• 식물분류학회지
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• 제46권1호
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• pp.65-82
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• 2016

서울대학교 수우표본관에서 완성한 KPF(Korean Peninsula Flora Database) 데이터베이스에서는 1850년부터 1945년까지 한반도에서 채집된 65,000개의 관속식물의 기록물을 관리하고 있다. 이 중 북한에서 채집된 기록은 33,000개인데 이 중 13%에 해당되는 4,287개가 1909년부터 1942년에 걸쳐 5명의 일본인(노무라, 오쿠야마, 후루미, 이마이, 사이토)과 1명의 미국인(밀즈)에 의해 채집되었다. 코마로프(Komarov, V.L), 나카이(Nakai, T) 이후 3번째로 많은 북한에서 채집된 표본이다. 이런 채집과 관련된 보고서는 지명사전으로 기존에 일부 발표하였지만, 본 논문에서는 보다 더 자세한 일정과 채집물에 대해 기록하였다. 사이토가 가장 많은 1,730개 표본을 채집하였고 밀즈, 노무라, 오쿠야마, 후루미, 이마이 순서로 1,067, 532, 510, 368, 370개의 표본을 채집하였다.

• 대한수학회보
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• 제60권5호
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• pp.1237-1252
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• 2023

A fundamental problem in coding theory is to find n_q(k, d), the minimum length n for which an [n, k, d]_q code exists. We show that some q-divisible optimal linear codes of dimension 4 over 𝔽_q, which are not of Belov type, can be constructed geometrically using hyperbolic quadrics in PG(3, q). We also construct some new linear codes over 𝔽_q with q = 7, 8, which determine n₇(4, d) for 31 values of d and n₈(4, d) for 40 values of d.

• Journal of Microbiology and Biotechnology
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• 제18권7호
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• pp.1286-1289
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• 2008

The ability of Lactococcus strains to inhibit the growth of intestinal bacteria was examined. In in vitro cocultures, we observed that among eighteen Lactococcus strains tested, the ability to inhibit growth of Escherichia coli varied, with the L. lactis N7 showing the greatest growth inhibition. Strain N7 ($8.94\times10^{10}$ CFU/day for 7 days) was orally administered to mice, and the viable count of strain N7 in feces appeared at a level of $10^{4-5}$ CFU/g. After administration, the proportion of Bacteroidaceae to total intestinal bacteria decreased. Lactococci may act as probiotic bacteria by inhibiting the growth of harmful bacteria.

• Animal cells and systems
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• 제16권3호
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• pp.254-259
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• 2012

The riffle beetle genus Leptelmis is newly recorded in the Korean fauna with descriptions of two new species, L. coreana, n. sp. and L. ochra, n. sp. Dorsal habitus and line-drawings of diagnostic characters are provided. The adults of L. coreana and L. ochra are similar to those of L. gracilis Sharp or L. parallela Nomura in general appearance, but can be distinguished by the absence of apical spurs on the middle and hind tibiae, light brown body color, smaller body size, and the shape of aedeagus apex. Leptelmis coreana can be distinguished from L. ochra by the absence of hindwings, lack of prominent humeri and wider elytra in posterior portion. Adults of both species occur in lowland streams and large rivers, but L. ochra were encountered relatively infrequently.

• 대한화장품학회지
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• 제40권4호
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• pp.341-347
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• 2014

본 연구에서는 노무라입깃해파리(Nemopilema nomurai) 가수분해 추출물의 미백활성에 대하여 검색하였다. 가수분해 시료(NHE, N. nomurai Hydrolized Extract)는 노무라입깃해파리를 상업용 단백질분해효소(Protamex, Alcalase, Flavourzyme, Neutrase)를 이용하여 $55^{\circ}C$에서 pH 5-8 조건으로 처리하는 과정을 거쳐 얻었다. 미백활성은 B16-F1 멜라노마 세포에서 멜라닌 색소 합성 저해능 평가를 통하여 확인하였다. 실험결과, Neutrase로 처리된 시료(N-NHE)에서 $100{\mu}g/mL$의 농도에서 멜라닌 생성이 가장 효율적으로 89.9% 감소되는 것을 관찰하였다. 이 시료는 또한 tyrosinase와 TRP-1 (tyrosinase related protein-1) 단백질의 발현을 억제하였다. 이상의 연구 결과는 노무라입깃해파리 가수분해 추출물의 화장품 미백 소재로의 개발 가능성을 보여주고 있다.

• Macromolecular Research
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• 제14권4호
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• pp.466-472
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• 2006

The kinetic behavior of emulsion polymerizations of styrene in the presence of sulfonated N-hydroxy ethyl aniline (SHEA) was investigated with two initiators: 2,2'-azobisisobutyronitrile (AIBN) and potassium persulfate (KPS). SHEA was synthesized using a stepwise polyurethane reaction method from 3-hydroxy-1-propane sulfonic acid sodium salt, isophorone diisocyanate (IPDI), and N-(2-hydroxyethyl) aniline. Stable core-shell poly(styrene/sulfonated N-hydroxy ethyl aniline, St/SHEA) latex particles were successfully prepared by using an appropriate amount of AIBN, in which SHEA plays the role of 'surfmer', i.e., acting as both a surfactant in the emulsion polymerization and a monomer in the chemical oxidative polymerization. The kinetic behavior was dissimilar to that of typical emulsion polymerization systems. A long inhibition period and low rate of polymerization were observed due to radical loss by the oxidative polymerization of SHEA. It was concluded, due to the low water-solubility of AIBN and retardation reaction by SHEA, that the initial loci of polymerization were monomer droplets. However, growing polymer particles as polymerization loci became predominant as polymerization proceeded. It was suggested that AIBN was more effective than KPS in the preparation of the core-shell type poly(St/SHEA) latex particles. With KPS, no substantial polymerization was observed in any of the samples.

