• 동의생리병리학회지
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• 제16권5호
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• pp.1035-1041
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• 2002

Ultrasonic nebulizer with the application of new engineering methodology and the design of electronic circuit and 766ppm Cd nebulizing solution were used to generate cadmium aerosol for inhalation toxicology study. The results of particle size analysis for cadmium aerosol were as following. The highest particle counting for source temperature 20℃ was 43.449 x 10³ in inlet temperature 250℃ and particle diameter 0.75㎛. The highest particle counting for source temperature 50℃ was 43.211 x 10³ in inlet temperature 100 ℃ and particle diameter 0.75㎛. The highest particle counting for source temperature 70℃ was 41.917x10³ in inlet temperature 250℃ and particle diameter 0.75㎛. The ranges of geometric mean diameter(GMD) were 0.677-1.009㎛ in source temperature 20℃, 0.716-0.963㎛ in source temperature 50℃, and 0.724-0.957㎛ in source temperature 70℃. The smallest GMD was 0.677㎛ in source temperature 20℃ and inlet temperature 20℃. and the largest GMD was 1.009㎛ in source temperature 20℃ and inlet temperature 20℃. The ranges of geometric standard deviation(GSD) were 1.635-2.101 in source temperature 20℃. 1.676-2.073 in source temperature 50℃, and 1.687-2.051 in source temperature 70℃. The lowest GSD was 1.635 in source temperature 20℃ and inlet temperature 20℃, and the highest GSD was 2.101 in source temperature 20℃ and inlet temperature 200℃. Aerosol generated for cadmium inhalation toxicology study was polydisperse aerosol. The ranges of mass median diameter(MMD) were 1.399-5.270㎛ in source temperature 20℃. 1.593-4.742㎛ in source temperature 50℃, and 1.644-4.504㎛ in source temperature 70℃. The smallest MMD was 1.399㎛ in source temperature 20℃ and inlet temperature 20℃, and the largest MMD was 5.270㎛ in source temperature 20℃ and inlet temperature 200℃. Increasing trends for GMD, GSD, and MMD were observed with same source temperature and increase of inlet temperature. MMD for inhalation toxicology testing in EPA guidance is less than 4㎛. In our results. inlet temperature 20 and 50℃ in source temperature 20℃, and inlet temperature 20 to 150℃ in source temperature 50 and 70℃ were conformed to the EPA guidance. MMD for inhalation toxicology testing in OECD and EU is less than 3㎛. In our results, inlet temperature 20 and 50℃ in source temperature 20, 50, and 70℃ were conformed to the OECD and EU guidance.

• 해양환경안전학회지
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• 제15권4호
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• pp.329-338
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• 2009

북부 가막만에서 해양환경의 변화에 따라 식물플랑크톤의 군집이 어떻게 변화하는지 기존에 발표된 식물플랑크톤 생리학적 자료를 이용하여 해석하였다. 해양환경 및 식물플랑크톤 조사는 2007년 11월부터 2008년 9월까지 2개 정점에서 관측하였다. 조사 동안 10%이상 점유율을 나타내는 우점종은 와편모조류 1종, 규조류 11종 등 총 12종이었다. 우점종의 출현 시기를 보면 규조류 Skeletonema costatum이 하계(7월과 8월)를 제외하고 우점하였으며, 특히 12월은 90% 이상의 매우 높은 우점율을 보였다. 그리고 나머지 기간은 규조류 Eucampia zodiacus와 Chaetoceros속이 우점하였다. 따라서 2008년 7월과 8월에 S. costatum이 우점하지 않는 이유를 생리학적 측면에서 살펴보면 1) S. costatum과 E. zodiacus는 모두 광온 광염성 종이지만, 하계의 수온에서는 E. zodiacus가 S. costatum보다 높은 성장속도를 보였고, 2) 7월에 낮은 부유물질의 농도는 높은 광량이 수중에 도달할 수 있어 E. zodiacus와 같이 광에 대한 친화성이 낮은 종도 우점할 수 있다. 또한 3) 인산염이 비교적 낮은 시기에는 성장전략을 보이는 S. costatum이, 높은 인산염 농도일 때 저장전략을 보이는 E. zodiacus종이 우점할 수 있기 때문으로 생각된다. 앞으로 더 구체적인 식물플랑크톤의 군집 변화를 알아보기 위해서는 계절별로 우점하는 대표 식물플랑크톤에 대한 생리실험이 필요할 것으로 보인다.

