• 제목/요약/키워드: chemical induction

검색결과 476건 처리시간 0.026초

Antitumor and Apoptosis Induction Effects of Paeonol on Mice Bearing EMT6 Breast Carcinoma

  • Ou, Yetao;Li, Qingwang;Wang, Jianjie;Li, Kun;Zhou, Shaobo
    • Biomolecules & Therapeutics
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    • 제22권4호
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    • pp.341-346
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    • 2014
  • Paeonol is a major phenolic micromolecular component of Moutan cortex Radicis, a traditional Chinese Medicine. It has shown antitumor effects in previous studies; however, the underlying mechanisms remain unknown. This study investigated the mechanism by giving treatments of placebo, cyclophosphamide, paeonol of 150 and 300 mg/kg to 4 groups of mice bearing EMT6 breast cancer. Apoptosis in tumor cells were confirmed by morphology analysis, including hematoxylin, eosin staining and TUNEL staining. The results showed that the weight of EMT6 breast tumor was significantly reduced in the groups treated with both 150 and 300 mg/kg of paeonol. Immunohistochemical and Western blot results showed that the expression of Bcl-2 was down-regulated while the expression of Bax, caspase 8 and caspase 3 was up-regulated respectively. These results suggest that paeonol exhibits antitumor effects and the mechanism of the inhibition is via induction of apoptosis, regulation of Bcl-2 and Bax expression, and activation of caspase 8 and caspase 3.

Isolation of human mesenchymal stem cells from the skin and their neurogenic differentiation in vitro

  • Byun, Jun-Ho;Kang, Eun-Ju;Park, Seong-Cheol;Kang, Dong-Ho;Choi, Mun-Jeong;Rho, Gyu-Jin;Park, Bong-Wook
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제38권6호
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    • pp.343-353
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    • 2012
  • Objectives: This aim of this study was to effectively isolate mesenchymal stem cells (hSMSCs) from human submandibular skin tissues (termed hSMSCs) and evaluate their characteristics. These hSMSCs were then chemically induced to the neuronal lineage and analyzed for their neurogenic characteristics in vitro. Materials and Methods: Submandibular skin tissues were harvested from four adult patients and cultured in stem cell media. Isolated hSMSCs were evaluated for their multipotency and other stem cell characteristics. These cells were differentiated into neuronal cells with a chemical induction protocol. During the neuronal induction of hSMSCs, morphological changes and the expression of neuron-specific proteins (by fluorescence-activated cell sorting [FACS]) were evaluated. Results: The hSMSCs showed plate-adherence, fibroblast-like growth, expression of the stem-cell transcription factors Oct 4 and Nanog, and positive staining for mesenchymal stem cell (MSC) marker proteins (CD29, CD44, CD90, CD105, and vimentin) and a neural precursor marker (nestin). Moreover, the hSMSCs in this study were successfully differentiated into multiple mesenchymal lineages, including osteocytes, adipocytes, and chondrocytes. Neuron-like cell morphology and various neural markers were highly visible six hours after the neuronal induction of hSMSCs, but their neuron-like characteristics disappeared over time (24-48 hrs). Interestingly, when the chemical induction medium was changed to Dulbecco's Modified Eagle Medium (DMEM) supplemented with fetal bovine serum (FBS), the differentiated cells returned to their hSMSC morphology, and their cell number increased. These results indicate that chemically induced neuron-like cells should not be considered true nerve cells. Conclusion: Isolated hSMSCs have MSC characteristics and express a neural precursor marker, suggesting that human skin is a source of stem cells. However, the in vitro chemical neuronal induction of hSMSC does not produce long-lasting nerve cells and more studies are required before their use in nerve-tissue transplants.

