Super-resolution fluorescent materials: an insight into design and bioimaging applications

Yang, Zhigang,Sharma, Amit,Qi, Jing,Peng, Xiao,Lee, Dong Yeop,Hu, Rui,Lin, Danying,Qu, Junle,Kim, Jong Seung The Royal Society of Chemistry 2016 Chemical Society reviews Vol.45 No.17

<P>Living organisms are generally composed of complex cellular processes which persist only within their native environments. To enhance our understanding of the biological processes lying within complex milieus, various techniques have been developed. Specifically, the emergence of super-resolution microscopy has generated a renaissance in cell biology by redefining the existing dogma towards nanoscale cell dynamics, single synaptic vesicles, and other complex bioprocesses by overcoming the diffraction-imposed resolution barrier that is associated with conventional microscopy techniques. Besides the typical technical reliance on the optical framework and computational algorithm, super-resolution imaging microscopy resorts largely to fluorescent materials with special photophysical properties, including fluorescent proteins, organic fluorophores and nanomaterials. In this tutorial review article, with the emphasis on cell biology, we summarize the recent developments in fluorescent materials being utilized in various super-resolution techniques with successful integration into bio-imaging applications. Fluorescent proteins (FP) applied in super-resolution microscopy will not be covered herein as it has already been well summarized; additionally, we demonstrate the breadth of opportunities offered from a future perspective.</P>

An Innovative Rotor Position Detection at Stand-Still and Low Speed with Carrier Phase-Shifted PWM Method

Kewang Qu,Guoqing Xu,차석원,Yanhui Zhang,Wei Feng,Junci Cao,Weili Li,Yihuang Zhang,Zhigang Wu 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.19 No.9

An innovative permanent magnet synchronous motor rotor position detection method using d-q reference-frames derived from PWM inverter switching is presented based on carrier phase-shift PWM method. It also gives the development the polarity identification at standstill for permanent magnet synchronies motor in the rotary frame with position detected of the neutral voltage. The new technique detects the motor position from simple measurements of the neutral point voltage of the motor influenced by the variation of inductances with respect to rotor position. The transfer is derived with constant element and 2nd harmonic element of selfinductance and mutual-inductance between three phase inductances and the inductance of d-axis and q-axis. Theoretical studies are carried out and verified using experiment results with variation rotor position over one electrical cycle at standstill. Rotor position estimation from stator inductance variation with rotor position is effective in zero speed and low speed.

Dynamic Characteristic Simulation of Helicopter Tail Drive Shaft System

Nie Junfeng,Yu Guangbin,Song Ye,Qu Zhigang,Zheng Minli,Zhao Xingfu 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.6

Helicopter with the advantage of light, flexible and hovering in the air, is widely used. In both military and civilian domain, it gets more and more attention. It becomes the main subject of research in the world. In the power transmission system of helicopter, the tail rotor shaft is an important part. It is one of the key technologies to predict the dynamic characteristics of the shaft accurately for improving the overall performance of the helicopter. Based on the theory of elastic mechanics, rotor dynamics and the finite element analysis, the former main drive shaft is taken as an example. The dynamic characteristics of the transmission shaft is calculated by the multi/few degrees of freedom finite element method. The validity of the finite element method with few degrees of freedom is determined. Then the structure characteristics of the helicopter tail drive shaft are analyzed, and the dynamic characteristics of the helicopter tail rotor shaft are calculated by using the finite element method with few degrees of freedom. The research results provide the basis and guidance for the design of the helicopter tail drive system.

Research on Nonlinear Vibration Characteristics of Spiral Bevel Gear

Nie Junfeng,Yu Guangbin,Song Ye,Qu Zhigang,Zheng Minli,Zhao Xingfu 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.2

Based on the concentrated parameters theory, a 7-freedom coupled vibration dynamic model of the spiral bevel gear transmission system is established, which includes transmission error, time-varying mesh stiffness and the tooth backlash clearance. In the model, the axial vibration, the torsion oscillation of the gear pair aroused by tooth meshing force and the lateral oscillations resulting from flexional deformation of the gear shaft are taken into account. The mesh stiffness fluctuation is developed as 5-order Fourier series and the tooth backlash clearance is fitted by 7-order polynomial function. Through the Gear method, the dynamic response of the system is obtained, and the vibration characteristics are analyzed.

HDWM-based Consensus Control for Multi-agent Systems Under Communication Delays and DoS Attacks

Hongfei Zhu,Jinhai Liu,Shuo Zhang,Zhigang Zhang,Fuming Qu 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.12

This paper develops a novel framework with hybrid-driven waiting mechanism (HDWM) of consensus control for multi-agent systems (MASs) in the presence of communication delays and denial-of-service (DoS) attacks. Different from the existing waiting mechanism, the proposed HDWM not only involves the event-driven mechanism, but also involves the time-driven mechanism. If DoS attacks causes partial information to be lost, the information in the buffer can still be transmitted to the controller to update the states of agent via the time-driven mechanism. Meanwhile, the communication delays and DoS attacks are considered in the proposed sampled-databased resilient controller. Under the proposed HDWM and resilient controller, the MASs can achieve consensus. Finally, the simulation example is conducted to verify the effectiveness of the proposed method.

