• Title/Summary/Keyword: Screening effect

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Review on Electric-field Transparent Conduct Electrodes Based on Nanomaterials (나노 소재 기반의 전기장 투과 전극에 관한 연구동향)

  • Lee, Jae Hyung;Shin, Jae Hyeok;Lee, Sang Il;Park, Won Il
    • Journal of the Microelectronics and Packaging Society
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    • v.27 no.1
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    • pp.9-15
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    • 2020
  • The 'field-effect' underlies the operation of most conventional electronic devices. However, effective control and implementation of the field-effect in semiconductor devices are limited due to screening of the electric-field by conducting electrodes. Thus far, the electronic devices have necessarily been designed to avoid or minimize the electric-field screening effect. As an alternative approach to this, a new type of conducting electrodes which would be transparent to both visible light and electric-field while being electrically conductive have been developed. Here, we define these electrodes as 'electric-field transparent electrodes' and provide a review on related work. Particular attention is paid to the material selection and design strategies to enhance the electric-field transparency of the electrodes while maintaining good electrical conductivity and optical transparency. We then introduce potential applications of the electric-field transparent electrodes in electronic and optoelectronic devices.

The Screening of Antioxidant Activity in some Korean Medicinal Plants (한국 약식동원 식물자원의 항산화 활성 비교)

  • Park Hong Ju;Lee Sung Hyeon;Kim Dae Ik;Hur Eun Young;Cho Soo Muk
    • The Korean Journal of Community Living Science
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    • v.15 no.4
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    • pp.11-16
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    • 2004
  • This study was conducted to find the powerful free radical scavenging effect in methanol extracts from 35 kinds of Korean medicinal plants obtained from the Plant Extract Bank as natural plant products. Antioxidant activity of the plant extracts was determined by measuring the scavenging effect of 1,1-diphenyl-2-picryl hydrazyl radical (DPPH). In the screening of plant extracts tested, at 200 ppm level, almost all plantex tracts showed significantly high antionidant activity. In the reinvestigation of 15 kinds of Korean medicinal plants at 50 ppm level selected as good sources with good free radical scavenging effect at 200 ppm level, the DPPH scavenging effects were similar to those of L-ascorbic acid in whole plant extract of Fragaria yezoensis (90.4%), in the plant stems and roots extract of Gingko biloba, and the leaves extract of Rhododendron mucronulatum var. ciliatum (90%). The fruits extract of Cornus officinalis showed the strongest antioxidant activity (95%). These results suggest that the methanol extracts from Korean medicinal plants can be a potential source of antioxidants that can be used to control oxidative stress in the body, But further study is needed to measure their safety for consumption

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Screening for Chemosensitizers from Natural Plant Extracts through the Inhibition Mechanism of P-glycoprotein

  • Ahn, Hee-Jeong;Song, Im-Sook
    • Journal of Pharmaceutical Investigation
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    • v.40 no.5
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    • pp.269-275
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    • 2010
  • P-gp plays a critical role in drug disposition and represents a mechanism for the development of multidrug resistance. Flavonoids, a major class of natural compounds widely present in foods and herbal products, have been shown to inhibit P-gp. Therefore, the aim of this study was to identify new candidate chemosensitizers by screening various plant extracts. The ability of natural plant extracts to inhibit P-gp activity was assessed by measuring cellular accumulation of calcein AM, daunorubicin and vincristine in P-gp overexpressing MDCKII-MDR1 cells. Among more than 800 plant extracts, eight were found to inhibit P-gp activity. Curcuma aromatica extract produced greatest inhibition, followed by Curcuma longa and Dalbergia odorifera extracts. Extracts of Aloe ferox, Curcuma zedoariae rhizome, Zanthoxylum planispinum, and Ageratum conyzoides showed moderate inhibitory effects. Curcumin and quercetin exhibited similar inhibition of P-gpmediated efflux of daunorubicin and vincristine, and flavones had a lesser effect. When chemosensitizing effect was evaluated by measuring daunorubicin sensitivity to MDCKII-MDR1 cells in the presence of natural plant extracts, Curcuma aromatica showed the most potent chemosensitizing effect based on daunorubicin cytotoxicity. In conclusion, natural plant extracts such as Curcuma aromatica can potently inhibit P-gp activity and may have potential as a novel chemosensitizers.

Anti-Helicobacter pylori Effect of Costunolide Isolated from the Stem Bark of Mgnolia Sieboldii

