Metabolic Syndrome and Insulin Resistance Syndrome among Infertile Women with Polycystic Ovary Syndrome: A Cross-Sectional Study from Central Vietnam

Minh Tam Le,Vu Quoc Huy Nguyen,Quang Vinh Truong,Dinh Duong Le,Viet Nguyen Sa Le,Ngoc Thanh Cao 대한내분비학회 2018 Endocrinology and metabolism Vol.33 No.4

Background: Polycystic ovarian syndrome (PCOS) is one of the most common endocrinopathies among reproductive-age women. Its metabolic features often overlap with those associated with metabolic syndrome (MS) and insulin resistance syndrome (IRS). Theobjective of this study was to determine the prevalence and predictors of MS and IRS in infertile Vietnamese women with PCOS. Methods: A cross-sectional study was conducted at a tertiary fertility centre at Hue University Hospital from June 2016 to November 2017. A total of 441 infertile women diagnosed with PCOS based on the revised 2003 Rotterdam consensus criteria were enrolled. MS and IRS were defined based on the National Heart, Lung, and Blood Institute/American Heart Association Adult Treatment Panel III 2005 and American College of Endocrinology IRS 2003 criteria, respectively. Complete clinical and biochemicalmeasurements of 318 women were available for analysis. Independent predictors of MS and IRS were identified using multivariatelogistic regression. Results: The overall prevalence of MS and IRS in women with PCOS was 10.4% and 27.0%, respectively. We identified older age(>30 years) and obesity as independent predictors of MS and IRS. Elevated anti-Müllerian hormone levels increased the risk of IRS,but not that of MS. Conclusion: MS and IRS are prevalent disorders among infertile Vietnamese women with PCOS. PCOS is not solely a reproductiveproblem. Screening and early intervention for MS and/or IRS based on anthropometric, metabolic, and reproductive hormone riskfactors should be an integral part of fertility care.

A two-stage approach of multiplicative dimensional reduction and polynomial chaos for global sensitivity analysis and uncertainty quantification with a large number of process uncertainties

Minh, Le Quang,Duong, Pham Luu Trung,Goncalves, Jorge,Kwok, Ezra,Lee, Moonyong Elsevier 2017 Journal of the Taiwan Institute of Chemical Engine Vol.78 No.-

<P><B>Abstract</B></P> <P>Uncertainties associated with estimates of model parameters are inevitable when simulating and modeling chemical processes and significantly affect safety, consistency, and decision making. Quantifying those uncertainties is essential for emulating the actual system behaviors because they can change the management recommendations that are drawn from the model. The use of conventional approaches for uncertainty quantification (<I>e.g</I>., Monte-Carlo and standard polynomial chaos methods) is computationally expensive for complex systems with a large/moderate number of uncertainties. This paper develops a two-stage approach to quantify the uncertainty of complex chemical processes with a moderate/large number of uncertainties (greater than 5). The first stage applies a multiplicative dimensional reduction method to approximate the variance-based global sensitivity measures (Sobol's method), and to simplify the model for the uncertainty quantification stage. The second stage uses the generalized polynomial chaos approach to quantify uncertainty of the simplified model from the first stage. A rigorous simulation illustrates the proposed approach using an interface between MATLAB and HYSYS for three complex chemical processes. The proposed method was compared with conventional approaches, such as the Quasi Monte-Carlo sampling-based method and standard polynomial chaos-based method. The results revealed the clear advantage of the proposed approach in terms of the computational efforts.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A two-stage approach of M-DRM and gPC proposed to UQ and SA. </LI> <LI> Sobol's indices detect non-influential inputs with little computational burden. </LI> <LI> The proposed method was compared with conventional gPC/QMC/MC methods. </LI> <LI> The computational cost was reduced by 10–100 times in comparison with the QMC method. </LI> <LI> The proposed method addresses global SA with UQ with large number of uncertain parameters. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

A cost-effective retrofit of conventional distillation sequence to dividing-wall prefractionator configuration

Minh, Le Quang,Pham, Tram Ngoc,Long, Nguyen Van Duc,Shin, Joonho,Lee, Moonyong Elsevier 2018 Computers & chemical engineering Vol.110 No.-