• 생명과학회지
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• 제16권3호
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• pp.454-458
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• 2006

출아효모인 Sacharomyces cerevisiae S288C균주를 이용한 효모의 게놈이 완성된 후 S. cerevisiae는 다양한 연구 모델로 이용되어져 왔다. 현재까지 효모를 이용한 기능 유전체학 측면에서의 연구는 laboratory strainin인 S288C 균주 또는 그 유래의 균주들이다. 그러나 자연에서 분리된 효모 또는 산업적으로 이용되어지고 있는 S. cerevisiae의 유전학 측면에서의 연구는 낮은 포자형성률 및 형질전환률, 그리고 S288C 균주와의 게놈상의 상이성 때문에 거의 이루어지지 않고 있다. 여기서 우리 연구진은 자연에서 분리된 Saccharomyces cerevisiae KNU5377 균주를 이용하여 random spore analysis를 통해 MATa 및 $MAT{\alpha}$ 타입의 각각의 haploid cell을 분리 후 이미 보고된 KanMX module를 가지고 round PCR기법에 의한 short flanking homology 기법을 이용하여 전사조절인자인 HSF1 유전자가 치환된 변이주를 구축할 수 있었다. 덧붙여, 모든 유전자에 이 기법을 적용할 수는 없다는 것을 확인하였다. 앞으로 이 변이주를 통해 기능 유전체학적인 측면에서 이 유전자의 스트레스와의 관련성을 연구하고자 한다.

• 한국작물학회지
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• 제27권4호
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• pp.361-370
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• 1982

The effects of climatic factors on organisms lire variable and complex, and it, however, can be interpreted in terms of those on the distribution and those on the population densities. The distribution of an organism may largely be determined by the temperatures, except some temporal organisms which are depended on the air mass movements. Population density of an organism is determined by various climatic factors, such as previous winter temperature, temperature of growing season and rainfall. The start of growing season of the rice plants has been shifted to earlier since last decade in Korea. This may mean that the overall climatic condition during the growing season might be considerably different from those in past years, and such a difference in climatic conditions might have close relation with the recent status of the diseases and insect pests through direct effects on the physiology and population dynamics of the organisms, as well as through on the biotic associations of the pest organisms. The white back planthopper and brown planthopper have become the key insect pests in Korea in recent years. They are migratory and have high reproductive pontentials and more generations than average residential insects. The synchronization of the migrants and physiological condition of the rice plants seems to be the important factors in relation to the recent outbreaks of these insects; the high reproductive rate can be obtained with the growth stage of rice being 30-50 days after transplanting. The modication of the microclimate associated with high plant density and some other introduced new cultural techniques also have some relation with the outbreak. The key diseases of the rice are the blast disease, sheath blight and the bacterial leaf blight. For the rice blast, the seedling blast and leaf blast during the early growing season and the neck blast, have become more serious, the former may be related to hotbed nursery and the later may be related to the high humidity in early August, and synchronization of the heading time which has been shifted to early part from middle or late part of August. In general, for the rice diseases, the development of the new races have been the most serious which are largely resulted from the introduction of the new varieties, but it also seems to be related with the prolonged periods of the favorable condition associated with the shifted growing seasons. In general, the diseases and insect pest problems have become much more variable and complex, and control measures should be based on the thorough knowledge of the ecology of the pest organisms, that is, effects of various environmental factors on the disease cycle; spore release, spore deposition, infection, colonization and sporulation of the disease organisms, and those on the development, reproductive potentials, dispersal, age specific responses of the insects. The well organized real-time pest management systems, such as alfalfa weevil management system developed at the Purdue University in U.S., is the prime importance for the implementation of the pest management principles.

