• Title/Summary/Keyword: quantitative models

Search Result 1,011, Processing Time 0.023 seconds

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

  • Hashemi, Nooshin;Dabbagh, Reza;Noroozi, Mostafa;Baradaran, Sama
    • Advances in environmental research
    • /
    • v.9 no.1
    • /
    • pp.65-84
    • /
    • 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.

Quantitative Assessment of the Effects of MMP-2 Polymorphisms on Lung Carcinoma Risk

  • Guo, Xiao-Tong;Wang, Jun-Feng;Zhang, Lin-You;Xu, Guang-Quan
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.13 no.6
    • /
    • pp.2853-2856
    • /
    • 2012
  • Background: Previous studies assessing associations between matrix metalloproteinase 2 (MMP-2) polymorphisms and lung cancer risk reported conflicting results. A meta-analysis was therefore performed to derive a more precise estimation. Method: Case-control studies assessing associations between MMP-2 C735T and C1306T polymorphisms and lung cancer risk were included. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were estimated. Results: 7 studies with a total of 3,189 lung cancer cases and 3,013 controls were finally included into this meta-analysis. Overall, the MMP-2 C735T polymorphism was associated with lung cancer risk under the homozygote model (CC versus TT: OR =1.44, 95% CI = 1.03-2.02, $I^2$ = 0%), while the MMP-2 C1306T polymorphism also associated demonstrated links with all four models (all P values less than 0.05). Subgroup analyses by race suggested obvious associations between MMP-2 C735T and C1306T polymorphisms and lung cancer risk in Asians but not in Caucasians. There was no evidence for publication bias. Conclusion: Currently available evidence supports teh conclusion that MMP-2 C735T and C1306T polymorphisms influence susceptibility to lung cancer in Asians.

Development of ACBIO: A Biosphere Template Using AMBER for a Potential Radioactive Waste Repository (AMBER를 이용한 방사성폐기물처분장 생태계 평가 템플릿 ACBIO 개발)

  • Lee Youn-Myoung;Hwang Yongsoo;Kang Chul-Hyung;Hahn Pil-Soo
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
    • /
    • v.3 no.3
    • /
    • pp.213-229
    • /
    • 2005
  • Nuclides in radioactive wastes are assumed to be transported in the geosphere by groundwater and probably discharged into the biosphere. Quantitative evaluation of doses to human beings due to nuclide transport in the geosphere and through the various pathways in the biosphere is the final step of safety assessment of the radioactive waste repository. To calculate the flux to dose conversion factors (DCFs) for nuclides appearing at GBIs with their decay chains, a template ACBIO which is an AMBER case file based on mathematical model for the mass transfer coefficients between the compartments has been developed considering material balance among the compartments in biosphere and then implementing to AMBER, a general and flexible software tool that allows to build dynamic compartment models. An illustrative calculation with ACBIO is shown.

  • PDF

Ligand Design of 5,5'-Diphenylimidazolidine-2,4-dione Analogues as A New Class of Potent Inhibitors of Fatty Acid Amide Hydrolase (새로운 Fatty Acid Amide Hydrolase 저해제로서 5,5'-Diphenylimidazolidine-2,4-dione 유도체의 리간드 설계)

  • Cho, Jong-Un;Soung, Min-Gyu;Sung, Nack-Do
    • Applied Biological Chemistry
    • /
    • v.51 no.2
    • /
    • pp.119-123
    • /
    • 2008
  • 3D-QSARs (3 dimensional quantitative structrue-activity relationships) on the inhibition activities of 3-substituted-5,5'-diphenylimidazolidine-2,4-dione derivatives (1-22) against FAAH (fatty acid amide hydrolase) were studied quantitatively using CoMFA (comparative molecular field analysis) and CoMSIA (comparative molecular similarity indice analysis) methods. The statistical results of the CoMFA 1A and CoMSIA 2F model are better predictability and fitness. And also, the designed X=I, Y=$N_{2}^{+}$-substituent (P1: $Pred.pI_{50}$=6.55), according to the contour maps with information of the two models, showed the most inhibition activity against FAAH.

