• Environmental Analysis Health and Toxicology
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• 제25권4호
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• pp.295-306
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• 2010

Objectives : This study was undertaken to examine the metabolomic changes due to gender and diurnal variation at sampling time and to identify an appropriate time point for urine sampling in epidemiologic studies using metabolomic profiles. Methods : Urine samples were collected twice a day (morning and afternoon) from 20 healthy Korean adults after fasting for 8 hours. The metabolomic assay was investigated using $^1H$ NMR spectroscopy coupled with the principal components analysis (PCA) and partial least squares discriminant analysis (PLS-DA). The metabolites responsible for differentiation between groups were identified through the loading plot of PLS-DA and quantified using Chenomx NMR Suite with a 600 MHz library. Results : Metabolites responsible for differentiation in gender and sampling time were creatinine, trimethyl anine oxide (TMAO), hippurate, mannitol, citrate and acetoacetate. Dimethylamine showed difference only as a factor of diurnal time. The level of creatinine was higher in men compared to women, and the levels of citrate, TMAO, hippurate, mannitol, and acetoacetate were higher in women compared to men. The levels of creatinine, TMAO, hippurate, dimethylamine and mannitol were higher in the morning rather than the afternoon while those of citrate and acetoacetate were higher in the afternoon rather than the morning. Conclusions : Since urinary metabolomic profiles varied by gender and diurnal cycle, urine sampling should be performed at the same time point for all participants in epidemiologic studies using metabolomic profiles.

• Korean Journal of Environmental Agriculture
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• 제13권1호
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• pp.90-97
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• 1994

This experiment was conducted to improve the analytical method of tricyclazole- and IBP-combined dust. When the tricyclazole and IBP active ingadients were analyzed by the official analytical method, their recovery rates were 89.5 and 100%, respectively. A reason of the lower recovery rate in tricyclazole was found to be due to strong binding to the minor inorganic compoments, $Al_2O_3$, $Fe_2O_3$, CaO and MgO, of talc and kaoline. However, addition of 0.2% dimethylamine to extraction solvent for tricyclazole- and IBP-combined dust effectively raised the recovery rate of tricyclazole by providing higher basicity than tricyclazole. We have suggest an improved analytical method which is applicable to effective and simultaneous analysis of the active ingradients of tricyclazole- and IBP-combined dust.

• Safety and Health at Work
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• 제3권4호
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• pp.257-267
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• 2012

Occupational neurotoxic diseases have become increasingly common in Taiwan due to industrialization. Over the past 40 years, Taiwan has transformed from an agricultural society to an industrial society. The most common neurotoxic diseases also changed from organophosphate poisoning to heavy metal intoxication, and then to organic solvent and semiconductor agent poisoning. The nervous system is particularly vulnerable to toxic agents because of its high metabolic rate. Neurological manifestations may be transient or permanent, and may range from cognitive dysfunction, cerebellar ataxia, Parkinsonism, sensorimotor neuropathy and autonomic dysfunction to neuromuscular junction disorders. This study attempts to provide a review of the major outbreaks of occupational neurotoxins from 1968 to 2012. A total of 16 occupational neurotoxins, including organophosphates, toxic gases, heavy metals, organic solvents, and other toxic chemicals, were reviewed. Peer-reviewed articles related to the electrophysiology, neuroimaging, treatment and long-term follow up of these neurotoxic diseases were also obtained. The heavy metals involved consisted of lead, manganese, organic tin, mercury, arsenic, and thallium. The organic solvents included n-hexane, toluene, mixed solvents and carbon disulfide. Toxic gases such as carbon monoxide, and hydrogen sulfide were also included, along with toxic chemicals including polychlorinated biphenyls, tetramethylammonium hydroxide, organophosphates, and dimethylamine borane. In addition we attempted to correlate these events to the timeline of industrial development in Taiwan. By researching this topic, the hope is that it may help other developing countries to improve industrial hygiene and promote occupational safety and health care during the process of industrialization.

• Food Science and Biotechnology
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• 제18권3호
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• pp.761-765
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• 2009

The effects of probiotic bacteria on the functional properties of squid by-products were investigated during fermentation. Bifidobacterium longum, Lactobacillus acidophilus, Lactobacillus brevis, Lactobacillus casei, Lactobacillus paracasei, Lactobacillus rhamnosus, and Pediococcus acidilactici were used to ferment the squid by-products for 96 hr at $37^{\circ}C$. The numbers of all probiotics increased to $10^7-10^8$ CFU/g after 96 hr fermentation. No substantial pH changes were observed. L. rhamnosus and P. acidilactici showed the highest 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activities. Interleukin-6 (IL-6) and tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$) secreted from B cells increased after adding the extracts of probiotic-fermented squid by-products. The human NK cells were grown well in the B cell-growing broth cultured with the extracts of squid by-products fermented by L. rhamnosus and P. acidilactici. Trimethylamine (TMA) and dimethylamine (DMA) contents were significantly decreased after probiotic-fermentation. Therefore, L. rhamnosus GG and P. acidilactici can be used for the fermentation of squid by-products and their use would provide benefits in functional food products.

