• 한국연소학회:학술대회논문집
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• 2015.12a
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• pp.213-214
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• 2015

Breakup and ignition of single droplet were experimentally investigated using two independent Nd-YAG lasers. The emulsified fuel was made from n-dodecane and water while varying the relative volumetric fraction. As a result of visualization, breakup and ignition behaviors were dependent on the fraction. Luminosity from the secondary droplets increased as the water fraction decreased. Ignition did not occur below 80% of the n-dodecane fraction.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.375-376
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• 2001

조개류의 발생에서 온도는 초기 난할기의 세포 분열과 유생의 발생 및 사육에 큰 영향을 미치며, 대사율과 성장율에는 직접적으로, 영향-환경 측면에는 간접적으로 영향을 미치는 요인이다. 발생속도에 관한 연구는 단일 수온 조건하에서의 수온이 발생에 미치는 영향을 파악한 연구가 대부분이다(Ventilla, 1982). 그러나, 최근들어 나타나는 이상기온현상으로 인한 수계의 불안정과 수질 오염 등으로 인해 기존의 연구, 즉 단일 수온 조건하에서의 연구가 수정과 발생의 범위를 넓히기 어렵다. (중략)

• Sleep Medicine and Psychophysiology
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• v.9 no.2
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• pp.115-121
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• 2002

Objectives: Although sleep paralysis (SP) has been known as one of the symptoms of narcolepsy, recently it has become recognized as occurring frequently in the general population. However, the prevalence of SP and its associated factors in patients with major psychiatric disorders remain unknown. This study investigated the prevalence of SP and a variety of associated experiences in those patients. Methods: The subjects were 160 psychiatric patients and 143 age- and sex-matched controls. The Korean version SP questionnaire as well as the Sleep-Wake Schedule, Epworth Sleepiness Scale and Insomnia Severity Index were administered to all the subjects. The patients were referred from Dong-A University Hospital and consisted of 74 diagnosed as schizophrenia (47.7%), 26 as bipolar disorder (16.8%) and 55 as major depression (35.5%). Results: Nearly 42% of the patient group and 39% of the control group had experienced at least one episode of SP in their lifetime, with no significant difference between the groups. However, the patient group had experienced SP more frequently than the control group. Among all subjects, no gender difference in SP incidence was found. The peak age of onset was in the range of 16-25 years for both groups. Over eight tenths of both groups reported hallucinations and over seven tenths of both groups experienced fear accompanying SP. Conclusion: This study shows that there is no difference in the lifetime prevalence of SP between psychiatric patients and the general population, whereas frequency of SP experience is higher in psychiatric patients. Terrifying hallucinations and fearful feelings frequently accompany SP in both groups.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.12
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• pp.48-58
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• 2006

The spray and combustion characteristics of liquid jet in cross flow with variation of injection angle are numerically studied. Numerical analysis was carried out using KIVA code, which may be used to generate numerical solutions to spray and chemical reactive fluid problem in three space dimensions and modified to be suitable for simulating liquid jet ejected into the cross flow. Wave model and Kelvin- Helmholtz(KH) /Rayleigh-Taylor(RT) hybrid model were used for the purpose of analyzing liquid column, ligament, and the breakup of droplet. Penetration length increases as flow velocity decreases and injection velocity increases. Numerical error increases as inflow velocity increases. The results of flame propagation contour in combustion chamber and local temperature distribution, combustion emissions were obtained.

• Korean Journal of Plant Tissue Culture
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• v.22 no.5
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• pp.277-281
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• 1995

The present study was performed to investigate the effect of calcium ion on the mesophyll protoplast culture of Arabidopsis thaliana. The mesophyll protoplase were isolated and cultured on an IMH medium supplemented with CaCl$_2$of various concentrations. When the protoplasts were cultured on the medium containing 0 to 12.5 mM CaCl$_2$, extreme vacuolization occurred without cell division. When the protoplasts were cultured with higher levels of CaCl$_2$ up to 50 mM, vacuolization decreased dose-dependent): and the number of plasma-rich cells increased. Cell division was induced when the protoplast were cultured on the medium with CaCl$_2$ higher than 25 mM. The highest plating efficiency (5-6%) was obtained with 50 mM CaCl$_2$. However the plating efficiency was markedly inhibited by 100mM CaCl$_2$ or above. These resole suggest that the relatively high concentration (50 mM) of calcium ion may be required for the culture of protoplasts.

• Proceedings of the Korean Society of Veterinary Pathology Conference
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• 2002.11a
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• pp.150-150
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• 2002

