• 한국미생물·생명공학회지
• /
• 제7권3호
• /
• pp.135-140
• /
• 1979

특이하게도 일단 어떤 원인으로든지 변성이 일어나서 침전이 형성되고 난 후에는 그 변성으로 인하여 다시 용해되지 않는 penicillinase를 생성분비하는 Streptomyces 속 균주 AS-727을 토양으로부터 얻었으며, 이 균의 효소생산성과 이 효소의 일반적성질을 검토한 결과는 다음과 같다. 1) 본 효소의 생산을 위해서는 질소원으로서 sodium nitrate, 탄소원으로서 glucose 나 maltose를 사용하여 4 일간 배양하는 것이 바람직했으며 2) 정제는ammonium sulfate로 완전포화시켜 생성된 침전을 원심분리로 모아 그것을 투석해서 조정제효소를 얻는데, 이때 투석할 때 침전은 용해 되지 않는다. 3) 본 효소의 최적 pH는 중성부근 (6.0~8.0)이며 최적온도는 4$0^{\circ}C$ 근처이고, 4) 안정 pH 범위는 4.0~9.0으로서 비교적 넓었으며 열에 대해서는 4$0^{\circ}C$에서는 안정했으며 6$0^{\circ}C$와 8$0^{\circ}C$에서 60 분간 처리하면 각각 약 30%와 40%가 실활되었다. 5) 본 효소의 활성에 있어서 zinc chloride가 $10^{-3}$ M 농도에서 약 20%, $10^{-2}$ M 이상의 고농도에서는 95% 이상을 조해하였다. 6) 그리고 동결이나 명종 고류 또는 유기용매로 일단 형성된 효소단백침전은 다시 용해되지 않는 특이한 성질을 가졌다.

• 한국가축번식학회지
• /
• 제23권3호
• /
• pp.221-227
• /
• 1999

미성숙한 소 난자 동결보존 기술의 개발은 체외수정, 복제동물 및 형질전환동물 생산에 필요로 하는 난자를 시간과 공간의 제약 없이 공급이 가능해지기 때문에 그 효용가치가 많으나 아직까지 성공 보고례가 없다. 본 연구에서는 전자현미경용 grid를 이용한 초급속 동결 방법에 의해 미성숙한 소 난자를 동결 보존한 후, 이 난자를 융해하여 체외성숙, 체외수정 및 배발달을 유도하였다. 동해제는 PBS에 40% ethylene glycol, 0.5M sucrose, 18%과 10% fetal bovine serum이 들어 있는 EFS40을 사용하였다 . 동결ㆍ융해 후의 난자의 생존율은 48% 정도로 대조군에 비해 현저히 낮았으나 metaphase-II까지의 성숙율은 78%로, 정상 자웅전핵 형성율 75%로 대조군에 비해 차이가 없었다. 또한 배반포까지의 배발달율은 대조군23%와 동결군은 5%로 동결 융해한 것이 낮았으며 수정후 108~120시간 째 배반포를 염색하여 세포수률 알아본 결과는 각각 128$\pm$5와 98$\pm$8이었다. 항동해제내 $Na^{＋}$ 이온의 농도에 따른 미성숙된 난자의 생존율, 성숙, 수정 및 배발달율을 조사하였으나 유의차가 없었다. 이상의 결과는 동결 보존된 미성숙 소 난자가 융해후 체외성숙 및 수정에 의해 배반포까지의 발달이 가능하다는 것을 시사하고 있다.

• 한국임상수의학회지
• /
• 제16권2호
• /
• pp.375-380
• /
• 1999

This study was conducted to develop an intrauterine inseminator (IUI) to deposit of frozen semen into uterus and to evaluate the results obtained after artificial insemination by IUI. Two Japanese spitzs (2 to 4 years of age) were used as semen donors. Semen was collected by manual masturbation into sterile glass collection tubes and separated into 3 fractions with only the sperm-rich fractions retained for further examination. Sperm motility >70%, sperm concentration of 200 to $400{\times}10^6 cells/ml$$\times$g for 5 min and poured out the suspended solution, and then diluted with 2 ml Tris-buffer which was consisted of 2.4 g Tris, 1.4 g citric acid, 0.8 g glucose, 0.1 $\mu\textrm{g}$/ml streptomycin, 100 IU/ml penicillin, 20 ml egg yolk to 100 ml mili-Q water (Ext I) or supplemented with 8 ml glycerol and 1 ml Equex STM paste to 100 rnl (Ext II). The diluted semen was cooled to 5$^{\circ}C$ in cold room, where the temperature in the sample reached 5$^{\circ}C$. Two h after beginning the cooling procedure, 2 ml of Ext II, also at 5$^{\circ}C$, was added and mixed by gently reversing the tubes several times during 1 h. The final sperm concentration for freezing was approximately $50{\times}10^6 cells/ml$. After equilibration, the semen was loaded into 0.5 ml straw and frozen on the liquid nitrogen vapour in styrofoam box. The straws were thawed at 7$0^{\circ}C$ for precisely 6 sec. After thawing of each straw, the frozen semen can survived over 50% motility. All the females were inseminated twice with 1 ml of $25{\times}10^6 cells/ml$

