An Artificial Tongue Fluorescent Sensor Array for Identification and Quantitation of Various Heavy Metal Ions

Xu, Wang,Ren, Changliang,Teoh, Chai Lean,Peng, Juanjuan,Gadre, Shubhankar Haribhau,Rhee, Hyun-Woo,Lee, Chi-Lik Ken,Chang, Young-Tae American Chemical Society 2014 ANALYTICAL CHEMISTRY - Vol.86 No.17

<P>Herein, a small-molecule fluorescent sensor array for rapid identification of seven heavy metal ions was designed and synthesized, with its sensing mechanism mimicking that of a tongue. The photoinduced electron transfer and intramolecular charge transfer mechanism result in combinatorial interactions between sensor array and heavy metal ions, which lead to diversified fluorescence wavelength shifts and emission intensity changes. Upon principle component analysis (PCA), this result renders clear identification of each heavy metal ion on a 3D spatial dispersion graph. Further exploration provides a concentration-dependent pattern, allowing both qualitative and quantitative measurements of heavy metal ions. On the basis of this information, a “safe-zone” concept was proposed, which provides rapid exclusion of versatile hazardous species from clean water samples based on toxicity characteristic leaching procedure standards. This type of small-molecule fluorescent sensor array could open a new avenue for multiple heavy metal ion detection and simplified water quality analysis.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancham/2014/ancham.2014.86.issue-17/ac501953z/production/images/medium/ac-2014-01953z_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ac501953z'>ACS Electronic Supporting Info</A></P>

Silica Nanoparticle-Enhanced Fluorescent Sensor Array for Heavy Metal Ions Detection in Colloid Solution

Peng, Juanjuan,Li, Junyao,Xu, Wang,Wang, Lu,Su, Dongdong,Teoh, Chai Lean,Chang, Young-Tae American Chemical Society 2018 ANALYTICAL CHEMISTRY - Vol.90 No.3

<P>Sensitivity and detection limit are two vital factors that affect fluorophores-based sensing and imaging system. However, it remains a challenge to improve the sensitivity and detection limit of fluorophores, largely due to their limited response and photophysical properties. In this study, we report for the first time, a novel approach to enhance the sensitivity and detection limit of probes using silica nanoparticles, also known as silica nanoparticles-enhanced fluorescence (SiEF). SiEF can drastically improve the fluorescence intensities and detection limit of fluorophores. A SiEF-improved fluorescent sensor array for rapid and sensitive identification of different heavy metal ions is achieved, and a 3D spatial dispersion graph is obtained based on the SiEF-improved fluorescent sensor array, which provides a lower concentration dependent pattern than fluorophores alone, allowing qualitative, quantitative, and sensitive detection of heavy metal ions. Furthermore, with UV lamp irradiation of the sensor–metal ion mixtures, the output signals enable direct visual of heavy metal ions with low concentration. Thus, the SiEF approach provides a simple and practical strategy for fluorescent probes to improve their sensitivity and detection limit in analytes sensing.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancham/2018/ancham.2018.90.issue-3/acs.analchem.7b02883/production/images/medium/ac-2017-02883t_0005.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ac7b02883'>ACS Electronic Supporting Info</A></P>

Piezo channels in the urinary system

Li Xu,Hu Junwei,Zhao Xuedan,Li Juanjuan,Chen Yuelai 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

The Piezo channel family, including Piezo1 and Piezo2, includes essential mechanosensitive transduction molecules in mammals. Functioning in the conversion of mechanical signals to biological signals to regulate a plethora of physiological processes, Piezo channels, which have a unique homotrimeric three-blade propeller-shaped structure, utilize a cap-motion and plug-and-latch mechanism to gate their ion-conducting pathways. Piezo channels have a wide range of biological roles in various human systems, both in vitro and in vivo. Currently, there is a lack of comprehensive understanding of their antagonists and agonists, and therefore further investigation is needed. Remarkably, increasingly compelling evidence demonstrates that Piezo channel function in the urinary system is important. This review article systematically summarizes the existing evidence of the importance of Piezo channels, including protein structure, mechanogating mechanisms, and pharmacological characteristics, with a particular focus on their physiological and pathophysiological roles in the urinary system. Collectively, this review aims to provide a direction for future clinical applications in urinary system diseases.

Optimal LQG Control for Networked Control Systems with Remote and Local Controllers

Xiao Liang,Juanjuan Xu,Xiao Lu,Qingyuan Qi,Haixia Wang,Rong Gao 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.1

We consider the finite horizon optimal LQG control problem for networked control systems with a remote controller, a local controller and communication channels with packet dropouts and transmission delays. The local controller can directly observe state signals and send them to the remote controller via a packet-dropout channel. Then the remote controller sends the received measurement signals to the local controller. Afterwards, the two controllers operate the plant through a delayed channel. The contributions of this paper are as follows: Firstly, at the side of the remote controller, we develop an optimal estimator to show that the separation principle holds. Secondly, we derive a non- homogeneous relationship between the state and the costate of systems in virtue of the maximum principle. Finally, a necessary and sufficient condition for the optimal control problem is derived in terms of the two coupled Riccati equations. Numerical examples are employed to illustrate the theoretical results.