Effects of Induction Heat Bending Process on Microstructure and Corrosion Properties of ASME SA312 Gr.TP304 Stainless Steel Pipes

  • Kim, Nam In;Kim, Young Sik;Kim, Kyung Soo;Chang, Hyun Young;Park, Heung Bae;Sung, Gi Ho
    • Corrosion Science and Technology
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    • 제14권3호
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    • pp.120-126
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    • 2015
  • The usage of bending products recently have increased since many industries such as automobile, aerospace, shipbuilding, and chemical plants need the application of pipings. Bending process is one of the inevitable steps to fabricate the facilities. Induction heat bending is composed of compressive bending process by local heating and cooling. This work focused on the effect of induction heat bending process on the properties of ASME SA312 Gr. TP304 stainless steel pipes. Tests were performed for base metal and bended area including extrados, intrados, crown up, and down parts. Microstructure was analyzed using an optical microscope and SEM. In order to determine intergranular corrosion resistance, Double Loop Electrochemical Potentiokinetic Reactivation (DL-EPR) test and ASTM A262 practice A and C tests were done. Every specimen revealed non-metallic inclusion free under the criteria of 1.5i of the standard and the induction heat bending process did not affect the non-metallic inclusion in the alloys. Also, all the bended specimens had finer grain size than ASTM grain size number 5 corresponding to the grain sizes of the base metal and thus the grain size of the pipe bended by induction heat bending process is acceptable. Hardness of transition start, bend, and transition end areas of ASME SA312 TP304 stainless steel was a little higher than that of base metal. Intergranular corrosion behavior was determined by ASTM A262 practice A and C and DL-EPR test, and respectively step structure, corrosion rate under 0.3 mm/y, and Degree of Sensitization (DOS) of 0.001~0.075% were obtained. That is, the induction heat bending process didn't affect the intergranular corrosion behavior of ASME SA312 TP304 stainless steel.

세파계 항생제, YH1226의 유전독성 평가 (Genetic Toxicity Studies of YH1226, a Cephalosporin Antibiotic)

  • 허광원;오혜영;박장환;허옥순;순수정;한의식;김명희;강희일
    • 한국환경성돌연변이발암원학회지
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    • 제18권2호
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    • pp.89-92
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    • 1998
  • The results of chromosome aberration test in mammalian cells in culture (Chinese hamster lung fibroblast cells) showed no induction of structural and numerical aberrations by YH1226, a cephalosporin antibiotic regardless of metabolic activation, while positive control group (mitomycin C and benzo(a)pyrene) showed structural chromosome aberrations of 25% and 10%, respectively. The in vivo induction of micronuclei was measured in polychromatic erythrocytes in bone marrow of male ddY mouse given YH1226 at 500, 250, 125 mg/kg by i.p. once. After 24 hours, animals were sacrificed and evaluated for the incidence of micronucleated polychromatic erythrocytes in whole erythrocytes. Although a positive response for induction of micronuclei in animals treated with mitomycin C demonstrated the sensitivity of the test system for detection of a chemical clastogen, YH1226 did not induce microunclei in bone marrow of ddY male mice.

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고성능 유도전동기 구동을 위한 자동 튜닝 Anti-windup 기법 (Tuning-free Anti-windup Strategy for High Performance Induction Machine Drives)

  • 석줄기;배상규;이동춘
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2004년도 전력전자학술대회 논문집(1)
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    • pp.312-315
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    • 2004
  • This paper presents a tuning-free conditional integration anti-windup strategy for induction machine with Proportional-Integral (PI) type speed controller. The on/off condition of integral action is determined by the frequency domain analysis of machine torque command without a prior knowledge of set-point changes. There are no tuning parameters to be selected by users for anti-windup scheme. In addition, the dynamic performance of the proposed scheme assures a desired tracking response curve with minimal oscillation and settling time even in the change of operating conditions. This algorithm is useful in many high performance induction machine applications not to allow the oscillation and overshoot of speed/torque responses. The main idea can be extended to general applications such as chemical processes and industrial robots.

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전자기 유도 방식을 이용한 비접촉식 2차원 위치 센서 (A Non-contact Two-Dimensional Position Sensing Device Using Electromagnetic Induction)

  • 유영기;고국원;김학수
    • 한국정밀공학회지
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    • 제29권11호
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    • pp.1159-1163
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    • 2012
  • In this paper, we would like to introduce two dimensional non-contact position sensor by using an electromagnetic induction based coil system and an algorithm to estimate the position of pointer. The sensor which will introduce in this paper is composed of a pointer including LC resonant circuit and a sensor board to detect the electromagnetic signal from the pointer. Because of the simplicity shape of the line antenna, low cost and free form curved shape of the sensor device is possible. In this research, we proposed a new two dimensional non-contact type electromagnetic sensor system and realized the proposed sensor device. From the experiments, the proposed device can be employed for the two dimensional position sensor.

