• Food Science and Biotechnology
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• 제18권4호
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• pp.842-848
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• 2009

The purpose of this study was to determine the extent of domoic acid (DA) a potent neurotoxin, responsible for the syndrome amnesic shellfish poisoning (ASP) contamination of various species of bivalve shellfish purchased from fish market in Korea and the implications for food safety. Liquid chromatography (LC) methods were applied to quantify DA in shellfish after sample clean-up using solid-phase extraction (SPE) with strong anion exchange (SAX) cartridges. Toxin detection was achieved using photodiode array ultraviolet (LC-UV) and electrospray ionization-mass (LC-ESI-MS). DA was identified in 4 bivalve shellfishes of 872 shellfishes collected from March, 2006 to October, 2007 in Korea. DA amount of 3 surf clams (Mactra veneriformis) collected at Seoul, Daejeon, and Daegu were 4.13, 1.99, and 1.94 mg/kg, respectively. DA amount of 1 pink butterfly shell (Peronidia venulosa) collected at Seoul was 3.02 mg DA/kg. The amounts of DA that were present in 4 bivalve shellfishes were within EU guideline limits for sale of shellfish (20 mg DA/kg).

• Archives of Pharmacal Research
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• 제21권5호
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• pp.555-558
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• 1998

chondroitin sulfates were isolated from the mud snail. For the quantitative analysis of enzymatic digestion products of isolated chondroitin sulfates, strong anion exchange-high performance liquid chromatography (SAX-HPLC) was performed. by the action of chondroitinase ABC, three unsaturated disaccharides$ 2-acetamide-2-deoxy-3-O-({\beta}-D-gluco-4-enepyranosyluronic acid)-D-galactose $$({\Delta}Di-OS), $2-acetamide-2-deoxy-3-O-({\beta}-D-gluco-4-enepyranosyluronic acid)-6-O-sulfo-D-galactose ({\Delta}Di-6S) and 2-acetamide-2-deoxy-3-O-({\beta}-D-gluco-4-enepyranosyluronic acid)-4-O-sulfo-D-galactose ({\Delta}Di-4S)$ were produced from the mud snail chondroitin sulfates. The analysis showed that relative proportion of ${\Delta}Di-OS/{\Delta}Di-6S/{\Delta}Di-4S$ was 58.7/3.1/38.2. The immunomodulating activity of chondroitin sulfate was examined by cell proliferation assay and these results suggest that it might be a immunosuppressant.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2007년도 가을 학술발표논문집 Vol.34 No.2 (C)
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• pp.66-71
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• 2007

멀티미디어 데이터에 대한 효율적인 검색을 지원하기 위해 제정된 MPEG7이나 TV-AnyTime 등의 표준들은 XML을 사용하여 Metadata를 효과적으로 표현할 수 방법을 제시하고 있다. 플랫폼에 독립적으로 사용가능하다는 XML의 강점에도 불구하고 Text 방식으로 데이터를 저장하기 때문에 보안에 취약할 수밖에 없으며, 대용량의 자료 처리에도 문제점을 드러낸다. 이를 보완하기 위하여 XML 문서를 RDBMS에 저장하는 방법들이 제안되고 있는데, 기존의 Model Mapping이나 Structure Mapping의 경우 노드 검색을 위해 Traversing을 할 경우 많은 조인이 필요하기 때문에 한정된 메모리와 낮은 처리능력을 갖춘 임베디드 멀티미디어 플랫폼에서는 비효율적일 수밖에 없다. 본 논문에서는 MPEG7 Metadata를 RDBMS에 저장하고, 이를 검색할 때, 조인의 횟수를 최소화할 수 있는 저장 모델을 제안하고 있다. 부모, 자식, 형제간의 노드를 효율적으로 검색할 수 있도록 path MetaSchema를 제안함으로써, 최소 1번의 검색으로 필요한 노드 정보들을 추출할 수 있도록 하였다. 그리고 Annotation 작성시에 XML의 Attribute와 Element로 삽입하였기에, 기존의 방법에서 Annotation을 분석하기 위해 필요했던 Annotation 파싱을 제거하고, SAX나 DOM을 사용할 수 있도록 제안함으로써, Annotation의 정보에 대한 접근이 효율적으로 개선되었다.

