• Title/Summary/Keyword: Reversal Effect

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Performance improvement of underwater target distance estimation using blind deconvolution and time of arrival method (블라인드 디컨볼루션 및 time of arrival 기법을 이용한 수중 표적 거리 추정 성능 향상 기법)

  • Han, Min Su;Choi, Jea Young;Son, Kweon;Lee, Phil Ho
    • The Journal of the Acoustical Society of Korea
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    • v.36 no.6
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    • pp.378-386
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    • 2017
  • Accurate distance measurement between maneuver target in underwater and measuring devices is required to perform quantitative test evaluation in marine weapons system R&D process. In general, the target distance is measured using a one-way ToA (Time of Arrival) method that calculates the time difference between transmitted and received signals from the two accurately synchronized devices. However, the distance estimation performance is degraded because of the multi-path environments. In this paper, the time-variant transfer function of complex underwater environment is estimated from each received data frame using RBD (Ray-based Blind Deconvolution), and the estimated time-variant transfer function is then used to get rid of the effect about complex underwater environment and to recover the data signal using PTRM (Passive Time Reversal Mirror). The result from the simulation and experimental data show that the suggested method improve the distance estimation performance when comparing with the conventional ToA method.

THE EFFECTS OF GLYCYRRHETINIC ACID AND OLEANOLIC ACID TO CYCLOSPORINE A INDUCED CELL ACTIVITY OF CULTURED GINGIVAL FIBROBLASTS (Glycyrrhetinic acid와 oleanolic acid가 배양 치은 섬유모세포의 cyclosporine A 유도 세포활성에 미치는 영향)

  • Kim, Young-Wook;Kim, Jae-Hyun;Shin, Hyung-Shik
    • Journal of Periodontal and Implant Science
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    • v.24 no.2
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    • pp.238-254
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    • 1994
  • Cyclosporine A is an immunosuppressant commonly used for patients receiving organ transplants. Gingival overgrowth is an adverse side-effect seen in about 8-26% of patients taking cyclosporine A which have been shown to increase the DNA synthesis of gingival fibroblast at the concentration of $10^{-9}g/ml$ in vitro. Glycyrrhetinic acid is the active pharmacological ingredients of licorice which exerts steroid-like action and anti-viral activity. Oleanolic acid, which were isolated from Glechoma hederacea, has been shown to act as inhibitors of tumor promotion in vivo and to be less cytotoxic retinoic acid. This study has been performed to evaluate the effects of glycyrrhetinic acid and oleanolic acid on cyclosporine A induced cell activity in vitro. Human gingival fibroblasts were isolated from explant cultures of healthy gingiva of orthodontic patients. Gingival fibroblasts were trypsinized and transferred to the walls of microtest plates. Fibroblasts were cultured in growth medium added $10^{-9}g/ml$ cyclosporineA and $50{\mu}l/ml$ lipopolysaccharides. Cells between the 4th and 6th transfer in culture were used for this study. The morphology of gingival fibroblst were examined by inverted microscope. The effects of cyclosporine A on the time course of DNA sythesis by human gingival fibroblasts were assessed by $[^3H]-thymidine$ uptake assays. Cyclosporine A was found to stimulate DNA synthesis of human gingival fibroblast at a concentration of $10^{-9}g/ml$. In the presence of lipopolysaccharide derived from Fusobacterium nucleatum, addition of cyclosporine A results in reversal of inhibition at the concentration which normally inhibits gingival fibroblast proliferation. The cell acitivities in the presence of glycyrrhetinic acid and oleanolic acid were decreased, and increased cell acitivities by cyclosporine A were decreased by glycyrrhetinic acid and oleanolic acid at the concentration of $200{\mu}g/ml$. These results suggested that the increased cell activities by cyclosporine A modulated by glycyrrhetinic acid and oleanolic acid.