비스페놀A 처리 수컷 잉어에서 비텔로제닌 mRNA의 발현 (Vitellogenin mRNA Induction in Male Carp Treated with Bisphenol A)

  • 박응로;최필선;이철우;류지성;남성숙;류홍일;전성환;나진균;박광식
    • Toxicological Research
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    • 제17권3호
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    • pp.181-186
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    • 2001
  • The estrogenic potency of bisphenol A using reverse trancriptase-PCR response of liver vitellogenin mRNA in male carp was studied. For this, six combination of primers which were synthesized on the basis of cDNA consensus region of various species, were evaluated and one pair of primers was selected as the best to show 286 bp size-transcript. By using the selected primers, vitellogenin mRNA induction in carp treated with bisphenol A was measured and the chemical showed dose-and time-dependent Induction response. From this result, it was concluded that RT-PCR technique wing the selected primers in this study can be wed to monitor the estrogenic effects exerted In carp living in Korean freshwater.

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Utility AC Frequency to High Frequency AC Power Frequency Converter without Electrolytic Capacitor Link for Consumer Induction Heating Appliances

  • Sugimura, H.;Eid, A.;Lee, H.W.;Kwon, S.K.;Suh, K.Y.;Nakaoka, M.
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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    • pp.1364-1367
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    • 2005
  • In this paper, a novel prototype topology of soft switching PWM controlled high frequency AC power conversion circuit without DC voltage smoothing chemical capacitor filter link from the voltage grid of utility frequency AC power supply source with 60Hz-100V or 60Hz-200V is proposed and introduced for innovative consumer induction heating(IH) boiler applications as hot water producer, steamer and super heated vapor steamer.

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Heme Oxygenase-1 as a Potential Therapeutic Target for Hepatoprotection

  • Farombi, Ebenezer Olatunde;Surh, Young-Joon
    • BMB Reports
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    • 제39권5호
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    • pp.479-491
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    • 2006
  • Heme oxygenase (HO), the rate limiting enzyme in the breakdown of heme into carbon monoxide (CO), iron and bilirubin, has recently received overwhelming research attention. To date three mammalian HO isozymes have been identified, and the only inducible form is HO-1 while HO-2 and HO-3 are constitutively expressed. Advances in unveiling signal transduction network indicate that a battery of redox-sensitive transcription factors, such as activator protein-1 (AP-1), nuclear factor-kappa B (NF-${\kappa}B$) and nuclear factor E2-related factor-2 (Nrf2), and their upstream kinases including mitogen-activated protein kinases play an important regulatory role in HO-1 gene induction. The products of the HO-catalyzed reaction, particularly CO and biliverdin/bilirubin have been shown to exert protective effects in several organs against oxidative and other noxious stimuli. In this context, it is interesting to note that induction of HO-1 expression contributes to protection against liver damage induced by several chemical compounds such as acetaminophen, carbon tetrachloride and heavy metals, suggesting HO-1 induction as an important cellular endeavor for hepatoprotection. The focus of this review is on the significance of targeted induction of HO-1 as a potential therapeutic strategy to protect against chemically-induced liver injury as well as hepatocarcinogenesis.

The Voltage-fed High Frequency Resonant Inverter Using Induction Heated Dry Steam Generator

  • Kim, Chil-Ryong;Lee, Jong-Kurl;Jung, Sang-Hwa;Mun, Sang-Pil;Kim, Sang-Don;Nakaoka, Mutsuo
    • 한국조명전기설비학회:학술대회논문집
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    • 한국조명전기설비학회 2008년도 춘계학술대회 논문집
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    • pp.415-418
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    • 2008
  • This paper presents an innovative prototype of a new conceptual electromagnetic induction-based fluid beating appliance using voltage-fed type scries capacitor-compensated load resonant high-frequency IGBT inverter with a phase-shifted PWM and a power factor correction schemes. Its operating characteristics in steady-state are illustrated including unique features and evaluated on the basis of its computer simulation and experimental results of 10kw breadboard appliance for hot water producer and superheated steamer. The promising cost effective inverter-fed boiler appliances for electromagnetic induction-heated type fluid-heating in the pipeline systems are proposed for induction-heated boiler, super heat steamer, high temperature water producer, hot gas producer and metal catalyst heating for exhaust gas cleaning in engine, which are more suitable and acceptable for industrial, chemical, and consumer energy utilization for household and business from a practical point of view.

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