• Applied Chemistry for Engineering
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• v.20 no.2
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• pp.126-133
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• 2009

The surfactants applied in household detergents and industrial cleansers should satisfy the requirement of not just the basic function such as emulsification, solubilisation, dispersion, detergency, wetting and foaming, but also the economical efficiency and the safety to human and environment. In the viewpoint of the sustainable development, the surfactants, moreover, have to reduce raw materials and energy consumption and waste disposal when they are being manufactured and also consumed for their purposes. New high-performance surfactants have been extensively studied and developed in order to respond the change in social and economical environment. Noticeable progresses have been achieved so far, which are the significant increase in solubility and surface activity through the minor modification of existing surfactant molecular structure and the synergistic increase in a surface activity shown in the mixed surfactant system of anionic and cationic surfactants. In this review, the important and meaningful progresses achieved recently in technological advance and practical application will be summarized and discussed.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2001.02a
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• pp.14-18
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• 2001

현대의 우리들의 생활환경 중에는 약 10만 종류 이상의 아주 많은 화학물질이 존재하고 있으며 매년 약 1000종류의 새로운 화합물이 상품화되고 있다고 알려져 있다. 이들 중 일부는 우리의 일상생활에 편리한 기능을 가져다 주는 역할을 하고 있으나 최근 생태계 및 인체에 유해한 영향을 미치는 물질로 판명되는 사례가 증가하고 있다. 그들 중에는, 성호르몬과 유사한 구조를 가지기 때문에 호르몬 수용체에 잘못 결합하여 호르몬 활성을 異常히 높이는 등의 영향을 미치는 것이 알려져 있으며, 또, 약물대사 효소의 유도나 효소활성의 저해 등에 의한 물질대사의 교란, 면역계통의 저해, 발암작용 등의 영향에도 미치는 것이 알려져 있다. 이러한 일군의 물질은 내분비계 장애물질(Endocrine disruptors; 환경 호르몬)로 불리며, 최근의 여성에 있어서 유방암의 발생율의 상승이나 남성의 정자수의 감소, 혹은 어떤 종의 야생 생물에 있어서 생식기능 장해(악어 수컷 생식기의 퇴화, 수컷 잉어등의 암컷화, 일부 권패류의 임포섹스 등)는 이러한 내분비계 장애물질에 의하여 유발되고 있다고 하는 가능성이 지적되고 있다. 그렇지만, 이러한 내분비계 장애물질의 환경 중에서의 분포나 다양한 생물에의 영향에 관한 연구는 세계적으로도 아직 부족하고 내분비계 장애물질의 실태나 그 메카니즘 및 그것이 가지는 의미에 대하여는 아직 명확하게 규명되어 있지 않고 있어, 그것에 의한 생체영향의 평가를 총합적으로 검토하기까지에는 이르지 않고 있다. 이러한 물질에 관한 연구는 최근 선진국을 중심으로 활발한 연구가 수행되고 있으나, 우리 나라에 있어서의 연구는 지금까지는 아직 미미한 수준에 머물고 있다. 따라서, 이러한 내분비계 장애물질을 빠른 시기에 발견하여 그것들에 의한 영향을 평가하고, 그 영향을 미연에 방지하는 데에 필요한 대책을 강구하기 위한 많은 연구가 필요 불가결하다. 본고에서는 이러한 환경호르몬 물질 중 본 연구실에서 수행한 내용을 중심으로 유해화학물질 오염 및 대책에 대하여 간단히 발표하고자 한다. 발표내용은, 남해안을 중심으로 조사한 유기주석화합물 오염, 광양만에서의 PAHs(다환방향족탄화수소류) 및 Bisphenol A 오염에 관한 연구결과와 이러한 유해화학물질 오염을 평가하고 관리하는 하나의 유용한 방법으로서 위해성 평가에 대하여 실례를 중심으로 간단히 소개하고자 한다.

