• 대한방사선기술학회지:방사선기술과학
• /
• 제5권1호
• /
• pp.55-62
• /
• 1982

Measurement of triiodothyronine($T_3$) concentration is useful for the diagnosic and treatment of thyroid gland diseases. Fundermental studies of measurement of $T_3$ concentration by radioimmunoassay were performed and values determined by commercially available kit, Coat-A-Count, Diagnostic Products Corporation. The optimal utilization of the radioimmunoassay in measuring $T_3$ concentrations is dependant not only on high quality performance of the assay, but also on their appropriate application to the clinical situation. These are several aspects that must be considered in every individual case. These include factors such as accurate pippeting in reagent preparation in the assay and through decanting to remove all visible moisture after incubation steps and so forth. In attempt to assess quality control of the radioimmunoassay of serum $T_3$, serum pools with high, medium, low $T_3$ concentrations were assayed for each of 5 samples. The results obtained with this study were as follow: 1. The coefficient of variation(C. V.) for the standard curve ranged between $0.2{\sim}3.5%$. 2. It was necessary that both incubation time and temperature should correctly be maintained all the in the assay performance. 3. The precison with the $T_3$ RIA procedure was good. 4. The measured values of serially diluted serum $T_3$ concentration with Ong/dl standard solution was proportional to the predicted values. However dilution curve of distilled water was not strait. 5. Calculated $T_3$ values of patient serum in normal group was $107.8{\pm}25.90ng/dl$ in male patient and $127.29{\pm}24.08ng/dl$ in female patient.

• 한국환경농학회지
• /
• 제16권4호
• /
• pp.295-303
• /
• 1997

수분조건(${\theta}$m 0.2, 0.3, 0.4, 0.5) 변화에 따른 토양내 우분퇴비의 질소와 탄소의 전환특성을 조사하기 위해 7월말에서 11월 초 사이 15주간 실내에서 Incubation 실험을 실시하였다. 실험기간동안에 토양 pH는 질산화 과정중 발생되는 수소의 영향으로 낮은 폭으로 지속적인 감소를 보였으며, 유기물과 수분처리량이 증가할수록 암모니아 질소의 발생률의 증대와 환원물질의 생성으로 토양 pH가 높아졌다. 전 질소의 감소율은 수분량이 증가할수록 증가하는 경향을 보였으나, 전 탄소는 이와 반대의 경향을 보였다. 따라서 낮은 수분조건(${\theta}$m 0.2)에서 C/N율은 시험기간동안 지속적으로 감소되어 지력이 증진됨을 볼 수 있었으나, ${\theta}$m 0.4 이상의 높은 수분조건에서는 지속적인 C/N율 증가가 발생되어 지력 감소와 토양 pH 감소 원인으로 작용하였다. 우분처리에 따른 $NO_3\;^--N$ 발생량은 ${\theta}$m 0.3 이하의 수분조건에서는 비교적 양호한 통기조건 때문에 지속적으로 증가되었으나, ${\theta}$m 0.4 이상의 조건에서는 초기에 큰 폭의 감소가 발생되었으며, 특히 ${\theta}$m 0.5에서는 2∼3주 이후 $NO_3\;^--N$가 발생되지 않았다. 그러나 $NH_4\;^+-N$의 발생량은 위와 반대경향을 보여, 수분함량이 증가함에 따라 발생량이 증대되는 경향을 보였다. 전 질소에 대한 무기태 질소의 비율로 나타낸 질소의 무기화율은 낮은 수분조건에서는 꾸준히 증가하였으나, 높은 수분조건에서는 초기 큰 폭의 감소가 발생된 후 서서히 증가되는 경향을 보였다. 이상의 결과를 종합할 때, 토양내 유기물 시용시 지력 유지 측면에서 토양내 수분조건은 대단히 중요하며, 높은 수분조건에서는 질소 손실량 증대에 의한 지력 감소가 발생될 것으로 예측되었다.${\theta}$ m 0.2 정도의 적정 수분조건에서는 양호한 통기성과 수분유지로 인한 질소 손실을 줄일 수 있었다.

