• Asian Pacific Journal of Cancer Prevention
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• 제13권12호
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• pp.6327-6332
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• 2012

Esophageal cancer is a common malignant tumor occurring in human esophageal epithelial tissue. The primary purpose of this paper was to define the effects of ${\beta}$-carotene and 1,25-dihydroxyvitamin $D_3$, alone and in combination, on cell proliferation, cell cycle and apoptosis of human esophageal cancer EC9706 cells. Treatment with different concentrations of ${\beta}$-carotene and/or 1,25-dihydroxyvitamin $D_3$. MTT assay showed that ${\beta}$-carotene and 1,25-dihydroxyvitamin $D_3$ significantly inhibited proliferation of EC9706 cells in a dose- and time-dependent manner. Further studies also demonstrated that ${\beta}$-carotene alone or 1,25-dihydroxyvitamin $D_3$ alone caused a marked increase on the induction of apoptosis in EC9706 cells. The percentage of G0/G1-phase cells significantly increased on addition of 1,25-dihydroxyvitamin $D_3$ alone, but there were no significant changes with ${\beta}$-carotene alone. These two agents in combination synergistically inhibited cell growth and induced apoptosis. Therefore, our results indicate that ${\beta}$-carotene and 1,25-dihydroxyvitamin $D_3$ in combination may provide a novel strategy for preventing and treating esophageal cancer.

• 생태와환경
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• 제50권4호
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• pp.363-373
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• 2017

본 연구는 온도, 광도, 인 등 서로 다른 환경 조건 하에서 Anabaena circinalis의 지오스민 생산 특성을 평가하기 위해 수행되었다. 실험에 사용한 남조류는 팔당호에서 분리되었다. 남조류 A. circinalis의 성장률과 지오스민 생산은 온도(10, 15, 20, $25^{\circ}C$), 광도(60, 120, $240{\mu}mol\;photons\;m^{-2}\;s^{-1}$), 인 농도(0.01, 0.05, 0.25, 0.50, $1.00mg\;L^{-1}$) 등 여러 요인들을 통해서 조사하였다. 최고 성장률과 Chl-a 농도는 온도 $25^{\circ}C$, 광도 $60{\mu}mol\;photons\;m^{-2}\;s^{-1}$ 및 인 농도 $1.00mgP\;L^{-1}$에서 각각 나타났다. 총 지오스민 생산량은 각 환경요인의 최적 성장 조건에서 가장 높았으며, 지오스민 생산 잠재력(Chl-a 농도에 대한 지오스민 생산 비율)은 늦가을 및 초겨울과 같은 저온 기간을 포함한 불리한 성장조건에서 높았다. 본 연구 결과는 A. circinalis의 지오스민 생산이 엽록소 합성과 직접적인 관련이 있고 세포 성장 조건에 따른 다양한 변화 가능성을 나타내었다.

• 한국응용곤충학회지
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• 제51권4호
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• pp.343-348
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• 2012

복숭아혹진딧물에 기생하는 목화면충좀벌의 발육기간, 머미율, 번데기 사망률, 성비를 20, 25, 30, $25^{\circ}C$ 인큐베이터에서 수행하였다. 실험을 위하여 피망잎이 놓인 콤팩트샤레를 사용하였다. 각각의 4개 온도에서 발육단계별로 복숭아혹진딧물을 사육하였고 기생을 유도하기 위하여 12시간 동안 목화면충좀벌에 제공하였다. 목화면충좀벌의 알에서 성충까지 발육기간은 $20^{\circ}C$ 18.3일, $25^{\circ}C$ 14.7일, $30^{\circ}C$ 10.4일, $35^{\circ}C$ 9.3일이었다. 복숭아혹진딧물에 기생한 목화면충좀벌의 머미율은 $20^{\circ}C$와 $25^{\circ}C$, 1령과 2령에서 가장 높았으나 $30^{\circ}C$와 $25^{\circ}C$에서는 3령충에서 84.4~85.0%로 가장 높았다. 목화면충좀벌의 기주섭식률은 $20{\sim}35^{\circ}C$까지 각각 12.5%, 17.3%, 16.0%, 10.9%였다. 목화면충좀벌 암컷의 성비는 온도별로 각각 49%, 46%, 69%, 60% 였다.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제25권1호
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• pp.1-5
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• 2018

It is proved that 'maximum' is actually attained in the following risk measure representation $${\rho}_m(X)={max \atop Q{\in}Q_m}E_Q[-X]$$.

• International Journal of Oral Biology
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• 제40권1호
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• pp.51-61
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• 2015

