• 제목/요약/키워드: phase-contrast

검색결과 833건 처리시간 0.031초

In Vitro Cytotoxic Activity of Seed Oil of Fenugreek Against Various Cancer Cell Lines

  • Al-Oqail, Mai Mohammad;Farshori, Nida Nayyar;Al-Sheddi, Ebtesam Saad;Musarrat, Javed;Al-Khedhairy, Abdulaziz Ali;Siddiqui, Maqsood Ahmed
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권3호
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    • pp.1829-1832
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    • 2013
  • In the present study, investigations were carried out to screen the anticancer activities of fenugreek seed oil against cancer cell lines (HEp-2, MCF-7, WISH cells), and a normal cell line (Vero cells). Cytotoxicity was assessed with MTT and NRU assays, and cellular morphological alterations were studied using phase contrast light microscopy. All cells were exposed toi 10-1000 ${\mu}g/ml$ of fenugreek seed oil for 24 h. The results show that fenugreek seed oil significantly reduced the cell viability, and altered the cellular morphology in a dose dependent manner. Among the cell lines, HEp-2 cells showed the highest decrease in cell viability, followed by MCF-7, WISH, and Vero cells by MTT and NRU assays. Cell viability at 1000 ${\mu}g/ml$ was recorded as 55% in HEp-2 cells, 67% in MCF-7 cells, 75% in WISH cells, and 86% in Vero cells. The present study provides preliminary screening data for fenugreek seed oil pointing to potent cytotoxicity against cancer cells.

Superconductivty and magnetic properties of $(Ru_{1-x}Nb_x)Sr_2(Sm_{1.4}Ce_{0.6})Cu_2O_z$

  • Lee, H.K.;Bae, S.M.;Lee, J.M.
    • 한국초전도ㆍ저온공학회논문지
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    • 제15권3호
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    • pp.1-4
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    • 2013
  • We investigated the effect of Nb substitution for Ru on the structural and magnetic properties of $(Ru_{1-x}Nb_x)\;Sr_2(Sm_{1.4}Ce_{0.6})Cu_2O_z$ Samples. X-ray diffraction measurements indicated that nearly single-phase samples are formed in the range from x = 0 to 1.0. The superconducting transition temperature determined from the inflection in the field-cooled magnetic susceptibility decreased only slightly from $T_c$ = 25 K for x = 0 to $T_c$ = 22 K for x = 1.0, in consistent with the change in room temperature thermopower of the samples. However, the Nb substitution for Ru above x = 0.25 significantly suppressed the weak ferromagnetic component of the field-cooled magnetic susceptibility. It was also found that the Nb substitution for Ru results in an enhanced diamagnetic susceptibility with Nb content above x = 0.5 in both zero field-cooled and field-cooled magnetization measurements, in contrast to the behavior of the samples with $x{\leq}0.5$ in which the diamagnetic susceptibility decreases as the Nb content increases.

청석면 분석 정도관리용 표준시료 개발 및 평가 (Development and Validation of Crocidolite Quality Control Samples for Proficiency Analytical Testing)

  • 이지현;김은영;노수진;박용진;정지연
    • 한국환경보건학회지
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    • 제37권1호
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    • pp.57-63
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    • 2011
  • Crocidolite quality control (QC) sampling created by the wet generation method has been validated by validation tests such as the accuracy, precision, and storage tests. For this study we designed and developed a manufacturing apparatus and standard operating procedure for making these QC samples. The most important step in the procedure of making QC samples was the stage eliminating static electricity in asbestos fibers. This static electricity hampers the fibers clog functioning. In accuracy and precision tests by phase contrast microscopy analysis, the difference between the reference values and the studied values was at maximum 17.8%. This satisfies the AIHA proficiency analytical test criteria for asbestos. We could confirm the nearly even distribution of crocidolite fibers on the membrane filter. Also, there was no loss of fibers in the storage test after the one month.