• 한국잠사곤충학회지
• /
• 제5권
• /
• pp.25-38
• /
• 1965

I. Breeding of tussah silkworm(preliminary report). The preliminary examination for bleeding has been carried out since 1963 in tussah silkworms. 1) The strain(l-MG-B)of the heaviest silk quantity was the green silkworm and brown cocoon in univoltine, and the strains(2-G-B, 2-MG-B) of the heaviest silk quantity were also the green silkwom and brown cocoon in bivoltine in both spring and fall in 1965. 2) It looks like the voltinism, the body color and the cocoon color have reached to pure line up to 1965. II. Best place for the winter of tussah pupa. This work was aimed to find out good ways for the winter of tussah pupa. 1) The hatch of bivoltine was better than that of univoltine. 2) The cocoons covered with the leaves were good in the emergence of moth. 3) The cocoons which were kept at natural temperature till the first emergence of moths would show bad in both hatch and emergence. 4) If some of the pupae kept under natural condition were controled at proper temperature for a few days, hatch and laying eggs were best. 5) The best places for the winter were the egg storage and the rearing room. III. Relation between incubation temperature and voltinism. 1) When the tussah pupa are kept at natural temperature during winter, the moths do not come out of the pupa. 2) There is no difference between about 18$^{\circ}C$ and about 25$^{\circ}C$ during incubation in hatching ratio. 3) The tussah silkworms of univoltine in mortality are stronger than that of bivoltine. 4) There is not any relation between voltinism and high or low temperature for pupa and eggs. IV. Induced mutation by gamma-ray and neutron in tussah silkworm. This work was carried out in order to induce the mutation by treating the pupa or the eggs of tussah silkworm with gamma my and neutron. The results obtained are as follows. 1. Though the whole pupa treated with neutron become moths, the moths have no ability to copulate each other. The only moths emerged from pupa treated with neutron, 4000${\gamma}$ are able to lay all un-fertilized eggs, some of which have a hole on the surface and nothing of contents. 2. The non-diapause eggs are treated with neutron in spring, but the hatching ratio is 50∼60 percent, but the whole eggs treated with gamma ray are never hatched. 3. The sensitivity of the pupa to neutron is weaker than that of the eggs. 4. The hatching ratio is in direct proportion to the gamma ray dose. 5. Author find out a new mutant which is excellent in the cocoon quality, so he will do the progeny test next hear.

• Journal of Microbiology and Biotechnology
• /
• 제24권5호
• /
• pp.639-647
• /
• 2014

Laccases have a broad range of industrial applications. In this study, we immobilized laccase on $SiO_2$ nanoparticles to overcome problems associated with stability and reusability of the free enzyme. Among different reagents used to functionally activate the nanoparticles, glutaraldehyde was found to be the most effective for immobilization. Optimization of the immobilization pH, temperature, enzyme loading, and incubation period led to a maximum immobilization yield of 75.8% and an immobilization efficiency of 92.9%. The optimum pH and temperature for immobilized laccase were 3.5 and $45^{\circ}C$, respectively, which differed from the values of pH 3.0 and $40^{\circ}C$ obtained for the free enzyme. Immobilized laccase retained high residual activities over a broad range of pH and temperature. The kinetic parameter $V_{max}$ was slightly reduced from 1,890 to 1,630 ${\mu}mol/min/mg$ protein, and $K_m$ was increased from 29.3 to 45.6. The thermal stability of immobilized laccase was significantly higher than that of the free enzyme, with a half-life 11- and 18-fold higher at temperatures of $50^{\circ}C$ and $60^{\circ}C$, respectively. In addition, residual activity was 82.6% after 10 cycles of use. Thus, laccase immobilized on $SiO_2$ nanoparticles functionally activated with glutaraldehyde has broad pH and temperature ranges, thermostability, and high reusability compared with the free enzyme. It constitutes a notably efficient system for biotechnological applications.

