• 대한인간공학회지
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• 제36권5호
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• pp.535-543
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• 2017

Objective: This study was designed to identify factors affecting pilots' +Gz tolerance recovery from +Gz induced exhaustion. Background: +Gz tolerance of pilots has been considered as a crucial factor to fly the modern high performance fighter aircrafts. However, the factors affecting pilots' G-tolerance recovery from +Gz induced exhaustion have not been examined in the acceleration research community. Method: A centrifuge profile consisting of a high +Gz run for pilot's exhaustion and a low +Gz run for pilot's recovery and another high +Gz runs for pilot's second exhaustion was designed. The subjects' +Gz tolerance recovery ratio was measured by ratio of second high +Gz run time to the first high +Gz run time. The subjects' +Gz tolerance recovery rate was measured by dividing the subjects' +Gz tolerance recovery ratio by the low +Gz run time. The subjects' G-tolerance recovery rate was analyzed with respect to the subjects' personal factors including subjects' anthropometric and physiologic characteristics, flight time, flying aircraft type and so on. Results: The subjects' previous three-month flight hours (r=-0.336, p=0.039), six-month flight hours (r=-0.403, p=0.012) and one-year flight hours (r=-0.329, p= 0.044) correlated with the subjects' G-tolerance recovery rate. Conclusion: The subjects' G-tolerance recovery rate is clearly related to the subjects' previous flight hours. However, the subjects' anthropometric and physiologic characteristics do not show any statistically significant correlation with the subjects' G-tolerance recovery rate. Application: This research provides a safety critical insight to aviation community by identifying the factors to affect the gravity-induced loss of consciousness (GLOC) of pilots.

• Journal of Microbiology and Biotechnology
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• 제32권2호
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• pp.248-255
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• 2022

Phlebia sp. MG-60 is the salt-tolerant, white-rot fungus which was isolated from a mangrove forest. This fungus expresses three kinds of manganese peroxidase (MGMnP) isozymes, MGMnP1, MGMnP2 and MGMnP3 in low nitrogen medium (LNM) or LNM containing NaCl. To date, there have been no reports on the biochemical salt-tolerance of these MnP isozymes due to the difficulty of purification. In present study, we established forced expression transformants of these three types of MnP isozymes. In addition, the fact that this fungus hardly produces native MnP in a high-nitrogen medium (HNM) was used to perform isozyme-selective expression and simple purification in HNM. The resulting MGMnPs showed high tolerance for NaCl compared with the MnP of Phanerochaete chrysosporium. It was worth noting that high concentration of NaCl (over 200 mM to 1200 mM) can enhance the activity of MGMnP1. Additionally, MGMnP1 showed relatively high thermo tolerance compared with other isozymes. MGMnPs may have evolved to adapt to chloride-rich environments, mangrove forest.

• 한국환경농학회지
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• 제18권2호
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• pp.174-178
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• 1999

안토시아닌 결핍 돌연변이 토마토 변종인 H957은 낮은 인산 공급에 대하여 내성(耐性)을 보인다. 본 저린산(低燐酸) 내성(耐性)을 연구하기 위해 미량의 인산을 포함한 조직배양 배지 위에서 H957의 생장도를 측정하였다. 이를 위하여 야생형의 모계품종(H883)과 공동 배양을 실시하여 생/건물질의 중량, callus/shoot 형성도, 무기질함량을 검사하였다. 본 연구에 사용된 배지의 인산 농도는 $0-400{\mu}M$ 사이의 일곱가지이다. 0과 12.5μM의 인 농도에서는 두 변종의 조직은 거의 생존하지 않았으나 $50-200M$에서는 H957이 H883을 앞선 것으로 나타났다. H957은 생/건물질 중량 부문에서 매우 앞선 것으로 나타났으며, cellus 및 shoot 형성도에 있어서도 미량의 인산 농도에 대해 H883보다 덜 민감한 것으로 나타났다. 이는 세포 및 조직 차원에 있어 H957의 높은 항저린산(抗低燐酸) 특성을 입증하는 것이다. 아울러, 인의 함량을 측정한 결과, H957 조직은 H883보다 낮은 농도의 인을 함유하고 있는 것으로 나타났다. 이 결과는 H957의 항저린산(抗低燐酸) 특성이 이미 흡수된 인의 세포 및 조직 차원에서의 높은 활용성에 기인함이라고 판단된다.

