• 대한소아치과학회지
• /
• 제37권1호
• /
• pp.82-90
• /
• 2010

본 연구는 불소함유 접착테잎의 법랑질 침식 예방효과를 평가하기 위해건강한 소의 치아를 절단하여 아크릴 주형에 매몰하고 정중선에 홈을 형성하여 대조면과 불소 제제를 도포할 실혐면으로 나누었다. 시편을 무작위로 18개씩 4군으로 나누었다. 1군은 APF gel를 도포하고, 2군은 불소 바니쉬를 도포하였으며, 3군과 4군은 5% NaF를 각각 첨가한 methyl cellulose와 poly vinyl alcohol 테잎을 부착하였다. 시편을 콜라에 5분, 증류수에 10분씩 6회 번갈아 처리하며 5일 동안 반복하였다. 시간 경과에 따라 표면미세경도를 측정하고 5일후 각 시편을 절단하여 침식병소의 깊이를 측정하여 다음과 같은 결과를 얻었다. 1. 표면미세경도 값은 5일째만 제외하고 2군, 3군, 4군의 실험면이 각각의 대조면에 비해 컸다 (p<0.05). 2군, 3군, 4군의 실험면 역시 5일째만 제외하고 1군의 실험면에 비해 표면미세경도가 컸다 (p<0.05). 3군과 4군 사이에는 표면미세 경도의 유의한 차이가 없었다(p>0.05). 1군의 실험면과 대조면은 표면미세경도의 유의차가 없었다(p>0.05). 2. 침식병소의 깊이는 2군, 3군, 4군의 실험면이 각각의 대조면에 비해 컸다(p<0.05). 2군, 3군, 4군의 실험면은 1군의 실험면에 비해 침식병소의 깊이가 얕았다 (p<0.05). 2군, 3군, 4군의 실험면 사이의 침식병소의 깊이는 유의차가 없었다(p>0.05). 상기 결과로 보아 새로 개발된 불소함유 접착테잎은 기존의 불소 바니쉬와 같은 법랑질 침식 예방효과가 분명하게 나타나, 법랑질 침식에 감수성이 높은 어린이 환자에게 임상적인 예방법으로서 활용할 수 있는 가능성이 높다고 사료된다.

• IMMUNE NETWORK
• /
• 제23권1호
• /
• pp.3.1-3.14
• /
• 2023

Microvilli are outer membrane organelles that contain cross-linked filamentous actin. Unlike well-characterized epithelial microvilli, T-cell microvilli are dynamic similar to those of filopodia, which grow and shrink intermittently via the alternate actin-assembly and -disassembly. T-cell microvilli are specialized for sensing Ags on the surface of Ag-presenting cells (APCs). Thus, these finger-shaped microprotrusions contain many signaling-related proteins and can serve as a signaling platforms that induce intracellular signals. However, they are not limited to sensing external information but can provide sites for parts of the cell-body to tear away from the cell. Cells are known to produce many types of extracellular vesicles (EVs), such as exosomes, microvesicles, and membrane particles. T cells also produce EVs, but little is known about under what conditions T cells generate EVs and which types of EVs are released. We discovered that T cells produce few exosomes but release large amounsts of microvilli-derived particles during physical interaction with APCs. Although much is unanswered as to why T cells use the same organelles to sense Ags or to produce EVs, these events can significantly affect T cell fate, including clonal expansion and death. Since TCRs are localized at microvilli tips, this membrane event also raises a new question regarding long-standing paradigm in T cell biology; i.e., surface TCR downmodulation following T cell activation. Since T-cell microvilli particles carry T-cell message to their cognate partner, these particles are termed T-cell immunological synaptosomes (TISs). We discuss the potential physiological role of TISs and their application to immunotherapies.

