• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.3
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• pp.542-548
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• 2004

This study consisted of designing a sensitive assay to measure the rate of L-ascorbic acid (AsA)-prompted release of ferritin iron, the use of ferrozine as a chelating agent to trap releases Fe(II). The initial rate of iron release was measured in the appearance of Fe(ferrozine)$_3$$^{2+}$ at 562 nm. The release of iron from ferritin by AsA was dependent on time and AsA conditions under aerobic and anaerobic conditions. Effect of oxygen on the release of iron from ferritin was also confirmed. It was suggested that the release of iron from ferritin was participate not only AsA but also $O_2$$^{[-10]}$ . In this study, it was found that iron can be released from ferritin and chelate as Fe(ferrozine)$_3$$^{2+}$ and the release was more than 50% in the presence of AsA without $O_2$$^{[-10]}$ . Based on the findings, the following can be assumed (1) AsA is diffused into ferritin (2) ferric ion is reduced to ferrous ion (3) is diffused from ferritin.tin.

• Analytical Science and Technology
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• v.28 no.1
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• pp.58-64
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• 2015

This study aimed to investigate the concentration distributions and formation characteristics of trihalomethanes (THMs) in drinking water supplies to rural communities. Water samples were collected twice from 40 rural households located on the outskirts of Chuncheon city of Gangwon Province in the summers of 2010 and 2011, and urban drinking water samples were collected from 20 faucets during the same period in 2011 for comparison purpose. Water temperature, pH, and residual chlorine (total and free) concentrations were measured in the field, and samples were analyzed for dissolved organic carbon (DOC) and THM concentrations in the laboratory. The average DOC concentrations in rural water samples were not greatly different between groundwater (n = 20) and surface water (n = 20) which were used as sources for drinking water (1.81 vs. 1.91 mg/L). However, the average concentrations of total THMs (TTHMs) in groundwater ($9.77{\mu}g/L$) were much higher than those in surface water ($2.85{\mu}g/L$) and similar to those in urban drinking water samples ($10.8{\mu}g/L$). Unlike urban water supply, rural water (particularly groundwater) contained more brominated THM species such as dibromochloromethane (DBCM), suggesting its relatively high content of bromide ion (Br-). This study showed that rural water supplies have different THM formation characteristics from urban water supplies, probably due to their differences in source water quality properties.

• KSBB Journal
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• v.22 no.4
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• pp.234-238
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• 2007

We used electrospary ionization ion trap tandem mass spectrometry (ESI-IT tandem MS) to structural elucidation of three different biantennary-type glycans having zero, one, two galactoses (G0, G1, G2). The highest fragment ion in the MS/MS spectra of three glycans was produced by 0,2-ring cleavage of fucose-linked N-acetylglucosamine (GlcNAc) in reducing end. The fragment ions both from precursor ions and 0,2-ring cleaved ions ($^{0.2}An$; n=5 for G0, n=6 for G1 and G2) were not overlapped each other. As results of $MS^n$ analyses, tandem fragmentation trees of each glycans were generated and 2,4-ring cleavages ($^{2.4}A_6$) were occurred in GlcNAc linked to reducing end GlcNAc. This structural elucidation and fragmentation study of N-linked glycans by tandem mass spectrometry can be applied to structural analysis of more complicated glycans.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2000.11a
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• pp.3-4
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• 2000