• Korean Chemical Engineering Research
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• 제56권6호
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• pp.895-900
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• 2018

In this study, the electroless deposition of Co-B and Co-W-B alloy thin films was developed and the effect of B and W contents on the hardness of the alloy thin films were investigated. An amorphous Co alloy film was successfully formed by electroless deposition and the contents of B and W in the film were controlled by varying the concentrations of dimethylamine borane and sodium tungstate dihydrate, which were used as a reducing agent and W source, respectively. The hardness of the thin films increased as the contents of B and W were increased because B and W act as impurities suppressing the propagation of dislocation in a film. In addition, it was found that the content of B and W in the Co alloy films can be increased significantly when aeration is not performed. Finally, the hardness of Co-W-B alloy thin film was improved up to 8.9 (${\pm}0.3$) GPa.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권4호
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• pp.337-343
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• 2006

Trimethylamine dehydrogenase (TMADH, EC 1.5.99.7), an iron-sulfur flavoprotein that catalyzes the oxidative demethylation of trimethylamine to form dimethylamine and formaldehyde, was purified from Methylophaga sp. strain SK1. The active TMADH was purified 12.3-fold through three purification steps. The optimal pH and temperature for enzyme activity was determined to be 8.5 and $55^{\circ}C$, respectively. The $V_{max}\;and\;K_m$ values were 7.9 nmol/min/mg protein and 1.5 mM. A genomic DNA of 2,983 bp from Methylophaga sp. strain SK1 was cloned, and DNA sequencing revealed the open reading frame (ORF) of the gene coding for TMADH. The ORF contained 728 amino acids with extensive identity (82%) to that of Methylophilus methylotrophus $W_3A_1$.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 한국표면공학회 2013년도 춘계학술대회 논문집
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• pp.137-137
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• 2013

본 연구에서는 반도체 검사 장비인 프로브 카드의 핵심 부품인 프로브 니들의 팁 부분의 내마모성을 향상시키기 위하여 무전해 Ni-B-W 합금 도금 실험을 실시하였다. 무전해 Ni-B-W 합금 도금 실험에서 여러 가지 제어인자 중 도금욕의 pH와 온도 그리고 환원제의 농도 등을 변수로 하였다. 도금욕 pH와 온도에 따른 전착속도 및 물성 변화를 관찰하였으며, 환원제 농도 변화에 의한 open circuit potential의 변화를 측정하였다.

• Korean Journal of Materials Research
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• 제6권10호
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• pp.1007-1016
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• 1996

무전해도금법에 의한 퍼멀로이 박막의 도금 최적조건 규명 및 자기적 특성 향상을 위하여 퍼멀로이 박막의 미세구조 및 자기적 특성 등을 연구하였다. 소지는 알루미나를 사용하였으며, 환원제는 boron을 포함하는 Ni-Fe-B도금막이 형성되는 DMAB(dimethylamine borane)를 사용하였다. 도금시 인가된 도금막이 무자장하에서 도금된 도금막과 비교하여 기공이 적고, 조밀한 막이 형성됨을 SEM을 통하여 확인하였다. 도금속도는 온도, pH, DMAB 농도가 증가할수록 증가하였다. 도금막에 함유되는 boron의 함량은 pH가 감소할수록, 온도와 DMAB농도가 증가할수록 증가하였다. 도금막 보자력값은 30$0^{\circ}C$에서 1시간 열처리하였을 때 약 4.5Oe로 감소하였고, 포화자기유도값은 3-5kG 정도 증가하였다. 이때 포화자기유도값은 자장하에서 도금된 후 열처리한 도금막이 무자장하에서 도금된 후 열처리한 도금막에 비하여 1.7kG 정도 높았다. 또한 열처리 후의 도금막이 열처리 전의 도금막에 비하여 기공이 적고 조밀한 도금막을 형성함을 볼 수 있었다.

• Journal of Nutrition and Health
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• 제15권1호
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• pp.30-38
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• 1982

Experiments were carried out in order to compare the natural antioxidants in the acetonitril extracts of raw and baked seeds of Korean sesame and perilla by thin layer and gas chromatography. The sample was dissolved in n-pentane and extracted with acetonitril and the acetonitril extract was separated by thin layer chromatography using silica gel. The spots were detected by spraying with 2, 6 -dichloroquinone -4-chlorimide, phosphomolybdic acid and dimethylamine as chromogenic reagents. Natural antioxidant, such as ${\delta}-tocopherol$ detected in raw and baked sesame and perilla seed oil by TLC and sesamol was detected only in raw and baked sesame seed oil by GC.

• YAKHAK HOEJI
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• 제34권2호
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• pp.133-138
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• 1990

The reaction of 2-aminobenzamide with phthalic acid anhydride In dioxane produced a bicyclic product 2,8-dioxoisoindole(1,2,a) quinazoline (I) in addition to hydrolysis product 2(2-Carboxyphenyl)-1,2-2H-quinazoline-4-one (II). The yields were 64% and 30% respectively. On the other hand, the same reaction in DMF afforded compound (I) and 2(2N-dimethyl carbamyl phenyl)-1,4-2H-quinazoline-4-one (III) in 30% and 60% yield respectively. The compound III was also obtained by the reaction of compound II with dimethylamine. However the reaction of 2-aminobenzamide with neat succinic acid anhydride gave only bicyclic product 2,8-oxopyrrolidine (2,1,a)-1,4-2H-quinazoline (IV) in 93%.