• 한국산림과학회지
• /
• 제4권1호
• /
• pp.46-53
• /
• 1965

광양지방(光陽地方)의 식재(植栽)된 11년생(年生), 8년생(年生), 6년생(年生)의 테나 송림(松林)과 리기다송림(松林) 그리고 6년생(年生)의 리기테다송림(松林)에 대(對)하여 성장상태(成長狀態)를 비교(比較) 조사(調査)하였다. 조사(調査)된 각임분(各林分)은 동일입지(同一立地)에 동일수령(同一樹齡)으로 열간혼식(列間混植)을 이루고 있다. (1) 테다송(松)은 리기다송(松)에 비(比)하여 수고성장(樹高成長) 비대성장(肥大成長) 공(共)히 우월(優越)한 성장(成長)을 나타내고 있으며, 리기테다송(松)은 테다송(松)보다는 못하나 리기다송(松)보다는 많은 성장(成長)을 보였다. (2) 수간석해목(樹幹析解木)에 의(依)한 성장경과(成長經過)를 보면 재적성장(材積成長)에 있어 테다송(松)은 리가다송(松)에 비(比)하여 약(約) 배(倍)의 성장(成長)을 나타내였다. (3) 내한성(耐寒成) 약(弱)한 테다송(松)의 조림(造林)은 광양지방(光陽地方)에 있어서는 추위의 피해(被害)를 받는 일이 극(極)히 적었다. (4) 테나송(松)은 식재초기(植載初期)에 있어서 풍해(風害)를 입는 일이 있었으므로 초령기(初齡期)에는 풍해대책(風害對策)이 요망(要望)된다.

• 한국통신학회논문지
• /
• 제35권1B호
• /
• pp.1-7
• /
• 2010

본 논문에서는 편향 자기 경로 제어 방법을 사용하는 새로운 고성능 고장 감내 스위칭 망을 제시한다. 기반이 되는 델타 망의 위상적 구조를 대수적 기법을 사용하여 해석한 결과로 부터, 편향 자기 경로 제어 알고리즘을 사용하는 다중 경로 스위칭 망인 다차원 링-델타 망을 유도한다. 제시된 스위칭 망에서는 델타 망의 링크들을 포함하는 모든 링크들이 결함 혹은 혼잡이 생긴 링크들을 우회하는 대체 경로들로써 사용된다. 본 연구에서 비균일 주소 분포를 가진 부하를 가했을 경우의 이 망의 성능을 시뮬레이션을 사용하여 분석하였다. 입력 셀의 도착률이 0.9이고, Hot Ratio가 0.8인 경우, $1024\;{\times}\;1024$ 크기의 제안된 스위칭 망의 통과율은 사이클릭 벤얀 망에 비해서 36.5% 우수하고, 2차원 링-벤얀 망에 비해서 13.3% 우수하다. 또한, $64\;{\times}\;64$ 크기의 제안된 스위칭 망의 신뢰도 는 Hui의 망에 비해 2.2배, 2차원 링-벤얀 망에 비해 46.6% 높다.

• 한국진공학회지
• /
• 제22권2호
• /
• pp.92-97
• /
• 2013

Migration-enhanced epitaxy 성장한 InAs/GaAs 양자점(quantum dots)의 광학적 특성을 PL (photoluminescence)과 Time-resolved PL 이용하여 분석하였다. InAs 양자점은 In을 9.3초 공급하고 5초 차단한 후 As을 3초, 4초, 6초, 또는 9초 공급하고 5초 차단하는 과정을 3회 반복하여 성장하였다. As을 3초 공급한 시료의 PL 피크는 1,140 nm에서 나타나고, PL 세기는 다른 세 시료에 비해 매우 약하게 나타났다. As 공급시간을 3초에서 증가하였을 때 모든 PL 피크는 1,118 nm로 청색이동하여 나타났으며, PL 세기는 증가하였다. As을 6초 공급한 시료의 PL 세기가 가장 강하게 나타나고, 반치폭(full width at half maximum)도 가장 좁게 나타났다. 이러한 결과는 양자점의 밀도와 균일도(크기변화)로 설명된다. 또한 발광파장에 따른 PL 소멸시간은 PL 피크 근처에서 가장 길게 나타났다.

