• Title/Summary/Keyword: Fixed Effect Analysis

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CO2 Mineral Carbonation Reactor Analysis using Computational Fluid Dynamics: Internal Reactor Design Study for the Efficient Mixing of Solid Reactants in the Solution (전산유체역학을 이용한 이산화탄소 광물 탄산화 반응기 분석: 용액 내 고체 반응물 교반 향상을 위한 내부 구조 설계)

  • Park, Seongeon;Na, Jonggeol;Kim, Minjun;An, Jinjoo;Lee, Chaehee;Han, Chonghun
    • Korean Chemical Engineering Research
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    • v.54 no.5
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    • pp.612-620
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    • 2016
  • Aqueous mineral carbonation process, in which $CO_2$ is captured through the reaction with aqueous calcium oxide (CaO) solution, is one of CCU technology enabling the stable sequestration of $CO_2$ as well as economic value creation from its products. In order to enhance the carbon capture efficiency, it is required to maximize the dissolution rate of solid reactants, CaO. For this purpose, the proper design of a reactor, which can achieve the uniform distribution of solid reactants throughout the whole reactor, is essential. In this paper, the effect of internal reactor designs on the solid dispersion quality is studied by using CFD (computational fluid dynamics) techniques for the pilot-scale reactor which can handle 40 ton of $CO_2$ per day. Various combination cases consisting of different internal design variables, such as types, numbers, diameters, clearances and speed of impellers and length and width of baffles are analyzed for the stirred tank reactor with a fixed tank geometry. By conducting sensitivity analysis, we could distinguish critical variables and their impacts on solid distribution. At the same time, the reactor design which can produce solid distribution profile with a standard deviation value of 0.001 is proposed.

Prognostic Impact of Elevation of Vascular Endothelial Growth Factor Family Expression in Patients with Non-small Cell lung Cancer: an Updated Meta-analysis

  • Zheng, Chun-Long;Qiu, Chen;Shen, Mei-Xiao;Qu, Xiao;Zhang, Tie-Hong;Zhang, Ji-Hong;Du, Jia-Jun
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.5
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    • pp.1881-1895
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    • 2015
  • Background: The vascular endothelial growth factor family has been implicated in tumorigenesis and metastasis. The prognostic value of each vascular endothelial growth factor family member, particular VEGF/VEGFR co-expression, in patients with non-small lung cancer remains controversial. Materials and Methods: Relevant literature was identified by searching PubMed, EMBASE and Web of Science. Studies evaluating expression of VEGFs and/or VEGFRs by immunohistochemistry or ELISA in lung cancer tissue were eligible for inclusion. Hazard ratios (HRs) and 95% confidence intervals (CIs) from individual study were pooled by using a fixed- or random-effect model, heterogeneity and publication bias analyses were also performed. Results: 74 studies covering 7,631 patients were included in the meta-analysis. Regarding pro-angiogenesis factors, the expression of VEGFA (HR=1.633, 95%CI: 1.490-1.791) and VEGFR1 (HR=1.924, 95%CI: 1.220-3.034) was associated separately with poor survival. Especially, VEGFA over-expression was an independent prognostic factor in adenocarcinoma (ADC) (HR=1.775, 95%CI: 1.384-2.275) and SCC (HR=2.919, 95%CI: 2.060-4.137). Co-expression of VEGFA/VEGFR2 (HR=2.011, 95%CI: 1.405-2.876) was also significantly associated with worse survival. For lymphangiogenesis factors, the expression of VEGFC (HR=1.611, 95%CI: 1.407-1.844) predicted a poor prognosis. Co-expression of VEGFC/VEGFR3 (HR=2.436, 95%CI: 1.468-4.043) emerged as a preferable prognostic marker. Conclusions: The expression of VEGFA (particularly in SCC and early stage NSCLC), VEGFC, VEGFR1 indicates separately an unfavorable prognosis in patients with NSCLC. Co-expression VEGFA/VEGFR2 is comparable with VEGFC/VEGFR3, both featuring sufficient discrimination value as preferable as prognostic biologic markers.