• 상하수도학회지
• /
• 제30권6호
• /
• pp.715-723
• /
• 2016

This study investigated the effect of high concentration of free ammonia on microalgal growth and substrate removal by applying real wastewater nitrogen ratio. To test of this, the conditions of free ammonia 1, 3, 6, 9, 12, 15 mg-N/L are compared. After 3 days of incubation, algal growth of Chlorella vulgaris and carbon removal rate are respectively lower in the reactors of FA 12, 15 mg-N/L compared to the others. This indicates that the high concentration of free ammonia, in this case, above 12 mg-N/L, has negative effect on algal growth and metabolic activity. Also, high concentration of free ammonia causes the proton imbalance, ammonium accumulation in algae and has toxicity for these reasons. So, we have to consider free ammonia in applying the microalgae to wastewater treatment system by the way of diluting wastewater or controlling pH and temperature.

• 한국어병학회지
• /
• 제11권2호
• /
• pp.143-150
• /
• 1998

바지락 조직과 주변 환경에 있는 세균의 특성과 분포를 여러 배지와 온도 그리고 생화학적 동정 kit를 사용하여 비교 분석하였다. 장내, 갯벌, 아가미 그리고 외부체액에 있는 미생물의 집락수는 사용한 BHIA, STA 그리고 SNA 배지에 영향을 받지 않는 것으로 나타났다. 그리고 $15^{\circ}C$ 배양조건에서의 증식속도는 $25^{\circ}C$와 $35^{\circ}C$의 조건에 비해 느린 것으로 나타났으나 총 세균 집락수는 $15^{\circ}C$에서의 것이 가장 높게 나타났다. 영양배지에서 자란 세균집락을 무작위적으로 선택배지에 옮기면 조직 시료를 직접 도말 한 경우에 비해 높은 비율로 집락형성을 하는 것을 보여 주었다. API 20E와 API 20NE를 사용하여 각 장기 또는 외부에 있는 세균의 종류를 동정한 결과 바지락 조직간에는 서로 유사한 종의 분포를 보이나 주위 환경이 되는 갯벌이나 외부체액에 있는 미생물군의 종류와는 다르게 나타났다. 바지락 주위의 갯벌이나 외부체액의 미생물군은 Pseudomonas 가 주종을 이루고 있는 조직내의 미생물군에 비해서 훨씬 높은 다양성을 보여 주었다. 이러한 결과는 바지락 조직이 주위 환경중의 세균에 대한 선택적 친화력이 있음을 의미한다고 할 수 있다.

• 한국식품과학회지
• /
• 제46권1호
• /
• pp.19-24
• /
• 2014

본 연구에서는 PET preform, 성형된 PET병, 그리고 PET병 생수에서 HS-SPME GC/MS를 통해 휘발성 물질을 동정하고 HDPE cap으로부터 생수에 이행된 2,4-DTBP의 이행량을 분석하였다. PET preform과 완성된 PET에서 nonanal과 decanal이 확인되었다. 이 물질들은 이취의 원인 물질로서 preform보다 PET병에서 농도가 더 높게 나타났으며, PET병에 대해 온도 증가에 따른 휘발성 물질을 분석한 결과 온도가 증가할수록 물질의 농도가 증가하였다. 특히 nonanal, vinyl benzoate, 그리고 decanal과 같이 온도에 민감한 휘발성 물질이 크게 증가하였다. 그리고 생수병의 HDPE cap에서 항산화제인 Irgafos 168을 정량한 결과 $206{\pm}20.1{\mu}g/g$의 농도를 나타내었다. 2,4-DTBP는 항산화제인 Irgafos 168의 분해 물질이므로 생수에서 검출된 2,4-DTBP는 cap에서 생수로 이행된 휘발성 물질로 확인되었으며 이행량은 $4.8{\pm}0.2{\mu}g/L$로 확인되었다. 따라서 PET병 생수의 관능학적 품질을 높이고 소비자의 안전을 위하여 PET 및 HDPE 제조 공정에서 가능한 온도를 낮게 제어하는 기술이 요구되며, 생수 제품의 유통 및 소비자 취급 시 적절한 온도 유지와 올바른 제품 보관을 통하여 저분자의 이취 원인 물질들을 줄이는 것이 중요할 것으로 판단된다.