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The Gender Observation Time Characteristics from Sight Fixation and the Leap of Pupil Index (시선의 고정과 도약 동공지표에 나타난 성별 주시시간 특성)

  • Lee, Jeong Ho;Kim, Jong-Ha
    • Korean Institute of Interior Design Journal
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    • v.27 no.1
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    • pp.29-38
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    • 2018
  • This research is to analyze the change of pupil size in gender through the eye-tracking experiment in large complex cultural space. It is meaningful that figured out the common characteristics and differences from gender observation characteristics. Through this research, the analyzed results of the observation time measurement that appeared from the fixation and saccades pupil indicator able to define as follows. Firstly, it was suggested that there were differences between each gender and participants through extract pupil size that can be the standard examples for the case from male and female and the process of extracting the relative pupil size change on the hourly range. From the specific time range, it was possible to indicate bending characteristics and reversal phenomena of Fixation and Saccades. Second, the result was found equally from both male and female group that the rapid increment of pupil size at initial time range immediately after the eye-tracking experiment has been initiated. This can be considered to actively accepting the stress given by the subject through the extended pupil after 10 seconds that compare to indicated very low pupil size between 0 to 10 seconds after starting the experiment. Third, meanwhile 0 to 10 seconds after initial observation are the time of sudden change in the pupil size, therefore these time range data cannot be regarded as observed in the appropriate condition. Thus, it able to define the highest times of emotional processing for male as 10 to 80 seconds, and for female as 10 to 70 seconds. There was no definition of the time range data for observation experiment from previous research, this data can be considered to stable time to observation through the pupil extension. Therefore, it is possible to set suitable time of observation experiment to be around 70 to 80 seconds exclude initial experiment time.

Liver Function Analyses and Spleen Histology Assessment Following the Co-administration of Cisplatin and Methanolic Extract of Portulaca Oleracea in Wistar Rats: An Experimental Study

  • Okafor, Izuchukwu Azuka;Nnamah, Uchenna Somtochukwu;Nnaka, Jude
    • Natural Product Sciences
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    • v.26 no.3
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    • pp.252-258
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    • 2020
  • This study investigated the biochemical and histological changes associated with the co-administration of cisplatin and methanolic extract of Portulaca oleracea (MEPO) in adult Wistar rats. Twenty-four (24) adult female Wistar rats were randomly divided into six (6) groups (A-F) (n = 4). Group A served as the control group for the experiment and received no treatment. Group B was given a single dose of cisplatin and served as the cisplatin control group. Group C and D received 400 mg/kg and 800 mg/kg of MEPO 6 hours after a single dose cisplatin injection respectively. Group E and F received 400 mg/kg and 800 mg/kg of MEPO 6 hours before cisplatin injection. The cisplatin injection was 2 mL/kg given intraperitoneally for all groups. There was a significant increase in the serum levels of ALT, ALP, AST, total bilirubin, and conjugated bilirubin following cisplatin treatment (p = 0.000, 0.000, 0.039, 0.000, 0.004 respectively) with a consequent reversal due to MEPO administration across all treated groups (p = 0.000, 0.000, 0.000, and 0.000) in a dose-dependent fashion. Cisplatin caused the expansion of the red and white pulp in the spleen which was attenuated by MEPO. MEPO demonstrated a protective effect against cisplatin-induced liver and spleen toxicity.

The effect of negated emotional words on polarity reversal and weakening value in valence (정서 단어 부정어가 정서가의 극성 전환 및 약화에 미치는 영향)

  • Rhee, Shin-Young;Ham, Jun-Seok;Kim, Mi-Sun;Bang, Green;Ko, Il-Ju
    • Korean Journal of Cognitive Science
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    • v.23 no.1
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    • pp.97-107
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    • 2012
  • Previous studies on opinion mining and sentiment analysis have supposed that the polarity and value of an emotional word is reversed when a negation word is attached. However, there are no quantitative studies on how much the polarity is changed when a negation word is following. Therefore, we measured the valence and arousal dimensions for Korean emotional words and their negations. Consequently, the polarity of valence and arousal was reversed on their intermediate level. Also, the value was reduced by about 30% to 50%. We propose this result as a guideline for processing negation words for studies on opinion mining and sentiment analysis.

