• Journal of Microbiology and Biotechnology
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• v.18 no.3
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• pp.503-511
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• 2008

An edible marine red alga, Grateloupia filicina, collected from Jeju Island of Korea was hydrolyzed by cheap food-grade carbohydrases (Viscozyme, Celuclast, AMC, Termamyl, and Ultraflo) to investigate its anticoagulant activity. Among the tested enzymatic extracts of G. filicina, a Termamyl extract showed the highest anticoagulant activity. Anion-exchange chromatography on DEAE-cellulose and gel-permeation chromatography on Sepharose-4B were used to purify the active polysaccharide from the crude polysaccharide fraction of G. filicina. The purified sulfated polysaccharide (0.42 sulfate/total sugar) showed ${\sim}1,357kDa$ molecular mass and was comprised mainly of galactose(98%) and 1-2% of glucose. The sample showed potential anticoagulant activity on activated partial thromboplastin time (APTT) thrombin time (TT) assays. The purified G. filicina anticoagulant (GFA) inhibited the coagulation factor X (92%), factor II (82%), and factor VII (68%) of the coagulation cascade, and the molecular interaction (protein-polysaccharide) was highly enhanced in the presence of ATIII (antithrombin III). The dissociation constant of polysaccharide towards serine proteins decreased in the order of FXa (58.9 nM) >FIIa (74.6 nM) >FVII (109.3 nM). The low/less cytotoxicity of the polysaccharide benefits its use in the pharmaceutical industry; however, further studies that would help us to elucidate the mechanism of its activity are needed.

• Proceedings of the Materials Research Society of Korea Conference
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• 1994.11a
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• pp.98-98
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• 1994

최근 청색반도체레이저의 실현을 위하여 ZnSe가 대표하는 II-Ⅵ족 화합물반도체와 Gan가 대표하는 III족 질화물반도체분야에서 집중적인 연구가 이루어지고 있으며, 아직까지 실용화 되지 않고 있는 청색반도체레이저의 출현에 대하여 많은관심이 모아지고 있다. III족 질화물반도체는 InM(Eg:1.9eV)부터 AIN(Eg: 6.2eV)에 이르기까지 전 조성영역에서 완전한 고용체를 이루며, 실온에서 직접천이형 에너지 대구조를 가지므로 청색 혹은 자외영역에서 동작하는 발광소자를 제작하는데 있어 유망시 되고 있는 소재이다. 특히 GaN와 InN의 3원흔정인 GaInN를 활성층으로 이용하면 그 발전파장을 370nm부터 650nm까지 즉 가시 전 영역으로부터 근 자외영역을 포함할 수 있게 된다. 이 연구에서는 AIGaN/GaInN 이중이종접합(DH) 구조의 고아여기에 의한 유도방출고아의 편광 특성을 조사하였다. 유기금속기상에피텍셜(MOVPE)법으로 성장한 AIGaN/GaInN DH 구조의 표면에 수직으로 펄스 발진 질소레이저(파장: 337.1cm, 주기 10Hz, 폭: 8nsec) 빔을 조사하고 DH구조의 단면으로부터의 유도방출광을 편광기를 통과 시킨 후 스펙트럼을 측정하였다. 입사고아 밀도가 증가함에 따라 약 402nm의 파장에서 유도발출에 의한 가도가 큰 피크가 나타났고, 그 반치폭은 약 18meV이었다. 실온에서 AIGaN/GaInN DH 구조로 부터의 유도방출에 필요한 입사광밀도의 임계치는 약 130㎾/$\textrm{cm}^2$이었다. 한편 편광각이 90$^{\circ}$일때는 발광스펙트럼의 강도가 매우 낮고 단지 자연방출에 의한 스펙트럼만이 나타났다. 편광각이 0$^{\circ}$일 때 최대의 방출광 강도를 나타내었으며, 편광각이 -90$^{\circ}$로 회전함에 따라 발고아강도의 강도가 감소하였다. 이와 같은 결과는 광여기에 의하여 AIGaN/GaInN DH 로 부터의 유도방출광이 GaInN활성층의 단면에 평행한 전기장의방향으로, 즉 TE모드로 선형적으로 편광됨을 의미한다. AIGaN/GanN DH 로 부터의 유도방출이 선형적으로 TE모드로 편광되는 것은 이 구조를 이용한 청색 및 자외선 반도체 레이저다이오드의 실현에 매우 유익한 것이다.