• Asian-Australasian Journal of Animal Sciences
• /
• 제17권2호
• /
• pp.164-167
• /
• 2004

This study was carried out to investigate in vitro fertilization and development of in vitro matured pig oocytes inseminated with the Duroc boar sperm by different sperm washing media after thawing of the 5 ml frozen straws. Immature follicular oocytes (30-40) were transferred into each well of a Nunc 4-well multidish containing $500{\mu}l$ mTCM199 maturation medium. The sperm rich portion of ejaculates was collected into a 250 ml insulated vacuum bottle and gradually cooled 22 to $24^{\circ}C$ over a 2 h period. Semen was centrifuged at 800 g for 10 min and the seminal plasma discarded. Sperm were esuspended in a lactose-egg yolk and N-acetyl-Dglucosamine (LEN) diluent to contain $1{\times}10^{9}$ sperm/ml and cooled to $5^{\circ}C$ over a 2 h period. Immediately before freezing, semen was rediluted with an equal volume of LEN+4% glycerol and packed into 5 ml straws. After thawing of the 5 ml straw, the 5 ml semen was diluted with 20 ml Beltsville thawing solution (BTS) at room temperature. Oocytes were inseminated with untreated (unwashed and nonpreincubated) or treated sperm (washed two times in BTS, mTLP-PVA and mTBM media, respectively and nonpreincubated) with $2{\times}10^{7}$ sperm concentration. Oocytes were coincubated for 6 h in $500{\mu}l$ mTBM fertilization. At 6 h after IVF, oocytes were transferred into $500{\mu}l$ NCSU-23 culture medium for further culture of 6 h. Sperm penetration, polyspermy and male pronuclear formation of oocytes at 12 h after IVF and developmental ability of oocytes at 48 h after IVF were evaluated. Sperm penetration rate, male pronuclear formation and rate of cleaved embryos were higher in the BTS, mTLP-PVA and mTBM treatments than the unwashed treatment (p<0.05). The rate of blastocysts from the cleaved oocytes (2-4 cell stage) were higher in the mTLP-PVA treatment than in the unwashed, BTS and mTBM treatments. In conclusion, we recommend the washing of frozen-thawed sperm with mTLP-PVA medium before in vitro fertilization of oocytes in mTBM medium.

• 한국도로학회논문집
• /
• 제17권3호
• /
• pp.85-95
• /
• 2015

PURPOSES : Recently, bonded concrete overlay has been used as an alternative solution in concrete pavement rehabilitation since its material properties are similar to those of the existing concrete pavements. Deteriorated concrete pavements need rapid rehabilitation in order to prevent traffic jams on Korean expressways. Moreover, speedy and effective repair methods are required. Therefore, the use of bonded concrete overlay with ultra-rapid hardening cement has increased in an effort to reopen promptly the expressways in Korea. However, mobile mixer is required for ultra-rapid hardening cement concrete mixing in the construction site. The use of mobile mixer causes various disadvantages aforementioned such as limitation of the construction supply, open-air storage of mixing materials, increase in construction cost, and etc. In this study, therefore, hydration accelerator in-situ mixing on polymer modified concrete produced in concrete plant is attempted in order to avoid the disadvantages of existing bonded concrete overlay method using ultra-rapid hardening cement. METHODS : Bonded concrete overlay materials using ultra-rapid hardening cement should be meet all the requirements including structural characteristics, compatibility, durability for field application. Therefore, This study aimed to evaluate the application of hydration accelerator in-situ mixing on polymer modified concrete by evaluating structural characteristics, compatibility, durability and economic efficiency for bonded concrete overlay. RESULTS : Test results of structural characteristics showed that the compressive, flexural strength and bond strength were exceed 21MPa, 3.15MPa and 1.4MPa, respectively, which are the target strengths of four hours age for the purpose of prompt traffic reopening. In addition, tests of compatibility, such as drying shrinkage, coefficient of thermal expansion and modulus of elasticity, and durability (chloride ions penetration resistance, freezing-thawing resistance, scaling resistance, abrasion resistance and crack resistance), showed that the hydration accelerator in-situ mixing on polymer modified concrete were satisfied the required criteria. CONCLUSIONS : It was known that the hydration accelerator in-situ mixing on polymer modified concrete overlay method was applicable for bonded concrete overlay and was a good alternative method to substitute the existing bonded concrete overlay method since structural characteristics, compatibility, durability were satisfied the criteria and its economic efficiency was excellent compare to the existing bonded concrete overlay methods.