• 한국발생생물학회지:발생과생식
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• 제16권4호
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• pp.295-300
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• 2012

Manganese ($Mn^{2+}$) is a trace element that is essential for normal physiology, and is predominantly obtained from food. Several lines of evidence, however, demonstrated that overexposure to $MnCl_2$ exerts serious neurotoxicity, immunotoxicity and developmental toxicity, particularly in male. The present study aimed to evaluate the effect of 0, 1.0, 3.3, and 10 mg/kg/day doses of $MnCl_2$ on the reproductive organs in the immature female rats. Rats (PND 22; S.D. strain) were exposed to $MnCl_2$ ($MnCl_2{\cdot}4H_2O$) dissolved in drinking water for 2 weeks. The animals were sacrificed on PND 35, then the tissues were immediately removed and weighed. Histological studies were performed using the uteri tissue samples. Serum LH and FSH levels were measured with the specific ELISA kits. Body weights of the experimental group animals were not significantly different from those of control group animals. However, ovarian tissue weights in 1 mg and 3.3 mg $MnCl_2$ dose groups were significantly lower than those of control animals (p<0.05 and p<0.01, respectively). Uterine tissue weights of 3.3 mg dose $MnCl_2$ groups were significantly lower than those of control animals (p<0.01), while the 1 mg $MnCl_2$ dose and 10 mg $MnCl_2$ dose failed to induce any change in uterine weight. Similarly, only 3.3 mg $MnCl_2$ dose could induce the significant decrease in the oviduct weight compared to the control group (p<0.05). Non-reproductive tissues such as adrenal and kidney failed to respond to all doses of $MnCl_2$ exposure. The uterine histology revealed that the $MnCl_2$ exposure could affect the myometrial cell proliferation particularly in 3.3 mg dose and 10mg dose group. Serum FSH levels were significantly decreased in 1mg $MnCl_2$ dose and 10 $MnCl_2$ mg groups (p<0.05 and p<0.01, respectively). In contrast, treatment with 1 mg $MnCl_2$ dose induced a significant increment of serum LH level (p<0.05). The present study demonstrated that $MnCl_2$ exposure is capable of inducing abnormal development of reproductive tissues, at least to some extent, and altered gonadotropin secretions in immature female rats. Combined with the well-defined actions of this metal on GnRH and prolactin secretion, one can suggest the $Mn^{2+}$ might be a potential environmental mediator which is involved in the female pubertal process.

• 한국해양학회지:바다
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• 제4권4호
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• pp.298-304
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• 1999

본 연구는 황복 Takifugu obscurus의 자치어를 이용하여 쓰레기 매립지 침출수의 독성도를 생물검정을 통해 평가하고, 침출수 해양방류가 수산생물에 미치는 영향 및 피해 등을 추론하는데 기본적인 자료로 제공하고자 수행되었다. 급성독성 단기실험은 인공수정에 의해 부화된 자치어(전장 5, 10, 15 mm)와 자연산 치어(전장 30, 45 mm)를 대상으로 실시되었다. 1996년 9월에 채수한 침출수의 부피비 0%~16%범위로 실험구를 설정한 후 실험을 실시하였고, 결과로 Spearman-karber Method를 이용한 반치사농도($LC_{50}$)를 구하였다. 전장별 5단계의 24hr-$LC_{50}$은 침출수 농도 3.03~8.57%, 48hr-$LC_{50}$은 2.73~6.21%, 72hr-$LC_{50}$은 2.45~5.53%, 96hr-$LC_{50}$은 2.38~4.93%로 나타났다. 또한, 96hr-$LC_1$은 0.69~1.51%로 나타났다. 행동 관찰 결과, 호흡수에 있어서는 침출수 농도 0.5%와 1%사이에서 영향이 나타났다(P < 0.05). 전장 5 mm의 자어 단계가 가장 높은 $LC_{50}$을 보였으며, 전장 약 15 mm까지는 감소의 경향을 보이다 15 mm이상에서부터 성장에 따라 $LC_{50}$이 증가하였다. 시간의 변화에 따라 $LC_{50}$은 감소하였으며, 감소양상은 성장에 따라 다르게 나타났다. 이상의 결과로부터, 황복의 자치어에 있어서 침출수 농도 3%이상에서 24시간 내에, 2%이상에서는 96시간 내에 50%의 사망률을 보여 치사의 영향이 나타나고, 침출수 농도 0.5%와 1%사이에서 어체에 생리적인 영향을 미치는 것으로 사료된다.