• Forest Science and Technology
• /
• 제14권4호
• /
• pp.160-168
• /
• 2018

The seeds of Elaeocarpus serratus, a tropical underutilized fruit tree are characterized by hard seed coat and consequent poor water uptake and low germination. To improve the regeneration through seeds, various parameters such as viability of seeds, water uptake, and effect of seed mass on germination and pretreatments were performed using a completely randomized design (CRD). Tetrazolium (TZ) test was conducted using fresh, mature seeds revealed $50{\pm}2.56%$ mean viability. Seeds of different weight classes showed similar pattern of water uptake and the saturation level was achieved at 60 hrs of soaking. Seeds belong to weight class 2.6-3.5g were germinated ($12.5{\pm}1.26%$) with $175{\pm}1.75days$ (d) of mean time taken for germination (MTG). Germination capacity of seeds varied significantly among different populations and Varkala population gave $12.5{\pm}1.1%$ germination with $174.6{\pm}2.5d$ MTG. Among various seed treatments, mechanical scarification was superior in germination and significant reduction in MTG ($p{\leq}0.05$). The mechanical scarification by complete removal of seed coat resulted in $49.2{\pm}1.52%$ germination within a short period of time ($9.52{\pm}0.89d$ MTG). However, the complete removal of seed coat without damaging to embryo is a difficult task. An alternate treatment (Mechanical scarification II) by making cracks on nut faces vertically followed by soaking in distilled water for 24 hrs gave $48.4{\pm}1.73%$ germination with significantly reduced MTG ($12.14{\pm}0.56d$) over unsoaked, untreated control ($6.5{\pm}1.84%$ germination and $197.18{\pm}1.79d$ MTG; $p{\leq}0.05$). This treatment (Mechanical scarification II) is therefore recommended for E. serratus seeds as it can adopt easily and can achieve 7 fold increases in germination over control. The recorded germination through mechanical scarification is in tune with realized viability percentage of the seeds.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2008년 영문 학술대회
• /
• pp.130-135
• /
• 2008

An aerodynamic optimization design process of multistage axial turbine is presented in this article: first, applying quasi-three dimensional(Q3D) design methods to conduct preliminary design and then adopting modern optimization design methods to implement multistage local optimization. Quasi-three dimensional(Q3D) design methods, which mainly refer to S2 flow surface direct problem calculation, adopt the S2 flow surface direct problem calculation program of Harbin Institute of Technology. Multistage local optimization adopts the software of Numeca/Design3D, which jointly adopts genetic algorithm and artificial neural network. The major principle of the methodology is that the successive design evaluation is performed by using an artificial neural network instead of a flow solver and the genetic algorithms may be used in an efficient way. Flow computation applies three-dimensional viscosity Navier Stokes(N-S) equation solver. Such optimization process has three features: (i) local optimization based on aerodynamic performance of every cascade; (ii) several times of optimizations being performed to every cascade; and (iii) alternate use of coarse grid and fine grid. Such process was applied to optimize a three-stage axial turbine. During the optimization, blade shape and meridional channel were respectively optimized. Through optimization, the total efficiency increased 1.3% and total power increased 2.4% while total flow rate only slightly changed. Therefore, the total performance was improved and the design objective was achieved. The preliminary design makes use of quasi-three dimensional(Q3D) design methods to achieve most reasonable parameter distribution so as to preliminarily enhance total performance. Then total performance will be further improved by adopting multistage local optimization design. Thus the design objective will be successfully achieved without huge expenditure of manpower and calculation time. Therefore, such optimization design process may be efficiently applied to the aerodynamic design optimization of multistage axial turbine.

