• Korean Journal of Pharmacognosy
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• v.10 no.2
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• pp.83-84
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• 1979

Caffeic aldehyde was isolated from the seeds of Phytolacca americana. This is the first reported occurrence of the compound in nature.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2019.10a
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• pp.154-154
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• 2019

• Journal of the Korean Society of Clothing and Textiles
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• v.37 no.7
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• pp.852-863
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• 2013

We investigate the immobilization of trypsin on chitosan nonwoven using glutaraldehyde (GA). The conditions for trypsin on chitosan nonwoven and GA cross-linking were optimized depending on different conditions. The order of GA cross-linking was determined by the activity of immobilized trypsin. The characteristics of chitosan nonwoven were examined by Fourier-transform infrared (FT-IR) and surface morphology analyses (SEM). Results showed that the optimal treatment conditions for trypsin on chitosan nonwoven were as follows: pH 8.5; temperature $37^{\circ}C$; trypsin concentration 15% (o.w.f); and treatment time 60 min. Those for GA cross-linking were: pH 10.0; GA concentration 3% (v/v); and treatment time 120 min. FT-IR analysis showed that GA was cross-linked on chitosan nonwoven. The SEM analysis also showed that trypsin was immobilized on chitosan nonwoven.

• Journal of the Korean Institute of Educational Facilities
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• v.21 no.6
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• pp.28-32
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• 2014

본 투고에서는 2008년 환경부의 용역으로 실시된 "보육시설의 실내공기질 진단 및 개선 시범사업"의 결과를 바탕으로 우리나라 보육시설의 실내공기 오염 실태와 함께 개선방안, 그리고 개선효과에 대하여 소개하였다. 서울, 경기, 인천 지역의 61개 시설을 대상으로 실내공기질 측정과 설문조사를 실시한 결과 폼알데하이드와 총 휘발성유기화합물은 일부시설에서 "다중이용시설 등의 실내공기질 관리법" 기준치를 초과하는 것으로 나타났다. 반면 이산화탄소와 미세먼지는 조사 대상 시설 중 50 % 이상이 기준치를 초과하는 것으로 나타났다. 따라서 보육시설의 실내공기질 개선을 위해서는 각 오염물질의 발생원별로 유지관리 대책이 필요한 것으로 조사되었다. 또한 오염원인별 분석결과, 대부분 시설의 실외오염물질 농도가 실내보다 낮게 나타나 외기의 오염이 실내에 미치는 영향은 미비한 것으로 나타났으며, 계절에 따른 실내공기오염은 동절기에 낮은 외기온도로 인하여 실내를 하기 때문에 하절기에 비해 더 높게 나타났다. 공간에 따른 오염물질의 농도는 이산화탄소와 미세먼지의 경우 아동이 늘 상주하는 교실의 오염이 가장 심한 것으로 나타났으며 폼알데하이드와 총휘발성유기화합물의 경우 놀이실의 오염도가 교실에 비해 더 높게 나타났다. 개선방안별 개선효과에 있어서는 환기계획 몇 환기설비 설치, 지하공간 습기 문제 개선에서 가장 높은 효과가 나타났다. 향후 보육시설의 쾌적하고 건겅한 실내환경의 유지관리를 위해서는 보육종사자들이 활용할 수 있는 유지관리 지침 또는 매누얼에 대한 보급이 필요할 것으로 판단된다.

• Korean Journal of Food Science and Technology
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• v.1 no.1
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• pp.45-50
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• 1969

On the basis of UV spectral changes and TBA reaction, malonaldehyde (MA) in aqueous solution receives considerable photochemical modification by UV light of short wavelengths around $260m{\mu}$. When aflatoxin is added in the solution, UV light of long wavelengths around $360m{\mu}$ induces such changes quite rapidly and although the rate of change is rather slow, it is also true even with ordinary laboratory illumination(fluorescent). The modification is irreversible in nature and the role of aflatoxin in this reaction is identified as a photosensitizer. The mechanism involved in this modification is apparently due to the parallel dimerization of MA molecules, but not by head to tail combination of the molecules.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.30 no.3
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• pp.116-122
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• 2018

The purpose of this study was to confirm the effects of flush-out in the reduction of formaldehyde concentration in newly built residential buildings. The field measurements were conducted on two complexes of multi-residential buildings which are located in the suburban area of Seoul. About eight samples of residential buildings were selected to measure the changes in formaldehyde concentrations after flush-out from the two apartment complexes. The concentration of formaldehyde was measured using DNPH cartridge and HPLC. From the results of the field measurements, it was established that indoor formaldehyde concentration decreases 27.6~54.2% in the samples after flush-out. The number of days that the flush-out were conducted was noted to have no significant influence on the reduction rate of formaldehyde concentration when the flush-out continued more than 7 days. The comparison with Bake-out showed that flush-out also can reduce formaldehyde in newly built buildings as same levels of it.

• Journal of Chest Surgery
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• v.39 no.4 s.261
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• pp.261-268
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• 2006