<P><B>Abstract</B></P> <P>A dividing-wall prefractionator configuration was investigated for a safe and economic retrofit of the conventional sequence using simple distillation columns. In the proposed retrofit configuration, the first column was modified to a dividing wall column as a prefractionator to supply prefractionated multi-feeds to the subsequent column. To investigate the effectiveness of the proposed configuration, nine near-ideal feed mixtures were considered for analysis. The proposed configuration was then compared with several other alternative configurations. The proposed dividing-wall prefractionator efficiently generates prefractionated multi-feed streams avoiding feed mismatch and remixing effect with low modification cost. Moreover, because the proposed retrofit configuration allows for flexible switching between the dividing-wall prefractionator and the conventional operating mode, a safe retrofit is also ensured by reducing the operational risks. Several industrial retrofit cases were studied to validate the proposed dividing-wall prefractionator configuration.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A dividing wall prefractionator configuration (DWPC) was studied for safe and cost-effective retrofit. </LI> <LI> A combined optimization method was proposed and applied for reliable design and fair comparison. </LI> <LI> Practical guideline was developed for the potential retrofit of DWPC. </LI> <LI> The performance of proposed DWPC was illustrated through several industrial cases. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Bubble point measurement and high pressure distillation column design for the environmentally benign separation of zirconium from hafnium for nuclear power reactor

Le Quang Minh,Gyeongmin Kim,Jongki Park,이문용 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.1

We examined the feasible separation of ZrCl4 and HfCl4 through high pressure distillation as environmen-tally benign separation for structural material of nuclear power reactor. The bubble point pressures of ZrCl4 and HfCl4mixtures were determined experimentally by using an invariable volume equilibrium cell at high pressure and tempera-ture condition range of 2.3-5.6MPa and 440-490 oC. The experimental bubble point pressure data were correlated withPeng-Robinson equation of state with a good agreement. Based on the vapor-liquid equilibrium properties evaluatedfrom the experimental data, the feasibility of high pressure distillation process for the separation of ZrCl4 and HfCl4was investigated with its main design condition through rigorous simulation using a commercial process simulator,ASPEN Hysys. An enhanced distillation configuration was also proposed to improve energy efficiency in the distillationprocess. The result showed that a heat-pump assisted distillation with a partial bottom flash could be a promising optionfor commercial separation of ZrCl4 and HfCl4 by taking into account of both energy and environmental advantages.

Global Sensitivity Analysis and Uncertainty Quantification of Crude Distillation Unit Using Surrogate Model Based on Gaussian Process Regression

Minh, Le Quang,Duong, Pham Luu Trung,Lee, Moonyong ACS AMERICAN CHEMICAL SOCIETY 2018 INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH - Vol.57 No.14

Global Sensitivity Analysis and Uncertainty Quantification of Crude Distillation Unit Using Surrogate Model Based on Gaussian Process Regression

Minh, Le Quang,Duong, Pham Luu Trung,Lee, Moonyong American Chemical Society 2018 INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH - Vol.57 No.14

<P>This study presents a global sensitivity analysis to simplify a surrogate-model-based uncertainty quantification of a crude distillation unit with a large number of uncertainties. To overcome the computational limitation of a conventional surrogate model-based approach where the number of simulations required grows exponentially as the input dimension increases, a novel two-stage approach was proposed in this study: in the first stage, a multiplicative dimensional reduction method is applied to identify factors that exert the highest influence on the model outputs. In the second stage, the Gaussian process regression is exploited for uncertainty quantification from the simplified model derived in the first stage. As a result, the computational efforts for uncertainty quantification were significantly reduced (approximately more than 95%) compared to the conventional Quasi Monte Carlo, while the predicted density functions by the proposed method closely matched with those from the Quasi Monte Carlo. The proposed two-stage approach was executed for sensitivity analysis and uncertainty quantification of a crude distillation unit by an interface between MATLAB and HYSYS. The economic revenue and the operating cost per unit of crude oil processed were selected as the output of interests for the crude distillation unit. The global sensitivity analysis result showed that the flow rates of crude oil and naphtha products are critical for both the economic revenue and the operating cost.</P> [FIG OMISSION]</BR>

Energy efficiency improvement of dimethyl ether purification process by utilizing dividing wall columns

