• Title/Summary/Keyword: quantitative models

Search Result 1,006, Processing Time 0.023 seconds

A Combined Pharmacophore-Based Virtual Screening, Docking Study and Molecular Dynamics (MD) Simulation Approach to Identify Inhibitors with Novel Scaffolds for Myeloid cell leukemia (Mcl-1)

  • Bao, Guang-Kai;Zhou, Lu;Wang, Tai-Jin;He, Lu-Fen;Liu, Tao
    • Bulletin of the Korean Chemical Society
    • /
    • v.35 no.7
    • /
    • pp.2097-2108
    • /
    • 2014
  • Chemical feature based quantitative pharmacophore models were generated using the HypoGen module implemented in DS2.5. The best hypothesis, Hypo1, which was characterized by the highest correlation coefficient (0.96), the highest cost difference (61.60) and the lowest RMSD (0.74), consisted of one hydrogen bond acceptor, one hydrogen bond donor, one hydrophobic and one ring aromatic. The reliability of Hypo1 was validated on the basis of cost analysis, test set, Fischer's randomization method and GH test method. The validated Hypo1 was used as a 3D search query to identify novel inhibitors. The screened molecules were further refined by employing ADMET, docking studies and visual inspection. Three compounds with novel scaffolds were selected as the most promising candidates for the designing of Mcl-1 antagonists. Finally, a 10 ns molecular dynamics simulation was carried out on the complex of receptor and the retrieved ligand to demonstrate that the binding mode was stable during the MD simulation.

Hologram Based QSAR Analysis of Caspase-3 Inhibitors

  • Sathya., B
    • Journal of Integrative Natural Science
    • /
    • v.11 no.2
    • /
    • pp.93-100
    • /
    • 2018
  • Caspases, a family of cysteinyl aspartate-specific proteases plays a central role in the regulation and the execution of apoptotic cell death. Caspase-3 has been proven to be an effective target for reducing the amount of cellular and tissue damage because the activation of caspases-3 stimulates a signalling pathway that ultimately leads to the death of the cell. In this study, Hologram based Quantitative Structure Activity Relationship (HQSAR) models was generated on a series of Caspase-3 inhibitors named 3, 4-dihydropyrimidoindolones derivatives. The best HQSAR model was obtained using atoms, bonds, and hydrogen atoms (A/B/H) as fragment distinction parameter using hologram length 61 and 3 components with fragment size of minimum 5 and maximum 8. Significant cross-validated correlation coefficient ($q^2=0.684$) and non cross-validated correlation coefficients ($r^2=0.754$) were obtained. The model was then used to evaluate the eight external test compounds and its $r^2_{pred}$ was found to be 0.559. Contribution map show that presence of pyrrolidine sulfonamide ring and its bulkier substituent's makes big contributions for improving the biological activities of the compounds.

HQSAR Study of Tricyclic Azepine Derivatives as an EGFR (Epidermal Growth Factor Receptor) Inhibitors

  • Chung, Hwan-Won;Lee, Kyu-Whan;Oh, Jung-Soo;Cho, Seung-Joo
    • Molecular & Cellular Toxicology
    • /
    • v.3 no.3
    • /
    • pp.159-164
    • /
    • 2007
  • Stimulation of epidermal growth factor receptor (EGFR) is essential in signaling pathway of tumor cells. Thus, EGFR has intensely studied as an anticancer target. We developed hologram quantitative structure activity relationship (HQSAR) models for data set which consists of tricyclic azepine derivatives showing inhibitory activities for EGFR. The optimal HQSAR model was generated with fragment size of 6 to 7 while differentiating fragments having different atom and connectivity. The model showed cross-validated $q^2$ value of 0.61 and non-cross-validated $r^2$ value of 0.93. When the model was validated with an external set excluding one outlier, it gave predictive $r^2$ value of 0.43. The contribution maps generated from this model were used to interpret the atomic contribution of each atom to the overall inhibition activity. This can be used to find more efficient EGFR inhibitors.