Shikonin, a major ingredient in the traditional Chinese herb Lithospermumerythrorhizon, exhibits multiple biological functions including antimicrobial, anti-inflammatory, and antitumor effects. It has recently been reported that shikonin displays antitumor properties in many cancers. This study was aimed to investigate whether shikonin could inhibit oral squamous carcinoma cell (OSCC) growth via mechanisms of apoptosis and cell cycle arrest. The effects of shikonin on the viability and growth of OSCC cell line, SCC25 cells were assessed by MTT assay and clonogenic assays, respectively. Hoechst staining and DNA electrophoresis indicated that the shikonin-treated SCC25 cells were undergoing apoptosis. Western blotting, immunocytochemistry, confocal microscopy, flow cytometry, MMP activity, and proteasome activity also supported the finding that shikonin induces apoptosis. Shikonin treatment of SCC25 cells resulted in a time- and dose-dependent decrease in cell viability, inhibition of cell growth, and increase in apoptotic cell death. The treated SCC25 cells showed several lines of apoptotic manifestation as follows: nuclear condensation; DNA fragmentation; reduced MMP and proteasome activity; decrease in DNA contents; release of cytochrome c into cytosol; translocation of AIF and DFF40 (CAD) onto the nuclei; a significant shift in Bax/Bcl-2 ratio; and activation of caspase-9, -7, -6, and -3, as well as PARP, lamin A/C, and DFF45 (ICAD). Shikonin treatment also resulted in down-regulation of the G1 cell cycle-related proteins and up-regulation of $p27^{KIP1}$. Taken together, our present findings demonstrate that shikonin strongly inhibits cell proliferation by modulating the expression of the G1 cell cycle-related proteins, and that it induces apoptosis via the proteasome, mitochondria, and caspase cascades in SCC25 cells.

• 대한기계학회논문집A
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• 제37권3호
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• pp.353-358
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• 2013

본 논문은 등온열처리 온도 및 시간에 따른 2.25Cr-1Mo강의 초음파 특성 변화를 조사하였다. Charpy 충격시험과 경도시험이 3종류의 열처리조건을 가지는 각 시편들에 대하여 실시되었다. 종파를 이용한 펄스-에코법이 초음파의 감쇠와 속도 측정에 사용되었다. 연취성천이온도(FATT)는 등온열처리 시간이 길어짐에 따라 증가하였는데, 이는 인성이 감소되고 있음을 의미한다. 등온열처리 시간과 온도의 증가와 함께 종파의 속도 및 초음파의 감쇠계수는 증가하였다.

• 한국환경과학회지
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• 제28권1호
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• pp.1-6
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• 2019

Ptecticus tenebriferwas incorporated to partially or totally replace the diets of juvenile white shrimp (Litopenaeus vannamei). Experimental groups of shrimp with an average initial body weight of $0.014{\pm}0.001g$ were fed each of the 5 diets formulated to include 0, 25, 50, 75, and 100% (C, T25, T50, T75, and T100, respectively) of Ptecticus tenebriferpowder substituted for commercial feed. After eight weeks of feeding trials, juvenile shrimp fed with diets T25 and T50 showed higher live weight gain ($2.298{\pm}0.405$ and $2.539{\pm}0.406$, respectively), and a better feed conversion ratio ($1.389{\pm}0.246$ and $1.536{\pm}0.246$, respectively) compared to those of shrimp fed a control diet. Survival rate was 98% in all experimental groups except for the T75 group ($66.67{\pm}57.73%$ survival). The levels of immune markers such as beta-glucan binding protein, prophenoloxidase, and crustin associated with the cellular and humoral immunity of shrimp were found to be higher in 25% and 50% commercial feed replacement groups. A reduction in total nitrogen, nitrite nitrogen, and ammonia levels was greater in T25 and T50 rather than in T75 and T100. These results clearly indicate that replacement of feed with 25 to 50% Ptecticus tenebriferpowder in juvenile white shrimp diet was optimal in promoting the growth performance of shrimp without any adverse effects.

• 한국결정학회지
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• 제10권2호
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• pp.130-135
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• 1999

The title compound consisting of a calix[4]arene molecule with four phenyl rings bridged by four methylene groups and arranged alternately in anti-orientation fashion, two 25,27-bis(1-pro-pyloxy) groups attached on the two lower rims of calix[4]arene, and crown-6 chain attached on the other set of lower rims of calix[4]arene offers a big cavity inside a molecule which might possess a potential for forming host-guest complexes. The molecular packing is accomplished by van der Waals forces.

• 한국측량학회지
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• 제37권2호
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• pp.91-97
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• 2019

In automatic map generalization, the formalization of cartographic principles is important. This study proposes and evaluates the selection method for road network generalization that analyzes existing maps using reverse engineering and formalizes the selection rules for the road network. Existing maps with a 1:5,000 scale and a 1:25,000 scale are compared, and the criteria for selection of the road network data and the relative importance of each network object are determined and analyzed using $T{\ddot{o}}pfer^{\prime}s$ Radical Law as well as the logistic regression model. The selection model derived from the analysis result is applied to the test data, and road network data for the 1:25,000 scale map are generated from the digital topographic map on a 1:5,000 scale. The selected road network is compared with the existing road network data on the 1:25,000 scale for a qualitative and quantitative evaluation. The result indicates that more than 80% of road objects are matched to existing data.

• Journal of Magnetics
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• 제6권1호
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• pp.27-30
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• 2001

We present a new procedure to evaluate the residual life of 1Cr-1Mo-0.25V steel from reversible magnetic permeability. The method is based on the existence of first harmonics in the differential magnetization around the coercive force. The apparatus is based on the detection of the voltage induced in a coil using a lock-in amplifier tuned to the frequency of the exciting coil. Results obtained for the first harmonics and Vickers hardness on aged samples show that the peak interval of reversible permeability and Vickers hardness decrease as aging time increases. The correlation between Vickers hardness and the peak interval of the reversible permeability may be used to evaluate the residual life of 1Cr-lMo-0.25V steel, nondestructively.