• 한국자원식물학회지
• /
• 제22권3호
• /
• pp.209-214
• /
• 2009

To facilitate the introgression of F. esculentum into the traits of F. homotropicum, several accessions of the hybrids between these two species were pollinated with F. esculentum as the recurrent parent. The embryo in vitro rescue was performed to increase the recovery of backcross progenies. The $F_{2}$ generation was more amenable than $F_{1}$ hybrids to produce backcross progenies. The $F_{1}$ hybrids were backcrossed twice with common buckwheat (pin-type F. esculentum) (recurrent backcrossing). Also, alternate backcrosses with common buckwheat and F. homotropicum (congruity backcrossing) were carried out. Pollen tube growth of BC$F_{1}$ ${\times}$ F. esculentum (thrum) and F. homotropicum ${\times}$ BC$F_{1}$ was the disturbed penetration exceeded for all initial interspecific hybrids, and its requirement was proportionally lower when the common buckwheat was used as the recurrent parent and as the last parent of congruity hybrids. Effects of both common buckwheat and F. homotropicum on seed success rate for hybridization were observed. Growth of hybrid embryos before rescue, regeneration of mature hybrids all increased recurrent and congruity backcrosses and inter-crosses between $F_{1}$ plants and selected fertile plants of the second congruity backcrosses.

• 대한토목학회논문집
• /
• 제14권3호
• /
• pp.523-534
• /
• 1994

본 연구의 목적은 간헐수문과정인 일강수계열의 모의발생 모델을 개발하는 것이다. 이를 위하여 연구(I)에서는 교대재생과정을 이용하여 강수발생과정을 해석하였으며, 본 연구(II)에서는 강수발생과정으로 Markov 연쇄를 이용하고 습윤일의 강수량 분포를 조합하여 일 강수계열을 모의발생하는 추계학적 모델을 개발하였다. Markov 연쇄로는 상태 2(건조, 습윤)의 1차 연쇄를 사용하였으며, 습윤일의 강수량 분포는 연속확률분포인 Gamma, Pearson Type-III(PT3), Extremal Type-III(T3E), Weibull 분포를 적용하였다. 일 강수계열 자료의 계절적 변동성을 고려하여 월별로 분리하여 해석하였으며, 강수발생과정과 습윤일의 강수량과정을 조합하여 구성한 두 개의 모의발생 모델 M-W, M-G 모델을 낙동강과 섬진강 유역의 7개 관측소에 적용하여 관측치와 모의발생치를 비교하므로써 모의발생 모델의 적용성을 확인하였다.

• 상하수도학회지
• /
• 제33권2호
• /
• pp.95-101
• /
• 2019

High voltage impulse(HVI) has been gained attention as an alternate technique controlling $CaCO_3$ scale formation. Investigation of key operational parameters for HVI is important, however, those had not been reported yet. In this study, the effect of temperature and applied voltage of HVI on $Ca^{2+}$ concentration was studied. As the applied voltage from 0 to 15kV and the temperature increased from 20 to $60^{\circ}C$, the $Ca^{2+}$ concentration decreased, indicating that the aqueous $Ca^{2+}$ precipitated to $CaCO_3$. The $Ca^{2+}$ concentration decreased up to 81% under the condition of 15kV and $60^{\circ}C$. Rate constant for the precipitation reaction, k was determined under different temper1ature and voltage. The reaction rate constant under the 15kV and $60^{\circ}C$ condition was evaluated to $66{\times}10^{-3}L/(mmol{\cdot}hr)$, which was 5 times greater than the k of the reaction without HVI at same temperature. The increases in k by HVI at higher temperature region(40 to $60^{\circ}C$) was much greater than at lower temperature region(20 to $40^{\circ}C$), which implies temperature is more important parameter than voltage for reducing $Ca^{2+}$ concentration at high temperature region. These results show that the HVI induction accelerates the precipitation to $CaCO_3$, particularly much faster at higher temperature.