Effect of Stevia rebaudiana on the Bioactive Compounds from Agarwood Leaf (Aquilaria spp.) by Lactic Fermentation and Spray Drying

( Lieu My Dong ),( Doan Trung Nam ),( Tran Thi Phuong ),( Dang Kim Thuy ) 한국미생물생명공학회(구 한국산업미생물학회) 2021 한국미생물·생명공학회지 Vol.49 No.2

Agarwood (Aquilaria spp) has high economic value. However, essential oil production from agarwood is a time-consuming process. Additionally, agarwood leaves have not been utilized even though they contain various bioactive ingredients. In this study, agarwood leaves were fermented using Lactobacillus plantarum ATCC 8014 with or without Stevia (4, 8, and 12%; v/v). The fermented fluid was mixed with maltodextrin (15%; w/v) and subjected to spray drying (inlet temperature, 120℃; outlet temperature, 65-70℃). The contents of polyphenols, polysaccharides, saponins, and flavonoids and the viability of L. plantarum were determined. Fermentation enhanced the levels of bioactive compounds. The contents of polyphenol (69.19 ± 4.05 mg GAE/g of sample), polysaccharide (20.75 ± 0.98 mg GE/g of sample), saponin (305.23 ± 4.21 mg OAE/g of sample), and flavonoid (7.86 ± 0.72 mg QE/g of sample), and the viability of L. plantarum (8.72 ± 0.17 log CFU/ml) were markedly upregulated in the samples containing Stevia (12%; v/v). This indicated that the supplementation of Stevia during fermentation decreases the fermentation time (9 h), upregulates bioactive compound production in agarwood leaves, enhances microencapsulation during spray drying, and increases the viability of L. plantarum under simulated gastric digestion conditions.

A multi-resolution approach for multi-material topology optimization based on isogeometric analysis

Lieu, Qui X.,Lee, Jaehong Elsevier 2017 Computer methods in applied mechanics and engineer Vol.323 No.-

<P><B>Abstract</B></P> <P>A novel multi-resolution scheme to perform the multi-material topology optimization in the framework of isogeometric analysis (IGA) is proposed. To create high resolution optimized designs with a lower computational cost, a new variable parameter space is supplemented to define design density variables and represent the optimal material distribution utilizing the bivariate B-spline basis functions. These functions are simply obtained by k -refinement strategy in the IGA. The non-uniform rational B-spline (NURBS) basis functions are employed to exactly describe geometric domains and approximate unknown solutions in finite element analysis (FEA) as well. An alternating active-phase algorithm associated with the block Gauss–Seidel method is employed to convert a multiphase topology optimization problem under multiple volume fraction constraints into many binary phase topology optimization sub-problems with only one volume fraction constraint. Accordingly, the number of design variables depends only on one active phase in each of those sub-problems regardless of the number of material phases and is significantly decreased in comparison with the original problem. The Optimality Criteria (OC) method is used as an optimizer to update solutions for such sub-problems. The effectiveness and robustness of the proposed method are verified via testing various benchmark examples.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A novel multi-material multi-resolution topology optimization (MTOP) scheme using isogeometric analysis (IGA) is proposed. </LI> <LI> A new variable parameter space is added to perform IGA-based MTOP. </LI> <LI> The proposed method associated with the alternating active-phase algorithm is presented first. </LI> <LI> Several benchmark problems are tested for validation of the present method. </LI> </UL> </P>

L’Analyse de la théorie d’André Antoine

LIEU Ji-Mi(류지미) 한국프랑스문화학회 2008 프랑스문화연구 Vol.17 No.-

프랑스 자연주의 연극의 선구자 앙드레 앙투안(André Antoine)의 사상은 현대 연극의 발전에 미친 영향이 크다. “연출은 그 시대의 유행을 따른다”라고 한 그의 주장은 시대별 연극의 구조 속에서, 기술적인 면에서 행해진 수많은 스타일들을 통해서, 각각의 세대별 연출가들의 작업을 통하여 입증되었다. 수많은 연출가들의 작업은 그들의 성향에 따라 각자의 색깔을 가지고 범주화된다. 여기서 앙투안이 자신의 연극 연출 개념을 통하여 일으켰던 연극적인 혁명은 연출사에 근본적인 변화의 초석을 마련한다. 그는 당대에 만연해 있던 낡은 구습의 연극적 관례(convention théâtrale)를 거부했다. 그가 주된 연출작업의 사상으로 사용한 자연주의는 그 당시 상연되었던 드라마들이 연극적인 고민 없이 관객들의 입맛에 맞추어 무작위로 무대에 오르는 것에 대해 고발하는 입장을 취했다. 오랜 연구 끝에 앙투안은 현실에서 퍼 올린 듯한 무대를 재현하는 데 성공한다. 앙투안은 그 시대의 기준에 비추어 상연불가로 여겨지던 작품들을 무대에 올리는 기염을 토하기도 했다. 그가 창시한 자유 극장 (Théâtre libre)은 영국과 독일에 그와 유사한 운동을 유도 해 냈고 그가 욕망하던 연극 텍스트 의 문학적 수용을 실현 시키던 장이 되기도 했다. 또한 그는 자신의 예술세계의 한 축으로 ‘제4의 벽’에 대한 각별한 인식을 가지고 있었다. 현대 연출가의 대부로서 명실 공히 자리 잡은 앙투안은 죽는 날까지 자신이 시작한 현대연극을 관찰하고 비평하는 자세를 늦추지 않았다. 현대를 살아가면서 현대적인 감각을 무시하고 연출 작업을 할 수 없는 연출가의 입장에서 그의 사상과 활동 등을 되돌아보며 오늘날 연출의 상황을 정리해 보고자 한다.

