• 한국자기학회:학술대회 개요집
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• 한국자기학회 2005년도 하계학술연구발표회 논문개요집
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• pp.206-207
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• 2005

• 대한약리학회지
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• 제17권2호
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• pp.31-36
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• 1981

Heavy metals which are present as trace elements in human body have been known to modify various enzymatic reaction. These metals can be essential or non-essential. Zinc, copper and calcium are essential in maintaining some biological processes, whereas non-essential metals such as cadmium, lead and mercury produce accumulatve toxic effect. Cadmium accumulated in pancreas can cause toxicity and damage of pancreatic cells, thereby influencing CHO metabolism. Lead compounds are known to produce toxic effects on the kidney, digestive system and brain fellowed by inhibition of activity of ${\rho}-aminolevulinic$ acid and biosynthesis of hemoproteins and cytochrome. Evidence has been accumulated that zinc not only acts as a cofactor in enzyme reaction but also prevents toxic effect induced by heavy metal such as copper and cadmium. To demonstrate the effect of heavy metals on pancreatic secretion, part of uncinate pancreas was taken and incubated in Krebs-Ringer bicarbonate buffer with heavy metals used. Additional treatment with CCK-OP was performed when needed. After incubation during different period of time, medium was analyzed for amylase activity using Bernfeld's method. The present study was attempted in order to elucidate the effect of several kinds of heavy metal on exocrine pancreatic secretion in vitro. The results obtained are as follows: 1) CCK-OP stimulated significantly amylase release from pancreatic fragments in vitro. 2) CCK-OP response of amylase release from pancreatic fragments was inhibited by treatmant with cadmium, especially high doses of cadmium. 3) CCK-OP response of amylase release from pancreatic fragments was inhibited when pretreated with $10^{-4}M$ copper chloride. 4) Lead chloride at the concentration of $10^{-3}M\;and\;10^{4}M$ stimulated the basal amylase release in vitro but CCK-OP response did not augment by lead chloride. 5) Zine chloride did not affect amylase release from pancreatic fragment in vitro. From the results mentioned above, it is suggested that CCK-OP response was inhibited it the amylase release from pancreatic fragments pretreated with cadmium and copper chloride.

• 대한임상검사과학회지
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• 제42권3호
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• pp.116-124
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• 2010

This study was aimed to clerify the cytotoxicity of some plant extracts such as Hosta longissima HONDA (HL), Hemerocallis fulva var. Kwanso REGL (HFVK), Hemerocallis fulva L (HF), Macrocapium officinale NAKAI (MO) and Mentha canadensis var. piperascens HARA (MCVP), the cultured NIH3T3 fibroblasts were treated with 25, 50, 100, 150 and $200{\mu}g/mL$ of five kinds of plant extracts for 48 hours, respectively. The cytotoxicity of plant extracts was measured by MTT and NR assays for the cell viability, and XTT assay for the cell adhesion activity. In this study, HL, MO and FHVK extracts showed the range of midtoxic-non toxic by the criteria of chemical cytotoxicity. While, the HF and MCVP extracts showed midtoxic. In the extract cytotoxicity, HL, MO and FHVK extracts showed non-toxic by the criteria of extract cytotoxicity. While, HF extract was determined as lower-toxic. In the responsive sensitivity of each plant extract on colorimetric assays, HF extract was sensitive to mitochondrial enzyme by MTT assay, lysosomal enzyme by NR assay and mitochondrial nucleus by XTT assay. While, MCVP extract was sensitive to mitochondrial enzyme by MTT assay and lysosomal enzyme by NR assay than other assays. While, HL, HFVK and MO extracts were most sensitive to NR assay. Cell culture is one of useful materials in the screening of cytotoxic and recovary effect on the putative chemical agents or plant extract. And also, colorimetric assay is regarded as very useful tools for quantitative measurement of cytotoxic effect on plant extracts in vitro.

• 한국항공우주학회지
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• 제47권5호
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• pp.335-343
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• 2019

한국형발사체 3단의 무추력 비행구간에서는 추력기 자세제어시스템에 의해 롤, 피치, 요 축에 대한 3축을 제어하고, 추력 비행구간에서는 롤 축에 대한 제어를 추력기 자세제어시스템에 의해 수행한다. 발사체 자세제어시스템으로 사용되는 추력기의 추진제는 하이드라진과 같은 전통적인 독성 추진제가 주로 사용되어 왔으나 최근에는 친환경적인 ADN 및 HAN 등과 같은 무독성(청정) 추진제가 많이 연구되고 있다. 특히, 과산화수소 추진제는 독성이 없고 제작 및 시험평가에 있어서 상대적으로 저렴해서 독성 추진제의 대안 중 하나로 떠오르고 있다. 본 논문에서는 한국형발사체 3단의 자세제어를 위해 개발 중인 50N 급 과산화수소 단일추진제 추력기 자세제어시스템의 설계내용 및 시제품 제작, 시험결과를 기술하였다.

• 한국군사과학기술학회지
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• 제27권2호
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• pp.304-310
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• 2024

Ricin is a highly toxic protein which is produced in the seeds of the castor oil plant. Ricin toxin A chain has ribosomal RNA N-glycosylase activity that irreversibly hydrolyses the N-glycosidic bond of the adenine residue at position 4324 within the 28S rRNA. In this study, we developed non-toxic recombinant ricin vaccine(R51) in E. coli expression system, and evaluated efficacy of the R51 according to adjuvants. When the R51 was administered using aluminum hydroxide as an adjuvant, the vaccine efficacy was higher than that of TLR agonists or aluminum phosphate. Because it is time-consuming to administer the vaccine three times at three-week intervals, we investigated the survival rate and antibody titer of mice according to the change of time interval of vaccination. Interestingly, there was no difference in survival rate and antibody titer when R51 was administered at 0, 1, and 3 weeks or 0, 2, and 4 weeks compared to when administered at 0, 3, and 6 weeks. Therefore, the developed R51 vaccine is promising to protect soldiers from Ricin attack.

