• Title/Summary/Keyword: time-dependent effect

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Effect of autophagy in human tongue squamous cell carcinoma SCC 25 cells from Scutellariae Radix by ethanol extract (에탄올에 의해 추출한 황금이 구강암 세포에서 나타나는 자가포식작용)

  • Choi, Byul Bo-Ra
    • Journal of Korean society of Dental Hygiene
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    • v.14 no.2
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    • pp.287-292
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    • 2014
  • Objectives : The purpose of the study is to examine the cell growth effect and autophagy effect of Scutellariae Radix by ethanol extract in SCC 25 cells. Methods : Cell growth inhibitory effect and autophagy induced by Scutellariae Radix were confirmed by WST-1 assay, monodansylcadaverine(MDC) stain, and flow cytometry by acridine orange(AO) stain. Results : The Scutellariae Radix treatment decreased the cell proliferation in a dose and time dependent manner. Scutellariae Radix has anticancer effects that autophagic vacuoles were apparent by MDC and AO staining in SCC 25 cells. Conclusions : Scutellariae Radix showed anticancer activity against SCC 25 cells via autophagy. The data provided the possibility that Scutellariae Radix may potentially contribute to oral cancer treatment.

Stimulation of Osteogenic Differentiation in Stromal Cells of Giant Cell Tumour of Bone by Zoledronic Acid

  • Yang, Tao;Zheng, Xiao-Fei;Li, Mei;Lin, Xi;Yin, Qing-Shui
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.9
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    • pp.5379-5383
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    • 2013
  • Therapeutic effects of zoledronic acid (ZOL) on giant cell tumour of bone (GCT) have been proven. Apoptosis induction was considered to be one of the mechanisms of ZOL tumour inhibition. In this study, we presented the possibility of an osteogenic differentiation stimulation mechanism of ZOL and further investigated dosage and time effects. We treated stromal cells of GCT (GCTSC) with ZOL for 48 hours at different concentrations ($0{\mu}M$, $0.01{\mu}M$, $0.1{\mu}M$, $1{\mu}M$, 5${\mu}M$, $30{\mu}M$) and assessed apoptotic and osteogenic differentiation markers with immunohistochemical techniques and real-time quantitative RT-PCR. Our results suggested that ZOL enhanced mRNA expression of Cbfa-1, osterix and osteocalcin genes with a maximum effect at $1{\mu}M$ in GCTSC. Time course experiments indicated a time dependent osteogenic differentiation effect. In conclusion, ZOL may be considered as an adjuvant in the treatment of GCT not only by inducing apoptosis but also by stimulating osteogenic differentiation of remaining tumor stromal cells after surgery.

A novel grey TMD control for structures subjected to earthquakes

  • Z.Y., Chen;Ruei-Yuan, Wang;Yahui, Meng;Timothy, Chen
    • Earthquakes and Structures
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    • v.24 no.1
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    • pp.1-9
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    • 2023
  • A model for calculating structure interacted mechanics is proposed. A structural interaction model and controller design based on tuned mass damping (TMD) was developed to control the induced vibration. A key point is to introduce a new analytical model to evaluate the properties of the TMD that recognizes the motion-dependent nonlinear response observed in the simulations. Aiming at the problem of increased current harmonics and low efficiency of permanent magnet synchronous motors for electric vehicles due to dead time effect, a dead time compensation method based on neural network filter and current polarity detection is proposed. Firstly, the DC components and the higher harmonic components of the motor currents are obtained by virtue of what the neural network filters and the extracted harmonic currents are adjusted to the required compensation voltages by virtue of what the neural network filters. Then, the extracted DC components are used for current polarity dead time compensation control to avert the false compensation when currents approach zero. The neural network filter method extracts the required compensation voltages from the speed component and the current polarity detection compensation method obtains the required compensation voltages by discriminating the current polarity. The combination of the two methods can more precisely compensate the dead time effect of the control system to improve the control performance. Furthermore, based on the relaxed method, the intelligent approach of stability criterion can be regulated appropriately and the artificial TMD was found to be effective in reducing cross-wind vibrations.