• 미생물학회지
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• 제37권3호
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• pp.228-233
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• 2001

Salmonella enterica serovar Typhimurium의 대수 생장기 산 적응기전(acid tolerance response; ATR)은 pH 4.5 이하 조건에서 산 적응결과 형성된 것이며, 이것은 세균세포가 강한 산성환경에 노출되었을 때 생존율을 높일 수 있는 기전이다. ATR은 세균의 생장단계에 따라 대수 생장기 ATR과 생장 정지기 ATR로 구분되어질 수 있으며, 각 생장 단계는 산 적응 과정에서 합성되는 고유의 ASP (acid shock protein)가 존재한다. ATR 기전은 낮은 온도 등과 같은 환경조건에 영향을 받는다는 것이 본 실험 결과를 통하여 발견되었다. 낮은 온도 및 약산성 조건에 노출되었을 경우 강한 산성 조건에서 세균의 생존율은 증가하는 양상을 보였으며, 이때의 생존율은 $37^{\circ}C$에서 보여졌던 것보다 높게 나타났다. $25^{\circ}C$에서 산 적응을 하지 않은 경우의 세균은 $37^{\circ}C$와 비교하였을 경우 약 10,000배 정도의 생존율 증가를 보여주었다. 산 내성 반응에 주요한 기능을 담당하는 rpoS 돌연변이주의 산 내성도는 $37^{\circ}C$의 결과와 비교해블 때 저온의 조건에서 산 내성능이 높게 나타났다. 비륵 rpoS 돌연변이주가 저온에서 산 적응 여부에 관계없이 pH 3.1에서 유사한 ATR 양상을 보여주고 있지만, $25^{\circ}C$의 산성 조건에서 rpoS$\Omega$Ap 돌연변이주는 지속적 산 내성도를 나타내지 않음으로써 저온에서도 rpoS 의존성 ATR 기전이 존재하고 있다는 것을 알 수 있었다. 결과적으로 저온 조건에서는 rpoS의존적 및 -비의존적 ATR기전 모두가 존재하는 것으로 여겨진다. 저온 조건과 ATR의 기초연구를 위해서 병원성 5. enterica serovar Typhimurium UK1에서 low temperature acid tolerance (lat) 유전자를 P22-MudJ(Km, lacZ)를 이용한 lacz 오페론 융합법을 사용하여 LF452 latA::MudJ를 분리하였다. LF452 latA::MudJ 돌연변이주는 저온에서 산 적응기전을 보유하지 않았으며, 결과적으로 latA는 $25^{\circ}C$에서 산 적응 내성 기전에 관여하는 중요 유전자로 판단되며, latA의 유전자는 Salmonella Genetic Map상의 21.5 min에 위치하고 있다.

• Biomolecules & Therapeutics
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• 제9권4호
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• pp.277-281
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• 2001