• 약학회지
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• 제34권3호
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• pp.215-218
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• 1990

An ion chromatographic method based on indirect photometric detection of UV transparent anions was developed. Separation of anion was accomplished on strong anion exchange column (Waters SAX) using UV detector at 254 nm. Among examined UV-active additives (Dns-H, Dns-glu, Dnsser, Dns-val), Dns-glu showed the highest sensitivity. Studies on the effects of the pH and ionic strength of eluent revealed that the increase of pH and ionic strength of the eluent decreased capacity factor. The best eluent for the separation of acetate, fluoride, chloride, nitrate and bromide was $1\;{\times}\;10^{-4}M$ Dns-glu in 5 mM phosphate buffer (pH 6.30). The detection limit of chloride ion was 2.1 ng in this condition.

• Bulletin of the Korean Chemical Society
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• 제23권4호
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• pp.580-586
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• 2002

We investigated the effect of ionic component on crystalline morphology development during isothermal annealing in a sodium neutralized sulfonated poly(ethylene terephthalate) ionomer (Ion-PET) by time-resolved small-angle x-ray scattering (TR-SAX S) using synchrotron radiation. At early stage in Ion-PET, SAXS intensity at a low annealing temperature (Ta = 120 $^{\circ}C)$ decreased monotonously with scattering angle for a while. Then SAXS profile showed a peak and the peak position progressively moved to wider angles with isothermal annealing time. Finally, the peak intensity decreased, shifting the peak angle to wider angle. It is revealed that ionic aggregates (multiplets structure) of several nm, calculated by Debye-Bueche plot, are formed at early stage. They seem to accelerate the crystallization rate and make fine crystallites without spherulite formation (supported by optical microscopy observation). From decrease of peak intensity in SAXS,it is suggested that new lamellae are inserted between the preformed lamellae so that the concentration of ionic multiplets in amorphous region decreases to lower the electron density difference between lamellar crystal and amorphous region. In addition, analysis on the annealing at a high temperature (Ta = 210 $^{\circ}C)$ by optical microscopy, light scattering and transmission electron microscopy shows a formation of spherulite, no ionic aggregates, the retarded crystallization rate and a high level of lamellar orientation.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2005년도 한국컴퓨터종합학술대회 논문집 Vol.32 No.1 (B)
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• pp.148-150
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• 2005

오늘날 XML이 디지털 정보교환의 표준으로 자리잡은 후 XML문서를 데이터베이스에 저장하고 원하는 정보를 효율적으로 질의하기 위한 연구가 활발히 진행되고 있다. 특히 XML질의어를 RDBMS 상에서 처리하기 위해 그리고 XML문서정보를 정확하게 추출하여 효율적으로 관리하기 위해 다양한 기법을 동원한 XML 인덱스 Table의 연구가 계속 되고 있다. 하지만 아무리 설계가 잘 된 XML인덱스 table이라 할지라도 이에 저장될 정보들을 XML문서로부터 빠른 시간에 파싱하여 관계형 테이블에 로드하기가 쉽지 않다. 이에 본 논문에서는 RDMS환경에서 XML문서를 관리하고 질의를 처리할 수 있도록 XML 인덱스 table을 디자인하였으며 이에 정확한 값이 좋은 성능을 가지면서 저장되도록 XML문서의 데이터 정보를 추출하는 XML Analyzer를 설계 및 구현하였다. 우선 Analyzer를 구현하기 위해서는 XML Parser를 사용해야 되는데 본 장에서는 이벤트 기반 방식인 SAX를 통해 XML문서를 파싱하여 데이터를 추출하고 그 결과값을 RDMS상의 XML 인덱스 Table에 저장한다. 마지막으로 이를 실제 구현하고 Test한 내용을 근거로 하여 본 장에서 소개하는 XML Analyzer가 다른 방식보다 성능면에서 훨씬 우수하다라는 사실을 입증한다.

