RISS 학술연구정보서비스

검색
다국어 입력

http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.

변환된 중국어를 복사하여 사용하시면 됩니다.

예시)
  • 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
  • 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
닫기
    인기검색어 순위 펼치기

    RISS 인기검색어

      검색결과 좁혀 보기

      선택해제
      • 좁혀본 항목 보기순서

        • 원문유무
        • 등재정보
        • 학술지명
        • 주제분류
        • 발행연도
        • 작성언어
        • 저자
          펼치기

      오늘 본 자료

      • 오늘 본 자료가 없습니다.
      더보기
      • 무료
      • 기관 내 무료
      • 유료
      • KCI등재

        Exploiting the Reversibility of GTBP1 Catalyzed One-pot Reactions for the Synergistical Synthesis of Ponasterone A and Phenolic Glycosides

        Yuqiang Li,Bingfeng Li,Tianyi Chen,Bin Wu,Jianlin Chu,Bingfang He 한국생물공학회 2021 Biotechnology and Bioprocess Engineering Vol.26 No.3

        In the process of glycosyltransferase-catalyzed transglycosylation, the synthesis of uridine diphosphate sugars is generally thermodynamically disfavored. This study found that GTBP1 from Bacillus pumilus BF1 displayed the potential to reversely synthesize uridine diphosphate glucose (UDPG, UDP-glucose), which catalyzed the deglycosylation of ponasteroside A and the transglycosylation of phenolic compounds in one-pot reaction. Sequence alignment and phylogenetic tree analysis of GTBP1 and other GTs with reversible glycosylation ability were also implemented. Using solvent engineering strategy, the reaction time in water-organic biphasic was shortened and the conversion was improved. The final conversion of ponasterone A was reached 93.4%, and the final yield of ferulic acid glycoside was 92.7%. Using the fed-batch technology with the coupled reaction, the cumulative product of ponasterone A was about 1.97 g/L, and the level of produced ferulic acid glycoside was about 1.52 g/L. The substrate specificity of the GTBP1 was also confirmed. It implies the diversity of GTBP1's ability to construct UDP cycles.

      • KCI등재

        Trajectory Tracking Control Design for Nonholonomic Systems with Full-state Constraints

        Zhongcai Zhang,Wenli Cheng,Yuqiang Wu 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.5

        A systematic control design strategy of the trajectory tracking controller is proposed for a class of chained nonholonomic systems with full-state constraints. The barrier Lyapunov function (BLF) with finite-time convergence, the technique of relay switching and the integral backstepping are applied to the development of the controller. The designed control law guarantees that the reference trajectory can be tracked by the system state asymptotically and the state constraints are not violated. The physical models of two mobile robots and simulation results are provided to demonstrate the effectiveness of the proposed control scheme.

      • KCI등재

        MPPT Adaptive Controller of DC-based DFIG in Resistances Uncertainty

        Yuliang Sun,Shaomin Yan,Bin Cai,Yuqiang Wu,Zhongcai Zhang 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.8

        A coordinated adaptive feedback linearization controller (FLC-A) based on a flux observer for DC-based DFIG to track the maximum power point (MPP) is introduced in this paper. The stator and rotor of DFIG are connected to DC grid directly by two voltage source converters. First, an adaptive controller is used to track the MPP on the system which is decoupled by a single-loop feedback linearization strategy. Meanwhile, the proposed controller can estimate and compensate the changes of stator and rotor resistances caused by physical environment in realtime, and improve the dynamic performance of the system; second, under the persistent excitation condition (PED), a stator flux observer with online resistance estimation in the stationary reference frame is adopted to replace the traditional flux calculation method or flux meter, which increases system reliability. The stability of adaptive control rate and nonlinear observer is proved by Lyapunov theory. Simulations are carried out to prove the effectiveness and robustness of the proposed control strategy.

      • KCI등재

        Barrier Lyapunov Functions-based Output Feedback Control for a Class of Nonlinear Cascade Systems With Time-varying Output Constraints

        Jing Yang,Jie Zhang,Zhongcai Zhang,Yuqiang Wu 제어·로봇·시스템학회 2024 International Journal of Control, Automation, and Vol.22 No.2

        In this study, a class of nonlinear systems with integral input to state stability (iISS) inverse dynamics and unknown control direction are examined for the issue of time-varying asymmetric output constraints of adaptive output feedback controller. To deal with unmeasured state variables and unknown directions, the state observer is constructed using a Rickati matrix differential equation with time variation. A backstepping-based method is recommended for establishing the dynamic output feedback control law. By ensuring boundedness for the timedependent barrier Lyapunov function (BLF) in the closed loop, we may not only maintain the boundedness and stability of other signals, but also avoid breaking the time-varying asymmetric constraint of the output. Finally, simulation analyses are used to confirm the scheme’s efficacy.

      • KCI등재

        Contrast-enhanced ultrasonography-based renal blood perfusion in brain-dead donors predicts early graft function

        Weiming He,Yuguang Xu,Chaoyang Gong,Xiaozhen Liu,Yuqiang Wu,Xi Xie,Jiazhen Chen,Yi Yu,Zhiyong Guo,Qiang Sun 대한초음파의학회 2023 ULTRASONOGRAPHY Vol.42 No.4

        Purpose: The aim of this study was to quantify renal microcirculatory perfusion in braindead donors using contrast-enhanced ultrasonography (CEUS), and to establish an accurate, noninvasive, and convenient index for predicting delayed graft function (DGF) post-transplantation. Methods: In total, 90 brain-dead donor kidneys (training group, n=60; validation group, n=30) examined between August 2020 and November 2022 were recruited in this prospective study. CEUS was performed on the kidneys of brain-dead donors 24 hours before organ procurement and time-intensity curves were constructed. The main measures were arrival time, time to peak, and peak intensity of the kidney segmental arteries, cortex, and medulla. Recipients were divided into DGF and non-DGF groups according to early post-transplant graft function. The area under the receiver operating characteristic curve (AUC) was used to assess diagnostic performance. Results: The arrival time of the kidney segmental artery and cortex and the time interval between the time to peak of the segmental artery and cortex were identified as independent factors associated with DGF by multivariate stepwise regression analysis. A new index for the joint prediction model of three variables, the contrast-enhanced ultrasonography/Kidney Donor Profile index (CEUS-KDPI), was developed. CEUS-KDPI showed high accuracy for predicting DGF (training group: AUC, 0.91; sensitivity, 90.5%; specificity, 92.3%; validation group: AUC, 0.84; sensitivity, 75.0%; specificity, 92.3%). Conclusion: CEUS-KDPI accurately predicted DGF after kidney transplantation. CEUS may be a potential noninvasive tool for bedside examinations before organ procurement and may be used to predict early renal function after kidney transplants kidneys from donors after brain death.

      연관 검색어 추천

      이 검색어로 많이 본 자료

      활용도 높은 자료

      해외이동버튼