Chromium is an essential nutrient and participates in glucose and lipid metabolism in human beings and animals. The present study was conducted to assess the effects of chromium picolinate (Cr-pic) on glucose tolerance and insulin sensitivity in type I and ll diabetic rats. The experimental groups were type I diabetic (streptozotocin-induced: 40 mg/kg, i.p.) and type II diabetic (Goto-Kakizaki rats) models. Each group was subdivided into control. low-dose and high-dose of Cr-pic treated groups. The Cr-pic was orally administered with Cr-pic (100 mg/kg for low dose group and 200 mg/kg for high dose group) for 4 weeks. And then we performed intraperitoneal glucose tolerance test (IPGTT) and insulin sensitivity test (ITT). The glucose tolerance test was carried out by inection of glucose (2 g/kg, i.p.). The peripheral insulin sensitivity test was con- ducted by injection of insulin (5 units/kg, s.c.) and glucose. We performed determining of blood glucose concentration at 0, 10, 30, 60, 90, and 120 min using automated glucose analyzer. The plasma insulin concentration was determined by rat insulin EIA kit. Administration of Cr-pic improved weight gain in all group s with higher significant in the low-dose group. There was no significance between the control and the Cr-pic treated groups in the area under the blood glucose curve and serum insulin concentration plots of IPGTT and peripheral ITT in type I diabetic rats. But Cr-pic treated groups showed significantly lower levels of the area under the blood glucose currie during IPGTT and ITT and the high-dose group showed less effects compared with the low-dose group in the type II diabetic rats. The plasma insulin concentration of both diabetic groups was not influenced by Cr-pic supplementation. We can conclude that chromium picolinate may improve the endogenous and exogenous insulin action and peripheral insulin sensitivity in type II diabetic rats.

• 환경생물
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• 제21권4호
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• pp.405-409
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• 2003

To study the tolerant capacity of anaerobic granular sludge (AGS) to oxygen using semi -dynamic batch experiment, the aerating time, pH of the basal media, reductive inorganic materials, microorganism, and microorganism metabolite were investigated. When the aerating time was higher or lower than 0.5 h, the producing gas activity of sludge was lower than that of the control. The oxygen tolerance of the experimental sludge was the highest at the initial pH 7.2. The producing gas activity of sludge I was higher than that of sludge II. And storage at $4^{\circ}C$ can low the lose of the oxygen tolerance capacity of granular sludge. The producing gas activity of sludge was the highest when KI was added. The growth of aerobic microorganisms and some metabolite could increase the producing gas activity of granular sludge.

• Molecules and Cells
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• 제41권5호
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• pp.413-422
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• 2018

Soybean transgenic plants with ectopically expressed AtABF3 were produced by Agrobacterium-mediated transformation and investigated the effects of AtABF3 expression on drought and salt tolerance. Stable Agrobacterium-mediated soybean transformation was carried based on the half-seed method (Paz et al. 2006). The integration of the transgene was confirmed from the genomic DNA of transformed soybean plants using PCR and the copy number of transgene was determined by Southern blotting using leaf samples from $T_2$ seedlings. In addition to genomic integration, the expression of the transgenes was analyzed by RT-PCR and most of the transgenic lines expressed the transgenes introduced. The chosen two transgenic lines (line #2 and #9) for further experiment showed the substantial drought stress tolerance by surviving even at the end of the 20-day of drought treatment. And the positive relationship between the levels of AtABF3 gene expression and drought-tolerance was confirmed by qRT-PCR and drought tolerance test. The stronger drought tolerance of transgenic lines seemed to be resulted from physiological changes. Transgenic lines #2 and #9 showed ion leakage at a significantly lower level (P < 0.01) than ${\underline{n}}on-{\underline{t}}ransgenic$ (NT) control. In addition, the chlorophyll contents of the leaves of transgenic lines were significantly higher (P < 0.01). The results indicated that their enhanced drought tolerance was due to the prevention of cell membrane damage and maintenance of chlorophyll content. Water loss by transpiration also slowly proceeded in transgenic plants. In microscopic observation, higher stomata closure was confirmed in transgenic lines. Especially, line #9 had 56% of completely closed stomata whereas only 16% were completely open. In subsequent salt tolerance test, the apparently enhanced salt tolerance of transgenic lines was measured in ion leakage rate and chlorophyll contents. Finally, the agronomic characteristics of ectopically expressed AtABF3 transgenic plants ($T_2$) compared to NT plants under regular watering (every 4 days) or low rate of watering condition (every 10 days) was investigated. When watered regularly, the plant height of drought-tolerant line (#9) was shorter than NT plants. However, under the drought condition, total seed weight of line #9 was significantly higher than in NT plants (P < 0.01). Moreover, the pods of NT plants showed severe withering, and most of the pods failed to set normal seeds. All the evidences in the study clearly suggested that overexpression of the AtABF3 gene conferred drought and salt tolerance in major crop soybean, especially under the growth condition of low watering.

