• 동의생리병리학회지
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• 제21권4호
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• pp.940-945
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• 2007

We have examined the induction of HL-60 cell differentiation by treatment of 2-chloromethyl-1-dihydroxyphosphinyl pyrrolidine(2C-1DPP), which is derivative of piperidine and pyrrolidine by ${\alpha}-phosphoramidoakylation$ reaction. It was observed that HL-60 cell proliferation was dose- and time-dependently inhibited by treatment with 2C-1DPP. 2C-1DPP treatment caused a significant change in NBT reduction and enhanced ATRA-induced NBT reduction. Treatment of 2C-1DPP to HL-60 cells increased only CD11b expression in the cells, and also increased markedly G0/G1 stage arrest of HL-60 cells. These results can suggest that 2C-1DPP induced the differentiation of HL-60 cells to granulocytes lineage and enhanced ATRA-induced differentiation. Moreover, DNA expression levels of p27 were up-regulated during 2C-1DPP-dependent HL-60 cell differentiation. Our results suggest that 2C-1DPP have potential as a therapeutic agent in human leukemia.

• 한국염색가공학회지
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• 제33권4호
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• pp.202-209
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• 2021

Natural dyes are more expensive than synthetic dyes and the dyeing process, which is mainly immersion of dye, is complicated. For this reason, relatively small-scale production methods were predominant. However, awareness and interest in environmental sustainability is rising globally, and the use of synthetic dyes causes various environmental problems such as wastewater and CO₂ emission, so the consumption of natural dyes is increasing. In addition, interest in digital textile printing, an eco-friendly dyeing method that can produce products of various designs and uses less water, is growing. In this study, natural indigo dye (Indigofera tinctoria) was used as a raw material for Digital Textile Printing ink, and ¹⁴C (Biocarbon) present in it was measured to confirm whether it was derived from natural ingredients. The performance was confirmed by testing the pH, viscosity, electrical conductivity, surface tension, and particle size analysis of natural indigo ink. In addition, the performance of natural indigo DTP ink and printing fabric was evaluated by inspecting the change in color fastness and corresponding index substances before and after digital printing with natural indigo DTP ink on textiles. Through this, the possibility of commercialization of DTP ink and printing fabric using natural indigo was confirmed.

• Journal of Ecology and Environment
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• 제46권1호
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• pp.85-98
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• 2022

Background: Korean white pine (Pinus koraiensis) is a major commercial species, and the importance of the oak trees (Quercus spp.) is increasing due to various factors such as environmental and ecological values. However, more information is required to clearly understand the growth characteristics of these species especially regarding thinning intensity. This study was performed to provide the basic information to develop the silvicultural guideline and field manual by analyzing tree and stand characteristics in line with thinning intensity in the Korean white pine plantation and oak-dominated natural deciduous forest. Results: Diameter at breast height (DBH) and volume changes by the thinning intensity in the Korean white pine plantation were significantly different from those in the oak-dominated deciduous natural forest. In particular, DBH distribution in the pine stand appeared that there were more large diameter trees as the thinning intensity was higher. DBH periodic annual increment (PAI) of the pine stand was higher as the thinning intensity was stronger and the growth period was shorter. This trend was similarly shown in the natural deciduous forest, but the amount of PAI was smaller than in pine stand. The volume PAI after thinning was not decreased over time. In each stand type, the PAI tended to be lower as stand density was higher. The volume PAI in the pine stand was significantly higher than that in the oak-dominated natural deciduous forest. Dead trees occurred the most in the unthinned plots of each stand type, and those were higher in the natural deciduous forest. Ingrowth trees were observed only in the natural deciduous forest, and its distribution was the lowest in unthinned plots; Korean white pine as ingrowth occurred the most frequently among many tree species. Conclusions: Different effects of thinning treatment on DBH and volume PAI, mortality, and ingrowth were observed for each stand. With respect to forest growth, Korean white pine plantation was superior to the oak-dominated natural deciduous forest. The results of this study offer fundamental information for the development of silvicultural guidelines for Korean white pine plantations and oak-dominated natural deciduous forests in Korea.