Background: Current vascular prostheses are still inadequate for reconstruction of small-diameter vessels. Autologous pericardium can be a good alternative for this purpose as it already possesses good blood compatibility and shows a mechanical behavior similar to that of natural arteries. However, the clinical use of autologous pericardial tissue as a small-diameter vascular graft has limitations due to mixed outcomes from uncertain biological behavior and difficulty to gain reliable patency results in animal experiments. To study this issue, we implanted fresh and glutaraldehyde-treated autologous pericardium as small-diameter arterial grafts in dogs, and compared their time-related changes histologically. Material and Method: As a form of 5mm-diameter arterial graft, one pair of autologous pericardial tissue was used for comparison between the glutaraldehyde-treated and the glutaraldehyde-untreated grafts in the bilateral carotid arteries in the same dog. The patency of the grafts were evaluated at regular intervals with Doppler ultrasonography. After the predetermined periods of 3 days, 2 weeks, 1 month, 3 months and 6 months, the grafts in each animal were explanted. The retrieved grafts were processed for light and electron microscopic analyses following gross observation. Result: Of 7 animals, 2 were excluded from the study because one died postoperatively due to bleeding and the other was documented as one side of the grafts being obstructed. All 10 grafts in the remaining 5 dogs were patent. Grossly, a variable degree of thromboses were observed in the luminal surfaces of the grafts at 3 days and 2 weeks, despite good patency. Pseudointimal smooth blood-contacting surfaces were developed in the grafts at f month and later. By light microscopy, mesothelial cell layers of the pericardial tissue were absent in all explanted grafts. Newly formed endothelial cell layers on the blood-contacting surface were observed in both the glutaraldehyde-treated and fresh grafts at 3 months and later. The collagen fibers became degraded by fragmentation in the fresh graft at 1 month and In the glutaraldehyde-treated graft at 3 months. At 6 months, the collagen layers were no longer visible in either the glutaraldehyde-treated or fresh grafts. By electron microscopy, a greater amount of coarse fibrin fibers were observed in the fresh grafts than in the glutaraldehyde-treated grafts and, more compact and well-arrayed layers were observed in the glutaraldehyde-treated grafts than in the fresh grafts. Conclusion: The glutaraldehyde-treated small-diameter pericardial arterial grafts showed a better endothelialization of the blood-contacting surface and a slower fragmentation of the collagen layers than the fresh grafts, although it has yet to be proven whether these differences are so significant as to affect the patency results between the groups.

• Journal of the Korea Concrete Institute
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• v.17 no.5 s.89
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• pp.811-818
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• 2005

It is well known that the fluidity and the fluidity loss of fresh concrete are affected by the kind of organic admixtures. Organic admixture can improve the properties of concrete. Sulfonated Naphthalene-Formaldehyde(SNF) Superplasticizer is used representatively, but has a problem in fluidity loss. In this study, we synthesized the Sulfonated Melamine-Formaldehyde(SMF) superplasticizer at the various synthetic conditions and compared the physical properties with SMF superplasticizer. SW superplasticizer is synthesized with four synthetic steps. Step 1 is hydroxymethylation, Step. 2 is Sulfonation, Step. 3 is Polymerization and Step. 4 is Stabilization. Synthesis of SMF superplasticizer depends on pH, temperature and reaction time. In this reaction, we changed the mole ratio of melamine to formaldehyde at 1:3, 1:4, and the amount of acid catalyst at Step. 3. After application of SMF superplasticizer and its mixture with SNF superplasticizer to cement pastes and mortars, we measured the physical properties of them at the different dosages(0.5, 1.0, 1.5 wt%) to cement. All samples including superplasticizer showed higher compressive strengths and slump, smaller pore size and porosity than CEM

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.1
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• pp.65-73
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• 2016

Korea Food and Drug Administration (KFDA) has officially announced 2,4-dinitrophenylhydrazine (DNPH) derivatization - high performance liquid chromatography (HPLC) methods for analysis of formaldehyde. This study was conducted to develop a convenient derivatization method for cosmetics by improving complex pre-treatment procedures included in KFDA method. To simplify pre-treatment procedures of KFDA method, reaction conditions including pH, time and temperature were optimized. This pre-treatment method does not require complicate pre-treatment steps of KFDA method such as pH adjustment of test solution with acetate buffer (pH 5.0), solvent-solvent partitioning with dichloromethane and concentrating procedure with vacuum evaporator. Formaldehyde-dinitrophenylhydrazone (formaldehyde-DNP) product produced by derivatization reaction was separated and quantified with a reversed-phase HPLC, which was slightly modified with KFDA method. The linearity test showed good results with 0.9999 of correlation coefficient ($r^2$) in the range of 2 ~ 40 ppm of standard solutions. In this method, limit of detection (LOD) and limit of quantitation (LOQ) values for formaldehyde were 0.2 ppm and 0.5 ppm, respectively. In addition, recovery test demonstrated that the method was also accurate and reproducible. Therefore, the proposed method can be applicable to rapid analysis of formaldehyde in cosmetics.

• The Journal of the Korea Contents Association
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• v.12 no.5
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• pp.323-330
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• 2012

The purpose of this study was to examine the occurrence level of harmful chemical substance and the riskiness caused by it at university laboratory, which had been faintly interested in safe health management. It measured and analyzed indoor pollutants by academic department targeting K university where is located in Seoul Metropolis for 6 days starting from May 26, 2010. As a result, the appearance of being furnished with MSDS, the appearance of installing the exposure-reduction facilities, and the present status of supplying protective equipment in order to grasp the present status of managing harmful chemical substance at university laboratory were relatively good in management at the Dept. of Chemistry, the Dept. of Physics, and the Dept. of Medical Science, which are basic science laboratories. The activity for managing harmful chemical substance in the Dept. of Dental Medicine and the Dept. of Fine Arts was surveyed to be insufficient. Also, the concentration of formaldehyde and TVOCs(total volatile organic compounds) inside laboratory was detected noticeably highly in the Dept. of Fine Arts compared to other laboratories. The concentration of formaldehyde in a group, which was collectivized by similar academic department, was indicated to be higher in other academic departments including the Dept. of Fine Arts and the Dept. of Life Science, thereby having shown significant difference. The concentration of formaldehyde and TVOCs showed significant difference at the laboratory without installation compared to the laboratory with installation of fume hood. Seeing the above results, it could be known that a whole drop in recognition on influence of chemical upon health leads to being able to increase occurrence level of hazardous factor due to being insufficient in activity of protecting exposure to chemical substance.