A New Strategy to Improve the Efficiency and Sustainability of Candida parapsilosis Catalyzing Deracemization of (R,S)-1-Phenyl-1,2-Ethanediol Under Non-Growing Conditions: Increase of NADPH Availability

( Yao Nie ),( Yan Xu ),( Qing Sen Hu ),( Rong Xiao ) 한국미생물 · 생명공학회 2009 Journal of microbiology and biotechnology Vol.19 No.1

Microbial oxidoreductive systems have been widely used in asymmetric syntheses of optically active alcohols. However, when reused in multi-batch reaction, the catalytic efficiency and sustainability of non-growing cells usually decreased because of continuous consumption of required cofactors during the reaction process. A novel method for NADPH regeneration in cells was proposed by using pentose metabolism in microorganisms. Addition of D-xylose, L-arabinose, or D-ribose to the reaction significantly improved the conversion efficiency of deracemization of racemic 1-phenyl-1,2-ethanediol to (S)-isomer by Candida parapsilosis cells already used once, which afforded the product with high optical purity over 97%e.e. in high yield over 85% under an increased substrate concentration of 15 g/l. Compared with reactions without xylose, xylose added to multi-batch reactions had no influence on the activity of the enzyme catalyzing the key step in deracemization, but performed a promoting effect on the recovery of the metabolic activity of the non-growing cells with its consumption in each batch. The detection of activities of xylose reductase and xylitol dehydrogenase from cell-free extract of C. parapsilosis made xylose metabolism feasible in cells, and the depression of the pentose phosphate pathway inhibitor to this reaction further indicated that xylose facilitated the NADPH-required deracemization through the pentose phosphate pathway in C. parapsilosis. moreover, by investigating the cofactor pool, the xylose addition in reaction batches giving more NADPH, compared with those without xylose, suggested that the higher catalytic efficiency and sustainability of C. parapsilosis non-growing cells had resulted from xylose metabolism recycling NADPH for the deracemization.

Robust Control for Bidirectional Stabilization System With Time Delay Estimation

Shu-sen Yuan,Wen-xiang Deng,Jian-yong Yao,Guo-lai Yang 제어·로봇·시스템학회 2024 International Journal of Control, Automation, and Vol.22 No.4

In this paper, to address the problem of high precision tracking control for bidirectional stabilization system of marching all-electric tank, a continuous nonsingular terminal sliding mode (CNTSM) control method combined with time delay estimation (TDE) technique is presented. First, the nonlinear mathematical model of the bidirectional stabilization system with consideration of actuator dynamics is established. Second, the TDE method is invoked to estimate the unknown system dynamics and provide fascinating model-free structures. Then, a CNTSM surface and a fast TSM reaching law are constructed to guarantee finite-time convergence. The proposed controller no longer requires system dynamics benefiting from TDE, while ensuring high accuracy, fast convergence and good robustness against lumped uncertainty due to the CNTSM manifold and the fast TSM reaching law. The stability and finite-time convergence of the closed-loop system are analyzed applying Lyapunov theory. Extensive comparative results verify the superiority with the proposed controller.

The Surgical Management of Traumatic Lower Cervical Spondylolisthesis with Posterior Percutaneous Pedicle Screw Fixation

Peng Luo,Wen-Fei Ni,Yao-Sen Wu,Ai-Min Wu,Xiang-Yang Wang,Hua-Zi Xu,Yong-Long Chi 대한척추외과학회 2015 Asian Spine Journal Vol.9 No.2

We reported a technical report of traumatic lower cervical spondylolisthesisca used by bilateral pedicle fracture, without neurological compression. The patient was treated with the minimally invasive technique of percutaneous pedicle screw fixation. Fracture healing and normal cervical motion were confirmed by plain films and physical examinations onthe18-monthpostoperatively. The technique of percutaneous pedicle screw fixation might be an alternative strategy for the treatment of traumatic lower cervical spondylolisthesis with pedicle fracture.

Reinforcement layout design for deep beam based on BESO of multi-level reinforcement diameter under discrete model

Hu-zhi Zhang,Peng Luo,Jian Yuan,Yao-sen Huang,Jia-dong Liu 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.84 No.4

By presetting various reinforcement diameters in topology optimization with the discrete model finite element analysis, an algorithm of bidirectional evolutionary structural optimization of multi-level reinforcement diameter is presented to obtain the optimal reinforcement topologies which describe the degree of stress of different parts. The results of a comparative study on different reinforcement feasible domain demonstrate that the more angle types of reinforcement are arranged in the initial domain, the higher utilization rate of reinforcement of the optimal topology becomes. According to the nonlinear finite element analysis of some deep beam examples, the ones designed with the optimization results have a certain advantage in ultimate bearing capacity, although their failure modes are greatly affected by the reinforcement feasible domain. Furthermore, the bearing capacity can be improved when constructional reinforcements are added in the subsequent design. However the adding would change the relative magnitude of the bearing capacity between the normal and inclined section, or the relative magnitude between the flexural and shear capacity within the inclined section, which affects the failure modes of components. Meanwhile, the adding would reduce the deformation capacity of the components as well. It is suggested that the inclined reinforcement and the constructional reinforcement should be added properly to ensure a desired ductile failure mode for components.