Effect of Ce Addition on Catalytic Activity of Cu/Mn Catalysts for Water Gas Shift Reaction (수성가스전이반응(Water Gas Shift Reaction)을 위한 Ce 첨가에 따른 Cu/Mn 촉매의 활성 연구)

  • PARK, JI HYE;IM, HYO BEEN;HWANG, RA HYUN;BAEK, JEONG HUN;KOO, KEE YOUNG;YI, KWANG BOK
    • Transactions of the Korean hydrogen and new energy society
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    • v.28 no.1
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    • pp.1-8
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    • 2017
  • Cu/Mn/Ce catalysts for water gas shift (WGS) reaction were synthesized by urea-nitrate combustion method with the fixed molar ratio of Cu/Mn as 1:4 and 1:1 with the doping concentration of Ce from 0.3 to 0.8 mol%. The prepared catalysts were characterized with SEM, BET, XRD, XPS, $H_2$-TPR, $CO_2$ TPD, $N_2O$ chemisorption analysis. The catalytic activity tests were carried out at a GHSV of $28,000h^{-1}$ and a temperature range of 200 to $400^{\circ}C$. The Cu/Mn(CM) catalysts formed Cu-Mn mixed oxide of spinel structure ($Cu_{1.5}Mn_{1.5}O_4$) and manganese oxides ($MnO_x$). However, when a small amount of Ce was doped, the growth of $Cu_{1.5}Mn_{1.5}O_4$ was inhibited and the degree of Cu dispersion were increased. Also, the doping of Ce on the CM catalyst reduced the reduction temperature and the base site to induce the active site of the catalyst to be exposed on the catalyst surface. From the XPS analysis, it was confirmed that maintaining the oxidation state of Cu appropriately was a main factor in the WGS reaction. Consequently, Ce as support and dopant in the water gas shift reaction catalysts exhibited the enhanced catalytic activities on CM catalysts. We found that proper amount of Ce by preparing catalysts with different Cu/Mn ratios.

An Analysis of Bed Change Characteristics by Bed Protection Work (바닥보호공 설치에 따른 하상변동 특성 분석)

  • Son, Ah Long;Kim, Byung Hyun;Moon, Bo Ram;Han, Kun Yeun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.35 no.4
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    • pp.821-834
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    • 2015
  • This study presents the analysis of flow and bed change characteristics considering bed protection work built on the immediate downstream of weir to protect river bed from scouring. The study area is 37km reach from Hyunpoong station to Masuwon station including Hapcheon- Changryoung multi-function weir in the Nakdong river. CCHE2D model is calibrated and validated for evaluating the flow and bed change characteristics during Typhoon Kompasu in 2010. Three simulation conditions are set up: Case 1 is a natural channel without installation of weir. Case 2 involves an installation of weir in the natural channel. Case 3 involves an installation of weir with bed protection in the natural channel. Flood frequency (50, 100 and 200yr) is applied to each scenario to analyze the effects of bed protection work. While the sediment rate is increased in the downstream of fixed gate and sluice-type gate, river bed scouring rate is increased in the downstream of lift-type gate in Case 2 comparing with the results of Case 1. The river bed scouring is not occurred in the immediate downstream of weir (~30m) due to the effect of bed protection, but larger amount of sediment is occurred in the downstream of weir (60m~) which the bed protection is not installed comparing with the results Case 1. Through the results of simulation considering bed protection work, this study would be helpful to expect bed change and operate the weir as well as manage.