• Journal of Oral Medicine and Pain
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• v.34 no.3
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• pp.227-235
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• 2009

Many of the protective functions of saliva can be attributed to the biological, physical, structural, and rheological characteristics of salivary glycoproteins. Therefore, the development of ideal saliva substitutes requires understanding of the rheological as well as biological properties of human saliva. In the present study, we investigated the changes of salivary enzymatic activities by saliva substitutes and compared viscosity of saliva substitutes with human saliva. Five kinds of saliva substitutes such as Moi-Stir, Stoppers4, MouthKote, Saliva Orthana, and SNU were used. Lysozyme activity was determined by the turbidimetric method. Peroxidase activity was determined with an NbsSCN assay. $\alpha$-Amylase activity was determined using a chromogenic substrate, 2-chloro-p-nitrophenol linked with maltotriose. The pH values of saliva substitutes were measured and their viscosity values were measured with a cone-and-plate digital viscometer at six different shear rates. Various types of saliva substitutes affected the activities of salivary enzymes in different ways. Stoppers4 enhanced the enzymatic activities of hen egg-white lysozyme, bovine lactoperoxidase (bLP), and $\alpha$-amylase. Saliva Orthana and SNU inhibited bLP activity and enhanced $\alpha$-amylase activity. MouthKote inhibited $\alpha$-amylase activity. Moi-Stir inhibited the enzymatic activities of bLP and $\alpha$-amylase. The pH values were very different according to the types of saliva substitutes. Stoppers4, MouthKote, and Saliva Orthana showed lower values of viscosity at low shear rates and higher values of viscosity at high shear rates compared with unstimulated and stimulated whole saliva. Moi-Stir and SNU displayed much higher values of viscosity than those of natural whole saliva. Collectively, our results indicate that each saliva substitute has its own biological and rheological characteristics. Each saliva substitute affects the enzymatic activity of salivary enzyme and finally oral health in different ways.

• Journal of Life Science
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• v.28 no.9
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• pp.1100-1117
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• 2018

The Ras superfamily of small G-proteins acts as a molecular switch on the intracellular signaling pathway. Upon ligand stimulation, inactive GTPases (Ras-GDP) are activated (Ras-GTP) using guanine nucleotide exchange factor (GEF) and transmit signals to their downstream effectors. Following signal transmission, active Ras-GTP become inactive Ras-GDP and cease signaling. However, the intrinsic GTPase activity of Ras proteins is weak, requiring Ras GTPase-activating protein (RasGAP) to efficiently convert RAS-GTP to Ras-GDP. Since deregulation of the Ras pathway is found in nearly 30% of all human cancers, it might be useful to clarify the structural and physiological roles of Ras GTPases. Recently, RasGAP has emerged as a new class of tumor-suppressor protein and a potential therapeutic target for cancer. Therefore, it is important to clarify the physiological roles of the individual GAPs in human diseases. The first RasGAP discovered was RASA1, also known as p120 RasGAP. RASA1 is widely expressed, independent of cell type and tissue distribution. Subsequently, neurofibromatosis type 1 (NF1) was discovered. The remaining GAPs are affiliated with the GAP1 and synaptic GAP (SynGAP) families. There are more than 170 Ras GTPases and 14 Ras GAP members in the human genome. This review focused on the current understanding of Ras GTPase and RasGAP in human diseases, including cancers.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.31-35
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• 2003