• Journal of the Korean Ceramic Society
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• v.53 no.3
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• pp.367-375
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• 2016

A novel strategy for the synthesis of $CoSb_2$ nanoparticles is demonstrated via preparation of novel organometallic complexes. Hydrated cobalt oleate (CoOl) and non-hydrated antimony oleate (SbOl) complexes are synthesized as precursors. The $CoSb_2$ nanoparticles are prepared by hot injection, which involves thermolysis of CoOl and SbOl in a non-coordinating solvent at $320^{\circ}C$. The coordination modes and distinct thermal behaviors of the intermediate non-hydrated SbOl complexes are comparatively investigated by thermo-analytical techniques. When the reaction temperature is increased, the particle size is found to increase linearly. The crystallinity of the $CoSb_2$ nanoparticles prepared at $250^{\circ}C$ is amorphous phase without any peaks. $CoSb_2$ structural peaks start to appear at $300^{\circ}C$ and dominant peaks with high crystallinity are synthesized at $320^{\circ}C$. The potential chemical structures of non-hydrated SbOl and their reaction mechanisms by thermolysis are elucidated. The elemental composition and crystallographic structure of $CoSb_2$ nanoparticles suggest a bimodal interaction of the organic shell and the nanoparticle surface, with a chemical absorbed inner layer and physically absorbed outer layer of carboxylic acid.

• Journal of Sasang Constitutional Medicine
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• v.29 no.3
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• pp.262-270
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• 2017

Objectives The purpose of this study was to investigate the difference in color perception among Sasang Constitution in "The dress" which has been arousing controversy whether its color is blue/black or white/gold. Methods 85 participants classified as Sasang Constitution were asked to answer three questions about "The dress". They were asked firstly the overall colors of the dress, secondly the colors of the specific parts of it, thirdly color ranges they perceived as gold, white, blue, black, respectively. These process were run twice. Results and Conclusions The overall colors of the dress were perceived as blue/black more than white/gold, regardless of Sasang Constitution. And also the ratio between blue/black and white/gold were not significantly different among Sasang Constitution. But when a specific part(spot ii) shown, Soyangin perceived its color as blue more than Taeeumin in the first process. In the case of color range, Soyangin perceived range of black wider than Taeeumin in the second process.

• Journal of Electrical Engineering and Technology
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• v.12 no.1
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• pp.346-355
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• 2017

Atrial fibrillation (AF) and Congestive heart failure (CHF) are increasingly widespread, costly, deadly diseases and are associated with significant morbidity and mortality. In this study, we analyzed three statistical methods for automatic detection of AF and CHF based on the randomness, variability and complexity of the heart beat interval, which is RRI time series. Specifically, we used short RRI time series with 16 beats and employed the normalized root mean square of successive RR differences (RMSSD), the sample entropy and the Shannon entropy. The detection performance was analyzed using four large well documented databases, namely the MIT-BIH Atrial fibrillation (n=23), the MIT-BIH Normal Sinus Rhythm (n=18), the BIDMC Congestive Heart Failure (n=13) and the Congestive Heart Failure RRI databases (n=25). Using thresholds by Receiver Operating Characteristic (ROC) curves, we found that the normalized RMSSD provided the highest accuracy. The overall sensitivity, specificity and accuracy for AF and CHF were 0.8649, 0.9331 and 0.9104, respectively. Regarding CHF detection, the detection rate of CHF (NYHA III-IV) was 0.9113 while CHF (NYHA I-II) was 0.7312, which shows that the detection rate of CHF with higher severity is higher than that of CHF with lower severity. For the clinical 24 hour data (n=42), the overall sensitivity, specificity and accuracy for AF and CHF were 0.8809, 0.9406 and 0.9108, respectively, using normalized RMSSD.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.4
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• pp.497-504
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• 2010

The treatment of Class II non-extraction cases, especially when premolar space is lost due to premature loss of the deciduous molars, usually requires distal movement of the maxillary molars. The Jones jig appliance is a non-compliant intraoral appliance and is effective for the distalization of the maxillary molars. It has unfavorable side-effects, however, so caution is needed to adjust the appliance and select appropriate cases. We reported four cases in which maxillary molar distalizations were concomitant with the alignment of palatally erupted premolars.