도시관광에서 현대적 진정성의 의미

심창섭(Shim Chang sup),상삼요(Sen yao Sang) 대한관광경영학회 2017 觀光硏究 Vol.32 No.2

우리나라를 방문하는 중국인 관광객들의 유형이 단체관광에서 개별관광으로 변화하고 있는 상황에서 도시관광은 개별관광객들이 선호하는 관광형태로 최근 많은 관심을 받고 있다. 특히 젊은층이 대다수를 차지하는 중국인 개별관광객들은 역사유적, 박물관, 자연자원 등 전통적인 관광매력물 뿐만 아니라 상업공간, 맛집 등을 방문하는 것을 선호하는 것으로 알려지고 있다. 이러한 현상을 이해하기 위하여 최근 관광연구자들은 진정성이 역사적·전통적인 관광대상에서만 경험이 가능한 것이 아니라 현대적인 관광대상을 통해서도 경험이 가능하다는 현대적 진정성에 관한 논의를 시작하고 있다. 따라서 본 연구에서는 현대적 진정성의 개념을 분석틀로 서울 신사동 가로수길을 방문한 20대 중국인들의 경험을 에스노그라피의 관점에서 정성적으로 분석하였다. 5차례에 걸쳐 실시된 FGI에 총 34명이 참여하였으며 조사 및 분석의 초점은 현대적 진정성의 하위차원을 탐색적으로 도출하는 것으로 하였다. 분석결과 현대적 진정성은 3개의 하위차원을 갖는 것으로 나타났다. 첫 번째 하위차원은 자연스러운 지역의 일상을 의미하는 일상적 진정성, 두 번째 하위차원은 최신 트렌드를 반영하는 시간적 진정성, 세 번째 하위차원은 미디어가 형성하는 미디어 진정성으로 나타났다. 본 연구의 결과는 도시관광은 물론 현대관광을 이해하는데 의미 있는 이론적, 실무적 시사점을 제공한다. As the number of individual tourists exceeded group tourists in the market of inbound tourism, more attention has been paid to urban tourism, which is preferred by individual tourists. In particular, Chinese individual tourists who are mostly young, tend to spend much time in commercial spaces and restaurants, rather than in traditional attractions like historical places, museums, and natural areas. To understand phenomenon, tourism researchers have recently discussed about contemporary authenticity, which suggests that authenticity can be experienced in contemporary places as well as in historical and traditional places. Therefore, this study aimed to identify sub-dimensions of contemporary authenticity perceived by young Chinese tourists visiting Sinsadong Garosugil from the perspective of Ethnography. The results show that contemporary authenticity contains three sub-dimensions: daily authenticity, current authenticity, and media authenticity. The current results provide some theoretical and practical implications for urban tourism and contemporary tourism.

Novel DNAH1 Mutation Loci Lead to Multiple Morphological Abnormalities of the Sperm Flagella and Literature Review

Zhuang Bao-Jun,Xu Su-Yun,Dong Liang,Zhang Pei-Hai,Zhuang Bao-Lin,Huang Xiao-Peng,Li Guang-Sen,You Yao-Dong,Chen Di'Ang,Yu Xu-Jun,Chang De-Gui 대한남성과학회 2022 The World Journal of Men's Health Vol.40 No.4

The protein encoded by dynein axonemal heavy chain 1 (DNAH1) is a part of dynein, which regulates the function of cilia and sperm flagella. The mutant of DNAH1 causes the deletion of inner dynein arm 3 in the flagellum, leading to multiple morphological abnormalities of the sperm flagella (MMAF) and severe asthenozoospermia. However, instead of asthenozoospermia and MMAF, the result caused by the mutation of DNAH1 remains unknown. Here we report a male infertility patient with severe asthenozoospermia and teratozoospermia. We found two heterozygous mutations in DNAH1 (c.6912C>A and c.7076G>T) and which were reported to be associated with MMAF for the first time. We next collected and analyzed 65 cases of DNAH1 mutation and found that the proportion of short flagella is the largest, while the bent flagella account for the smallest, and the incidence of head deformity is not high in the sperm of these patients. Finally, we also analyzed 31 DNAH1 mutation patients who were treated with intracytoplasmic sperm injection (ICSI) and achieved beneficial outcomes. We hope our research will be helpful in the diagnosis and treatment of male infertility caused by DNAH1 mutation.