Many researchers are interested in the synthesis and characterization of carbon nitride and diamond-like carbon (DLq because they show excellent mechanical properties such as low friction and high wear resistance and excellent electrical properties such as controllable electical resistivity and good field electron emission. We have deposited amorphous carbon nitride (a-C:N) thin films and DLC thin films by shielded arc ion plating (SAIP) and evaluated the structural and tribological properties. The application of appropriate negative bias on substrates is effective to increase the film hardness and wear resistance. This paper reports on the deposition and tribological OLC films in relation to the substrate bias voltage (Vs). films are compared with those of the OLC films. A high purity sintered graphite target was mounted on a cathode as a carbon source. Nitrogen or argon was introduced into a deposition chamber through each mass flow controller. After the initiation of an arc plasma at 60 A and 1 Pa, the target surface was heated and evaporated by the plasma. Carbon atoms and clusters evaporated from the target were ionized partially and reacted with activated nitrogen species, and a carbon nitride film was deposited onto a Si (100) substrate when we used nitrogen as a reactant gas. The surface of the growing film also reacted with activated nitrogen species. Carbon macropartic1es (0.1 -100 maicro-m) evaporated from the target at the same time were not ionized and did not react fully with nitrogen species. These macroparticles interfered with the formation of the carbon nitride film. Therefore we set a shielding plate made of stainless steel between the target and the substrate to trap the macropartic1es. This shielding method is very effective to prepare smooth a-CN films. We, therefore, call this method "shielded arc ion plating (SAIP)". For the deposition of DLC films we used argon instead of nitrogen. Films of about 150 nm in thickness were deposited onto Si substrates. Their structures, chemical compositions and chemical bonding states were analyzed by using X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy and infrared spectroscopy. Hardness of the films was measured with a nanointender interfaced with an atomic force microscope (AFM). A Berkovich-type diamond tip whose radius was less than 100 nm was used for the measurement. A force-displacement curve of each film was measured at a peak load force of 250 maicro-N. Load, hold and unload times for each indentation were 2.5, 0 and 2.5 s, respectively. Hardness of each film was determined from five force-displacement curves. Wear resistance of the films was analyzed as follows. First, each film surface was scanned with the diamond tip at a constant load force of 20 maicro-N. The tip scanning was repeated 30 times in a 1 urn-square region with 512 lines at a scanning rate of 2 um/ s. After this tip-scanning, the film surface was observed in the AFM mode at a constant force of 5 maicro-N with the same Berkovich-type tip. The hardness of a-CN films was less dependent on Vs. The hardness of the film deposited at Vs=O V in a nitrogen plasma was about 10 GPa and almost similar to that of Si. It slightly increased to 12 - 15 GPa when a bias voltage of -100 - -500 V was applied to the substrate with showing its maximum at Vs=-300 V. The film deposited at Vs=O V was least wear resistant which was consistent with its lowest hardness. The biased films became more wear resistant. Particularly the film deposited at Vs=-300 V showed remarkable wear resistance. Its wear depth was too shallow to be measured with AFM. On the other hand, the DLC film, deposited at Vs=-l00 V in an argon plasma, whose hardness was 35 GPa was obviously worn under the same wear test conditions. The a-C:N films show higher wear resistance than DLC films and are useful for wear resistant coatings on various mechanical and electronic parts.nic parts.

• Proceedings of the Korean Geotechical Society Conference
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• 1991.10a
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• pp.87-102
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• 1991

It has been reported that the failure of Carsington Dam in Eng1and occured due to the existence of a thin yellow clay layer which was not identified during the design work, and due to pre-existing shears of the clay layer. The slope stability analyses during the design work, which utilized traditional circular arc type failure method and neglected the existence of the clay layer, showed a safety factor of 1.4. However, the post-failure analyses which utilized translational failure mode considering the clay layer and the pre-existing shear deformation revealed the reduction of safety factor to unity. The post-failure analysis assumed 10。 inclination of the horizontal forces onto each slice based on the results of finite element analyses. In this paper, Bishop's simplified method, Janbu method, and Morgenstern-Price method were used for the comparison of both circular and translational failure analysis methods. The effects of the pre-existing shears and subsquent movement were also considered by varying the soil strength parameters and the pore pressure ratio according to the given soi1 parameters. The results showed factor of safefy 1.387 by Bishop's simplified method(STABL) which assumed circular arc failure surface and disregarding yellow clay layer and pre-failure material properties. Also the results showed factor of safety 1.093 by Janbu method(STABL) and 0.969 by Morgenstern-Price method(MALE) which assumed wedge failure surface and considerd yellow clay layer using post failure material properties. In addition, dam behavior was simulated by Cam-Clay model FEM program. The effects of pore pressure changes with loading and consolidation, and strength reduction near or at failure were also considered based on properly assumed stress-strain relationship and pore pressure characteristics. The results showed that the failure was initiated at the yellow clay layer and propagated through other zones by showing that stress and displacement were concentrated at the yel1ow clay layer.