• Tuberculosis and Respiratory Diseases
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• v.44 no.4
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• pp.922-929
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• 1997

Relapsing polychondritis is a systemic disorder characterized by recurrent inflammation and degeneration of cartilaginous tissue throughout the body. The association with HLA-DR4 and the occurrence of antibodies to type II collagen and other autoantibodies suggest that an immunologic mechanism is involved in its pathogenesis. The eyes, ears, nose, larynx, trachea and articular areas are commonly involved. Airway narrowing or collapse from respiratory tract involvement occurs in up to 50% of patients with relapsing polychondritis. Treatment consists of administration of corticosteroids and other anti-inflammatory and immunosuppresive drugs. We experienced a case of relapsing polychondritis involving the tracheobronchial tree, nose and ears in a 49-year-old woman. The patient was clinically and histologically diagnosed as relapsing polychondritis according to McAdam's and Damiani's criteria. We report this case with a review of the literature.

• Food Science and Biotechnology
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• v.17 no.5
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• pp.983-989
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• 2008

Two flavonoids, isorhamnetin 3-O-$\beta$-D-glucopyranoside (1) and quercetin 3-O-$\beta$-D-glucopyranoside (2), from slander glasswort (Salicornia herbacea, Korean name hamcho) were isolated. Antioxidative and matrix metalloproteinase-9(MMP-9) inhibitory effects of these compounds were investigated in HT 1080 cell lines. These compounds suppressed the electron spin resonance (ESR) signal intensity on generation of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical in a free-cellular system. Their scavenging effects on generation of intercellular reactive oxygen species (ROS) also exhibited similar trends with DPPH radical in the free cellular system. Also, a control group combined only with Fe(II)-$H_{2}O_2$ resulted in DNA apoptosis by oxidative stress, whereas treatments with these compounds suppressed radical-mediated DNA damage. Intracellular glutathione (GSH) levels were slightly increased in the presence of compound 1 and 2. Moreover, these compounds led to the reduction of the expression levels of MMP-9 without cytotoxic influence. These results suggest that these compounds have a potential as a valuable natural antioxidant and MMP inhibitor related to oxidative stress. Therefore, these compounds not only can be developed as a candidate for a therapeutic potential but also a source for use as ingredients of health foods or functional foods to prevent metastasis involving MMP-9, closely related to ROS.

• Korean Journal of Veterinary Research
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• v.41 no.3
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• pp.387-393
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• 2001

The chemical composition of fish feeds(mackerel, gizzard shad, shrimp and formula feed) were analyzed and compared with those of untreated and irradiated (5 kGy) feeds, and the effects of gamma irradiation (5 kGy) and butylated hydroxyanisole (BHA, 200ppm) on feeds spoilage were investigated by determination of thiobarbituric acid (TBA) value and peroxide value for 14 days at $20^{\circ}C$, $4^{\circ}C$ or $-20^{\circ}C$. Crude protein, crude lipid, crude fiber, crude ash and nitrogen free extract were not significantly changed by gamma irradiation with the dose of 5 kGy. Immediately gamma irradiation increased the initiative oxidation of feeds as expected. But BHA was found to be greatly effective in minimizing the radiation-induced peroxidation (p<0.05). The TBA value and peroxide value increased with the elapse of the storage period. The level of lipid oxidation was increased depending on the rise in storage temperature. But the additions of BHA inhibited the lipid oxidation (p<0.05).

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.45 no.1
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• pp.42-51
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• 2013

In this study, oil palm biomass such as empty fruit bunch (EFB) and palm kernel shell (PKS) was used as raw materials for making pellets. Hardwood sawdusts were also mixed with EFB and PKS for making pellets. For improving a bad forming behavior in a pelletizer, 1 to 3 per cent of corn starch based on oven-dried weight biomass was added. The starch contributed to the decrease of dust generation in addition to the improvement of forming capability during pellet forming. Heating values of every pellets made of EFB and PKS were higher than 4,300 kcal/kg for the first grade pellet, irrespective of addition of sawdusts. However, the pellets made of EFB and PKS had ash contents over 3 per cent, which made it impossible to be applied for home use. Instead, they could be applied for industrial use. For studying their combustion characteristics, the pellets from the mixtures of EFB, PKS and sawdusts were analyzed using thermal gravimetric analyzer (TGA). From the TGA results, thermal decomposition of EFB and PKS occurred following three including endothermic reaction and dehydration, devolatilization of the major chemical components, and finally combustion of residual lignin and char.