Analysis of Ventricular Electromechanical Characteristics by Lesions in Sudden Myocardial Infraction: Computer Simulation Study (급성 심근경색 병변에 따른 심실의 전기 역학적 특성 분석: 컴퓨터 시뮬레이션 연구)

  • Baek, Dong Geun;Jeong, Da Un;Lim, Ki Moo
    • Journal of Biomedical Engineering Research
    • /
    • v.38 no.6
    • /
    • pp.313-320
    • /
    • 2017
  • Myocardial infarction is a disease caused by stenosis of the coronary arteries. The high risk of sudden cardiac death due to myocardial infarction has triggered related researches that have been actively studied so far. However, these studies focused on the clinical results, which are mainly based on observations of symptoms due to infarction through electrocardiograms. Therefore, in this study, we tried to analyze the behavior of heart according to the position and volume of infarction lesion through the computer simulation study using three dimensional ventricular models. In order to implement infarction, commercial software was used to simulate cell necrosis due to blockage of a specific coronary. In addition, the conduction block due to infarction was mimicked by reducing the electrical conduction in the infarcted area, which was 100 times less than the electrical conduction of the whole ventricular lattice implemented by the finite element analysis method. Thus, this study classified the infarcted cases into the upper, middle, lower, and apex according to lattice data of eight different infraction areas. In other words, we assumed that myocardial infarction would have inherent electro-dynamic characteristics depending on the location and extent, and analyzed the ventricular electromechanical responses for infarction lesions using a three dimensional cardiac physiome model. The results showed that the volume of infarction did not directly affect the cardiac responses, but the location of the infarction lesions could influence the ventricular pumping efficiency. These suggest that the occlusion of specific coronary arteries may have a fatal effect on the decline in ventricular performance. In conclusion, although location of myocardial infarction lesions is considered to be an important variable to be considered clinically rather than lesion size, quantitative predictions should be made more in the future considering physiological factors such as lesion location and direction of myocardial fiber at that location.

An association of urinary sodium-potassium ratio with insulin resistance among Korean adults

  • Park, Yeong Mi;Kwock, Chang Keun;Park, Seyeon;Eicher-Miller, Heather A.;Yang, Yoon Jung
    • Nutrition Research and Practice
    • /
    • v.12 no.5
    • /
    • pp.443-448
    • /
    • 2018
  • BACKGROUND/OBJECTIVES: This study was conducted to investigate the effects of sodium-potassium ratio on insulin resistance and sensitivity in Korean adults. SUBJECTS/METHODS: Subjects were 3,722 adults (1,632 men and 2,090 women) aged 40-69 years participating in the Korean genome and epidemiology study_Ansan and Ansung study. Insulin resistance was assessed using homeostasis model assessment of insulin resistance (HoMA-IR) and fasting insulin, and insulin sensitivity was assessed by using the quantitative insulin sensitivity check index (QUICKI). The 24-h urinary sodium and potassium excretion were estimated from spot urinary samples using the Tanaka formula. The generalized linear model was applied to determine the association between urinary sodium-potassium ratio and insulin resistance. RESULTS: HoMA-IR (P-value = 0.029, P-trend = 0.008) and fasting insulin (P-value = 0.017, P-trend = 0.005) levels were positively associated with 24-h estimated urinary sodium-potassium ratio in the multivariable model. QUICKI was inversely associated with 24-h estimated urinary sodium-potassium ratio in all models (P-value = 0.0002, P-trend < 0.0001 in the multivariate model). CONCLUSION: The present study suggests that high sodium-potassium ratio is related to high insulin resistance and low insulin sensitivity. Decreasing sodium intake and increasing potassium intake are important for maintaining insulin sensitivity. Further studies are needed to confirm these findings in longitudinal studies.

Chicken consumption and insulin resistance in non-diabetic older adults

  • Yeum, Kyung-Jin;Kim, Young-Sang;Joo, Nam-Seok
    • Journal of Nutrition and Health
    • /
    • v.53 no.4
    • /
    • pp.356-368
    • /
    • 2020
  • Purpose: Histidine-containing dipeptides, which are rich in chicken, have been reported to reduce the risk of metabolic abnormalities via anticarbonylation mechanism in animal models. To determine the effect of dietary histidine-containing dipeptides on metabolic risk factors in humans, the relation between chicken consumption and insulin resistance were determined in a population consuming high carbohydrate and low protein. Methods: A total of 7,183 subjects (2,929 men and 4,254 women) aged ≥ 50 years from the Korea National Health and Nutrition Examination Survey (KNHANES) were divided into three groups according to chicken consumption (rarely, monthly, and weekly), and evaluated for the metabolic risk factors using homeostasis model assessment for insulin resistance (HOMA-IR) and quantitative insulin sensitivity check index (QUICKI) in this cross-sectional study. The fourth and fifth (IV-1-3 & V-1) KNHANES, which had blood insulin data, were chosen for the current study. Results: The chicken consumption was significantly associated with insulin (p for trend = 0.018) and HOMA-IR (p for trend = 0.023) in men. In particular, the 'weekly' chicken consuming men in the lowest tertile (< 65.0%) of carbohydrate intake group had significantly lower HOMA-IR (p for trend = 0.033) and higher QUICKI (p for trend = 0.043) than the 'rarely' intake group. In addition, the odds ratio for abnormal HOMA-IR was 0.55 (95% confidence interval [CI], 0.31-0.99) and QUICKI was 0.47 (95% CI, 0.26-0.86) for the 'weekly' chicken consuming group. Conclusion: The 'weekly' chicken consumption had a beneficial effect on insulin resistance and it may partially be due to the major bioactive components in chicken, histidine-containing dipeptides.

