• 식물병연구
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• 제17권1호
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• pp.25-31
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• 2011

녹병은 다양한 작물의 품질과 수확량에 큰 영향을 끼친다. 따라서 이들을 방제하기 위하여 효과적이고 환경친화적인 살균제의 개발이 절실하다. 본 연구에서는 한약재로부터 항균 물질을 탐색하는 과정에서, 당귀 메탄올 추출물이 Puccinia recondita에 의해 발생하는 밀 붉은녹병에 대하여 우수한 방제효과를 나타내는 것을 확인하였다. 밀 붉은녹병에 대하여 활성을 보이는 한 개의 항균물질을 silica gel chromatography, alumina column chromatography와 $C_{18}$ preparative HPLC를 통해 분리, 정제하였다. 분리한 항균물질은 EI-MS와 $^1H$-NMR의 기기 분석 결과 decursinol angelate로 동정되었다. 이 물질은 시험한 6개의 식물병 중에서 밀 붉은녹병과 고추 탄저병에 대하여 우수한 항균활성을 보였다. 또한, 당귀의 에틸아세테이트 추출물의 수화제도 밀 붉은녹병에 대해 우수한 항균활성이 보였다. 따라서 decursinol angelate와 이를 포함한 당귀 추출물을 이용할 경우 밀 붉은녹병을 방제할 수 있는 새로운 살균제의 개발이 가능하리라 생각된다. 본 논문에서 decursinol angelate에 의한 밀 붉은녹병 방제 효과를 처음 보고하는 바이다.

• Bulletin of the Korean Chemical Society
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• 제31권5호
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• pp.1149-1154
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• 2010

Liquid chromatography/mass spectrometry using isotope dilution method has been established as a primary method for the measurement of cortisol in human serum. Verification of this method was accomplished by the participation in Consultative Committee for Amount of Substance-Metrology in Chemistry (CCQM) pilot study. Two levels of cortisol certified reference materials were prepared and certified by the established method. They were used as sample materials for the proficiency testing. The expanded uncertainty in the measurement of cortisol in human serum was approximately 1.2% at 95% confidence level. The results of the proficiency testing showed a good precision among the participants, but some bias to the certified values. This means that commercial field laboratories should keep traceability chain to SI unit through available reference measurement procedures and/or available reference materials.

• IMMUNE NETWORK
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• 제2권2호
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• pp.115-124
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• 2002

Background: The chemical characteristics of the exo-secretion from Phellinus linteus (referred to as exo-secretion) including the compositions of amino acids and monosaccharides were investigated. In addition, cytotoxicity of the exo-secretion on 5 tumor cell lines derived from human cancers and its antitumor activity against ascitic sarcoma-180 cells were examined. Methods: The antitumor activity of exo-secretion from Phellinus linteus was determined by measuring parameters including tumor weight, life span of mice, chemotatic activity of leukocytes, counts of immune cells, and activity of cytokines. Results: The exo-secretion from Phellinus linteus showed no direct cytotoxicity to the five tumor cell lines tested, but it had a strong antitumor activity against sarcoma-180 cells in ICR mice as measured by tumor weight and life span of mice. The exo-secretion stimulated the chemotaxis of leukocytes and production of immune cells and cytokines. Conclusion: These results suggest that the exo-secretion from Phellinus linteus do not act as a direct cytotoxic substance to cancer cells but as an immunomodulator.

• 대한화학회지
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• 제43권1호
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• pp.52-57
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• 1999

In($C_6F_5)_3{\cdot}D(D=CH_3CN$, O($C_2H_5)_2$)와 ($CH_3)_3SiC_6F_5$/CsF, $C_6F_5$MgBr 또는 Cd($C_6F_5)_2$을 반응시켜 [In($C_6F_5)_4$]- 음이온 화합물을 합성하였으나, 이들 indium(III) 음이온 화합물들은 온도에 민감하고 습기에 대해 불안정하다. 안정한 indium(III) 음이온 착물은 PNPCl(PNP=bis(triphenylphosphino)ammonium)과의 양이온 치환반응시켜 얻었으며, 관 크로마토 그래피를 이용하여 분리 정제하였다. 합성된 화합물의 특성은 핵자기 공명 분석법, 적외선 분광분석법, 분자량 측정, DTA/TG 그리고 원소분석법을 이용하여 조사하였다.

• Bulletin of the Korean Chemical Society
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• 제29권1호
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• pp.94-98
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• 2008

A fundamental study was developed concerning the novel solvent extraction of the tetravalent metal ions; zirconium(IV), hafnium(IV) and thorium(IV). Their extraction behavior in toluene was investigated with a recently synthesized naphthol-derivative Schiff base, 1-({[4-(4-{[(E)-1-(2-hydroxy-1-naphthyl)methyliden]amino}phenoxy) phenyl]imino}methyl)-2-naphthol (HAPMN). The spectrophotometrical examination of the complex formation between HAPMN and the Zr(IV), Hf(IV) and Th(IV) ions in acetonitrile revealed the formation of stable 1:1 complexes in the solution. After the thorium extraction in toluene, it was found that [Th(OH)3HA] was the respective deriving substance. While, in the case of zirconium and hafnium extraction, the extracted adduct was found to be [M4(OH)8(H2O)16Cl62HA]. The stoichiometric coefficients of these extracted species were determined by the slope analysis method. The extraction reaction followed a cation exchange mechanism.

