• Bulletin of the Korean Chemical Society
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• 제33권11호
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• pp.3565-3570
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• 2012

Until now, few groups reported the antifreeze activity of cyclic glycopeptides; however, the tedious synthetic procedure is not amenable to study the intensive structure activity relationship. A series of N-linked cyclic glycopeptoids and glycopeptide have been prepared to evaluate antifreeze activity as a function of peptide backbone cyclization and methyl stereochemical effect on the rigid Thr position. This study has combined the cyclization protocol with solid phase peptide synthesis and obtained significant quantities of homogeneous cyclic glycopeptide and glycopeptoids. Analysis of antifreeze activity revealed that our cyclic peptide demonstrated RI activity while cyclic glycopeptoids showed no RI activity. These results suggest that the subtle changes in conformation and Thr orientation dramatically influence RI activity of N-linked glycopeptoids.

• Ocean and Polar Research
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• 제36권4호
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• pp.319-326
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• 2014

Mineral dust in the polar snow plays an important role both in the climate system of the Earth and in global biogeochemical cycles. Analysis of the concentration and the particle size distribution of mineral dust has been carried out in the snow from the Antarctic surface snow and the Greenland snowpit. Among the various particle size determination techniques, a Multisizer 3 Coulter Counter in a class 100 clean bench counted all particles between 1.1 and $30.0{\mu}m$ with a $50{\mu}m$ aperture tube. The aperture tube size, the concentration of electrolytes and the accuracy of the particle size distribution were determined in this study. The number concentrations from the Antarctic surface snow were 81,843 particles $mL^{-1}$, but those from the Greenland snowpit were 10,666 particles $mL^{-1}$. In the volume distribution, the distributions of mineral dust in both the Antarctic surface snow and the Greenland snowpit showed lognormal distribution in the size interval 1.1 to $6.0{\mu}m$ with the mode, 3.562 and $3.836{\mu}m$, respectively. The analysis technique using a coulter counter for mineral dust could be used for reconstructing paleoclimates from polar ice cores.

• 지구물리
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• 제8권2호
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• pp.63-66
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• 2005

전 지구적 환경 모니터링을 위한 빙하 시추의 예비 탐사로서 남극 리빙스톤섬에서 GPR (Ground Penetrating Radar) 탐사를 실시하였다. 탐사지역은 세종기지가 위치한 킹죠지섬으로부터 남서쪽으로 80 km 위치한 곳으로 해발 340 m의 Mt. Charra 부근에 위치한다. 총 5개의 측선을 탐사했으며 3개의 반사법과 2개의 CMP(Common Midpoint) 방법을 실시하였다. 탐사결과 연구지역에서 빙하층은 전자기파의 속도와 반사단면의 특징으로 3개로 나누었다. 빙하의 두께는 80∼110 m에 이르는 것으로 추정되고 층에 따라 빙하 내부에 다량의 물과 화산재를 포함하고 있는 것으로 해석된다.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 1998년도 한국우주과학회보 제7권1호
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• pp.50-51
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• 1998

No Abstract.See Full-text

• 한국제4기학회지
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• 제19권2호
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• pp.7-12
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• 2005

• 한국제4기학회지
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• 제19권2호
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• pp.45-49
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• 2005

• 지구물리와물리탐사
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• 제15권3호
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• pp.144-149
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• 2012

극지연구소는 2010 ~ 2011년 제 24차 남극하계탐사기간 동안 남극 킹조지섬에 3성분 초광대역 지진계를 성공적으로 설치하였다. 미국 IRIS PASSCAL에서 개발한 지진관측시스템을 활용하였으며, 이는 POLENET 지진관측시스템과 완벽히 호환된다. 지진계설치 및 운용의 목적은 크게 두가지로 나누어 지는데, 첫번째로 킹조지섬 주변의 지진 및 빙권관련 신호를 관측하는데 있으며, 두번째로는 극한환경에서의 지진관측장비 성능검사이다. 관측이 성공적으로 수행된다면, 다음 목표로 관측시스템의 추가확보를 통하여 남극반도 라르센 빙붕시스템과 같은 빙붕 주변으로 관측장소를 이동하여 지권과 빙권간 상호작용을 이해하고, 빙권의 움직임등 동역학적인 해석을 위한 연구를 수행하고자 한다. 이 보고서에서 우리는 지진파 배경잡음분석을 통하여 지진관측시스템 성능 및 특성 파악에 관한 내용과 관측시스템 운용관련 정보를 제공하고자 한다.

• Ocean and Polar Research
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• 제25권4호
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• pp.569-591
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• 2003

Marine benthic flora was investigated in an Arctic bay. Specimens of chlorophyte, phaeophyte, and rhodophyte were collected and examined over the period from July to August 2003 from Kongsfjorden Spitsbergen in Svalbard Islands. A total of 28 genera and 32 species (5 chlorophytes, 18 phaeophytes, and 9 rhodophytes) was identified and described. A green alga Enteromorpha linza(Linnaeus) J. Agardh, a brown alga Asperococcus compresus Griffiths ex Hooker, and three red algae Gracilaria gracilis (Stackhouse) Steentoft et al., Rhodymenia pacifica Kylin and Schizochlaenion rhodotrichum Wynne et Norris were recorded in Svalbard Islands for the first time.

• Ocean and Polar Research
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• 제30권4호
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• pp.467-472
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• 2008

Antarctic krill has a strong proteolytic enzyme system, which comes from a combination of several proteases. This powerful activity can be easily detected by krill's superior post mortem autolysis. Mammalian skin consists of epidermis and dermal connective tissue, and functions as a barrier against threatening environments. A clot in a wound site of the skin should be removed for successful skin regeneration. Epithelial cells secrete proteases to dissolve the clot. In previous studies Antarctic krill proteases were purified and characterized. The proteolytic enzymes from Antarctic krill showed higher activity than mammalian enzymes. It has been suggested that these krill clean up the necrotic skin wound to induce a natural healing ability. The enzymes exhibited additional possibilities for several other biomedical applications, including dental plaque controlling agent and healing agent for corneal alkali burn. Considering that these versatile activities come from a mixture of several enzymes, discovering other proteolytic enzymes could be another feasible way to enhance the activity if they can be used together with krill enzymes. Molecular cloning of the krill proteases should be carried out to study and develop the applications. This review introduces possible roles of the unique Antarctic krill proteases, with basic information and suggestion for the development of an application to skin regeneration.

• Ocean and Polar Research
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• 제26권3호
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• pp.501-506
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• 2004

The observational proxy estimates suggest that the North Atlantic overturning stream function associated with the North Atlantic Deep Water (NADW) production and outflow was substantially weaker during the last glacial maximum (LGM) than that observed under present conditions. The impact of the changes in overturning circulation on the glacial carbon budget is investigated using a box model. The carbon box model reveals that the atmospheric $CO_2$ concentration is more sensitive to change in the overturning circulation of the North Atlantic than that of the Southern Ocean, especially when North Atlantic overturning becomes weaker. For example, when the strength of the North Atlantic overturning circulation is halved, the atmospheric $CO_2$ concentration is reduced by 50ppm of that associated with the accumulation of $CO_2$ in the deep ocean. This result implies that a weaker North Atlantic overturning circulation may play an important role in the lowering of LGM atmospheric $CO_2$ concentration.