40두 규모의 농장에서 사육된 홀스타인 종, 4개월령의 수컷 송아지에서 거세 후 고열, 식욕부진, 기침 등의 증상과 함께 전신 체표 림프절의 종대가 관찰되어 백혈병으로 잠정진단 하고 도태를 권유하였으나 축주가 치료를 원해 항생제와 해열제 및 기타 대증요법을 실시한 후 치료반응이 없어 폐사하여 부검을 실시하였다. 혈액 검사상 이상핵과 다형핵을 가진 다수의 림프구 및 백혈구, 호중구, 림프구 및 단핵구의 증가가 관찰되었다. 또한 백혈병 바이러스에 대한 분리 및 PCR 검사는 음성이었다. 부검 소견으로 체표 림프절, 슬관절 부위 및 비장과 간의 종대가 관찰되었으며 비장 중심에 12x11 cm의 종괴와 폐의 전엽부 유착 및 폐문, 종격동 림프절의 심한 종대가 관찰되었다. 견갑전 림프절을 비롯하여 대퇴골 전, 서혜, 폐문, 이하림프절 등 전신 림프절의 종대 및 소성의 연한 황색의 매끄러운 절단면을 보였다. 전지 관절의 종대와 관절강 내부는 증가된 농성 활액을 보였으며 고관절 강 내에 농성 활액의 증가와 공기 노출 후 젤리양 응고를 보였다. 심장은 장액성 위축과 함께 섬외막성 점상출혈이 나타났다. 병리조직학적 소견으로 비장은 지주 주변에 미성숙형의 세포들의 침윤이 보이며 유사분열상이 다수 관찰되었고 백색 수질에도 유사분열상의 증가와 함께 림프아구성 세포들이 다수 나타났다. 이들 주요한 비정상 세포들은 다형성의 큰 핵을 가진 다양한 림프아구의 형태를 지녔으며 핵내 공포가 인정되었다. 비장의 종괴 주변에는 증식된 섬유조직으로 둘러싸여 있었으며 미세농양 형성되어 있고, 일부 석회화가 진행된 부위도 있었다. 간소엽성 중심성 울혈과 가벼운 간세포내 지방침윤, 혈관 내 림프아구 형태의 세포와 소수의 호중구가 관찰되었다. 간삼조 주변에는 가볍거나 중등도의 단핵세포의 침윤이 미만성으로 관찰되었다. 폐에서는 중등도의 기관지 폐렴과 함께 일부는 무기폐가 관찰되었으며 폐포강과 세기관지내에는 염증성 삼출물이 다량 들어 있었다. 다병소성 미세농양과 함께 괴사가 있었고 실질의 섬유화가 진행되어 있었다. 또한 중등도의 간질성 신장염과 림프절은 지주 주변에 간극 내 비정상 림프구 세포의 형태는 비장의 그것과 유사하였으며 적수와 백수의 구이 힘들며 림프소절이 증가되어 있었다. 한 시야에서 유사분열상이 6-8 개로 그 지수가 매우 높으며 이와 더불어 큰 림프구가 전반에 걸쳐 침윤되어 있었다. 주변부 동(sinus)에는 많은 물질들이 침윤되어 있으며 렴프소절내 미만성의 성상현상이 관찰되었다. 회장은 파이어판내 심한 림프구 소실이 나타났다. 이상의 소견을 바탕으로 본 증례는 산재성 송아지 백혈병으로 진단되었다

• Korean Journal of Plant Tissue Culture
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• v.25 no.3
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• pp.153-158
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• 1998

The internal structures of Arabidopsis thaliana infected with beet curly top virus (BCTV) were studied by light microscopy. Hyperplasia was observed in the inflorescence stems of Arabidopsis thaliana ecotype Sei-O at 2 weeks after BCTV-Logan inoculation and callus was induced on symptomatic tissues at 4 weeks after virus inoculation. The infection processes were revealed as follows: hyperplasia of phloem tissue, necrosis of hyperplastic phloems, lacuna formation of necrotic tissues, elongation and enlargement of cortex and epidermal cells surrounding the lacuna formed phloem tissues, induction of cell division in the enlarged cortex and epidermal cells, and induction of callus tissue. Callus formation on Arabidopsis was caused by the virus infection, and virus inclusion body was observed in both phloem and callus tissue by azure-A staining.

• Journal of Life Science
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• v.33 no.11
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• pp.950-955
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• 2023

Cell division is an essential process for the survival and development of living organisms. It is critical that duplicated chromosomes are properly segregated into daughter cells during mitosis. The centrosome is the core organelle that forms the microtubule-organizing center (MTOC), which generates the microtubules that make up the mitotic spindle during cell division. The centrosome is also involved in cell signaling and motility. In normal cells, there is one centrosome in G1 that replicates into two in the S phase and matures through G2. During the M phase, duplicated centrosomes move to both ends of the cell, and spindle microtubules that are generated from MTOC move the chromosome to both ends. The cells then split into two to complete the cell division. However, a phenomenon called centrosome amplification (CA), in which the number of centrosomes is higher than normal, is common in cancer cells and can lead to chromosome instability (CIN). This paper discusses the process of centrosome replication and the role of PLK4 in this process. The possible consequences of centrosome amplification and how the PLK4 inhibitor may be able to treat certain types of cancer cells, such as breast cancer and neuroblastoma, will also be discussed.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.6
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• pp.51-58
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• 2006

The spray characteristics of liquid jet injected into subsonic cross-flow were investigated experimentally. Spray trajectories were captured using CCD camera. Droplet sizes were measured using PDPA and Image Express. The nozzle diameter was 0.5 mm, and its length-to-diameter ratios (L/D) ran$4.11{\times}10^6$ged from 1.0 to 6.0. Experimental results indicate that the breakup point is delayed by increasing gas momentum ratio and the penetration length is decreased by increasing Weber number. At low injection angle(${\theta}$ < $90^{\circ}$), Weber number is dominant parameter for trajectories, but at high injection angle(${\theta}$ > $90^{\circ}$), L/D is dominant parameter for trajectories rather than Weber number.

• Korean Journal of Weed Science
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• v.15 no.2
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• pp.141-147
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• 1995

Glyphosate(N-[phosphonomethyl]glycine) applied to the assimilate-exporting leaves or sprayed to the whole plants of tomato(Lycopersicon esculentum Mil var. Moneymaker). Glyphosate induced the rapid accumulation of shikimic acid within 24 h. The accumulation of shikimic acid companied with chlorophyll loss in meristematic leaves, i.e. apical leaves. The chlorosis was acropetal in apical region of young growing leaf. The degradation of chlorophyll seems to be a secondary or tertiary effect of glyphosate. However, the level of shikimic acid accumulated was reduced except for roots and apical leaves from 5 days after treatment. The accumulating levels are considerably differed through the applicated regions. The level of shikimic acid is highest at the apical meristem 4 days after the application to 3rd old leaf.