• 대한안전경영과학회지
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• 제16권3호
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• pp.101-110
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• 2014

This study tried to identify the effects of ergonomic risk factors for absence from work of fire fighters in Korea. A self-administered questionnaire was prepared for this study. The questionnaire consisted of several parts such as 'general information', 'work-related factors', 'physical & chemical risk factors', 'ergonomic risk factors', and 'absence information'. A total of 7,098 fire fighters participated in this study. The data obtained from the survey was mainly analyzed by logistic regression. A total of 856 out of 7,098 fire fighters experienced absence from work. The risk factors such as gender, age, marital status, education level, total work year, work area. position, job rotation, noise, dust, organic solvent, skin contact with chemical substance, toxic waste, regional vibration, manual material handling, continuous standing posture, awkward working posture were associated with absence from work. Specifically, awkward working posture and manual material handling from ergonomic risk factors were major risk factors for absence from work.

• 한국물환경학회지
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• 제21권6호
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• pp.569-574
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• 2005

In this study, alginic acid that had an high affinity for a heavy metal and was noted for biological adsorbent was modified by an oxidizer, $KMnO_4$. Chemical modification changed hydroxyl of the alginic acid into carboxyl and compare with alginic acid, modified alginic acid exhibited a characteristics that carboxyl groups are comparatively high. For the use of them as an adsorbent, beads were prepared by dropping alginic acid and modified alginic acid solution in dilute 2 wt% $CaCl_2$ solution for non water soluble. The amount of removed $Cu^{2+}$ and $Pb^{2+}$ by modified alginic acid beads showed 84.7 mg and 90.9 mg per gram of beads, respectively. And it showed the amount of adsorbed heavy metal ions 10~20% higher than that of alginic acid beads in range of pH 4~7. In particular, modified alginic acid have a good adsorption capacity for $Cu^{2+}$ and $Pb^{2+}$ by Freundlich adsorption isotherm. According to this study, it is verified that alginic acid that is a nature high molecular substance improved capacity for actual application by increased heavy metal adsorption capacity by chemical modification.

• 산업기술연구
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• 제26권B호
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• pp.163-171
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• 2006

Human immunodeficiency virus type 1 (HIV-1) integrase plays a critical role in the life cycle of the HIV virus. An ability to accurately map its electrostatic potential, and then use this information to predict the manner in which DNA will bind to the active site of the catalytic domain could provide a foundation for inhibitory design. Attempts to discern the crystal structure of HIV-1 integrase have proven problematic, especially in the region of enzymatic activity, that being those residues involved in the catalysis of the integration of viral DNA into the host cell. However, there is a structural correlation in to the region of interest with avian sarcoma virus (ASV), so a homology model utilizing this similarity was constructed to approximate the behavior/structure of the undetermined portions of the HIV-1 integrase crystal. After this model was constructed and its energy minimized, electrostatic calculations were carried out on the substance, so that an electrostatic potential map was constructed. Using this information, it was determined that DNA binding was oriented so as to exploit the regions of positive potential nearby the active site, as well as the positive potential of the magnesium cofactors.

• 한국안전학회지
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• 제32권2호
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• pp.66-71
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• 2017

The autoignition temperature (AIT) is crucial combustible characteristics which need attention in chemical process that handle hazardous materials. The AIT, also to as minimum spontaneous ignition temperature(MSIT), is the lowest temperature of a hot surface at which the substance will spontaneously ignite without any obvious sources of ignition such as a spark or flame. The AIT may be used as combustion property to specify operating, storage, and materials handling procedures for process safety. This study measured the AITs of n-propanol+acetic acid system from ignition delay time(time lag) by using ASTM E659 apparatus. The AITs of n-propanol and acetic acid which constituted binary system were $435^{\circ}C$ and $212^{\circ}C$, respectively. The experimental AITs of n-propanol+acetic acid system were a good agreement with the calculated AITs by the proposed equations with a few A.A.D.(average absolute deviation). In the case of n-propanol and acetic acid system, the minimum autoignition temperature behavior (MAITB), which is lower than the lower AIT, is shown among the two pure substances constituting the mixture.

• 한국산업보건학회지
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• 제30권2호
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• pp.226-235
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• 2020

Objectives: This study was to investigate the signs and notations of skin absorption, carcinogenicity, germ cell mutagenicity, and reproductive toxicity in the occupational exposure limits of Korea and of other advanced countries. Methods: Information on occupational exposure limits in Korea, the USA, the UK, Germany, and Japan was investigated through the Internet, and items marked as carcinogenicity and skin absorption were compared by country. Results: Legal occupational exposure limits have been greatly simplified. However, in the case of HSE WEL, skin absorption, carcinogenicity classification, sensitization, and in the case of DFG MAK, skin absorption, carcinogenicity, pregnancy risk group, germ cell mutagenicity, airway and skin sensitization, photo contact sensitization, and vapor pressure were provided. Conclusions: It is desirable to indicate the carcinogenicity and skin absorption within permissible limits, and to include information on critical effects in chemical substance exposure limits to uphold the right to know of industrial hygienists and workers in Korea. It is also necessary to clarify the precautions, limitations and protections for skin absorption.