• 한국전기전자재료학회논문지
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• 제17권11호
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• pp.1218-1223
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• 2004

Porous silicon materials have been shown to have bright prospects for applications in light emitting, solar cell, as well as light- and chemical-sensing devices. In this report, structures of porous silicon prepared by anodic etching in HF-based solution with various etching times were studied in detail by Atomic Force Microscopy and Small Angle X -ray Scattering technique using the high energy beam line at Pohang Light Source in Korea. The results showed the coexistence of the various pores with nanometer and submicrometer scales. For nanameter size pores, the mixed ones with two different shapes were identified: the larger ones in cylindrical shape and the smaller ones in spherical shape. Volume fractions of the cylindrical and the spherical pores were about equal and remained unchanged at all etching times investigated. On the whole uniform values of the specific surface area and of the size parameters of the pores were observed except for the larger specific surface area for the sample with the short etching time. The results implies that etching process causes the inner surfaces to become smoother while new pores are being generated. In all SAXS data at large Q vectors, Porod slope of -4 was observed, which supports the fact that the pores have smooth surfaces.

• FOCUS: LIFE SCIENCE
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• 제1호
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• pp.5.1-5.3
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• 2024

The document discusses the regeneration of Partisil/Partisphere ion-exchange columns in chromatography. It mentions that column efficiency can diminish with use due to the accumulation of sample and/or mobile phase impurities at the head of the column. This can lead to a change in back pressure, lower column efficiency, and sometimes a change in selectivity. The document outlines a procedure that may restore column performance. The document also provides everyday practices to enhance the lifetime of a column. These include using only high-purity HPLC solvents and buffers, using freshly prepared mobile phases and buffers, filtering mobile phases to remove particulates, using appropriate sample clean-up procedures, using a guard column or pre-column filter, and working within the pressure and flow rate limitations of the column. For the regeneration of Partisil/Partisphere SAX, SCX, WAX, and WCX columns, the document suggests passing 20 column volumes of various mobile phases through the column. These include a buffer wash, distilled water, an acid wash, a chelating wash, a methanol wash, and a buffer for separation. The document emphasizes that not all of these wash steps are required for every column clean-up and that some chromatographers require only a combination of certain steps.

• 동의생리병리학회지
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• 제18권4호
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• pp.1089-1097
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• 2004

This study was designed to elucidate the synergistic cytotoxic mechanisms of the cotreatment of Gagamsibjeondaebo-tang (GSD) and AS₂O₃ in human lung cancer cell line, H-460. The combination of GSD and AS₂O₃ synergistically augmented the cytotoxicity of GSD and AS₂O₃ in H-460 cells. The nature of cytotoxicity was revealed as apoptosis which was characterized by chromatin condensation and fragmentaton in DAPI staining. The apoptotic cytotoxicity of GSD and AS₂O₃ was accompanied by the cleavage of PARP. Of note, the expression of pro-apoptotic BclXS protein was increased, but the expressions of Sax and BclXL was not affected in H-460 cells treated with GSD and AS₂O₃. In addition, antioxidant NAC completely blocked the apoptotic death of H-460 cells by GSD and AS₂O₃. In conclusion, this results suggest that the cotreatment of GSD and AS203 induces the synergistic apoptotis of human large cell lung cancer cell line, H-460 via the induction of BclXS and reactive oxygen species (ROS).

• 한국정보과학회논문지:데이타베이스
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• 제35권4호
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• pp.307-318
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• 2008

XML 메시지 중계기에서의 주요 이슈들 중 하나는 XML 스트림에 대한 다중 연속 XPath질의를 효율적으로 처리하는 방안이다. 본 연구는 이 문제를 효과적으로 해결하기 위한 시스템을 제안한다. 제안되는 시스템에서는 XPath 질의집합을 XP-table이라는 새로운 영역 기반 데이터 구조로 변환한다. XP-table은 대상 질의들의 공통적인 선택조건들을 공유하며, 실행시간 질의 수행 전에 구축된다. XML 스트림은 XP-table과의 효율적 매칭을 위해 스트림 릴레이션(SR)으로 실행시간에 변환된다. 제안된 시스템에서는 XML의 구조적 특성을 반영한 XP-table과 SR 간의 효과적인 매칭 전략이 제시된다. 또한, YFilter나 LazyDFA와 같은 기존 방법론과의 비교를 포함한 일련의 실험들을 통해, 제안 시스템이 질의 처리의 실행시간 부하를 줄임으로써 시간 효율성이 중요한 스트림 환경에서의 안정적 데이타 처리 능력을 보여준다.