Le Quang Minh,Moon Yong Lee,Nguyen Van Duc Long 한국화학공학회 2012 Korean Journal of Chemical Engineering Vol.29 No.11

The alternative fuel, dimethyl ether (DME), which can be synthesized from natural gas, coal or biomass syngas, has been traditionally used as a diesel substitute or additive. DME purification processes with a conventional distillation sequence consume a large amount of energy. We used dividing wall columns (DWCs) to improve the energy efficiency and reduce the capital cost of the DME purification process. Various possible DWC arrangements were explored to find the potential benefits derived from thermally coupled distillations. The results show that utilizing DWCs can significantly reduce both the energy consumption and investment cost of the DME purification process. The lower energy consumption also results in the reduction of the CO2 emission.

Ag-doped graphitic carbon nitride photocatalyst with remarkably enhanced photocatalytic activity towards antibiotic in hospital wastewater under solar light

Nguyen Le Minh Tri,김지태,Bach Long Giang,T.M. Al Tahtamouni,Pham Thi Huong,이창하,Nguyen Minh Viet,Do Quang Trung 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.80 No.-

In this study a novel Ag-doped graphitic carbon nitride (g-C3N4) photocatalyst was synthesized and appliedas high efficientmaterial under solarlight towardsemerging antibiotic pollutantin hospital wastewater. Thetetracycline (TC) was chosen as a target pollutant and the content of Ag doping at 3 mmol revealed thehighest photocatalytic degradation efficiency of TC (96.8%) after 120 min under solar light irradiation. Thephotoluminescence and UV–vis analysis confirmed the enhancement of charge separation and transfer inthe graphitic carbon structure after Ag-doping. The removal efficiency of TC using g-C3N4 and Ag-doped g-C3N4 (AgCN) underdark conditions was only 25.6 and 31.8%, respectively. While under solarlight conditions,the removal efficiency of TC increased to 68.3 and 96.8% for g-C3N4 and AgCN, respectively. The reusabilityprocess showed that AgCN displayed extremely high stability after 6 cycles without significant drop inantibiotic degradation efficiency. The application of AgCN was tested for treatment of TC from hospitalwastewater and it showed high removal efficiency of 89.6% within 120 min reaction time. In addition, theintermediatesgeneratedandreductionof total organiccarbon(TOC)duringthephotocatalyticreactionweredetected to support information of possible TC removal mechanism.

Soil Fertility Capability Classification for Rice Soils in the Mekong Delta, Vietnam

Vo Quang Minh,Le Quang Tri 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Study Design for the 2016 Baseline Survey of a Health System Strengthening Project in Quoc Oai District, Hanoi, Vietnam

Van Minh Hoang,오주환,Bao Ngoc Nguyen,Le Minh Dat,이종구,Thi Giang Huong Tran,Van Huy Nguyen,이승표,방경숙,조영태,김선영,이화영,Quang Cuong Le,Narshil Choi,Thai Son Dinh,Ngoc Hoat Luu 대한의학회 2019 Journal of Korean medical science Vol.34 No.5

Background: In order to provide essential scientific evidence on the population's health status and social health determinants as well as the current capacity of the health care system in Vietnam to health policy makers and managers, Vietnam Ministry of Health, Hanoi University of Public Health, Hanoi Medical University, and Ho Chi Minh University of Medicine and Pharmacy collaborated with Seoul National University (Korea) and conducted a health system survey in the Quoc Oai district (of Hanoi capital) that represented northern rural Vietnam. Methods: The study design was a cross-sectional study. The survey covered different topics (more than 200 questions) and was administered in three separate questionnaires: 1) Basic information of all household members; 2) Household characteristics; and 3) Individual characteristics. Socio-demographic characteristics among the households and individuals were collected from 2,400 households sampled by multi-stage cluster sampling method: more than 200 questions. Results: The household size of Quoc Oai was larger than the national average and there was no significant difference in gender composition. In addition, the proportions of pre-elderly, age 55–64, and elderly group (65 years old and over) were higher than the national population statistics. In this context, demographic transition has begun in Quoc Oai. Conclusion: This study design description provides the basic information about a baseline survey of a future prospective cohort (as a part of a collaborative project on strengthening the health system in Vietnam) to the prospective data user of this survey.