Estimation of Medical Ultrasound Attenuation using Adaptive Bandpass Filters (적응 대역필터를 이용한 의료 초음파 감쇠 예측)

  • Heo, Seo-Weon;Yi, Joon-Hwan;Kim, Hyung-Suk
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.47 no.5
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    • pp.43-51
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    • 2010
  • Attenuation coefficients of medical ultrasound not only reflect the pathological information of tissues scanned but also provide the quantitative information to compensate the decay of backscattered signals for other medical ultrasound parameters. Based on the frequency-selective attenuation property of human tissues, attenuation estimation methods in spectral domain have difficulties for real-time implementation due to the complexicity while estimation methods in time domain do not achieve the compensation for the diffraction effect effectively. In this paper, we propose the modified VSA method, which compensates the diffraction with reference phantom in time domain, using adaptive bandpass filters with decreasing center frequencies along depths. The adaptive bandpass filtering technique minimizes the distortion of relative echogenicity of wideband transmit pulses and maximizes the signal-to-noise ratio due to the random scattering, especially at deeper depths. Since the filtering center frequencies change according to the accumulated attenuation, the proposed algorithm improves estimation accuracy and precision comparing to the fixed filtering method. Computer simulation and experimental results using tissue-mimicking phantoms demonstrate that the distortion of relative echogenicity is decreased at deeper depths, and the accuracy of attenuation estimation is improved by 5.1% and the standard deviation is decreased by 46.9% for the entire scan depth.

The Effect of CYP2D6/3A5 Genotypes on Plasma Concentrations of Haloperidol after Adjunctive Treatment of Aripiprazole

  • Shim, Joo-Cheol;Ahn, Jung-Mi;Jung, Do-Un;Kong, Bo-Geum;Kang, Jae-Wook;Liu, Kwang-Hyeon;Shin, Jae-Gook
    • Korean Journal of Biological Psychiatry
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    • v.18 no.2
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    • pp.95-100
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    • 2011
  • Objectives To evaluate the drug interactions between aripiprazole and haloperidol, authors investigated plasma concentrations of those drugs by genotypes. Method Fifty six patients with a confirmed Diagnostic and Statistical Manual of Mental Disorders 4th edition diagnosis of schizophrenia were enrolled in this eight-week, double blind, placebo-controlled study. Twenty-eight patients received adjunctive aripiprazole treatment and twenty-eight patients received placebo while being maintained on haloperidol treatment. Aripiprazole was dosed at 15 mg/day for the first 4 weeks, and then 30 mg for the next 4 weeks. The haloperidol dose remained fixed throughout the study. Plasma concentrations of haloperidol and aripiprazole were measured by high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) at baseline, week 1, 2, 4 and 8. $^*1$, $^*5$, and $^*10$ B alleles of CYP2D6 and $^*1$ and $^*3$ alleles of CYP3A5 were determined. The Student's T-test, Pearson's Chi-square test, Wilcoxon Rank Sum test and Logistic Regression analysis were used for data analysis. All tests were two-tailed and significance was defined as an alpha < 0.05. Results In the frequency of CYP2D6 genotype, $^*1/^*10$ B type was most frequent (36.5%) and $^*1/^*1$ (30.8%), $^*10B/^*10B$ (17.3%) types followed. In the frequency of CYP3A5 genotype, $^*3/^*3$ type was found in 63.5% of subjects, and $^*1/^*3$ type and $^*1/^*1$ were 30.8% and 5.8% respectively. The plasma levels of haloperidol and its metabolites did not demonstrate significant time effects and time-group interactions after adjunctive treatment of aripiprazole. The genotypes of CYP2D6 and 3A5 did not affect the plasma concentration of haloperidol in this trial. No serious adverse event was found after adding aripiprazole to haloperidol. Conclusion No significant drug interaction was found between haloperidol and aripiprazole. Genotypes of CYP2D6 and 3A5 did not affect the concentration of haloperidol after adding aripiprazole.