충청남도 여성의 의복형태에 관한 연구(I) (The Study on the Women's Costume around chung Cheung Nam-Do)

  • 남윤숙
    • 대한가정학회지
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    • 제19권3호
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    • pp.33-40
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    • 1981
  • The purpose of this research was to see through the special qualities and prospects I different localities as to compare the actual conditions of clothes for everyday wear of the city with the town. The results investigated the style of dress in Deajeon city and youseong town throughout Winter, Spring, and Summer were as follows: 1) In hair style, commonly throughout Winter, Spring, summer, permanent style was superior in number as compared with the chignon In youseong, throughout Winter and Spring, chignon far out-numbered permanent one. 2) In winter, while citizens wore more half coats than long ones, the townsfolk had long coats on as many as that. In Spring and Summer, people dressed in blouse were shown aplenty both Deajeon and youseong and it was the latter that became more and more conspicuous I Summer. The degrees of wearing korean clothing were shown at a high rate in youseong I Spring. In both regions, throughout the year, adjusting themselves forward was of frequent occurrence. 3) In Winter and Spring, both of them put long skirts on and in Summer put normal skirts to frequent use respectively. jean pants were shown in Daejeon remarkable in spring, while the townsfolk wore Mon-pae and korean clothing. 4) throughout Spring and Summer, slippers were frequent use commonly in both regions. And in Spring, people put on more Ko Mu, sin than shoes, especially in youseong. The downward-phase shoestype has been shown markedly in both regions but Daejeon has shown a sharp contrast to youseong.

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LED Backlight Driving Circuits and Dimming Method

  • Kwon, Oh-Kyong;Jung, Young-Ho;Lee, Yong-Hak;Cho, Hyun-Suk;Nam, Ki-Soo;In, Hai-Jung
    • Journal of Information Display
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    • 제11권4호
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    • pp.173-181
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    • 2010
  • In this paper, light-emitting-diode (LED) backlight driving circuits and dimming method for medium-sized and large liquid crystal displays (LCDs) are proposed. The double loop control method, the intelligent-phase-shifted PWM dimming method, the fast-switching current regulator, and the current matching techniques are proposed to improve not only the current regulation characteristics and the power efficiency but also the current matching characteristics and the transient response of the LED current. The brightness of the backlight using the proposed local dimming method was determined from the histogram of the local block to reduce the power consumption of the backlight without image distortion. The measured maximum power efficiency of the LED backlight driving circuit for medium-sized LCDs was 90%, and the simulation results showed an 88% maximum power efficiency of the LED backlight driving circuit for large LCDs. The maximum backlight power-saving ratio of the proposed dimming method was 41.7% in the simulation with a high-contrast image. The experiment and simulation results showed that the performance of LEDs as LCD backlight units (BLUs) improved with the proposed circuits and method.

한국 토양으로부터 새로운 무독성 Bacillus thuringiensis 균주의 분리 (Isolation of Novel Non-Toxic Bacillus thuringiensis from Soil Samples in Korea)

  • 노종열;박현우;김호산;진병래;강석권
    • 한국응용곤충학회지
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    • 제34권4호
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    • pp.373-377
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    • 1995
  • 전국의 토양시료로부터 3가지의 곤충목인, 나비목, 파리목, 딱정벌레목에 속하는 10종의 곤충에 대하여 독성을 보이지 않는 4종의 Bacillus thunngiensis 균주를 분리하였다. 이들 4종의 균주를 각각 NTB-1, NTB-2, NTB-3, NTB-4로 명명하였다. 취상차 현미경과 주사전자현미경을 통해 관찰된 이들 4종 균주의 내독소 단백질 형태는 모두 원형이었으며, 각 균주의 내독소 단백질과 plasmid DNA 특성을 규명하기 위해 단백질 전기영동과 제한효소 분석을 실시하였다. 그 결과 이들 균주의 내독소 단백질과 plasmid DNA pattern은 이미 알려져 있는 무독성 균주들과는 다른 양상을 보여, 기존의 무독성 균주와 다른 새로운 균주임을 알 수 있었다.

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Lysophosphatidic Acid Inhibits Nitric Oxide-induced Apoptosis via p70S6kinase Pathway in Rabbit Articular Chondrocytes

  • ;김송자
    • 대한의생명과학회지
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    • 제15권4호
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    • pp.349-353
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    • 2009
  • Lysophosphatidic Acid (LPA) is a bioactive lysophospholipid that is a potent signaling molecule able to provoke a variety of cellular responses in many cell types such as differentiation, inflammation and apoptosis. In this study, we have investigated the effect of LPA on Nitric oxide (NO)-induced apoptosis in rabbit articular chondrocytes. LPA dramatically reduced NO induced apoptosis of chondrocytes determined by phase contrast microscope and MTT assay. When chondrocytes alone treated with LPA, LPA induced phosphorylation of p70S6kinase, a serine/threonine kinase that acts downstream of phosphatidylinositol 3,4,5-trisphosphate (PIP3) and phosphoinositide-dependent kinase-1 (PDK-1) in the PI3 kinase pathway, dose-dependently detected by Western blot analysis. Phosphorylation of p70S6k with LPA was reduced expression of p53 in NO-induced apoptosis of chondrocytes. Also, inhibition of p70S6kinase with rapamycin was enhanced expression of p53 in chondrocytes. Our findings collectively suggest that LPA regulates NO induced apoptosis through p70S6kinase pathway in rabbit articular chondrocytes.