• 한국양식학회지
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• 제22권1호
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• pp.122-125
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• 2009

Salinity tolerance on survival rate of 2, 4 and 6-week-old larvae and juvenile of black porgy Acanthopagrus schlegeli was investigated at 0, 7.5, 15, 22.5 and 30 psu for 21 days. In the 2 and 4-week-old larvae and juvenile (TL: 1.23 and 1.72 cm) were all died within 12 and 26 hours after to the 0 psu transfer, respectively. However, survival rate of other experimental group (7.5, 15, 22.5 and 30 psu) was significantly difference in the range between 27.3% and 95% (P<0.05). However survival rate of 6-weeks-old juvenile (TL: 2.83 cm) were over 99.0% during experimental periods and they appeared in good health. There was no significant difference in survival those reared to the salinities of all experimental groups (P>0.05). The present study suggests that the freshwater and saline groundwater of low salinity could be used to grow early juveniles of black porgy and it may be possible to culture in freshwater.

• 한국광학회:학술대회논문집
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• 한국광학회 2003년도 하계학술발표회
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• pp.104-105
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• 2003

We have fabricated a side-illuminated p-i-n photodetectors with evanescently-coupled waveguides for surface hybrid integration in low-cost modules. We adopted WGPD of evanescently-coupled type to have high responsivity and coupling tolerance, and to avoid any reliability problem. This proposed photodetectors have a high responsivity of 1.10 A／W at a wavelength of 1.55 ${\mu}{\textrm}{m}$. The 1dB coupling tolerance to cleaved fiber and photodetectors is $\pm$3.5 ${\mu}{\textrm}{m}$ in the vertical direction and $\pm$11 ${\mu}{\textrm}{m}$ in the horizontal direction.

• Asian-Australasian Journal of Animal Sciences
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• 제16권5호
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• pp.726-731
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• 2003

The aim of this research was to identify candidate probiotic lactic bacteria among indigenous dadih lactic isolates. Dadih is an Indonesian traditional fermented milk of West Sumatra which is fermented naturally. Viability of the strain is critical in determining the capacity of lactic bacteria to induce immune stimulation as well as to colonize in the intestinal tract. Therefore, LAB are proposed to exert health promoting or probiotic effects in human, such as inhibition of pathogenic microflora, antimutagenic, and the reduction of cholesterol levels. This manuscript reports in vitro probiotic properties of indigenous dadih lactic bacteria, especially some important colonization factors in GI tract, such as lysozyme, acid and bile tolerance. Bile Salt Hydrolase (BSH) activity, spectrum of bacteriocin, and antimutagenic activity of bacterial cells were also assessed. Twenty dadih lactic isolates were screened further for their tolerance to low pH, at pH 2 and 3 as well as their bile tolerance. There were ten isolates classified as acid and bile acid tolerant, and further screened for lysozyme tolerance, BSH activity. The spectrum of bacteriocin activity of isolates was assayed using cell-free neutralized supernatants by agar spot test against variety of pathogens. Lc. lactis subsp. lactis IS-10285, IS-7386, IS-16183, IS-11857 and IS-29862, L. brevis IS-27560, IS-26958 and IS-23427, Leu.mesen.mesenteroides IS-27526, and L. casei IS-7257 each has good survival rate at low pH values and in the presence of lysozyme, and short lag time in the presence of 0.3 % oxgall. Lc. lactis subsp. lactis IS-11857 and IS-29862 each has high BHS activity, Lc. lactis subsp. lactis IS-10285 and IS-16183 each had a positive spectrum of bacteriocin activity against E. coli 3301 and Lysteria monocytogenes ATCC 19112, while L. brevis IS-26958 has high BHS activity as well as positive spectrum of bacteriocin against E. coli 3301, Lysteria monocytogenes ATCC 19112, and S. aureus IFO 3060. All of the ten dadih lactic strains performed in vitro acid and bile tolerance, indicating a possibility to reach the intestine alive, and display probiotic activities.