Identification of proteins affected by iron in saccharomyces cerevisiae using proteome analysis

Lieu, Hae-Youn,Song, Hyung-Seok,Yang, Seung-Nam,Kim, Jae-Hwan,Kim, Hyun-Joong,Park, Young-Doo,Park, Cheon-Seok,Kim, Hae-Yeong 경희대학교식량자원개발연구소 2007 硏究論文集 Vol.26 No.1

Shape and size optimization of functionally graded sandwich plates using isogeometric analysis and adaptive hybrid evolutionary firefly algorithm

Lieu, Qui X.,Lee, Jaewook,Lee, Dongkyu,Lee, Seunghye,Kim, Donghyun,Lee, Jaehong Elsevier 2018 Thin-Walled Structures Vol.124 No.-

<P><B>Abstract</B></P> <P>The paper presents an effective methodology for modeling and simultaneously optimizing the layer thicknesses (shape) and the ceramic volume fraction distribution (size) of functionally graded (FG) sandwich plates under free vibration in the framework of isogeometric analysis (IGA). The multi-patch B-spline basis functions separately defined in each of the layer thicknesses are used to represent the ceramic volume fraction distribution. Accordingly, the <SUP> C 0 </SUP> − continuity at layer interfaces can be naturally satisfied without any additional conditions. Furthermore, this multi-patch B-spline representation still ensures the continuously and smoothly varying material properties across each layer thickness. The effective material properties are then estimated by either the rule of mixture or the Mori-Tanaka scheme. A non-uniform rational B-splines (NURBS)-based isogeometric finite element model associated with the third-order shear deformation theory (TSDT) is utilized for the plate free vibration analysis. A recently developed adaptive hybrid evolutionary firefly algorithm (AHEFA) with the improvement on the convergence speed and the solution accuracy is employed as an optimizer. Design variables are the layer thicknesses and the ceramic volume fractions at control points located in the thickness direction. Several numerical examples of two types of optimization problems of the FG sandwich plates, including (i) the first natural frequency maximization with volume constraints, and (ii) mass minimization with frequency constraints, are presented to illustrate the effectiveness and reliability of the proposed method.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Shape and size optimization of FG sandwich plates under free vibration is presented. </LI> <LI> Multi-patch B-spline-based volume fraction representation is introduced first. </LI> <LI> TSDT-based IGA is utilized for the plate free vibration analysis. </LI> <LI> The AHEFA is employed as an optimizer. </LI> <LI> Two types of optimization problems are examined. </LI> </UL> </P>

A reliability-based optimization approach for material and thickness composition of multidirectional functionally graded plates

Lieu, Qui X.,Lee, Jaehong Elsevier Science Ltd 2019 Composites Part B, Engineering Vol.164 No.-

<P><B>Abstract</B></P> <P>A reliability-based design optimization (RBDO) methodology is first proposed to simultaneously optimize material and thickness distribution of multidirectional functionally graded (MFG) plates for compliance minimization under uncertainties of design variables and system parameters. The modified sequential optimization and reliability assessment (MSORA) method is integrated into the recently suggested adaptive hybrid evolutionary firefly algorithm (AHEFA) to release a novel RBDO approach which is the so-called MSORA-AHEFA. The MSORA is refined from its original for computational cost savings by eliminating the iterative process of finding most probable points (MPPs). An isogeometric multimesh design (IMD) approach is presented to form two separate non-uniform rational B-spline (NURBS) surfaces via the k − refinement strategy. In which, a coarser design NURBS one is employed to define design variables of the ceramic volume fraction and z − axis coordinate of the top side coincidentally assigned at each of control points. A finer analysis NURBS one constructed by the isogeometric analysis (IGA) and a generalized shear deformation theory (GSDT) is used for bending analyses of MFG plates with arbitrary thickness. Applying such two separately defined surfaces dramatically lessens the number of design variables and the computational cost in optimization problems, yet still manifesting optimal profiles properly. Meanwhile, mechanical behavior of the plate in analysis ones is precisely simulated as well. For the validation of the suggested MSORA-AHEFA, its results for the benchmark welded beam are compared with those of formerly published work. Several numerical examples regarding RBDO of MFG plates are then executed to attest the effectiveness of the current paradigm.</P>