• The Korean Journal of Ecology
• /
• 제18권3호
• /
• pp.323-332
• /
• 1995

Effects of wintering and temperature on nitrogen fixation activity of nodules of Melilotus suaveolens Ledeb. grown in the field and growth chamber conditions were investigated. The biennial plants transfered to the growth chamber from winter field recovered the activity in 3 weeks of incubation and attained the maximum rate of $153{\mu}mol\;C_2H_4{\cdot}g$ fr wt $nodule^{-1}{\cdot}h^{-1}$ in 5 weeks. When root nodules which adapted to different temperatures, were pretreated with 10, 20 and $30^{\circ}C$ for 1 hour, and then transfered to $30^{\circ}C$, nitrogen fixation activity was promoted in the nodules exposed to lower field temperature ($12^{\circ}C$) with 1$0^{\circ}C$ pretreatment. M. suaveolens maintained nitrogen fixation activity in the wide range of temperatures, and was more tolerant to lower temperature than those of other woody leguminous plants, Diurnal changes of nodule activity showed increase with sunrise and decrease with sunset during spring and autumn, but the activity was inhibited during July and August because of high temperature with stron irradiation. Nitrogen fixation activity of annual plant appeared in mid-April, and showed two peaks (104 and 43 mol $C_2H_4{\cdot}g$ fr wt $nodule^{-1}{\cdot}h^{-1}$) in July and September, and then disappeared after October. Nitrogen fixation activity of biennial plant reappeared in mid-March after wintering and attained two peaks (102 and 82 ${\mu}mol\;C_2H_4{\cdot}g$ fr wt $nodule^{-1}{\cdot}h^{-1}$) in April and June of flowering period, and then disappeared after July due to plant withering by severe drought.

• 한국균학회지
• /
• 제40권4호
• /
• pp.191-203
• /
• 2012

우리나라 산림에서 수집한 외생균근균 8종 27개 균주에 대한 균사 생장 특성을 다양한 배양 조건(배지, 온도, pH)에서 조사하였다. 60일 배양 후, 모든 균주는 PDA와 MMN 배지에서 생장하였으나, 송이를 포함한 일부 균주들은 MEA나 SDA 배지에서 전혀 생장하지 않았다. 또한 대부분의 균주들을 PDA 배지에서 배양했을 때에 저온($10^{\circ}C$)보다 고온($30^{\circ}C$)에서 균사 생장이 저조하였다. 또한 PDA 배지 상에서의 최적 생장온도는 $20-25^{\circ}C$, PDB 배지 내 균사 생장을 위한 최적 pH는 4-5로 나타났다. Carboxymethyl cellulose(CMC) 활성은 모든 시험 균주에서 나타났으며, CMC(pH 5.0) 한천배지 상에서 최대의 셀룰라아제 활성을 나타낸 균주는 송이(1266)였다.

• Journal of Microbiology and Biotechnology
• /
• 제17권1호
• /
• pp.104-109
• /
• 2007

Lactic acid bacteria that accumulated ${\gamma}-aminobutyric$ acid (GABA) in culture medium were screened to identify strains with high GAB A-producing ability. One strain, MS, which was isolated from kimchi, showed the highest GABA-producing ability among the screened strains. MS was identified as Lactobacillus buchneri based on Gram-staining, metabolic characteristics, and 16S rDNA sequence determination, Optimum culture conditions for GABA production were determined: MRS broth containing 5% MSG, 1% NaCl, and 1% glucose, at an initial pH of 5.0, the incubation temperature at $30^{\circ}C$ for 36 h. Under these conditions, MS produced GABA at a concentration of 251 mM with a 94% GABA conversion rate. Moreover, culture extracts of Lb. buchneri MS partially or completely protected neuronal cells against neurotoxicantinduced cell death.