의 2곳에서 계절별로 진행되었다. 출현종수 및 출현종 구성과 생물량 분포, 다양도지수의 측면에서 분석한 결과 배수구 정점의 조간대 저서무척추 동물 군집은 대조정점의 군집과 뚜렷한 차이를 나타내지 않았다. 생물량의 면에서는 배수구 정점의 군집 생물량이 대체적으로 대조정점 군집의 생물량보다 많은 결과를 보였는데, 이러한 것은 특히 겨울철 조사에서 뚜렷하였다. 본 연구의 결과는 조사지역 발전소의 온배수가 조간대 저서무척추동물 군집에 미치는 부정적 영향은 거의 없으며, 오히려 해수온도를 높여 군집의 생물량 증가에 기여하고 있음을 시사하고 있다. The effects of heating overflow produced from the Taean Thermoelectric Power Plant on the intertidal invertebrate community in the adjacent sea to were studied in 1998. The invertebrate community of the station near the waterway showed no remarkable differences compared with that of control station in the respect of the number of species, species composition, biomass distribution, and diversity index. Heating overflow of the power plant had a tendency to effect positively on the increase of intertidal invertebrate biomass, especially in winter season. These results suggest that the heating overflow of the power plant nearly does not effect negatively on the intertidal invertebrate community in the study area. On the contrary, it may effect positively on the invertebrate community in increasing the biomass by promoting the growth of organisms.

메탈로티오네인의 기능

정혜광,김시욱,고문주 조선대학교 생명과학연구소 1998 생명과학 연구 Vol.6 No.-

For four decades after the original discovery of the small protein, metallothionein, its functional significance remains unclear. It is generally accepted that the principal roles of metallothioneins are detoxification of heavy metals and regulation of metabolism of essential trace metals. Nowadays there are emerging accounts on the function of metallothionein as an antioxidant. This manuscript reviews the structure, functions and induction of metallothioneins, especially focuses on the function as antioxidant. The medical implications of the free radical scavenging properties of metallothioneins are also discussed.

재조합 파아지 항체계에서 ScFvB9 변이주의 유도 및 발현에 관한 연구

양은심,장영춘 조선대학교 생명과학연구소 1998 생명과학 연구 Vol.6 No.-

RPAS를 통해 발현된 파아지-유래 항원과의 결합력과 항원특이성을 검증하였다. 일부 변이된 항체나 ScFvB9 모두 자기 항원인 LDL에만 특이적으로 반응하였으며, BSA나 알부민과 같은 다른 단백질에는 거의 반응하지 않았다. ScFvB9, 변이된 ScFvB9-6와 ScFvB9-17간에는 LDL에 대한 결합력 차이가 일정하였다. The recombinatn phage antibody system(RPAS) is designed to clone antibody genes and express and detect functional antibodies. Recombinant single-chin fragment(ScFv) of the murine monoclonal antibody B9(MabB9) were generated by using a polymerase chain reaction(PCR) from the Fab fragment of MabB9. The recombinant ScFv fragment(variable heavy-linker-variable light) was cloned into the pCANTAB 5E phagemid vector and transformed into E. coli TG1 and E. coli HB2151. respectively. Each phage displyed ScFv and soluble andtibody protein were expressed and detected as functional antibodies by enzyme-linked immunosorbent assay(ELISA) and Western blotting analysis.

Factors influencing cell division in protoplasis culture of cucumber : Cucumis sativus L.

Seo, seung-hee,Park, Hyeon-Young 조선대학교 생명과학연구소 1998 생명과학 연구 Vol.6 No.-

Methods were developed for an efficient protoplast culture of cucumber in this experiment. Protoplasts from mesophyll tissue were digested within 5h using 1.2% cellulase and 0.6% macerozyme R 10. Calcium chloride (20 mM) and casein hydrolysate (200 ㎎/L) were influenced to be important factors for the successful protoplast culture. A plating density of more than 1 × 10^(5) protoplast/ml was required for sustaining of division. First division occurred 4 days after culture, and then second-third division occurred within 5∼6 days. Microcalli formation usually appeared on 14∼20 days after culture. Microcalli were transferred onto solid media for futher growth and plant regeneration. Minicalli developed bud primordia within 2 weeks after transferring onto shoot induction medium.

시차분해 형광분광법을 이용한 Eu^(3+)와 2-나프토산 유도체 복합체에 관한 연구

이정희,유정아 조선대학교 부설생명과학 연구소 1999 생명과학 연구 Vol.7 No.-

정류상태 스펙트럼과 시차분해 형광스펙트럼을 측정하여 Eu^(3+)와 2-나프토산 유도체 복합체의 에너지 전이에 대하여 연구하였다. 다양한 들뜸 파장에서 관찰한 시차분해 형광스펙트럼은 들뜬 2-naphthoate (2-NA)나 2-naphthyacetate (2-NAAc)의 단일 항은 계간 전이에 의하여 에너지를 삼중항으로 전달하고 전달된 에너지는 삼중항의 진동 이완(일반적으로 수용액에서 ~10^(12)s^(-1))보다 빠른 속도로 Eu^(3+)의 ^(5)D_(3)준위에 전달된다. 에너지를 받은 Eu^(3+)의 ^(5)D_(3)는 ^(5)D_(3) → ^(5)D_(1), ^(5)D_(0)로 비복사 전이를 한 후 ^(5)D_(1) → ^(7)F_(2)와 ^(5)D_(0) → ^(7)F_(1)로 전이하며 형광을 방출한다. 동시에 ^(5)D_(1)의 에너지 일부는 ^(5)D_(1) → ^(5)D_(0)로 비복사 전이를 한 후 ^(5)D_(0) → ^(7)F_(1)로 전이하며 형광을 방출한다. Nanosecond time-resolved emission measurements have been conducted on Eu^(3+) with 2-naphthoate (2-NA) and 2-naphthyacetate (2-NAAc). The excitation was carried out in the ligand-centered or the metal-centered band in uv-visible region and time resolved emission spectra of Eu^(3+) in the spectral region 570 nm-660 nm were obtained. The obtained results imply that the excited singlet state of 2-NA and 2-NAAc populates triplet state via inter system crossing, and followed by energy migration to^(5)D_(3) level of Eu^(3+) with a rate 10^(12)s^(-1). The ^(5)D_(3) level deexcited to the luminescent ^(5)D_(1) and ^(5)D_(0) states.