• Animal cells and systems
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• 제3권3호
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• pp.275-283
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• 1999

Korean R. plancyi occupies a restricted area in western South Korea and shows a relatively low level of genic variability (%P＝15.2, Ho=0.052, He＝0.048). In contrast, R. nigromaculata is broadly distributed in South Korea. The observed low level of variability of R. nigromaculata (%P＝14.3, Ho＝0.042, He＝0.043) is probably due to its recent colonization. Populations of R. nigromaculata exhibited considerable genetic differentiation (F$_{sT}$=0.149) and low level of gene flow (Nm＝1.427) among populations, compared to those of R. Plancyi (F$_{sTF$_{sT}$}$=0.096, Nm＝2.354), which occupies a restricted area. The observed levels of gene flow among populations of R. nigromaculata (Nm＝1.427) over a broad geographic range is relatively higher than other amphibian species. The high level of gene flow is probably the result of the high dispersal abilities of R. nigromaculata. A survey of temporal genic variation of R. nigromaculata showed that there was no significant change on the overall average genetic diversity from 1978 (average He＝0.044) to 1997 (average He＝0.040). Wright's F-statistics also indicated no significant genetic differentiation from 1978 (F$_{sT}$＝0.118) to 1997 (F$_{sT}$＝0.108). This suggests that the environmental change appears to have had little influence on the genetic composition of R. nigromaculata in the study areas during the past 20 years. The low level of temporal variation might be due to the result of high dispersal abilities and wide migration range of this species.

• Journal of Korean Dental Science
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• 제4권1호
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• pp.14-19
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• 2011

Purpose: The aim of our study was to evaluate natural recovery of neurologic injury after minor dental surgery based on subjective neurologic evaluation. Materials and Methods: From December 2005 through July 2009, 30 patients from Seoul National University Bundang Hospital were identified as having been treated with minor dental surgery. The patients were composed of 12 men and 18 women, with a mean age of 50.6 years. The median duration of this study was 62 weeks. Results: The patients were treated by implants (17 cases), tooth extractions (6 cases), bone grafts (4 cases), inferior alveolar nerve transpositions (2 cases) and periodontal surgery (1 case) prior to the occurrence of altered sensation. Areas of altered sensation after minor surgery included the lip (36.7%), chin (30.0%) and tooth (21.7%), and at final follow-up, there was no change of ranking. Altered sensations expressed by patients included numbness (33.3%), discomfort (22.9%), relieving sense (14.6%), tingling (14.6%) and itching (14.6%). There was no change of ranking of altered sensation at the last follow-up. Patients experienced the altered sensation always (47.8%), during tactile stimulation (26.1%), when chewing food (13.0%), and talking (13.0%). Mean visual analogue scale (VAS) was $3.43{\pm}2.84$ for pain and $6.64{\pm}2.72$ for paresthesia. VAS of pain was decreased significantly between the first visit and the end of follow-up, and paresthesia also showed a significant difference. Conclusion: Altered sensations may occur at any time after minor dental surgery, but we observed that natural recovery of altered sensation occurred as time went on.

• Smart Structures and Systems
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• 제15권2호
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• pp.335-353
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• 2015

Previous long-term measurements of the Uldolmok tidal current power plant showed that the structure's natural frequencies fluctuate with a constant cycle-i.e., twice a day with changes in tidal height and tidal current velocity. This study aims to improve structural health monitoring (SHM) techniques for offshore structures under a harsh tidal environment like the Uldolmok Strait. In this study, lab-scale experiments on a simplified offshore structure as a lab-scale test structure were conducted in a circulating water channel to thoroughly investigate the causes of fluctuation of the natural frequencies and to validate the displacement estimation method using multimetric data fusion. To this end, the numerical study was additionally carried out on the simplified offshore structure with damage scenarios, and the corresponding change in the natural frequency was analyzed to support the experimental results. In conclusion, (1) the damage that occurred at the foundation resulted in a more significant change in natural frequencies compared with the effect of added mass; moreover, the structural system became nonlinear when the damage was severe; (2) the proposed damage index was able to indicate an approximate level of damage and the nonlinearity of the lab-scale test structure; (3) displacement estimation using data fusion was valid compared with the reference displacement using the vision-based method.