• Analytical Science and Technology
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• v.30 no.6
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• pp.348-354
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• 2017

In this study, patterns of proteome expression were monitored and specifically expressed proteins in human milk were detected in collected human milk after 1 week, 3 weeks, and 6 weeks from delivery. A quantitative shotgun proteomic approach was used to identify human milk proteins and reveal their relative expression amounts. For each sample, two independent human milk samples from two mothers were pooled, and then three replicated shotgun proteomic analyses were carried out. Casein, which is a highly abundant protein in human milk, was removed, and then trypsin was treated to produce a digested peptide mixture. The peptides were loaded in the home-made reversed-phase C18 fused-silica capillary column, and then the eluted peptides were analyzed by using a linear ion-trap mass spectrometer. The relative quantitation of proteins was performed by the normalized spectral count method. For each sample, 81-109 non-redundant proteins were identified. The identified proteins consisted of glycoproteins, metabolic enzyme, and chaperon enzymes such as lactoferrin, carboxylic ester hydrolase, and clusterin. The comparative analysis for the 63 proteins, which were reproducibly identified in all three replications, revealed that 25 proteins were statically significant differentially expressed. Among the differentially expressed proteins, Ig lambda-7 chain C region and tenascin drastically decreased with the delivery time.

• Journal of Microbiology and Biotechnology
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• v.16 no.10
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• pp.1583-1590
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• 2006

T4 endonuclease V (T4 endo V) [EC 3. 1. 25. 1], found in bacteriophage T4, is responsible for excision repair of damaged DNA. The enzyme possesses two activities: a cyclobutane pyrimidine dimer DNA glycosylase (CPD glycosylase) and an apyrimidic/apurinic endonuclease (AP lyase). T4 denV (414 bp cDNA) encoding T4 en do V (138 amino acid) was synthesized and expressed using either an expression vector, pTriEx-4, in E. coli or a baculovirus AcNPV vector, pBacPAK8, in insect cells. The recombinant His-Tag/T4 endo V (rHis-Tag/T4 endo V) protein expressed from bacteria was purified using one-step affinity chromatography with a HiTrap Chelating HP column and used to make rabbit anti-His-Tag/T4 endo V polyclonal antibody for detection of recombinant T4 endo V (rT4 endo V) expressed in insect cells. In the meantime, the recombinant baculovirus was obtained by cotransfection of BacPAK6 viral DNA and pBP/T4 endo V in Spodoptera frugiperda (Sf21) insect cells, and used to infect Sf21 cells to overexpress T4 endo V protein. The level of rT4 endo V protein expressed in Sf21 cells was optimized by varying the virus titers and time course of infection. The optimal expression condition was set as follows; infection of the cells at a MOI of 10 and harvest at 96 h post-infection. Under these conditions, we estimated the amount of rT4 endo V produced in the baculovirus expression vector system to be 125 mg/l. The rT4 endo V was purified to homogeneity by a rapid procedure, consisting of ion-exchange, affinity, and reversed phase chromatographies, based on FPLC. The rT4 endo V positively reacted to an antiserum made against rHis-Tag/T4 endo V and showed a residual nicking activity against CPD-containing DNA caused by UV. This is the first report to have T4 endo V expressed in an insect system to exclude the toxic effect of a bacterial expression system, retaining enzymatic activity.

• The Korean Journal of Pesticide Science
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• v.9 no.4
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• pp.292-302
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• 2005

Condition of Ion-Trap gas chromatography-mass spectrometry (GC-MS) for rapid screening of 206-pesticides residues in agricultural foodstuffs was optimized. As applying a wide-bore column (10 m${\times}$0.53 mm, DF 0.25 um) connected with a fused silica restrictor (0.6 m${\times}$0.1 mm), a significant retention time reduction was obtained. Additionally, the shape of peaks was sharper and higher than classical GC's and GC-MS's, which allowed lower detection limits. To easily manage many spectral data, both of Electron Ionization(EI) and Chemical Ionization(CI) techniques were adopted in screening procedure. At the following steps, MS-MS technique were used to confirm screened analytes in complicated matrices.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1991.06a
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• pp.37-44
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• 1991

