• Title/Summary/Keyword: R-Q model

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HQSAR Study on Substituted 1H-Pyrazolo[3,4-b]pyridines Derivatives as FGFR Kinase Antagonists

  • Bhujbal, Swapnil P.;Balasubramanian, Pavithra K.;Keretsu, Seketoulie;Cho, Seung Joo
    • Journal of Integrative Natural Science
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    • v.10 no.2
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    • pp.85-94
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    • 2017
  • Fibroblast growth factor receptor (FGFR) belongs to the family of receptor tyrosine kinase. They play important roles in cell proliferation, differentiation, development, migration, survival, wound healing, haematopoiesis and tumorigenesis. FGFRs are reported to cause several types of cancers in humans which make it an important drug target. In the current study, HQSAR analysis was performed on a series of recently reported 1H-Pyrazolo [3,4-b]pyridine derivatives as FGFR antagonists. The model was developed with Atom (A) and bond (B) connection (C), chirality (Ch), hydrogen (H) and donor/acceptor (DA) parameters and with different set of atom counts to improve the model. A reasonable HQSAR model ($q^2=0.701$, SDEP=0.654, NOC=5, $r^2=0.926$, SEE=0.325, BHL=71) was generated which showed good predictive ability. The contribution map depicted the atom contribution in inhibitory effect. A contribution map for the most active compound (compound 24) indicated that hydrogen and nitrogen atoms in the side chains of ring B as well as hydrogen atoms in the side chain of ring C and the nitrogen atom in the ring D contributed positively to the activity in inhibitory effect whereas, the lowest active compound (compound 04) showed negative contribution to inhibitory effect. Thus results of our study can provide insights in the designing potent and selective FGFR kinase inhibitors.

Topomer-CoMFA Study of Tricyclic Azepine Derivatives-EGFR Inhibitors

  • Chung, Jae-Yoon;Pasha, F.A.;Chung, Hwan-Won;Yang, Beom-Seok;Lee, Cheol-Ju;Oh, Jung-Soo;Moon, Myoung-Woon;Cho, Seung-Joo;Cho, Art E.
    • Molecular & Cellular Toxicology
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    • v.4 no.1
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    • pp.78-84
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    • 2008
  • EGFR has been intensively investigated as a target to block the signal transduction pathway which stimulates cancer growth and metastasis. Studies about structure-activity relationship for tricyclic azepine derivatives were performed with topomer-CoMFA. The derived topomer-CoMFA model with steric and electrostatic field parameters based on fragment units gave reasonable statistics ($q^2$=0.561, $r^2$=0.679). The model explains why a halogen atom at the meta position of aniline is important to increases inhibitory activity. This comes from an electrostatically negative groups are favored near this region. The model also shows that there are sterically favored regions around methoxy group extended from oxazepine derivatives. The findings about steric and electrostatic effects can be utilized for designing new inhibitors.

Optimization of uranium biosorption in solutions by Sargassum boveanum using RSM method

  • Hashemi, Nooshin;Dabbagh, Reza;Noroozi, Mostafa;Baradaran, Sama
    • Advances in environmental research
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    • v.9 no.1
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    • pp.65-84
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    • 2020
  • The potential use of Sargassum boveanum algae for the removal of uranium from aqueous solution has been studied by varying three independent parameters (pH, initial uranium ion concentration, S. boveanum dosage) using a central composite design (CCD) under response surface methodology (RSM). Batch mode experiments were performed in 20 experimental runs to determine the maximum metal adsorption capacity. In CCD design, the quantitative relationship between different levels of these parameters and heavy metal uptake (q) were used to work out the optimized levels of these parameters. The analysis of variance (ANOVA) of the proposed quadratic model revealed that this model was highly significant (R2 = 0.9940). The best set required 2.81 as initial pH(on the base of design of experiments method), 1.01 g/L S. boveanum and 418.92 mg/L uranium ion concentration within 180 min of contact time to show an optimum uranium uptake of 255 mg/g biomass. The biosorption process was also evaluated by Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherm models represented that the experimental data fitted to the Langmuir isotherm model of a suitable degree and showed the maximum uptake capacity of 500 mg/g. FTIR and scanning electron microscopy were used to characterize the biosorbent and implied that the functional groups (carboxyl, sulfate, carbonyl and amine) were responsible for the biosorption of uranium from aqueous solution. In conclusion, the present study showed that S. boveanum could be a promising biosorbent for the removal of uranium pollutants from aqueous solutions.