Estimating the Determinants for Transaction Value of B2B (Business-to-Business): A Panel Data Model Approach (패널 데이터모형을 이용한 기업간전자상거래 거래액 결정요인 추정에 관한 연구)

  • Kim, Hee-Cheul;Shin, Hyun-Dae
    • Journal of the Korea Society of Computer and Information
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    • v.15 no.11
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    • pp.225-231
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    • 2010
  • Transaction value of business-to-business(B2B) is composed of various factors for groups and time series. In this paper, we use the panel data for finding various variables and using this we analyse the factors that is major influence to transaction value of business-to-business. For analysis we looked at transaction value of business-to-business of 7 groups such as manufacturing industry, electric, gas and piped water industry, construction industry, retail & wholesale trade, traffic industry, publish, image; broad-casting & telecommunication and information service industry, etc. In our analysis we looked at the transaction value of business-to-business during the period from 2005.01 to 2009.12. We examined the data in relation to the transaction value of cyber shopping mall, company bond, composite stock price index, transaction value of credit card, loaned rate of interest in deposit bank, rate of exchange looking at the factors which determine the transaction value of business-to-business, evidence was produced supporting the hypothesis that there is a significant positive relationship between the transaction value of cyber shopping mall, composite stock price index and loaned rate of interest in deposit bank, rate of exchange. The company bond is negative relationship, transaction value of credit card is positive relationship and they are not significant variables in terms of the transaction value of business-to-business.

Long-term Trend Analysis of Key Criteria Air Pollutants over Air Quality Control Regions in South Korea using Observation Data and Air Quality Simulation (관측자료와 대기질 모사를 이용한 주요 기준성 대기오염물질의 권역별 장기변화 분석)

  • Ju, Hyeji;Kim, Hyun Cheol;Kim, Byeong-Uk;Ghim, Young Sung;Shin, Hye Jung;Kim, Soontae
    • Journal of Korean Society for Atmospheric Environment
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    • v.34 no.1
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    • pp.101-119
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    • 2018
  • In this study, we analyzed long-term measurements and air quality simulation results of four criteria air pollutants ($PM_{10}$, $O_3$, $NO_2$, and $SO_2$) for 10 years, from 2006 to 2015, with emphasis on trends of annual variabilities. With the observation data, we conducted spatial interpolation using the Kriging method to estimate spatial distribution of pollutant concentrations. We also performed air quality simulations using the CMAQ model to consider the nonlinearity of the secondary air pollutants such as $O_3$ and the influence of long-range transport. In addition, these simulations are used to deduce the effect of long-term meteorological variations on trends of air quality changes because we fixed the emissions inventory while changing meteorological inputs. The nation-wide inter-annual variability of modeled $PM_{10}$ concentrations was $-0.11{\mu}g/m^3/yr$, while that of observed concentrations was $-0.84{\mu}g/m^3/yr$. For the Seoul Metropolitan Area, the inter-annual variability of observed $PM_{10}$ concentrations was $-1.64{\mu}g/m^3/yr$ that is two times rapid improvement compared to other regions. On the other hand, the inter-annual variability of observed $O_3$ concentrations is 0.62 ppb/yr which is larger than the simulated result of 0.13 ppb/yr. Magnitudes of differences between the modeled and observed inter-annual variabilities indicated that decreasing trend of $PM_{10}$ and increasing trend of $O_3$ are more influenced by emissions and oxidation states than meteorological conditions. We also found similar patterns in $NO_2$. However, $NO_2$ trends showed greater regional and seasonal differences than other pollutants. The analytic approach used in this study can be applicable to estimate changes in factors determining air quality such as emissions, weather, and surrounding conditions over a long term. Then analysis results can be used as important data for air quality management planning and evaluation of the chronic impact of air quality.