• 동의생리병리학회지
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• 제22권4호
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• pp.948-953
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• 2008

The purpose of this study was to analyze harmful heavy metals, sulfur dioxide and residual pesticides in 27 kinds of oriental medical materials. This study was carried out on 27 samples of oriental medical materials. The GC-ECD(Varian, CP-3800) was used to analyze residual pesticides. ICP-OES(Varian, Vista-MPX) was used to analyze lead, arsenic, cadmium. Mercury was analyzed by amalgamation method. A modified Monier-Williams method was used to analyze sulfur dioxide. Arsenic was detected less than 3(mg/kg) in 14 samples and was not detected 13 samples. Lead was detected less than 5(mg/kg) in 15 samples and was not detected 12 samples. Mercury was detected less than 0.2(mg/kg) in 15 samples and was not detected 12 samples. Cadmium was detected more than 0.3(mg/kg) in 3 samples was detected less than 0.3(mg/kg) in 16 samples and was not detected 11 samples. A few residual pesticides was detected, but all residual pesticides was safe. Sulfur dioxide was detected in all samples, but all residual sulfur dioxide was safe.

• 동의생리병리학회지
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• 제21권5호
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• pp.1226-1232
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• 2007

Phellinus linteus is a well-known Oriental medicinal fungus that has various biological activities, including immunomodulatory and anti-tumor activities, the mechanisms of which are poorly understood. In the present study, we investigated the anti-proliferative activity of the methanol extract of P. linteus-Barley corn (MEPLB) in human lekemic U937 cells. It was found that exposure of U937 cells to MEPLB resulted morphological change and growth inhibition in a dose-dependent manner as measured by trypan blue count and MTT assay. Upon treatment with MEPLB, U937 cells developed many of the hallmark features of apoptosis, including condensation of chromatin and an increase in the sub-G1 population suggesting that the anti-proliferative effect of MEPLB is associated with the induction of apoptosis. The anti-proliferative and apoptotic effects of MEPLB were connected with a marked induction of the pro-apoptotic Bax and cyclin-dependent kinase (Cdk) inhibitor p21 in a p53-independent manner. Additionally, MEPLB treatment significantly induced the caspase-3 activity in U937 cells. Taken together, the present results suggest that apoptotic signals evoked by MEPLB in human leukemic U937 cells may converge caspase-3 activation through an up-regulation of Bax rather than a down-regulation of Bcl-2 or Bel-xL.