  • Park, Jong-Beak;Lee, Chong-Kyo;Park, Hee-Juhn
    • Archives of Pharmacal Research
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    • v.20 no.3
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    • pp.275-279
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    • 1997
  • Helicobacter pylori (H. pylorl) infection is now established as the major pathogenic factor in chronic gastritis and peptic ulcer disease. in addition, there is accumulating evidence that H. pylori plays an important role in the process of gastric carcinogenesis. On the other hand, oriental traditional medicines have been used for stomach disease for thousands of years. In the present study, methanol extract from the stem bark of Magnolia sieboldii (M. sieboldii) and its components were investigated on their inhibitory effects against urease activity and growth of H. pylori in vitro. The methanol extract of M. sieboldii significantly inhibited the growth of H. pylori ATCC 43504 at 5 mg/ml. From the further fractionation, the chloroform fraction inhibited the bacterial growth dose-dependently. Among four fractions separated from the chloroform fraction by silica gel column chromatography, MS-C-2 was the most potent. Costunolide was isolated from the MS-C-2 subtraction by preparative TLC and recrystallization using n-hexane. Anti-H. pylori effect of costunolide was investigated using one commercial strain (H. pylori ATCC 43504) and three clinical strains (H. pylon 4, 43, 82548). Costunolide exhibited potent anti-H. pylori activity, and the MIC was around $100-200{\mu}g/ml$. However, costunolide had no inhibitory effect of H. pylori urease activity at the concentration used for the growth inhibition assay. From these results, we conclude that costunolide inhibits the, growth of H. pylori by the independent manner of H. pylori urease inhibition.

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Correlations between Obesity and Blood Pressure, Smoking and Drinking Habits (비만지표와 혈압, 음주, 흡연과의 상관관계)

  • Lee, Byeong-Yee;Jang, Gun
    • Journal of Korean Medicine for Obesity Research
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    • v.6 no.2
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    • pp.85-94
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    • 2006
  • Objectives : To examine the correlation between obesity and blood pressure, smoking and drinking (define drinking: do you mean alcohol?) habit in adolescence. Methods : Data collected on 524 subjects from among Kyungwon University students who had participated in a health screening test were reviewed. With the exception of 20 subjects whose health status was deemed to be abnormal based on current illness or results of the health screening test, 504 healthy cases were analysed. We investigated the correlation between obesity as defined by BMI and blood pressure, smoking and drinking habit. Results : 1. The blood pressure of the obese group was high. 2. blood pressure was higher in smokers, and drinking did not influence blood pressure. 3. Smoking had an effect on obesity and drinking had no significant effect on obesity. Conclusions : Obesity is related to blood pressure and smoking habit. Drinking had no significant effect on obesity and blood pressure in this sample.

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The Psychological Effect of Visual and Auditory Stimuli on the Road Traffic Noise (시청각 정보에 의한 도로교통소음의 심리적 저감효과)

  • Jang, Gil-Soo;Baek, Gun-Jong;Song, Min-Jeong;Shin, Hoon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.11a
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    • pp.1177-1182
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    • 2007
  • This study aims at identifying the effect of preferred visual and auditory stimuli on the road traffic noise perception through the series of psychoacoustic experiments. The first experiment was designed to find the addition effect of a sound reproducing system in a square where lay adjacent to roads with road traffic noise, provide appropriate music corresponding to the varying conditions of weather in the given space. In result, it was found that the rating around the square improved toward more positive adjectives. The second experiment was designed to assess the visual effect of twelve roadsides with different landscapes on the road traffic noise perception. As a result, approx. 3 to 5 dB(A) of psychological reduction was seen in places where natural landscape was preferred, compared to the others, although the noise levels were similar. The third experiment was designed to evaluate the effect of visual screen from adjacent roads on road traffic noise perception by means of ME method in a laboratory. In result, the effect of psychological reduction was observed at 65dB(A) or lower. Especially, complete screening from adjacent roads led to 5 to 10% of loudness reduction effect, compared to non-screening cases. Finally, the fourth experiment was designed to evaluate the effect of visual and auditory information with ME method and 7-point SD rating scale in a laboratory. In result, up to 10% of loudness reduction and about 2dB(A) of noise perceptional reduction were seen at 65dB(A) or lower.

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Success of a Cervical Cancer Screening Program: Trends in Incidence in Songkhla, Southern Thailand, 1989-2010, and Prediction of Future Incidences to 2030

  • Sriplung, Hutcha;Singkham, Phathai;Iamsirithaworn, Sopon;Jiraphongsa, Chuleeporn;Bilheem, Surichai
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.22
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    • pp.10003-10008
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    • 2014
  • Background: Cervical cancer has been a leading female cancer in Thailand for decades, and has been second to breast cancer after 2007. The Ministry of Public Health (MoPH) has provided opportunistic screening with Pap smears for more than 30 years. In 2002, the MoPH and the National Health Security Office provided countrywide systematic screening of cervical cancer to all Thai women aged 35-60 years under universal health care coverage insurance scheme at 5-year intervals. Objectives: This study characterized the cervical cancer incidence trends in Songkhla in southern Thailand using joinpoint and age period cohort (APC) analysis to observe the effect of cervical cancer screening activities in the past decades, and to project cervical cancer rates in the province, to 2030. Materials and Methods: Invasive and in situ cervical cancer cases were extracted from the Songkhla Cancer Registry from 1990 through 2010. Age standardized incidence rates were estimated. Trends in incidences were evaluated by joinpoint and APC regression models. The Norpred package was modified for R and was used to project the future trends to 2030 using the power of 5 function and cut trend method. Results: Cervical cancer incidence in Songkhla peaked around 1998-2000 and then dropped by -4.7% per year. APC analysis demonstrated that in situ tumors caused an increase in incidence in early ages, younger cohorts, and in later years of diagnosis. Conclusions: Both joinpoint and APC analysis give the same conclusion in continuation of a declining trend of cervical cancer to 2030 but with different rates and the predicted goal of ASR below 10 or even 5 per 100,000 women by 2030 would be achieved. Thus, maintenance and improvement of the screening program should be continued. Other population based cancer registries in Thailand should analyze their data to confirm the success of cervical cancer screening policy of Thailand.