영산강 하구언 방조제의 건설로 인한 항만 및 이의 인접해역 해면의 변화는 예상한 바 있으며 실제 여러개소에서 월 2회정도의 주기로 목포 구항부근 상업지역에서 해면상승에 따라 주기적으로 침수되는 현상이 나타나고 있다 목포항의 영산강 하구언 방조제 조성으로 인한 조류성분중 최고기록을 가진 수로에서는 6kts 정도로 감소된 것으로 보고되고 있으나 주위자연환경 변화에 따른 수면 상승 및 해수면의 주기적인 변화 등에 대한 상세한 언급 및 깊이 있는 분석은 회피되어왔다. 수자원의 효율적관리를 위해 하구언 방조제는 이미 건설되었고 앞으로 대규모의 항만개발과 대불산업단지조성을 위해 추가 3개의 만입해안해역에 댐으로 해역을 막아 매립공사를 추진하고 있다 그러나 이 지역에 대한 분석은 타당성의 여부만을 강조한 상업적 용역이 이루어지고 있고 장래 개발에 대해 학술적이고 실질적인 문제점 추출과 해결방아네 대해서는 무시하거나 경시한 바가 많다 더구나 태풍 저기압 등과 같은 자연재해를 고려한 분석은 시도되지 못하고 있다 따라서 개발전후의 현상에 대한 상세한 자료 및 현장 조사와 극한 상태를 고려하여 개발에 따른 수위상승 부진동, 조류 수질등 이해역의 변화요소를 수집하고 분석하며 과학적 접근방법에 기초를 둔 수치모델의 실험을 포함하여 현장관측 및 측정자료를 검증하는 것이 필수적이라고 사료되어 종합분석의 한단계로 여기서는 하구언 및 하구간척(Land Reclamatic of Estuary barren)으로 해역축소에 따른 해면변화의 실제현상을 조사하여 정리하고 이를 수치모델을 통해 시뮬레이션하여 보았다 이는 종합개발의 좋은 기초자료로 이용됨은 물론이로 이지역의 개발에 기여할 것으로본다.적절하게 가정된 지반의 응력-변형률 관계와 간극수압특성에 의하여 고려되었다. 그 결과 응력 및 변위가 심하게 발생하는 지역은 황색 점토층이었으며 이로부터 황색 점토층에서 부터 파괴면이 생성되어 다른 지역으로 전파되었음을 유추할 수 있었다.form trap with 2.88[eV] deep of injected space charge from the chathode in the crystaline regions. The origin of ${\alpha}$$_2$ peak was regarded as the detrapping process of ions trapped with 0.9[eV] deep originated from impurity-ion remained in the specimen during production process of the material, in the crystalline regions. The origin of ${\beta}$ peak was concluded to be due to the depolarization process of "C=0"dipole with the activation energy of 0.75[eV] in the amorphous regions. The origin of ${\gamma}$ peak was responsible to the process combined with the depolarization of "CH$_3$", chain segment, with the activation energy of ca

• KOREAN JOURNAL OF CROP SCIENCE
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• v.67 no.4
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• pp.211-221
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• 2022

Recently, the demand for the cultivation of upland soil has been increasing, and the rate of conversion of paddy soil into upland soil is also increasing. Theincrease in uneven precipitation due to climate change has resulted in dramatic effects of waterlogging stress on upland crops. Therefore, the present study was conducted to investigate the changes in growth characteristics and the expression patterns of proteins at the two-leaf stage of adzuki beans. The domestic cultivar, Arari (Miryang No. 8), was used to test waterlogging stress. At the two-leaf stage of adzuki beans, plant height slightly decreased androot fresh weight showed significant changes after 3 days of waterlogging treatment. Chlorophyll content was also significantly different after 3 days of waterlogging treatment compared to its content in control plants. Using two-dimensional gel electrophoresis, more than 400 protein spots were identified. Twenty-one differentially expressed proteins from the two-leaf stage were analyzed using linear trap quadrupole-Fourier transform-ion cyclotron resonance mass spectrometry. Of these 21 proteins, 9 were up-regulated and 12 were down-regulated under waterlogging treatment. Protein information resource (https://pir.georgetown.edu/) categories were assigned to all 49 proteins according to their molecular function, cellular component localization, and biological processes. Most of the proteins were found to be involved in the biological process, carbohydrate metabolism and were localized in chloroplasts.