Effects of Electrical Stimulation on the Mast Cell of Skin in Rats (전기자극이 흰쥐의 피부 비만세포에 미치는 영향)

  • Lee Jae-Hyoung;Jekal Seung-Joo;Park Seung-Teack
    • The Journal of Korean Physical Therapy
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    • v.11 no.3
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    • pp.81-87
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    • 1999
  • The purpose of this study was to determine the effect of electrical stimulation on the number of MCs and percent of degranulated MCs in rat skin. Twelve male Sprague-Dawley rats were divided into two group; electrical stimulation group (n=6) and control group (n=6). Each animals hair on the back was removed. The electrical stimulation group received an positive rectangular pulsed electrical stimulation, while the control group was given the same treatment without electricity. The biopsy specimens were fixed in formalin, embedded in paraffin and stained with toluidine blue-nuclear fast red and alcian blue-safranin O. respectively. The MCs were counted using a light microscope and computerized image analysis system and calculated as the density and the percent. A t-test showed a significantly higher density of MCs in the electrical stimulated rats than control rats(p<0.05), and the percent of degranulated MCs in the electrical stimulated rats was higher than in the control rats (p<0.05) in toluidine blue stained sections. The density of MCs was significantly higher in the electrical stimulated rats than the control rats in alcian blue-safranin O Stained sections (P<0.01). An analysis of variance showed that the densities of CTMCs was significantly lower than the densities of MMCs and mixed MCs in electrical stimulated rat in alcian blue-safranin O Stained sections (p<0.05). These results suggest that the electrical stimulation may have potential for increasing the number of MCs and lead to degranulate the MCs in rat skin.

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The Efficacy and Safety of Moclobemide Twice Daily : An Open Trial in Patients with Major Depressive Disorder (1회 2회 분복 투여하는 Moclobemide의 효과와 안전성 : 주요우울장애 환자에서 개방 시험)

  • Yoon, Jin-Sang;Lee, Hyung-Young;Kook, Seung-Hee;Choi, Young
    • Korean Journal of Biological Psychiatry
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    • v.3 no.1
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    • pp.102-108
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    • 1996
  • This was an open trial to evaluate the efficacy and safety of moclobemide twice daily for treatment of Korean patients with major depressive disorder(DSM-III-R). The duration of the trial was 6 weeks with the initial dose of moclobemide being fixed lor the first two weeks at 300mg/day(150mg twice daily, each token after morning and evening meals). Thereafter, when necessary, the dose was allowed to increase to 600mg/day or decrease to 150mg/day according to the seventy of the depression and/or the tolerability of the drug. Hypnotics and/or sedatives from a benzodiazepine group could be concomitantly administered at usual dosage. Patients were assessed at baseline and at days 14, 28 and 42. Efficacy was primarily judged on the Hamilton Rating Scale for Depression(HAM-D) and Beck Depression Inventory(BDI). Patients had to score at least 17 respectively an both scales to enter the trial. Secondary efficacy parameters included Clinical Global Impression(CGI) for severity of illness and improvement. Safety and tolerability were judged on reported adverse events, vital signs and laboratory parameters. In addition, there was a series of questions and assessments for the psychiatrists and patients to complete at the end of the trial Twenty nine patients completing trial were included in the analysis of efficacy : of thirty one patients participating in the safety and tolerability analysis, those who withdraw voluntarily without particular reasons or violated the treatment schedule were not included. The efficacies as determined by HAM-D, BDI or CGI were found to be significant compared to baseline. The number of responders defined as patients with a total score of 10 or less or with a total score of 50% or less of the baseline score on HAM-D and BDI were 17(59%) and 18(62%) respectively. Regarding safety and tolerability, nine patients(29%) reported mild adverse events probably related to moclobemide : of these one patient dropped out because of poor tolerability : however, there were no appreciable changes in blood pressure, pulse rate, body weight or laboratory parameters for all patients over the trial period. Furthermore, the physicians' and patients' opinions at final evaluation showed that moclabemide has a good antidepressant effect as well as a favorable tolerability. In conclusion, a twice-daily dosage schedule with maclobemide is recommendable for the treatment of Korean patients with major depressive disorder since its efficacy and safety were demonstrated in this study.

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