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Cloning and Functional Characterization of Putative Escherichia coli ABC Multidrug Efflux Transporter YddA

  • Feng, Zhenyue;Liu, Defu;Liu, Ziwen;Liang, Yimin;Wang, Yanhong;Liu, Qingpeng;Liu, Zhenhua;Zang, Zhongjing;Cui, Yudong
    • Journal of Microbiology and Biotechnology
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    • v.30 no.7
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    • pp.982-995
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    • 2020
  • A putative multidrug efflux gene, yddA, was cloned from the Escherichia coli K-12 strain. A drug-sensitive strain of E. coli missing the main multidrug efflux pump AcrB was constructed as a host and the yddA gene was knocked out in wild-type (WT) and drug-sensitive E. coliΔacrB to study the yddA function. Sensitivity to different substrates of WT E.coli, E. coliΔyddA, E. coliΔacrB and E. coliΔacrBΔyddA strains was compared with minimal inhibitory concentration (MIC) assays and fluorescence tests. MIC assay and fluorescence test results showed that YddA protein was a multidrug efflux pump that exported multiple substrates. Three inhibitors, ortho-vanadate, carbonyl cyanide m-chlorophenylhydrazone (CCCP), and reserpine, were used in fluorescence tests. Ortho-vanadate and reserpine significantly inhibited the efflux and increased accumulation of ethidium bromide and norfloxacin, while CCCP had no significant effect on YddA-regulated efflux. The results indicated that YddA relies on energy released from ATP hydrolysis to transfer the substrates and YddA is an ABC-type multidrug exporter. Functional study of unknown ATP-binding cassette (ABC) superfamily transporters in the model organism E. coli is conducive to discovering new multidrug resistance-reversal targets and providing references for studying other ABC proteins of unknown function.

Properties of Low Operating Voltage MFS Devices Using Ferroelectric $LiNbO_3$ Film ($LiNbO_3$ 강유전체 박막을 이용한 저전압용 MFS 디바이스의 특징)

  • Kim, Kwang-Ho;Jung, Soon-Won;Kim, Chae-Gyu
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.36D no.11
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    • pp.27-32
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    • 1999
  • Metal-ferroelectric-semiconductor devices by susing rapid thermal annealed $LiNbO_3/Si$(100) structures were fabricated and demonstrated nonvolatile memory operations. The estimated field-effect electron mobility and transconductance on a linear region of the fabricated FET were about $600cm^2/V{\cdot}s$ and 0.16mS/mm, respectively. The ID-VG characteristics of MFSFET's showed a hysteresis loop due to the ferroelectric nature of the $LiNbO_3 films. The drain current of the on state was more than 4 orders of magnitude larger than the off state current at the same read gate voltage of 0.5V, which means the memory operation of the MFSFET. A write voltage as low as ${\pm}3V$, which is applicable to low power integrated circuits, was used for polarization reversal. The ferroelectric capacitors showed no polarization degradation up to $10^{10}$ switching cycles with the application of symmetric bipolar voltage pulse (peak-to-peak 6V, 50% duty cycle) of 500kHz.

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An Investigation of the Phenomenon of the Decentralization of the Asian Look and its Method (아시안 룩의 탈중심화 현상과 그 기법에 대한 연구)