• 한국환경농학회지
• /
• 제36권4호
• /
• pp.288-292
• /
• 2017

BACKGROUND: Silicon tetrachloride reacts with moisture in the atmosphere to generate hydrogen chloride, which affects the environment. Since silicon tetrachloride and its by-products are dispersed in the atmosphere in a short time after the silicon tetrachloride release into the atmosphere, it is difficult to directly assess the extent of environmental impact. In the present study, the exposure test of silicon tetrachloride or hydrogen chloride was examined in order to establish the criterion of the range affected by the silicon tetrachloride release, and the actual crops in the area exposed to silicon tetrachloride leakage were analyzed. METHODS AND RESULTS: For the experiment of exposure to silicon tetrachloride or hydrogen chloride, the leaves of red-pepper and corn were used in glass sealed containers. In the actual accident area, 59 samples from 10 different kinds of crops were collected. The pretreatment of the sample was performed by freezing and grinding, and then extracted using distilled water. The pH and concentration of chloride ($Cl^-$) ion of the extracted solution were measured using pH meter and ion chromatograph, respectively. CONCLUSION: Exposure to silicon tetrachloride caused visible damage, increasing the concentration of chloride ion, and decreasing the pH as well as hydrochloric acid. In the actual crops of the affected area, the tendency was the same as the result of the laboratory test, and the range of influence could be estimated through the concentration of $Cl^-$ ion over 2,000 mg/kg, and the correlation evaluation between the concentration of $Cl^-$ and pH. Therefore, the concentration of $Cl^-$ ion and the correlation between $Cl^-$ and pH would be considered as the factors to estimate the influence range of silicon tetrachloride release.

• 한국가축번식학회지
• /
• 제16권3호
• /
• pp.199-208
• /
• 1992

These studies were carried out to investigate optimal physological conditions for in vitro fertilization (IVF) of mouse ova. The unfertilized ova were obtained by superovulation from ICR mice of 4 to 6 weeks old. Tyrode's 280 solution was used as basal media, and pH and osmolality of basal media were adjusted with the supplementation of sodium bicarbonate and sodium chloride, respectively. The optimal pH, and osmolality of culture media and the optimum period of sperm preincubation were examined in fertilization in vitro of mouse ova and the subsequent culture in vitro of embryos. The pH range of media examined was designed from 6.5 to 7.5 with 0.2 interval and the range of osmolality from 250 to 370 mOsm with 20 interval, and the period of sperm preincubation examined was 30, 60, 120, and 180 minutes. The ova developed to 2-cell embryosafter 26hrs. of incubation with preincubated sperm were evaluated as in vitro fertilized ones. The results obtained were summarized as follows: 1. The percentage of in vitro fertilized ova was highest (64.7%) in media of pH 7.1 and lowest (38.0%) in pH 6.7. No significant difference in % fertilized ova was found from the media of pH 7.1 to 7.5. Compared with the result from pH 7.1 medium, the pollyspermy was increased signifciantly (p<0.05) in the media of pH over 7.5 and below 6.9;, and the % degenerated ova was significantly (p<0.05) increased in the media of pH below 6.9. 2. The percentage of in vitro fertilized ova was highest (69.4%) in media of osmolality 330 mOsm and lowest (47.9%) in osmolality 250 mOsm. No significant difference in % fertilized ova was found from the media of osmolality 310 to 350 mOsm. Compared with the result from osmolality 330 mOsm in medium, the polyspermy aws increased significantly(p<0.05) in the media of osmolality over 350 mosmol and blow 290 mOsm, and the % degenerated ova was significantly (P<0.05) increased in the media of osmolality below 290 mOsm. 3. The percentate of in vitro fertlilized ova was highest (62.7%) in media of period sperm preincubation 180 min. and lowest (40.4%) in sperm preincubation 30 minutes. No significant difference in % fertilized ova was found from the media of sperm preincubation 120 to 180 minutes. Compared with the result from sperm preincubation 180 minutes in medium, the polyspermy was low differ no significantly(P<0.05) in the media of period sperm preincubation, and the % degenerated ova was signifciantly(P<0.05) increased in the media of sperm presincubation below 60 minutes.