Study on Multi Objective Optimization Method and It Application in Aviation and Deceleration Device

Yu Guang-bin,Song Ye,Duan Yuan-wang,Zhao Xing-fu,Qu Zhigang,Sun Yong-guo 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.5

A two-photon fluorescent probe records the intracellular pH through ‘OR’ logic operation via internal calibration

Podder, Arup,Won, Miae,Kim, Soobin,Verwilst, Peter,Maiti, Mrinmoy,Yang, Zhigang,Qu, Junle,Bhuniya, Sankarprasad,Kim, Jong Seung Elsevier 2018 Sensors and actuators. B Chemical Vol.268 No.-

<P><B>Abstract</B></P> <P>Mapping the intracellular location and concentration of hydronium ions (H<SUB>3</SUB>O<SUP>+</SUP>) and their dynamics could be a useful diagnostic tool in modern clinical science. Current needs motivated us to develop a molecular pH probe <B>1</B>, operating as a logic gate, and its analogue <B>2</B>. The pyridyl moiety in <B>1</B> played a significant role in proton capture and release, in acidic to alkaline pH environments. In contrast, <B>2</B> failed to show a similar spectroscopic behavior. <B>1</B> shows emission maximum at 450 nm that is independent on the pH, with excitation at 353 nm or 410 nm in acid and alkaline pH, respectively. <B>1</B> was employed to provide input-dependent (excitation wavelength) fluorescence images in a cellular milieu to detect pH changes in cellular organelles such as lysosomes and mitochondria. Furthermore, <B>1</B> provided information on the variation of the pH in the presence of cellular ROS. <B>1</B> was also found to enable the real-time monitoring of cell acidification due to nutrient starvation, which is closely associated with mitochondrial malfunction, fusion and mitophagy processes. We envision that in due course <B>1</B> can open up new research avenues in the diagnostic sector for validating the pH in the cellular milieu.</P> <P><B>Highlights</B></P> <P> <UL> <LI> This is the first example of a “OR” Logic operative two-photon probe for pH determination. </LI> <LI> Probe <B>1</B> enables the tracking of a wide pH range in cellular organelles without interference from cellular autofluorescence. </LI> <LI> This nontoxic probe can detect pH fluctuation due to ROS, such as H<SUB>2</SUB>O<SUB>2</SUB> and others. </LI> <LI> Probe <B>1</B> can provide dual-mode emission/cell images either by single photon or two-photon modes. Therefore, it is a unique cellular pH probe. </LI> <LI> Finally, <B>1</B> revealed pH fluctuations due to nutrient starvation, which is related to mitochondrial malfunction, fusion, and mitophagy. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>“OR” logic gated pH probe (1) detects the pH in cell organelles in the presence of ROS and under nutrient starvation conditions.</P> <P>[DISPLAY OMISSION]</P>

Nanomaterial designing strategies related to cell lysosome and their biomedical applications: A review

Rathore, Bhowmira,Sunwoo, Kyoung,Jangili, Paramesh,Kim, Jiseon,Kim, Ji Hyeon,Huang, Meina,Xiong, Jia,Sharma, Amit,Yang, Zhigang,Qu, Junle,Kim, Jong Seung Elsevier 2019 Biomaterials Vol.211 No.-

<P><B>Abstract</B></P> <P>Lysosomes, an important organelle of eukaryotic cells, are covered with the cell membrane and contain an array of degradative enzymes. The disrupt in lysosomal functions may lead to the development of severe diseases. In nanotechnology, nanomaterials working mechanism and its biomedical output are highly dependent on the lysosomes as it plays a crucial role in intracellular transport. Several nanomaterials specifically designed for lysosome-related actions are highly advantageous in trafficking and delivering the loaded imaging/therapeutic agents. But for other applications, especially gene-based therapeutic delivery into the sub-organelles such as mitochondria and nucleus, lysosomal related degradation could be an obstacle to achieve a maximal therapeutic index. In order to understand the relationship between lysosomes and designed nanomaterials for kind of desired application in biomedical research, complete knowledge of their various designing strategies, size dependent or ligand supportive cellular uptake mechanisms, trafficking, and localizations in eukaryotic cells is highly desired. In this review, we intended to discuss various nanomaterial types that have been applied in biomedical applications based on lysosomal internalization and escape from endo/lysosomes and explored their related advantages/disadvantages. Additionally, we also deliberated nanomaterials direct translocation mechanism, their autophagic accumulation and the underlying mechanism to induced autophagy. Finally, some challenges and critical issues in current research from clinical application perspective has also been addressed. Great understanding of these factors will help in understanding and facilitating the development of safe and effective lysosomal related nanomaterial-based imaging/therapeutic systems for future applications.</P>