  • Seo, Bong-Ha
    • Journal of the Korean Society of Costume
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    • v.61 no.2
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    • pp.20-31
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    • 2011
  • Decentralization is an effort to liberalize people from its character of neutralizing or restraining people while indwelling in the previous thought system. Decentralization in fashion is one of the phenomenon of post-modernism fashion, and it is closely related to de-culturalism, crossover, abolition of rank, and etc, and it is in line with Asian look which includes orientalism fashion. The study intends to consider the Phenomenon of Decentralization of Asian Look and its Method depicted in the western fashion. The study focuses on documentary data, and the it is held with the basis of Asian look shown in western fashion. If ideology which influenced the formation of folk costume of Asia, Asian look is the dissolution of such ideology, and post-modern amusement is substituting it. The most conspicuous characteristic of decentralization phenomena of Asian look is pastiche which is a combination and reallocation of external style of many cultural zones and many folk costumes, and it shows mutual irrelevance, and it is a neutral imitation which has internal meaning and humor disappeared. Also, Asian look shows characteristics of parody and irony, which are reversal characteristics of aesthetic value which is expressed through methods of addition, modification, distortion, exaggeration, inversion, dissolution, and etc. Parody which is expressed through imitation regarding previous style shows effect of humor or satire, but its characteristics show that it expresses respect or admiration regarding the original The method of irony is showing sarcasm with ironical method regarding the peculiar style of Asian folk costume, and it pursues unexpected shock and joy, and it is closely related to orientalism fashion. Expansion and constancy of Asian look reflects the interest regarding folk of Asia and Asia, and it is a movement which intends new attempt by abolishing stereotype, and furthermore, it is expressing liberty of humans.

Effects of Polyamine Inhibitors and Polyamines on the Adventitious Root Formation from Soybean Cotyledons (Polyamine 합성 저해제와 Polyamine이 대두 자엽 부정근의 형성에 미치는 영향)

  • 한태진;이동원;이순희
    • Korean Journal of Plant Tissue Culture
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    • v.21 no.2
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    • pp.105-110
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    • 1994
  • In order to study on the effect of polyamine inhibitors and polyamines on adventitious root formation the correlation between adventitious root formation and polyamine levels were investigated in cultured soybean (Glycine max L.) cotyledons. Adventitious root formation was inhibited in medium containing 10$^{-4}$ -10/ sup -2/ M polyamine inhibition such as $\alpha$-difluoromethylornithine (DFMO), $\alpha$-difluoromethylarginine (DFMA), cyclohexylammonium sulfate (CHA), dicyclohexyl-amine (DCHA) and methylglyoxal-bis (guanylhydrazone) (MGBG). An inhibitory effects at 10$^{-3}$ M MCBG were much higher than other treatments. Treatment with 10$^{-3}$ M MGBG plus 10$^{-5}$ M spermine led to reversal of the effects of MGBG alone. The polyamine levels were sharply increased in the first few days in each treatnent compared to control. The remarkably increasing polyamine contents were observed in medium supplemented spermine.

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Pharmacological Activities of Paecilomyces japonica, A New Type Cordyceps sp. (눈꽃 동충하초의 약물활성)

  • Shim, Jin-Young;Lee, Yeon-Sil;Lim, Soon-Sung;Hyun, Jin-Ee;Kim, Seung-Yeun;Lee, Eun-Bang;Shin, Kuk-Hyun
    • Korean Journal of Pharmacognosy
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    • v.31 no.2
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    • pp.163-167
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    • 2000
  • Cordyceps is reputed for its broad biological activities and as a tonic for replenishing vital function in Chinese traditional medicines. As an attempt to obtain fundamental data for the development of a new type Cordyceps, the effects of the fruiting bodies of cultivated fungus of Paecilomyces japonica grown on silkworm larvae on hyperglycemia induced by streptozotocin(STZ) and by epinephrine in rats and in mice as well as on immunological functions in mice were investigated. The 70% methanol extract of the fungus, when administered orally at 100 and 300 mg/kg in STZ-induced hyperglycemic rats, caused a significant decrease in blood glucose level 3hr after sample treatments. The methanol extract, when administered p.o. at the same dose levels in epinephrine-induced hyperglycemic mice, also caused a significant decrease in serum glucose levels as well as a significant reversal of the liver glycogen contents suggesting its hypoglycemic activity might be due to glycogen breakdown in the liver. Treatment of normoglycaemic mice with the methanol extract of the fungus exhibited a significant glucose tolerance up to 3hr after oral glucose load(2.0 g/kg). The methanol extract also showed immuno-stimulating activity as measured by carbon clearance in mice and a significant antifatigue effect as measured by weight loaded forced swimming performance in mice.

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