Experimental Study on the Antidepressant Effect of Ginseng Radix Alba and Cyperi Rhizoma (인삼(人蔘)과 향부자(香附子)의 항우울효과(抗憂鬱效果)에 관한 실험적 연구)

  • Lee, Dong-Won;Kim, In-Jae
    • Journal of Oriental Neuropsychiatry
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    • v.15 no.1
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    • pp.101-119
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    • 2004
  • Ginseng Radix Alba and Cyperi Rhizoma were investigated for their anti-depressant effects. For this purpose, forced-swimming test, tail suspension test, hot plate test, reserpine-induced hypothermia, aggressive behavior test were performed. In addition, the brain content of 5-hydroxyindoleacetic acid(a metabolite of serotonin), the monoamine oxidase activity, anticonvulsant effect, sleep enhancement effect were determined. The results are as follows: In the forced swimming test, Ginseng Radix diminished the duration of immobility by 45.5% compared to the control group, while Cyperi Rhizoma showed weaker effect (12.4% reduction) at 2g/kg. In the tail suspension test, the effect of Ginseng Radix(43.7% reduction) are also better than that of Cyperi Rhizoma(15.6% reduction) at 2g/kg. In the hot plate test, Ginseng Radix showed no difference as compared to control, while Cyperi Rhizoma increased the jump latency time by about 25% after administration for 10 days. In the reserpine-induced hypothermia test, both drugs slowly dropped the body temperature compared to the control group, especially the rate of hypothermia of Ginseng Radix was 24.0% at 1g/kg. In the aggressive behavior test, both drugs delayed the onset time, decreased the duration and frequency, of which effects were better in Cyperi Rhizoma. The content of 5-hydroxyindoleacetic acid in mice brain was slightly increased in Ginseng Radix, while Cyperi Rhizoma increased its level almost to the control group. Both drugs inhibited the monoamine oxidase activity in a dose-dependent manner, but the effect(51.2%) of Cyperi Rhizoma was more potent than the effect(11.8%) of Ginseng Radix. In the pentobarbital-induced sleep test, Cyperi Rhizoma exhibited no significant difference against the control group, while Ginseng Radix showed about two-fold enhancement at 2g/kg. The anticonvulsant effect of both drugs delayed the onset time, shortened the duration of convulsion and diminished the lethality, but Ginseng Radix were better than Cyperi Rhizoma.

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Size-dependent Optical and Electrical Properties of PbS Quantum Dots

  • Choi, Hye-Kyoung;Kim, Jun-Kwan;Song, Jung-Hoon;Jeong, So-Hee
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.186-186
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    • 2012
  • This report investigates a new synthetic route and the size-dependent optical and electrical properties of PbS nanocrystal quantum dots (NQDs) in diameters ranging between 1.5 and 6 nm. Particularly we synthesize ultra-small sized PbS NQDs having extreme quantum confinement with 1.5~2.9 nm in diameter (2.58~1.5 eV in first exciton energy) for the first time by adjusting growth temperature and growth time. In this region, the Stokes shift increases as decreasing size, which is testimony to the highly quantum confinement effect of ultra-small sized PbS NQDs. To find out the electrical properties, we fabricate self-assembled films of PbS NQDs using layer by layer (LBL) spin-coating method and replacing the original ligands with oleic acid to short ligands with 1, 2-ethandithiol (EDT) in the course. The use of capping ligands (EDT) allows us to achieve effective electrical transport in the arrays of solution processed PbS NQDs. These high-quality films apply to Schottky solar cell made in an glass/ITO/PbS/LiF/Al structure and thin-film transistor varying the PbS NQDs diameter 1.5~6 nm. We achieve the highest open-circuit voltage (<0.6 V) in Schottky solar cell ever using PbS NQDs with first exciton energy 2.58 eV.

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Analysis of Thermo-Viscoplastic Behavior of Structures Using Unified Constitutive Equations (통일구성방정식을 이용한 구조물의 열점소성 거동에 관한 해석)

  • 윤성기;이주진
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.15 no.1
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    • pp.190-200
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    • 1991
  • Certain structural components are exposed to high temperatures. At high temperature, under thermal and mechanical loading, metal components exhibit both creep and plastic behavior. The unified constitutive theory is to model both the time-dependent behavior(creep) and the time-independent behavior(plasticity) in one set of equations. Microscopically both creep and plasticity are controlled by the motion of dislocations. A finite element method is presented encorporating a unified constitutive model for the transient analysis of viscoplastic behavior of structures exposed to high temperature.

Induction of Apoptosis by (-)-epigallocatechin-3-gallate in HL-60 Cells (인체 혈액암세포주(HL-60)에서 (-)-epigallocatechin-3-gallate에 의한 Aapoptosis 유도)