The Effect of Screening of Stomach Cancer on Stage Shift (위암의 조기검진에 의한 병기이전(stage shift) 효과)

  • Koo, Jung-Wan;Park, Cho-Hyun;Han, Ji-Youn;Chung, In-Sik;Paik, Nam-Sun;Kim, Hoon-Kyo;Lee, Won-Chul
    • Journal of Preventive Medicine and Public Health
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    • v.33 no.1
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    • pp.25-30
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    • 2000
  • Objectives : This study was performed to evaluate the effect of stage shift according to screening of stomach cancer. Methods : Total 840 cases of stomach cancer patients, undergone a surgical operation at Department of Surgery, Kangnam St. Mary's Hospital, The Catholic University of Korea from Jan. 1989 to Dec. 1995, were reviewed by stomach cancer working sheet, and classified as asymptomatic and symptomatic group based on the presence of subjective symptoms on their hospital visit. Their histopathologic stages were analysed. We compared the histopathologic stages of asymptomatic stomach cancer patients with those of symptomatic patients. Results : From the total of 840 patients, asymptomatic patients group comprised 28 cases (3.3%). Proportion of asymptomatic patients tended to increase from 1.9% in 1990, 0.9% in 1991 to 8.6% in 1995. Proportions of asymptomatic patients by stages were 78.6% (stage I), 3.6% (stage III), 17.9% (stage IV) and that of symptomatic patients by stages were 38.2% (stage I), 16.5% (stage II), 24.8% (stage III), 19.1% (stage IV). In less than 40 years old, 50.5% of symptomatic patients were diagnosed as stage I. With increment of ages, proportions of stage I were makedly decreased. It was significantly different between proportion of early gastric cancer in asymptomatic patients (60.1%) and that in symptomatic patients (25.0%). Conclusions : We confirmed stage shift according to screening of stomach cancer. And proportion of early gastric cancer in asymptomatic patients was higher than that in symptomatic patients. This results suggest that screening of gastric cancer be important to reduce mortality and if be indirectly started from 40 years old.

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Breast cancer screening rates-related factors Korea women ever considering area environmental characteristics: The fourth Korea National Health and Nutrition Examination Survey(KNHANES IV) (지역 환경적 요인이 한국 여성의 유방암 조기검진 수검률에 미치는 영향 : 국민건강영양조사 제 4기를 중심으로)

  • Lee, Mi-Hwa;Kim, Sang-Hyun
    • Journal of Digital Convergence
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    • v.12 no.11
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    • pp.437-449
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    • 2014
  • In this study, we analyzed an effect of area-environmental factor on breast cancer screening rates using multi-level analysis. It was intended for the KNHANES-IV. Total subjects were 14338. Among them, 4143 subjects met the inclusion criteria. When we applied only empty Model, a variance of breast cancer screening rates was 0.061 in each region. When we applied Model with individual level variables, the variance was 0.034. However, when we applied both Model with individual level variables and Model with area level variables, the variance was 0.023. We drew applied only individual level variables parallel applied 3 regional variances which could explain variance of inspection of breast cancer up to 18.04% compared with applied only individual level variables. Area level variables could reduce a variance of region. This means besides individual level variables. The group can share a same thing and can effect to breast cancer screening rates. We need to discover factors which area level variables and suggest that make a standard for inspection of breast cancer.

Anti-herpetic Activity of Various Medicinal Plant Extracts

  • Woo, Eun-Rhan;Kim, Hyoung-Ja;Jong, Hwan-Kwak;Lim, Young-Kwern;Park, Seong-Kyu;Kim, Hae-Soo;Lee, Chong-Kyo;Park, Hokoon
    • Archives of Pharmacal Research
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    • v.20 no.1
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    • pp.58-67
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    • 1997
  • In order to find antiviral compounds against Herpes simplex virus type I (HSV-1) and II (HSV2) from natural products, a convenient virus-induced cytopathic effect (CPE) inhibition assay was introduced. More than 300 fractions were prepared by solvent fractionation from sixty collected plants or purchased herbal medicines, and their anti-herpetic activities were evaluated. Among them, several medicinal plants showed potent anti-herpetic activity. Selective indexes (SI) of the EtOAc extract of Caraganae Radix (Caragana sinica) against HSV-1 and HSV-2 were more than 8.06 and 24.79, SI of the MeOH extract of Acer okamotoanum leaves were 3.92 and 3.51, SI of the $CH_{2}Cl_{2}$ extract of Veratri Rhizoma et Radix (Veratrum patulum) were 5.49 and 1.31 and SI of the MeOH extract of aerial part of Osmundae Rhizoma (Osmunda japonica) were more than 3.45 and 1.25, respectively.

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