• Journal of Microbiology and Biotechnology
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• 제14권6호
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• pp.1256-1266
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• 2004

2-Bromooctanoic acid (2-BrOA) is known to block the formation of polyhydroxyalkanoic acid (PHA) in Pseudomonasfluorescens BM07 without any influence on the cell growth when grown on fructose, but it inhibits the cell growth when grown on octanoate (OA) (Lee et al., Appl. Environ. Microbiol. 67: 4963- 4974, 2001). We investigated the role of 2-BrOA in the PHA synthesis of the bacterium grown with mixtures of fructose and fatty acids. OA, 11­phenoxyundecanoic acid (1 1-POU), and 5-phenylvaleric acid (5-PV) were selected as model substrates. When supplemented with 50 mM fructose, all these carboxylic acids suppressed the formation of PHA from fructose, however, the ~-oxidation coenzyme A monomers derived from the carboxylic acids were efficiently polymerized, but the conversion yield [(mol of carboxylate substrate converted into PHA)/(mol of carboxylate substrate in the feed)] was low (e.g., maximally $\~53\%$ for 5 mM 11-POU). Addition of 2-BrOA (up to 5 mM) to the mixed carbon sources raised the conversion yield sensitively and effectively only at low levels of the acid substrates (e.g., 2 mM 1 1-POU or 5 mM OA): For instance, $100\%$ of 2 mM ll-POU were converted into PHA in the presence of 5 mM 2-BrOA, whereas only $\~10\%$ of the 1 1-POU were converted in the absence of 2-BrOA. However, at highly saturated suppressing levels (e.g., 5 mM ll-POU), 2-BrOA inhibitor showed no significant additional effect on the conversion ($60- 70\%$ conversion irrespective of 2-BrOA level). The existence of competitive and compensative relationship between 2­BrOA and all the carboxylic acid substrates used may indicate 'Present address: Section on Brain Physiology and Metabolism, Bldg. 10, Rm. 6N202, National Institute on Agmg, National Institute of Health, Bethesda, MD 20892, U.S.A. that all the acid substrate-derived inhibiting species bind to the same site as the 2-BrOA inhibiting species does. We, therefore, suggest that 2-BrOA can be used for efficiently increasing the yield of conversion of expensive substituted fatty acids into PHA and then substituted 3-hydroxyacids by hydrolyzing it.

• 한국산림과학회지
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• 제76권3호
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• pp.243-248
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• 1987

The U.S. Forest Service administers the world's largest forestry research organization. From its modest beginning in 1876, some 30 years before the United States national forest system was established, the research branch has devoted its effort to meet current and future information needs of the forestry community of the United States, not just for the U.S. Forest Service. The research branch is one of three major administrative units of the U.S. Forest Service. The others being the National Forest System and State and Private Forestry. Currently the National Forest System comprises 155 national forests, 19 national grasslands, and 18 utilization projects located in 44 states. Puerto Rico, and the Virgin Islands. The National Forest System manages these areas for a large array of uses and benefits including timber, water, forage, wildlife, recreation, minerals, and wilderness. It is through the State and Private Forestry branch that the U.S. Forest Service cooperates and coordinates forestry activities and programs with state and local governments, forest industries, and private landowners. These activities include financial and technical assistance in disease, insect, and fire protection ; plan forestry programs ; improve harvesting and marketing practices ; and transfer forestry research results to user groups. Forestry research is carried out through eight regional Forest Experiment Stations and the Forest Product Laboratory. Studies are maintained at 70 administrative sites, and at 115 experimental forest and grasslands. All of the current sciences that composed modern forestry are included in the research program. These range from forest biology (i. e. silviculture, ecology, physiology, and genetics) to the physical, mathematical, engineering, managerial, and social sciences. The levels of research range from application, developmental, and basic research. Research planning and priority identification is an ongoing process with elements of the research program changing to meet short-term critical information needs(i. e. protection research) to long-term opportunities(i. e. biotechnology). Research planning and priority setting is done in cooperation with National Forest Systems, forest industries, universities, and individual groups such as environmental, wilderness, or wildlife organizations. There is an ongoing review process of research administration, organization, and science content to maintain quality of research. In the U.S. Forest Service the research responsibility is not completed until the new information is being applied by the various user group : I. e. technology transfer program. Research planning and development in the U.S. Forest Service is a dynamic activity. Porgrams for the year 2000 and beyond are now in the planning stage.