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습도에 따른 DLC 코팅의 마찰 거동 (Tribological Behavior of DLC Coatings at Various Humidities)

  • 조경만;안효석;김대은
    • 대한기계학회논문집A
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    • 제26권9호
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    • pp.1842-1848
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    • 2002
  • Although DLC coatings have good tribological properties, these are dependant on the deposition method, the property of contact surface, and test condition. Humidity, which has little influence on tribological behavior in macro scale, is an important factor of tribological behavior in small devices like MEMS. The objective of this study is to investigate the tribological behavior of DLC coatings with particular attention to their wettability at various humidities. DLC coatings were deposited on Si substrates and tested using a reciprocating friction tester against Si$_3$N$_4$balls at various humidities. The results showed that the tribological behavior of DLC coatings was dependant on relative humidity and wettablility of DLC coatings. Friction coefficient at high relative humidity was higher thar that at low relative humidity. The tungsten-containing DLC coatings had a good wear resistance at low relative humidity whereas DLC coatings derived from argon(Ar)+cesium(Cs) gases showed a good wear resistance at high relative humidity.

GaAs와 InP에 격자정합된 GaINAsP 이중조직에서 불순물 확산에 의한 상호확산 촉진 (Impurity Diffusion Enhancement of Interdiffusion in GalnAsP Heterostructures Lattice Matched to GaAs and InP)

  • 박효훈;이경호;남은수;이용탁
    • ETRI Journal
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    • 제11권4호
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    • pp.84-97
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    • 1989
  • The influence of Zn, Si and Te diffusion on the interdiffusion in $GaAs-Ga_1_-xIN_xAs_1__yP_y$and InP$Ga_1__xIn_xAs_1__yP_y$ heterostructures was studied. The heterostructures were grown by liquid phase epitaxy, and the impurity diffusion into the heterostructures was carried out using metal compound or element sources. The extent of interdiffusion for both group III and V atoms was observed by depth profiling of matrix elements with secondary ion mass spectrometry and Auger electron spectroscopy. Selective enhancement of cation interdiffusion was observed by the concurrent Zn diffusion in both the GaAs based-and InP based-crystals. In contrast to the Zn diffusion, the Si diffusion in the GaAs based-crystal and the Te diffusion in the InP based-crystal enhanced both cation and anion interdiffusion to the same extent. A kick-out mechanism is proposed to explain the selective enhancement of the cation interdiffusion due to Zn, and a single vacancy mechanism is proposed for the interdiffusion due to Si and Te.

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Asbestos Exposure among Mitering Workers

  • Phanprasit, Wantanee;Sujirarat, Dusit;Musigapong, Pirutchada;Sripaiboonkij, Penpatra;Chaikittiporn, Chalermchai
    • Safety and Health at Work
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    • 제3권3호
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    • pp.235-240
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    • 2012
  • The objectives are to compare the airborne asbestos concentrations resulted from mitering of abestos cement roof sheets by a high-speed motor and a hand saw, and to monitor whether other workers near the test sites are vulnerable to the fibers exceeding the occupational exposure limit. Four test cases were carried out and altogether 7 personal and 4 area air samples were collected. The NIOSH method 7400 was employed for the air samplings and analysis. Using the phase contrast microscopy, fiber counting was conducted under Rule A. The study showed that the fiber concentration medians for personal air samples gathered from the two tools were 4.11 fibers/cc (ranged: 1.33-12.41 fibers/cc) and 0.13 fibers/cc (ranged: 0.01-5.00 fibers/cc) respectively. The median for the area samples was 0.59 fibers/cc (ranged: 0.14-3.32 fibers/cc). Comparing each study case, the concentration level caused by the high-speed motor saw was more than twice that of the hand saw. According to the area samples, the workers nearby the test site are at risk from high exposure to asbestos.