  • 이해미;김연정;박태선
    • Journal of Nutrition and Health
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    • v.36 no.4
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    • pp.382-388
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    • 2003
  • (-)-Epigallocatechin-3-gallate (EGCG) is a polyphenolic compound found in peen tea leaves, and has been known to be one of the most potent catechin species which inhibits cell growth most possibly through an apoptotic cell death. We investigated the apoptotic activity of (-)-EGCG on the human myeloid leukemia cell line, HL-60. Our results of MTT test indicated that (-)-EGCG had a significant antiproliferation effect in HL-60 cells with $IC_{50}$/ (50% inhibition concentration) value of 65 $\mu$M. Giemsa statining of HL-60 cells treated with (-)-EGCG (100 $\mu$M) for 6hrs showed a typical apoptosis-specific morphological change including shrinkage of the cytoplasm, membrane blobbing and compaction of the nuclear chromatin. The DNA fragmentation was observed from the agarose gel electrophoresis of cells treated with (-)-EGCG for 3hrs or longer, and was progressed to a greater degree as treatment time increases. Treatment of the cells with (-)-EGCG (100 $\mu$M) resulted in a rapid release of mitochondrial cytochrome c into the cytosol, and a subsequent cleavage of caspase-3 to an active form in a treatment-time dependent manner. (-)-EGCG (100 $\mu$M) also stimulated proteolytic cleavage of poly-(ADP-ribose) polymerase (PARP) to an active form in HL-60 cells. Tlken together, (-)-EGCG appears to induce the apoptosis in human myeloid leukemia cells via a caspase-dependent pathway. These results suggest the possible application of (-)-EGCG, the major active compound in green tea, as an antiproliferative agent for cancer prevention.

Effect of Growth Temperature on the Luminescence Properties of InP/GaP Short-Period Superlattice Structures

  • Byun, Hye Ryoung;Ryu, Mee-Yi;Song, Jin Dong;Lee, Chang Lyul
    • Applied Science and Convergence Technology
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    • v.24 no.1
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    • pp.22-26
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    • 2015
  • The optical properties of InP/GaP short-period superlattice (SPS) structures grown at various temperatures from $400^{\circ}C$ to $490^{\circ}C$ have been investigated by using temperature-dependent photoluminescence (PL) and emission wavelength-dependent time-resolved PL measurements. The PL peak energy for SPS samples decreases as the growth temperature increases. The decreased PL energy of ~10 meV for the sample grown at $425^{\circ}C$ compared to that for $400^{\circ}C$-grown sample is due to the CuPt-B type ordering, while the SPS samples grown at $460^{\circ}C$ and $490^{\circ}C$ exhibit the significant reduction of the PL peak energies due to the combined effects of the formation of lateral composition modulation (LCM) and CuPt-B type ordering. The SPS samples with LCM structure show the enhanced carrier lifetime due to the spatial separation of carriers. This study represents that the bandgap energy of InP/GaP SPS structures can be controlled by varying growth temperature, leading to LCM formation and CuPt-B type ordering.

Apoptotic Effects of 6-Gingerol in Human Breast Cancer Cells

  • Kim, Hyun-Woo;Oh, Deuk-Hee;Koh, Jeong-Tae;Lim, Young-Chai
    • International Journal of Oral Biology
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    • v.40 no.4
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    • pp.223-228
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    • 2015
  • 6-Gingerol exerts anti-tumor effects in various cancer cell models. We evaluated the effect of 6-gingerol on the growth of MCF-7 breast cancer cells and MCF-10A breast epithelial cells to determine whether any growth-inhibitory effects found were attributable to apoptosis, and to elucidate the underlying mechanism of action. 6-Gingerol inhibited the viability of both cell lines in a dose- and time-dependent manner; however, the degree of inhibition was greater in MCF-7 than MCF-10A cells. By flow cytometry, induction of dose- and time-dependent apoptosis was found, and the magnitude of apoptosis was also markedly greater in MCF-7 than MCF-10A cells. Expression of caspase-3 and poly (ADP-ribose) polymerase (PARP) was observed in MCF-7 cells treated with 6-gingerol, and further cleavage of PARP occurred in these cells. We suggest that 6-gingerol induces apoptosis in human breast cancer cells mainly by promoting caspase-3 expression and subsequent degradation of PARP.

Prediction of Time-dependent Lateral Movement Induced by Differential Shortening in Tall Buildings Using Construction Stage Analysis

  • Ha, Taehun;Kim, Sangdae;Lee, Sungho
    • International Journal of High-Rise Buildings
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    • v.6 no.1
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    • pp.11-19
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    • 2017
  • High-rise buildings move during construction due to time-dependent material properties of concrete (creep and shrinkage), construction sequences, and structural shapes. The building movements, including vertical and horizontal displacements, result from the sum of axial and lateral deformation of vertical members at each level. In addition to the vertical shortenings, the lateral movement induced by differential shortening can have adverse effects on the construction tolerance and serviceability of non-structural elements such as elevators and curtain walls. In this study a construction stage analysis method is developed to predict lateral movement induced by shortening, including the effect of creep and shrinkage. The algorithm of construction stage analysis is combined with the FE analysis program. It is then applied to predict lateral movement of a 58-story reinforced concrete building that was constructed in Kuala Lumpur, Malaysia. Gravity induced lateral movement of this building is predicted by the construction stage analysis. A field three-dimensional laser scanning survey is carried out to verify the prediction results, and satisfactory agreement is obtained.