A Study on the System Dynamics Analysis for Human Factors in Ship′s Collision Accidents (시스템 다이내믹스에 의한 선박충돌사고의 인적요인 분석에 관한 연구)

  • Keum, Jong-Soo;Yang, Weon-Jae;Jang, Woon-Jae
    • Journal of Navigation and Port Research
    • /
    • v.27 no.5
    • /
    • pp.493-498
    • /
    • 2003
  • Ship is being operated under a highly dynamic environments and many factors are related with ship's collision and those factors are interacting. So, An analysis on the ship's collision muses is very important to prepare countermeasures which will ensure the safe navigation. And the analysis confirmed that ship's collision is occurred most frequently and the muse is closely related with human factor. The main purpose of this study is to build a model of human factors in ship's collision muse using SD(System Dynamics} approach and to measure a effect which is risk control countermeasures of ship's collision. To achieve this aim, the structure analysis on the muses of ship's collision using FSM are performed, and the structure was changed by quantitative, qualitative factors and their feedback loops in casual map. This model was performed over 20 years(1993-2012) in a standard simulation model and 8 policy simulation models.

Ratio of fat to energy intake independently associated with the duration of diabetes and total cholesterol levels in type 2 diabetes

  • Yim, Jung-Eun;Kim, Young-Seol;Cho, Mi-Ran;Choue, Ryo-Won
    • Nutrition Research and Practice
    • /
    • v.5 no.2
    • /
    • pp.157-162
    • /
    • 2011
  • The importance of dietary intake in the treatment of type 2 diabetes was emphasized. This study was performed to investigate the dietary intakes of Korean type 2 diabetes patients according to the treatment and duration of diabetes and to examine the relationships between their diet and serum lipid profiles. The subjects were 111 type 2 diabetic patients who were treated by medical nutrition therapy only, oral hypoglycemic agents (OHA), or insulin with medical nutrition therapy. Dietary intake was assessed by a registered dietitian using semi-quantitative food frequency questionnaires Comparisons according to treatment type were made using covariance analyses. General linear models identified the independent effects of the different treatments after covarying for age, duration of diabetes, and 2-way interactions. There were no significant differences in age and BMI but was in duration of diabetes according to treatment type in these subjects. Carbohydrate to energy ratio was higher in the OHA group (P < 0.05), whereas the fat to energy ratio was higher in the insulin group for males (P < 0.05). Carbohydrate ($R^2$ = 0.24, P = 0.005) and fat ($R^2$ = 0.26, P = 0.02) to energy ratios were independently associated with the duration of diabetes after covarying for age, sex, treatment, and 2-way interactions. The levels of triglyceride (TG; $R^2$ = 0.32, P = 0.02) and total cholesterol (TC) were associated independently with energy intake and the carbohydrate ($R^2$ = 0.15, P = 0.02) and fat ($R^2$ = 0.15, P = 0.01) to energy ratios, respectively. The concern that the independent association of dietary intake with either duration of diabetes or dietary factors affects blood lipid levels could suggest that specific dietary recommendations may work better for identifiable groups of diabetes patients.

A Methodology for Evaluating the Effects of Transportation Policies Related to Greenhouse Gas Reduction (교통온실가스 감축정책의 효과분석 방법론 연구)

  • LEE, Kyu Jin;YI, Yongju;CHOI, Keechoo
    • Journal of Korean Society of Transportation
    • /
    • v.36 no.1
    • /
    • pp.1-12
    • /
    • 2018
  • The purpose of this study is to establish a methodology for evaluating quantitative effects of transportation GHG (greenhouse gas) reduction-related policies that were implemented based on the reduction goals of transportation GHG and effective implementation plans. This study uses a modal utility function and demand estimation models as well as a GHG emission basic unit estimation model by each transportation mode based on actual traffic and emission data. The results showed that the effects of GHG reduction policies such as electric vary from region to region, and from vehicle to vehicle. It is also confirmed that an eco-drive promotion policy, one of the lowest budget policies, is expected to contribute to high reduction in GHG. In addition, not only automobile emission improvement policies but also the promotion policies of public transportation are expected to highly reduce GHG as confirmed quantitatively in this study. The results of this study are expected to be useful for national and local governments' evaluation of GHG reduction policies to cope with the post 2020.