Development of a Mathematical Model for Simulating Removal Mechanisms of Heavy Metals using Biocarrier Beads (미생물 담체를 이용한 납 제거기작 모의를 위한 수학적 모델의 개발)

  • Seo, Hanna;Lee, Minhee;Wang, Sookyun
    • Journal of Soil and Groundwater Environment
    • /
    • v.18 no.4
    • /
    • pp.8-18
    • /
    • 2013
  • Biocarrier beads with dead biomass, Bacillus drentensis, immobilized in polymer polysulfone were synthesized to remove heavy metals from wastewater. To identify the sorption mechanisms and theoretical nature of underlying processes, a series of batch experiments were carried out and a mathematical model was developed to quantify the biosorption of Pb(II) by the biocarrier beads. A series of mass balance equations for representing mass transfer of metal sorbents in biocarrier beads and surrounding solution were established. Major model parameters such as external mass transfer coefficient and maximum sorption capacity, etc. were determined from pseudo-first-order kinetic models and Langmuir isotherm model based on kinetic and equilibrium experimental measurements. The model simulation displays reasonable representations of experimental data and implied that the proposed model can be applied to quantitative analysis on biosorption mechanisms by porous granular beads. The simulation results also confirms that the biosorption of heavy metal by the biocarrier beads largely depended on surface adsorption.

Field Strength Prediction Program Using Terrain and Land Usage Data for Cheju (제주의 지형 및 토지이용 데이터를 이용한 전계강도 예측 프로그램)

  • 홍성욱;김흥수
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.9 no.6
    • /
    • pp.824-832
    • /
    • 1998
  • The significant additional path loss is caused by scattering, diffraction, and attenuation of propagation. Most of the wave propagation models for rural areas mainly have considered the influence of topography but ignored the effects due to land usage. The goal of this paper is development of the field strength prediction program for Cheju which is used the contour map and the effects due to land usage. In oder to classify the propagation path and divide the environment of land, data of the terrain and the land-cover are formed into a pixel. Two-ray model is transformed into equivalent model by the predicted reflection coefficient and the slope of terrain. For non line of sight, the additional loss is determined by quantitative analysis. The result show good accord and the wave propagation model program can be applied to predicted the service region in rural area of Cheju.

  • PDF

Quantitative Assessment of Nonpoint Source Load in Nakdong River Basin

  • Kwon, Heon-Gak;Lee, Jae-Woon;Yi, Youn-Jeong;Cheon, Se-Uk
    • Journal of Environmental Science International
    • /
    • v.23 no.1
    • /
    • pp.7-23
    • /
    • 2014
  • This study estimates unit for the nonpoint source(NPS), classified according to the existing Level-1(large scale) land cover map, by monitoring the measurement results from each Level-2(medium scale) land cover map, and verifies the applicability by comparison with previously calculated units using the Level-1 land cover map. The NPS pollutant loading for a basin is evaluated by applying the NPS pollutant unit to Dongcheon basin using the Level-2 land cover map. In addition, the BASINS/HSPF(Better Assessment Science Integrating point & Non-point Sources/Hydrological Simulation Program-Fortran) model is used to evaluate the reliability of the NPS pollutant loading computation by comparing the loading during precipitation in the Dongcheon basin. The NPS pollutant unit for the Level-2 land cover map is computed based on precipitation measured by the Sangju observatory in the Nakdong River basin. Finally, the feasibility of the NPS pollutant loading computation using a BASINS/HSPF model is evaluated by comparing and analyzing the NPS pollutant loading when estimated unit using the Level-2 land cover map and simulated using the BASINS/HSPF models.

A Study on the Individual and Societal Risk Estimation for the Use and Storage Facility with Toxic Materials (독성물질 사용.저장시설에 대한 개인적 위험성 산정에 관한 연구)

  • Kim, S.B.;Kim, Y.H.;Lee, C.;Um, S.I.;Ko, J.W.;Baek, J.B.
    • Journal of the Korean Society of Safety
    • /
    • v.12 no.1
    • /
    • pp.51-59
    • /
    • 1997
  • These days leakage incidents of toxic materials cause serious effects on the nearby residents as well as the workers around the accidents accompanying massive material losses and human damages through widening influential areas. The risk measure through adequate quantitative analysis as well as the qualitative analysis of the leakage incidents of toxic materials becomes an urgent issue. The damage of the leakage incident on the surrounding area of the dangerous toxic material facilities was calculated quantitatively by adopting several models in this research. First, the calculations of the leakage velocity from the factories were performed by using source model for the assessment of the influential area, and the damages on the nearly residents were calculated by using the dispersion model and the effort model. The probability of the Incidents was computed based on "The manual for classification and priorization of major incidents" published by IAEA( International Atomic Energy Agency ). Above calculated damage area and incident probability were further adopted in this study to induce the individual and societal risk, quantitatively. The calculated data of the real Incident of the toxic material leakage showed reasonable agreements to the actual damage of the incidents, which showed a validity of this study. The result of this study might be a helpful measure for predicting damages and preparing safety systems for similar kinds of incidents.incidents.