• 한국미생물·생명공학회지
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• 제23권6호
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• pp.770-776
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• 1995

For the purpose of development of non-toxic and biodegradable flocculant, chitosan complex was isolated from Ganoderma lucidum wastes. The isolated complex was identified as the expected chitosan-glucan complex by IR specta. The complex was extracted by treatment of 50% NaOH solution at 120$\circ$C for 5 hrs, namely optimal condition and solubilized with 2% acetic acid for fur-ther use as flocculant. Preliminary experiments showed that the solubilized complex had higher flocculation activity of 1.3 fold than commercial chitosan at 400 mg/l concentration in soybean curd wastewater. Also the solubilized complex removed 83% of MLSS and 60% of COD in the soybean curd wastewater treated by photosynthetic bacteria, 50% of turbidity and 21% of MLSS in sugar industry wastewater, and 90% of turbidity and 89% of MLSS in alcohol fermentation wastewater. Bacterial cell flocculation activities of the solubilized chitosan-glucan complex were 89% in Bacillus subtilis broth, 81% in Streptococcus lactis broth, and more than 90% in Escherichia coli broth after standing for 2 days. The results reveal that chitosan-glucan complex from Ganoderma lucidum wastes can substitute for commercial chitosan as non-toxic and biodegradable flocculant.

• 약학회지
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• 제56권1호
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• pp.14-19
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• 2012

Nonalcoholic steatohepatitis(NASH) is serious metabolic disease related to fatty acid. According to "two hit theory", fatty acid-induced oxidative stress is important factor to progress nonalcoholic steatohepatitis from steatosis. In this study, we evaluated stearic acid induced oxidative stress in human hepatocarcinoma SK-Hep-1 cell. Cell viability, reactive oxygen species (ROS) production, glutathione (GSH), malondialdehyde and expression of antioxidant enzymes were determined at various time-points and concentrations of stearic acid. At 0.2 mM, non-toxic concentration, of stearic acid, production of ROS was significantly increased at 24 hours and the level of GSH was significantly decreased. Expression of superoxide dismutase-1 and 2 was slightly increased in 0.2 mM stearic acid at 24 hours. These results represent that the non-toxic concentration of stearic acid resulted in oxidative stress, suggesting that stearic acid may play a critical role in development of steatohepatitis.

• 한국안전학회지
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• 제20권4호
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• pp.63-70
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• 2005

It has been used so many kinds of architectural materials and interior products in current building construction, and use of composite architectural materials is increasing with the development of chemical technology. As the green architecture has become the center of public interest, much effort is conducted in advanced countries on the LCA point of view, such as restriction of architectural materials that emitting pollution substances, developing of Non-Toxic architectural materials, and recycling of used materials, etc. with the cooperation of related organizations, material manufacture companies, and construction companies. Because the kinds of materials to be used in building constructions are so various, there might be some possibility of personal and subjective choice at the time of materials selection resulting the missing the requirements of building components and the choice of harmful materials to human. One way to resolve the material problem is to present the green architectural materials which coincide with the quality performance at service and not harmful to man and nature. At this point of view, this study aims to develop the material classification model by investigating the major labelling system about green architectural materials in both domestic and abroad and to implement an efficient material selection system by making a powerful database of environmental standard and quality basis of building requirements.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.414-414
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• 2010

KSTAR vacuum vessel has been boronized by carborane ($C_2B_{10}H_{12}$) to reduce various kinds of impurities including carbon and oxygen from the wall, since carborane is solid, non-toxic, non-explosive and is easily evaporated, while diborane ($B_2D_6$) is toxic and explosive. To find the best wall condition for the removal of contaminants before application to KSTAR, various amounts (0.3g, 0.5g, 1g) of carborane are tested in a test chamber, where filament discharge was generated in the mixture of helium and carborane with the same KSTAR target pressure (~ 5 mTorr) from base pressure (${\sim}10^-7\;Torr$). Discharge is performed by a pulse sequence mode with 3 second power on and 5 second power off. Deposited films of a-C/B:H are characterized by ellipsometery, AES and XPS, and are compared with those of KSTAR.

• 한국가시화정보학회지
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• 제5권1호
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• pp.30-36
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• 2007

The global environment is deteriorating at an alarming rate, despite of enhanced international environmental regulation. Many studies have been performed to reduce toxic pollutants. Recently, plant-based phytoremediation technology for moving toxic contaminants from soil and water has been receiving large attention. Arsenic-contaminated soil is one of the major pollutant sources for drinking water. Pteris erotica has been known as a hyper-accumulator of arsenic from soils. In this study, we investigated the effect of arsenic absorption on sap flow inside xylem vessels of Pteris. The synchrotron X-ray micro-imaging technique was employed to monitor the refilling process of water containing arsenic inside the xylem vessels of Pteris's leaves and stems non-invasively. The captured phase-contrast X-ray images show both anatomy of internal structure and transport of water inside Pteris. The exposure of Pteris to arsenic solution was found to increase largely the water raise speed in xylem vessels. The present results would provide important information needed for understanding the mechanisms of accumulation and transportation of toxic materials in plants.