• 구강회복응용과학지
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• 제28권3호
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• pp.233-243
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• 2012

이 연구의 목적은 임플란트 보철물과 자연치 사이의 인접접촉강도의 경시적 변화를 평가하는 것이다. 단일 임플란트 보철물을 장착한 31명(상악제2대구치; 13명, 하악 제2대구치; 18명)의 피험자에게서 측정이 이루어졌다. 측정은 교합되지 않은 안정 상태에서 임플란트 보철 장착 직후, 1개월 그리고 6개월 후에 이루어졌다. 임플란트 보철물과 자연치 사이의 접촉강도는 상악(p<.01), 하악(p<.05) 모두 시간이 흐름에 따라 감소하였다.

• 대한화학회지
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• 제36권1호
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• pp.28-32
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• 1992

몇 가지 요소-수용액에서 Dodecylpyridinium bromide의 임계미셀농도 변화를 1${\sim}$2000 bar 및 $25^{\circ}C$에서 전기전도도법으로 측정하였다. 수용액에 요소가 첨가됨에 따라 전압력 범위에서 임계 미셀농도가 증가하는 경향을 보였으며, 요소-수용액에서 압력의 증가에 따라 임계미셀농도가 증가하다가 어떤 압력이상에서는 압력의 증가에 따라 다시 감소하는 경향을 나타내었다. 한편 미셀 형성에 대한 분몰부피변화$({\Delta}V^m_o)$는 요소의 농도가 증가함에 따라 감소하는 경향성을 보였다. 이 결과로부터 단량체 상태의 계면활성제의 탄화수소사슬 주위의 물의 "icerberg" 구조가 요소에 의해 효과적으로 파괴된다는 것을 알 수 있었다.

• 디지털융복합연구
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• 제19권12호
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• pp.513-521
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• 2021

본 연구의 목적은 동양의학에서 생명 활동 체계 부분의 문헌적 분석을 통해 항노화에 대한 헬스케어 방안을 제시하는 데 있다. 이를 위해 먼저 기의 승강출입운동을 통한 자연계와 인간 생명활동과정 시스템인 신기(神機)와 기립(氣立)에 관한 이론적 배경을 살펴보았다. 자연계와 인체의 생명활동과정이 정상적으로 유지되고 발전, 변화되는 근원은 내적으로 신기의 생장화수장(生长化收藏), 외적으로 기립의 생장장로이(生長壯老已)의 생명활동과정 시스템이 동태적인 협조평형에 있다. 그래서 자연계와 인체의 생명활동과정이 정상적으로 유지되고 발전, 변화되는 근원으로 분석되었다. 이로써 기의 승강출입운동을 응용한 항노화 헬스케어의 방법인 정적인 호흡법과 동적인 복부마사지가 결합한 '호흡마사지'로 인체 생명력의 근원인 진기의 자연치유력을 솟아나게 하면 생명활동과정 시스템인 신기와 기립이 조화를 이루어 건강수명 연장에 도움이 되리라 여겨진다.

• 한국농공학회논문집
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• 제61권3호
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• pp.1-14
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• 2019

North Korea has frequently suffered from extreme agricultural crop droughts, which have led to food shortages, according to the Food and Agriculture Organization (FAO). The increasing frequency of extreme droughts, due to global warming and climate change, has increased the importance of enhancing the national capacity for drought management. Historically, a meteorological drought index based on data collected from weather stations has been widely used. But it has limitations in terms of the distribution of weather stations and the spatial pattern of drought impacts. Satellite-based data can be obtained with the same accuracy and at regular intervals, and is useful for long-term change analysis and environmental monitoring and wide area access in time and space. The Evaporative Stress Index (ESI), a satellite-based drought index using the ratio of potential and actual evaporation, is being used to detect drought response as a index of the droughts occurring rapidly over short periods of time. It is more accurate and provides faster analysis of drought conditions compared to the Standardized Precipitation Index (SPI), and the Palmer Drought Severity Index (PDSI). In this study, we analyze drought events during 2015-2017 in North Korea using the ESI satellite-based drought index to determine drought response by comparing with it with the SPI and SPEI drought indices.