• 한국수산과학회지
• /
• 제51권5호
• /
• pp.499-509
• /
• 2018

This study optimized the bone-softening and fishy odor-reducing process for mackerel Scomber japonicus products using response surface methodology (RSM). The RSM showed that the optimum concentrations of doenjang and citric acid for reducing the fishy odor in bone-softened mackerel were 11.8% and 0.04%, respectively, and the optimum immersion time was 52.2 min. The estimated overall acceptance, salinity, and acidity of the products under these optimum conditions were 7.7 points, 1.1%, and 202.6 mg/100 g, respectively, which were similar to the actual measured values of $7.6{\pm}1.2$ points, $1.0{\pm}0.1%$ and $203.2{\pm}3.8mg/100g$. Moreover, the heating temperature and time for bone-softening based on RSM were $107.3^{\circ}C$ and 4.4 h, respectively. The estimated hardness and proportion of skin removed from the product under the optimal conditions were $161.5g/cm^2$ and 0.09%, respectively, which were also similar to the actual measured values of $171.1{\pm}12.6g/cm^2$ and $0.10{\pm}0.02%$. The optimum bone-softening and fishy odor-reducing process for mackerel consisted of the following steps: thawing (${\leq}10^{\circ}C$, 8 h), filleting, washing/dewatering, immersing in an 11.8% doenjang -0.04% citric acid solution for 52 min, washing/dewatering, heating ($107.3^{\circ}C$, 4.4 h), freezing, depanning, internal and external packaging, and X-ray detection treatment.

• 폴리머
• /
• 제32권3호
• /
• pp.246-250
• /
• 2008

본 연구에서는 분해성 고분자의 종류와 제조조건에 따른 나노입자의 분산 안정성을 평가하기 위하여 광산란 입도 분석기를 이용하여 입자 크기 변화를 조사하였다. 이를 위해 생분해성 고분자인 폴리(D,L-락타이드-co-글리콜라이드) 단독과 폴리(L-락타이드)와의 블렌드, 그리고 폴리(L-락타이em)-g-폴리(에틸렌 글리콜)과의 블렌드, 세 종류를 개선된 자발적 에멀션/용매 확산 방법을 이용하여 나노입자를 제조하였다. 제조조건의 영향을 파악하기 위하여서는 나노입자의 제조시에 대표적인 분산 안정제인 폴리(비닐 알코올)(PVA)의 사용 유무의 영향을 조사하였다. 시간이 진행함에 따라 분산 안정제가 적용되지 않은 경우에서는 나노입자의 분해와 분해를 통해 붕괴된 입자의 응집에 의하여 입자의 크기가 bimodal 분포를 나타내었다. 나노입자가 분산된 수용액에 단백질 용액을 투입한 경우에는 분산 안정제인 PVA의 사용 유무에 의해 극명한 차이를 나타내었으며 PVA가 분산 안정성에 크게 기여함을 확인할 수 있었다. 또한 낮은 분자량의 폴리(에틸렌 글리콜)이 그래프트 고분자를 미량 블렌드함에 따라 입자의 단백질 흡착에 대한 분산 안정성은 침전이 일어나지 않고 1일 정도 분산 상태를 유지하는 것으로부터 일부 향상됨을 확인하였다.

• 한국가축번식학회지
• /
• 제15권1호
• /
• pp.49-57
• /
• 1991

생쥐 수정란의 동결보존법을 개선하고자 유리화 동결과정에서 제1보존액에서의 평형시간, 제2보존액에서의 전냉각 여부 및 straw loading 방법에 따른 동결보존 후 수정란의 생존율을 조사하고, 또한 유리화 동결보존 과정에서 수정란의 부분적인 손상 여부를 확인하기 위하여 동결보존 후 배양하여 수정란의 할구수를 Hoechst 33342로 염색하여 조사하였던 바 그 결과는 다음과 같다. 1. 동결융해 후 생존율은 Medium-1에서 10분간 평형시간을 준 경우(81.0%)는 5분간(40.0%) 및 15분간(74.1%)의 평형시간을 준 경우보다 유의적(P<0.05)으로 높았다. 2. Double Medium-2 column방법으로 얻은 생존율(81.0%)은 single Medium-2 column방법으로 얻은 생존율(62.8%)보다 유의적(P<0.01)으로 높았다. 그리고 Double Medium-2 column방법에서는 유리화 용액이 희석액에 오염되지 않아 순수하게 투명한 유리화를 이룰 수 있었다. 3. 전냉각을 않은 경우에 비하여 전냉각한 Medium-2로 동결한 수정란은 생존율에 있어서 다소 높은 성적을 보였으나 유의적인 효과는 없었다. 4. 상실배기의 수정란을 24~28시간동안 배양하여 얻은 후기 배반포를 Hoechst 33342로 염색하여 할구수를 조사하였던 바 신선란(53.3${\pm}$1.6)보다 동결란(41.4${\pm}$1.5)에서 유의적(P<0.05)으로할구수가 적었다. 이는 동결융해 과정에서의 부분적인 손상에 의하였던 것으로 사료된다.