폴리카보네이트는 내열성과 투명성이 우수한데 비해 내후성이 좋지 않아 황변 및 물성이 저하되고, 내찰상성이 약하여 긁히기 쉬운데다 이물질에 의해 오염되기 쉬워 투명성이 저하되는 문제점이 있다. 이러한 단점을 극복하고, 사용하는 용도에 따라 요구되는 다양한 기능성을 부여하기 위하여 폴리카보네이트 표면에 기능성층을 형성시킴으로써 그 목적을 달성하고자 한다. 본 논문에서는 이온 주입기술을 이용하여, 폴리카보네이트 표면의 전기전도도 특성을 향상시키고, 피부암 및 백내장 등을 유발하는 유해한 자외선 (UV-A, UV-B)을 차단하려 한다. 표면전기전도도의 향상은 이물질로부터 오염되는 정도를 낮추며, 정전기를 방지할 수 있다. PC(Polycarbonate) 표면에 $N^+,\;Ar^+,\;Kr^+,\;Xe^+$ 이온을 에너지 20keV에서 50keV을 사용하여, 주입량 $5{\times}10^{15}\;{\sim}\7{\times}10^{16}\cm^2$ 로 조사하였다. 이온 주입된 PC의 표면을 두 접점 방법의 표면 저항 측정으로 표면전기전도도 특성을 알아보았고, 자외선차단 특성은 UV-Vis 로 분석하였다. 이들 전기적 광학적 특성간의 상관관계를 관찰하고, 이러한 특성을 나타내는 화학적 기능그룹들의 변화를 보기 위해 FTIR 분석법으로 관찰하였다. 이온조사량의 증가에 따라 표면저항은 $10^7{\Omega}/sq$까지 감소하여 표면전기특성을 증가시키며, 자외선 차단 특성은 UV-A를 95%까지 차단하여 인체에 유해한 자외선 차단에 유용함을 확인하였다. 이러한 특성은 PC 표면에 카본 네트워크 형성과 $\pi$전자들의 운동량을 증가시키는 구조로 고분자 사슬들의 결합구조 변형에 의한 것으로 생각된다.블을 가지고 파서를 설계하였다. 파서의 출력으로 AST가 생성되면 번역기는 AST를 탐색하면서 의미적으로 동등한 MSIL 코드를 생성하도록 시스템을 컴파일러 기법을 이용하여 모듈별로 구성하였다.적용하였다.n rate compared with conventional face recognition algorithms. 아니라 실내에서도 발생하고 있었다. 정량한 8개 화합물 각각과 총 휘발성 유기화합물의 스피어만 상관계수는 벤젠을 제외하고는 모두 유의하였다. 이중 톨루엔과 크실렌은 총 휘발성 유기화합물과 좋은 상관성 (톨루엔 0.76, 크실렌, 0.87)을 나타내었다. 이 연구는 톨루엔과 크실렌이 총 휘발성 유기화합물의 좋은 지표를 사용될 있고, 톨루엔, 에틸벤젠, 크실렌 등 많은 휘발성 유기화합물의 발생원은 실외뿐 아니라 실내에도 있음을 나타내고 있다.>10)의 $[^{18}F]F_2$를 얻었다. 결론: $^{18}O(p,n)^{18}F$ 핵반응을 이용하여 친전자성 방사성동위원소 $[^{18}F]F_2$를 생산하였다. 표적 챔버는 알루미늄으로 제작하였으며 본 연구에서 연구된 $[^{18}F]F_2$가스는 친핵성 치환반응으로 방사성동위원소를 도입하기 어려운 다양한 방사성의 약품개발에 유용하게 이용될 수 있을 것이다.었으나 움직임 보정 후 영상을 이용하여 비교한 경우, 결합능 변화가 선조체 영역에서 국한되어 나타나며 그 유의성이 움직임 보정 전에 비하여 낮음을 알 수 있었다. 결론: 뇌활성화 과제 수행시에 동반되는 피험자의 머리 움직임에 의하여 도파민 유리가 과대평가되었으며 이는 이 연구에서 제안한 영상정합을 이용한 움직임 보정기법에 의해서 개선되었다. 답이 없는 문제, 문제 만들기, 일반화가 가능한 문제 등으

• Journal of Life Science
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• v.34 no.5
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• pp.356-364
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• 2024

Lymph nodes (LNs) are crucial sites where immune responses are initiated to combat invading pathogens in the body. LNs are organized into distinctive compartments by stromal cells. Stromal cell subsets constitute special niches supporting the trafficking, activation, differentiation, and crosstalk of immune cells in LNs. Fibroblastic reticular cells (FRC) are a type of stromal cell that form the three-dimensional structure networks of the T cell-rich zones in LNs, providing guidance paths for immigrating T lymphocytes. FRCs imprint immune responses by supporting LN architecture, recruiting immune cells, coordinating immune cell crosstalk, and presenting antigens. During inflammation, FRCs exert both spatial and molecular regulation on immune cells through their topological and secretory responses, thereby steering immune responses. Here, we propose a model in which FRCs regulate immune responses through a three-part scheme: setting up, supporting, or suppressing immune responses. FRCs engage in bidirectional interactions that enhance T cell biological efficiency. In addition, FRCs have profound effects on the innate immune response through phagocytosis. Thus, FRCs in LNs act as gatekeepers of immune responses. Overall, this study aims to highlight the emerging roles of FRCs in controlling both innate and adaptive immunity. This collaborative feedback loop mediated by FRCs may help maintain tissue function during inflammatory responses.