Effect of Lactic Fermentation and Spray Drying Process on Bioactive Compounds from Ngoc Linh Ginseng Callus and Lactobacillus plantarum Viability

( Lieu My Dong ),( Nguyen Thi Thuy Linh ),( Nguyen Thi Hoa ),( Dang Thi Kim Thuy ),( Do Dang Giap ) 한국미생물 · 생명공학회 2021 한국미생물·생명공학회지 Vol.49 No.3

Ngoc Linh ginseng is one of the most valuable endemic medicinal herbs in Vietnam. In this study, Ngoc Linh ginseng callus was fermented by Lactobacillus plantarum ATCC 8014 (at 6, 7, and 8 log CFU/ml) to evaluate the extraction efficiency of bioactive compounds. The post-fermentation solution was spray-dried using maltodextrin with or without Stevia rebaudiana (3% and 6% v/v) as the wall material. Bioactive compounds such as polyphenols, polysaccharides, and total saponins, and L. plantarum viability during fermentation and after spray-drying, as well as under simulated gastric digestion, were evaluated in this study. The results showed that probiotic density had a significant effect on bioactive compounds, and L. plantarum at 8 log CFU/ml showed the best results with a short fermentation time compared to other tests. The total content of polyphenols, polysaccharides, and saponins reached 5.16 ± 0.18 mg GAE/g sample, 277.2 ± 6.12 mg Glu/g sample, and 4.17 ± 0.15 mg/g sample, respectively after 20 h of fermentation at the initial density of L. plantarum (8 log CFU/ml). Although there was no difference in the particle structure of the preparation, the microencapsulation efficiency of the bioactive compound in the samples containing S. rebaudiana was higher than that with only maltodextrin. The study also indicated that adding S. rebaudiana improved the viability of L. plantarum in gastric digestion. These results showed that S. rebaudiana, a component stimulating probiotic growth, combined with maltodextrin as a co-prebiotic, improved the survival rate of L. plantarum in simulated gastric digestion.

Modeling and optimization of functionally graded plates under thermo-mechanical load using isogeometric analysis and adaptive hybrid evolutionary firefly algorithm

Lieu, Qui X.,Lee, Jaehong Elsevier 2017 COMPOSITE STRUCTURES -BARKING THEN OXFORD- Vol.179 No.-

<P><B>Abstract</B></P> <P>The paper presents an effective numerical approach for modeling and optimizing the ceramic volume fraction distribution of functionally graded (FG) plates in the thermo-mechanical environment. Ceramic volume fraction design variables at control points whose coordinates are located along the plate thickness by <I>Greville abscissae</I> are used to describe the material distribution using the B-spline basis functions. Continuously altering macroscopic material properties can therefore be easily captured by selecting a proper order of these B-spline functions without any extra terms. The temperature-dependent material properties are then evaluated by either the rule of mixture or the Mori-Tanaka scheme. A non-uniform rational B-splines (NURBS)-based isogeometric finite element model associated with the third-order shear deformation theory (TSDT) is utilized for the static analysis of the FG plates. A recently proposed adaptive hybrid evolutionary firefly algorithm (AHEFA) is employed to solve compliance minimization problems with volume constraints. This algorithm effectively enhances the trade-off between the global and local search abilities, the solution accuracy and the convergence speed are thus improved dramatically. Several numerical examples are examined to confirm the effectiveness and robustness of the present method.</P>

Identification of proteins affected by iron in saccharomyces cerevisiae using proteome analysis

Lieu, Hae-Youn,Song, Hyung-Seok,Yang, Seung-Nam,Kim, Jae-Hwan,Kim, Hyun-Joong,Park, Young-Doo,Park, Cheon-Seok,Kim, Hae-Yeong 경희대학교 생명자원과학연구원 2007 생명자원과학연구원 연구논문집 Vol.26 No.-

Two new species of Camellia (Theaceae) from Vietnam

Lieu Thi Nguyen,Ninh Tran,Uematsu CHIYOMI,Katayama HIRONORI,Dung Van Luong,Son Thanh Hoang,Ky Danh NGUYEN,Hung Viet NGUYEN,Toan Canh THAI 한국식물분류학회 2018 식물 분류학회지 Vol.48 No.2

Two new species of Camellia (Theaceae) are described from Vietnam: Camellia vuquangensis Luong, Tran & L. T. Nguyen and Camellia hatinhensis Luong, Tran & L. T. Nguyen. The new taxa were col- lected from Vu Quang National Park in the center of Vietnam. The new finds are morphologically dissimilar to all known Camellia species. Recent Camellia discoveries have increased the number of species recorded in Viet- nam from 50 to 75, making Vietnam a center of diversity and a crucial area for more research into the diversity and distributions of Camellia.