NON-LTE EFFECTS ON THE H3+ ROVIBRATIONAL POPULATION IN THE JOVIAN IONOSPHERE

  • Kim, Yong-Ha
    • Journal of The Korean Astronomical Society
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    • v.45 no.2
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    • pp.39-48
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    • 2012
  • We investigate non-LTE effects on the $H_3^+$ level populations to help the analysis of the observed 2 and 3.5 micron $H_3^+$ emissions from the Jovian ionosphere. We begin by constructing a simple three-level model, in order to compute the intensity ratio of the R(3,4) line in the hot band to the Q(1,0) line in the fundamental band, which have been observed in the Jovian auroral regions. We find that non-LTE effects produce only small changes in the intensity ratios for ambient $H_2$ densities less than or equal to $5{\times}10^{11}cm^{-3}$. We then construct two comprehensive models by including all the collisional and radiative transitions between pairs of more than a thousand known $H_3^+$ rovibrational levels with energies less than 10000 $cm^{-1}$. By employing these models, we find that the intensity ratios of the lines in the hot and fundamental bands are affected greatly by non-LTE effects, but the details depend sensitively on the number of collisional and radiative transitions included in the models. Non-LTE effects on the rovibrational population become evident at about the same ambient $H_2$ densities in the comprehensive models as in the three-level model. However, the models show that rotational temperatures derived from the intensities of rotational lines in the ${\nu}_2$ and $2{\nu}_2$ bands may differ significantly from the ambie temperatures in the non-LTE regime. We find that significant non-LTE effects appear near and above the $H_3^+$ peak, and that the kinetic temperatures in the Jovian thermospheric temperatures derived from the observed line ratios in the 2 and 3.5 micron $H_3^+$ emissions are highly model dependent.

Comparative Molecular Similarity Indices Analysis (CoMSIA) on the Melanogenesis Inhibitory Activities of Alkyl-3,4-dihydroxy- benzoate and N-alkyl-3,4-dihydroxybenzamide Derivatives.

  • Kim, Sang-Jin;Sung, Nack-Do;Lee, Sang-Ho
    • Proceedings of the SCSK Conference
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    • 2003.09a
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    • pp.733-740
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    • 2003
  • To find a new substance with superior melanogenesis inhibitory activity, the bioactivities of alkyl-3,4-dihydroxy-5-substituted benzoate (A) and N-alkyl-3,4-dihydroxy-5-substituted benzamide (B) derivatives as substrate of tyrosinase were measured in mouse melanoma cells. And the bioactivities analyzed using comparative molecular similarity indices analysis (CoMSIA). From the CoMSIA model, when cross-validation value (q$^2$) is 0.713 at four components, the pearson correlation coefficient ($r^2$) is 0.900. Unknown compounds were predicted, using QSAR analyzed results from the CoMSIA methods. Excellent agreement was obtained between the measured and the predicted bioactivities of unknown compounds. As the results of prediction from CoMSIA, we could conclude that the bioactivities were increased from pl$_{50}$=3.18-4.80 to above 5.17 by creation of 6-methylheptyl, n-pentylphenyl and 2-hydroxypentylphenyl group etc,.,.

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Development of a Gas Mixing System for Controlled Atmosphere(CA) Chambers

  • Yun, Hong-Sun;Lee, Hyun-Dong;Lee, Won-Ock;Chung, Hun;Cho, Kwang-Hwan
    • Agricultural and Biosystems Engineering
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    • v.2 no.1
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    • pp.31-36
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    • 2001
  • Based on the viscous flow characteristics of gas through capillary tube, a simple and cheap gas mixing system was developed for controlling gas compositions in CA chambers. The gas flow rate through capillary tube had a linear relationship with pressure, (length)$^{-1}$ and (radius)$^4$ of capillary tube, which agreed well with Hagen-Poiseuille’s law. The relationship between flow rate and combined parameters was described as Q=0.000209724($\pi$ r$^4$P/$\mu$L) and the coefficient of determination was 0.9984. The developed system could control gas concentrations in CA chambers within $\pm$0.3% deviation compared to the preset concentrations. It was possible to predict the required time and required gas flow rate for exchanging the gs in CA chamber to a certain concentration of gas by using the mathematical model developed in this study.

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The Impact of Intellectual Capital Efficiency on Jordanian Companies Performance: The Moderating Roles of CEO Duality

  • ABDELGHAFOUR JOS, Rawan;MAT HUSIN, Norhayati;ISMAIL HYARAT, Hamza
    • The Journal of Asian Finance, Economics and Business
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    • v.9 no.10
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    • pp.85-96
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    • 2022
  • CEO duality and its impact on firm performance represent one of the most contentious issues in both academia and business. This study, therefore, aims to examine the moderating role of CEO duality in the relationship between intellectual capital Efficiency (human, structural, relational, Capital Employed, and Innovation) and firm performance (earnings per share and Tobin's Q) among Jordanian companies. The study sample consists of services listed companies on Amman Stock Exchange. The study used panel data for the period 2014-2018 with a sample size of 230 observations. SPSS software was used to analyze the collected data. The regression results indicate a significant relationship between, IC and firm performance. When CEO Duality is incorporated into the model as a moderator, there is an increase in the R2 by 7.9%. The findings from this study expand the theoretical underpinning of corporate governance research by identifying the performance implications of CEO duality within the Jordanian context. It also contributes significantly to the literature review about the current status of the practices taken in the intellectual capital components efficiency among companies listed on the Amman Stock Exchange. Findings from this study also provide contributions to the concerned policymakers such as the Ministry of Finance, Securities Commission, and Amman Stock Exchange in Jordan, to improve the current policies related to intellectual capital efficiency.