• Applied Biological Chemistry
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• v.49 no.1
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• pp.55-59
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• 2006

This study was designed to investigate the optimum manufacturing condition of germanium-fortified yeast, and the binding properties of germanium (Ge) in germanium-fortified yeast. The nutritional optimum conditions were glucose 3.0 (w/v) %, yeast extracts 0.3 (w/v) % and peptone 0.5 (w/v) %, and the amounts of yeast cells were 67.4 mg/ml. And, the standard germanium-fortified yeast was produced under the condition at the ratio of yeast cell and germanium solution was 1 : 0.5 (50%), pH 6.5 and $35-40^{\circ}C$ during fermentation. In results of the identification, binding of germanium-protein showed structural difference between the inorganic Ge $(GeO_2)$ added during fermentation process and germanium-fortified yeast. Therefore, germanium-fortified yeast made by biosynthetic technology formed structurally safe organic germanium during fermentation process. Germanium-fortified yeast can be applied as a new functional material far the improvement of health, the prevention and treatment of chronic degenerative disease like cancer, and the enforcement of immune system.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.3 s.151
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• pp.386-395
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• 2006

Chitosan, a natural polymer has been used to nonwoven fabrics based polypropylene for sanitary top sheets. The changes in mechanical properties relating to the surface structure of functionally improved nonwoven fabrics were investigated with respect to the molecular weight and concentration of chitosan that was used. Low molecular weight(LMW) chitosan treated fabric was found to be evenly coated on the fabrics. It was shown that the bending and shearing characteristics of chitosan treated fabrics increased, which helped to make it stronger and harder, while shape stability improved following treatment using high molecular weight(HMW) chitosan. And the surface structure of treated fabrics was smooth and the sensitivity of its bulk improved somewhat. The treated fabrics were not overly stiff because the increase in Koshi value was not considerable compared to that of the bending characteristics. In the change of hand value relating to chitosan treated fabrics, THV generally improved. In the case of a 0.5$\%$ chitosan, HMW chitosan treated fabrics produced better THV than LMW chitosan treated fabrics. However, in the case of a 1.0$\%$ chitosan, THV of LMW chitosan treated fabrics produced outstanding results.

• Journal of The Korean Association For Science Education
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• v.15 no.1
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• pp.6-16
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• 1995

The purpose of this study is to investigate elementary school 6th grade children's preconception on body's digestion, circulation, breathing and excretion. By means of questionnaire, teacher is presented with misconception which students may have. On the basis of this way, firstly they draw up and put in free-concepts were investigated from objective test and sought after misconeption which student had and inquired whether the result of response made difference by sex and areas or not The result of study is as follows: 1. In the course of investigating and analyzing mis-preconecptios, teacher had misconceptions partially, as like students. 2. Many a student have misconceptions: nourishment in made for itself in body. 3. In circulation range most of students know that heart is making blood, and they don't make conception that blood is nourishment which was eaten from food. 4. They know the breath is only physiological function: they breathe to live. All air-breathing is necessary. 5. They are not relevant blood in course of urine and sweat formation they have non-scientific conceptions which water eaten is so. They know that all of sweat and urine and ordure is excretion. To sum up, many student have misconceptions as for digestion and circulation and breath and excretion of body especially. Circulation and excretion is more so. if inspection in a field of sex, they will know male had less misconceptions than female. in a field of region, student from rural are as had more misconceptions than the one from urban areas.

• Journal of the Korea Computer Graphics Society
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• v.23 no.2
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• pp.1-10
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• 2017

A variety of filters are applied to improve the quality of noise and low resolution medical images. This is necessary to reduce the radiation dose of the patient and to improve the utilization of the conventional spherical imaging equipment. In the conventional method, it is common to perform filtering using the CPU of the PC. However, it is difficult to produce results in real time by applying various calculations and filters to high-resolution human images using only the CPU performance of a PC used in a hospital. In this paper, we analyze the structure and performance of Intel integrated GPU in CPU and propose a method to perform image filtering using OpenCL parallel processing function. By applying complex filters with high computational complexity to medical images, high quality images can be generated in real time.