Optimal Control with Terminal State Constraints for Multichannel Input Linear Systems

Qichao Sun,Juanjuan Xu,Huanshui Zhang 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.10

This paper is concerned with the linear quadratic (LQ) control problem with multiple input channels and terminal state constraints. The problem can be solved by augmenting all the inputs into one. However, the calculation will be much more involved especially for the case with large scale of inputs. To overcome this complexity, we adopt a leader-follower game theory approach. The optimal controller is obtained in the feedback of the state in terms of Riccati equations. A numerical example is provided to demonstrate the effectiveness of the derived result.

Stabilization and Optimal Control for Markov Jump Linear System With Two Controllers Over Multiple Erasure Channels

Xueyang Li,Juanjuan Xu,Wei Wang,Chunyan Han 제어·로봇·시스템학회 2024 International Journal of Control, Automation, and Vol.22 No.1

This paper considers the stabilization and optimal control of networked control systems possessing two controllers, in which the local controller and the remote controller transmit state information over multiple erasure channels. Multiple controllers are introduced for the first time in this multi-mode system. The coupling of the two controllers and the dependence of the adjacent-time jumping parameters make the control problem more difficult. For the finite horizon, the existence conditions and the explicit solutions to the optimal controllers are given in virtue of two coupled difference Riccati equations (CDREs). For the infinite horizon, the necessary and sufficient conditions of stabilizability are presented and the corresponding optimal controllers are derived with a new set of coupled algebraic Riccati equations (CAREs). Numerical examples are used to demonstrate the effectiveness of the proposed algorithms.

Game Theory Approach to Optimal Control Problem with Multi-Channel Control

Wei Wang,Juanjuan Xu,Huan-Shui Zhang 제어·로봇·시스템학회 2015 International Journal of Control, Automation, and Vol.13 No.1

In this paper, we mainly study the optimal control problem with multi-channel control. The main contribution is to treat the optimal control problem as a leader-follower problem with multihierarchy decision makers in game theory. According to the sequence of the decision makers, the optimal controller is derived by the maximum principle. It is worth mentioning that the optimal solution is in the feedback form related to two symmetric Riccati equations with same dimension as the original state. Furthermore, the obtained solution is sufficient and necessary.

Stackelberg Strategy of Two-player Stochastic Difference Game With Time Delay

Jingmei Liu,Wei Wang,Juanjuan Xu,Huanshui Zhang 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.9

In this paper, we study the open-loop Stackelberg strategy of the stochastic Stackelberg game with time delay. The main contribution is to give the explicit Stackelberg strategy in terms of Riccati equations. The key to solving the problem is the explicit solvability of the forward and backward stochastic difference equations (FBSDEs). Moreover, the optimal costs are indicated by using the initial value of the state.

Solution to Mixed H2/H∞ Control for Discrete-time Systems with (x,u,v)-dependent Noise

Xiaoqian Li,Wei Wang,Juanjuan Xu,Huanshui Zhang 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.2

In this paper, the stochastic H2=H∞ control problem for linear discrete-time systems with (x;u;v)-dependent noise is studied. By applying the leader-follower stochastic game approach, the disturbance is treatedas the follower and the control input is treated as the leader, respectively. Necessary and sufficient conditions forthe mixed control problem are presented which guarantee the existence and uniqueness of the optimal solution. Byapplying the stochastic maximum principle, the follower first solves a stochastic linear quadratic optimal controlproblem which is given in the form of H∞-norm with the aid of stochastic Riccati equations. Then the leader solves astochastic linear quadratic problem with the aid of forward and backward equations. The main technique is to introducetwo new co-states to capture the future information, the encountered difficulty is to establish a homogeneousrelationship between the new co-states.

Finite Element Analysis and Dynamics Simulation of Mechanical Flux-Varying PM Machines with Auto-Rotary PMs

Huang, Chaozhi,Zhang, Zhixuan,Liu, Xiping,Xiao, Juanjuan,Xu, Hui The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.3

A new type of auto-rotary PM mechanical flux-varying PM machine (ARPMMFVPMM) is proposed in this paper, which can overcome the problem where the air-gap magnetic field of a PM machine is difficult to freely adjust. The topology structures of the machine and the mechanical flux-adjusting device are given. In addition, the operation principle of flux-adjusting is analyzed in detail. Furthermore, the deformation of a spring with the speed variation is obtained by virtual prototype technology. Electromagnetic characteristics including the flux distribution, air gap flux density, flux linkage, electromagnetic-magnetic-force (EMF), and flux weakening ability are computed by 2D finite element method (FEM). Results show that the machine has some advantages such as the good field control ability.