• 한국초전도ㆍ저온공학회논문지
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• 제24권3호
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• pp.19-23
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• 2022

We have been developing a magnetic separation device that can be used in low magnetic fields for paramagnetic materials. Magnetic separation of paramagnetic particles with a small particle size is desired for volume reduction of contaminated soil in Fukushima or separation of iron scale from water supply system in power plants. However, the implementation of the system has been difficult due to the needed magnetic fields is high for paramagnetic materials. This is because there was a problem in installing such a magnet in the site. Therefore, we have developed a magnetic separation system that combines a selection tube and magnetic separation that can separate small sized paramagnetic particles in a low magnetic field. The selection tube is a technique for classifying the suspended particles by utilizing the phenomenon that the suspended particles come to rest when the gravity acting on the particles and the drag force are balanced when the suspension is flowed upward. In the balanced condition, they can be captured with even small magnetic forces. In this study, we calculated the particle size of paramagnetic particles trapped in a selection tube in a high gradient magnetic field. As a result, the combination of the selection tube and HGMS (High Gradient Magnetic Separation-system) can separate small sized paramagnetic particles under low magnetic field with high efficiency, and this paper shows its potential application.

• 한국초전도ㆍ저온공학회논문지
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• 제25권3호
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• pp.13-17
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• 2023

Magnetic separation technology for small paramagnetic particles has been desired for the volume reduction of contaminated soil from the Fukushima nuclear power plant accident and for the separation of scale and crud from nuclear power plants. However, the magnetic separation for paramagnetic particles requires a superconducting high gradient magnetic separation system applied, hence expanding the bore diameter of the magnets is necessary for mass processing and the initial and running costs would be enormous. The use of high magnetic fields makes safe onsite operation difficult, and there is an industrial need to increase the magnetic separation efficiency for paramagnetic particles in as low a magnetic field as possible. Therefore, we have been developing a magnetic separation system combined with a selection tube, which can separate small paramagnetic particles in a low magnetic field. In the previous technique we developed, a certain range of particle size was classified, and the classified particles were captured by magnetic separation. In this new approach, the fluid control method has been improved in order to the selectively classify particles of various diameters by using a multi-stage selection tube. The soil classification using a multi-stage selection tube was studied by calculation and experiment, and good results were obtained. In this paper, we report the effectiveness of the multi-stage selection tube was examined.

• 한국초전도ㆍ저온공학회논문지
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• 제25권3호
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• pp.18-21
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• 2023

Pollution of the environment by micro-plastics is now a worldwide problem. Plastics are difficult to decompose and put a great load on the marine environment. Especially a plastic with a size of 5 mm or less is defined as micro-plastic and are carried by ocean currents over long distances, causing global pollution. These are not easily decomposed in the natural environment. In this paper, we aimed to experimentally demonstrate that micro-plastics in seawater can be continuously separated by electromagnetic Archimedes force. Using polyethylene particles of 3 mm in diameter as the separation target, a flow channel was fabricated and separation conditions were investigated by particle trajectory calculations for separation experiments. Based on the calculation results, a solenoid-type superconducting magnet was used as a source of magnetic field to conduct separation experiments of micro-plastics in seawater. Although a high separation rate was assumed in the simulation results, the experimental results did not show any significant improvement in the separation rate due to the electromagnetic Archimedes force. It was found that the gas generated by the electrolytic reaction may have inhibited the migration of the particles.

• Journal of Microbiology and Biotechnology
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• 제21권4호
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• pp.405-411
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• 2011

Avian influenza virus vaccines produced in oil-emulsified inactivated form with antigen content of at least 160 hemagglutinin units (HAU) induced immunity in birds. However, in addition to enhancing the effect of the adjuvant(s), other additional supplemented biological compounds included in inactivated vaccines could produce higher levels of antibody. We examined in chickens, Vietnamese ducks, and muscovy ducks the adjuvant effect of Sophy ${\beta}$-glucan (SBG), a ${\beta}$-1,3-1,6 glucan produced by the black yeast Aureobasidium pollulans strain AF0-202, when administered with an avian influenza H5 subtype vaccine. In Experiment 1, 40 chickens (ISA Brown hybrid), allocated to four groups of ten each, were immunized with Oil-H5N1(VN), Oil-H5N1(CN), Oil-H5N2(CN), and saline (control group), respectively. In Experiment 2, chickens (ISA Brown hybrid), muscovy ducks (French hybrid), and Vietnamese ducks (indigenous Vietnamese) were used to further assess the effect of SBG on immunogenicity of the Oil-H5N1(VN) Vietnamese vaccine. ELISA and hemagglutination inhibition (HI) assays were used to assess the antibody response. The H5 subtype vaccines initiated significantly higher immune responses in the animals dosed with SBG, with 1.0-1.5 $log_2$ higher HI titers and 10-20% ELISA seroconversion, compared with those not dosed with ${\beta}$-glucan. Notably, some of the animals dosed with SBG induced HI titers higher than 9.0 $log_2$ following boosting immunization. Taken together, our serial studies indicated that SBG is a potential effector, such as enhancing the immune response to the H5 vaccines tested.