  • PDF

Investigation of the Wing Design and Performance of a Gliding Flying Fish (글라이딩하는 날치의 날개형상 및 성능에 관한 연구)

  • Park, Hyung-Min;Choi, Hea-Cheon
    • 한국전산유체공학회:학술대회논문집
    • /
    • 2008.03b
    • /
    • pp.97-100
    • /
    • 2008
  • Various flyers in nature have attracted great interests with a recent need for developing versatile and small-size flight vehicles. In the present study, we focus on the flying fish which has been observed to glide a long distance just above a seawater surface. Since previous studies have depended on the field observation or measurement of the physical parameters only, quantitative data of the flying fish flight has not been provided so far. Therefore, we evaluate the wing performance of the flying fish in gliding flight by directly measuring the lift, drag and pitching moment on real flying fish models (Cypselurus hiraii) in a wind tunnel. In addition, we investigate the roles of wing morphology like the enlarged pectoral and pelvic fins, and lateral dihedral angle of pectoral fins. With both the pectoral and pelvic fins spread, the lift-to-drag ratio is larger and the longitudinal static stability is enhanced than those with the pelvic fins folded. From the glide polar, we find that the wing performance of flying fish is equivalent to those of medium-size birds like the petrel, hawk and wood duck. Finally, we examine the effect of water surface underneath the flying fish and find that the water surface reduces the drag and increases the lift-to-drag ratio.

  • PDF

Relationships between Fatty Acid Intake and Serum Lipids in Postmenopausal Women (폐경 후 여성의 지방산 섭취실태와 혈청 지질농도와의 관련성)

  • 이보경
    • Journal of Nutrition and Health
    • /
    • v.32 no.4
    • /
    • pp.437-447
    • /
    • 1999
  • The intake of fatty acids, and the effects of fatty acid intake patterns on serum lipid concentrations was investigated in 112 postmenopausal women. Dietary intakes of fatty acids were assessed by means of a semi-quantitative food questionnaire with food models and other measuring tools. The intakes of saturated fatty acid(SFA), monounsaturated fatty acid(MFA) and polyunsaturated fatty acid(PUFA) were 10.85g, 11.89g and 12.09g, respectively. The ratios of P/M/S and $\omega$6/$\omega$3 fatty acid were 1.19 : 1.10 : 1 and 6.65 ; 1, respectively. Serum lipid concentrations were adjusted for age, menopausal period, BMI, stress scores, exercise habit and energy intake and the relationship between fatty acid intake and serum lipids was measured using Pearson's correlation coefficient. Serum cholesterol concentration was positively correlated with dietary intake of SFA (p<0.10), MUFA(p<0.05), palmitic acid(p<0.10), stearic acid(p<0.05), oleic aicd(p<0.05), and arachidonic acid(p<0.10). Serumk LDL-cholesterol concentration was positively correlated with MUFA(p<0.10), oleic acid(p<0.10), oleic acid(p<0.10), and arachidonic acid (p<0.10). Serum triglyceride concentration was positively correlated with arachidonic acid(p<0.10). However, serum HDL-cholesterol concentration was not found to be significantly correlated with any fatty acids.

  • PDF

Mapping a Quantitative Trait Locus for Growth and Backfat on Porcine Chromosome 18

  • Wu, X.L.;Lee, C.;Jiang, J.;Peng, Y.L.;Yang, S.L.;Xiao, B.N.;Liu, X.C.;Shi, Q.S.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.14 no.12
    • /
    • pp.1665-1669
    • /
    • 2001
  • A QTL was localized near S0120 on porcine chromosome 18. The QTL was significant (p<0.05) for average daily gain (ADG) of body weight and backfat thickness (BFT). The estimates of additive and dominance effects for the QTL were 0.0135 kg/day (p<0.001) and 0.0138 kg/day (p>0.5) for ADG and 1.6115 mm (p<0.001) and 0.9281 mm (p>0.05) for BFT. The location of this QTL coincided with a few growth hormone pathway genes. This study suggested that a QTL allele probably resulted from a mutation responsible for physiological lipase deficiency favoring obesity. This QTL might be important to obesity as well as growth in pigs.