Development of Prediction Model of Chloride Diffusion Coefficient using Machine Learning (기계학습을 이용한 염화물 확산계수 예측모델 개발)

  • Kim, Hyun-Su
    • Journal of Korean Association for Spatial Structures
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    • v.23 no.3
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    • pp.87-94
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    • 2023
  • Chloride is one of the most common threats to reinforced concrete (RC) durability. Alkaline environment of concrete makes a passive layer on the surface of reinforcement bars that prevents the bar from corrosion. However, when the chloride concentration amount at the reinforcement bar reaches a certain level, deterioration of the passive protection layer occurs, causing corrosion and ultimately reducing the structure's safety and durability. Therefore, understanding the chloride diffusion and its prediction are important to evaluate the safety and durability of RC structure. In this study, the chloride diffusion coefficient is predicted by machine learning techniques. Various machine learning techniques such as multiple linear regression, decision tree, random forest, support vector machine, artificial neural networks, extreme gradient boosting annd k-nearest neighbor were used and accuracy of there models were compared. In order to evaluate the accuracy, root mean square error (RMSE), mean square error (MSE), mean absolute error (MAE) and coefficient of determination (R2) were used as prediction performance indices. The k-fold cross-validation procedure was used to estimate the performance of machine learning models when making predictions on data not used during training. Grid search was applied to hyperparameter optimization. It has been shown from numerical simulation that ensemble learning methods such as random forest and extreme gradient boosting successfully predicted the chloride diffusion coefficient and artificial neural networks also provided accurate result.

Association of SNP Haplotypes at the Myostatin Gene with Muscular Hypertrophy in Sheep

  • Gan, S.Q.;Du, Z.;Liu, S.R.;Yang, Y.L.;Shen, M.;Wang, X.H.;Yin, J.L.;Hu, X.X.;Fei, J.;Fan, J.J.;Wang, J.H.;He, Q.H.;Zhang, Y.S.;Li, N.
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.7
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    • pp.928-935
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    • 2008
  • The myostatin gene of seven important meat (Beltex (Australia), Beltex$\times$Huyang (F1), Meat and Multi-Prolific Chinese Merino Fine Wool, Meat Chinese Merino Fine Wool and Dorper (South Africa)) and non-meat (Huyang and Kazak) sheep breeds was analyzed to study the genetic basis of muscular hypertrophy (double muscling) phenotype in sheep. SNPs, four in regulatory regions and several in the introns in the myostatin gene, were identified, and the former four SNPs were used for further studies. Twelve haplotypes were predicted by PHASE program, of which four main haplotypes (1, 3, 7, 9) were present in 90% of the 364 sheep in the study. Haplotypes 1-4 were mainly present in meat breeds while haplotypes 7 and 9 dominated the non-meat breeds. The association between haplotypes and average daily gain (ADG) was analyzed among 116 sheep with production data, Haplo2 (CGAA) and Haplo8 (TGAA) were identified to have significant (p<0.05) effect on ADG by the model (JMP5.1 software) taking into account the effects of breed, family background, haplotype, birth weight and sex. ADG of these haplotype groups also correlated well (r = 0.82) with hypertrophic phenotype scores. In conclusion, the mutations -956 (T$\rightarrow$C), -41 (C$\rightarrow$A) and 6223 (G$\rightarrow$A) involved in Haplo2 and 8 may be associated with the double-muscling trait by influencing myostatin function and be suitable markers in selecting meat sheep.

ECG Signal Compression based on Adaptive Multi-level Code (적응적 멀티 레벨 코드 기반의 심전도 신호 압축)

  • Kim, Jungjoon
    • Journal of the Korean Institute of Intelligent Systems
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    • v.23 no.6
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    • pp.519-526
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    • 2013
  • ECG signal has the feature that is repeated in a cycle of P, Q, R, S, and T waves and is sampled at a high sampling frequency in general. By using the feature of periodic ECG signals, maximizing compression efficiency while minimizing the loss of important information for diagnosis is required. However, the periodic characteristics of such amplitude and period is not constant by measuring time and patients. Even though measured at the same time, the patient's characteristics display different periodic intervals. In this paper, an adaptive multi-level coding is provided by coding adaptively the dominant and non-dominant signal interval of the ECG signal. The proposed method can maximize the compression efficiency by using a multi-level code that applies different compression ratios considering information loss associated with the dominant signal intervals and non-dominant signal intervals. For the case of long time measurement, this method has a merit of maximizing compression ratio compared with existing compression methods that do not use the periodicity of the ECG signal and for the lossless compression coding of non-dominant signal intervals, the method has an advantage that can be stored without loss of information. The effectiveness of the ECG signal compression is proved throughout the experiment on ECG signal of MIT-BIH arrhythmia database.