Silver nanoparticle-induced degranulation observed with quantitative phase microscopy.

Yang, Wenzhong,Lee, Seungrag,Lee, Jiyong,Bae, Yoonsung,Kim, Dugyoung SPIE--the International Society for Optical Engine 2010 JOURNAL OF BIOMEDICAL OPTICS Vol.15 No.4

<P>Monitoring a degranulation process in a live mast cell is a quite important issue in immunology and pharmacology. Because the size of a granule is normally much smaller than the resolution limit of an optical microscope system, there is no direct real-time live cell imaging technique for observing degranulation processes except for fluorescence imaging techniques. In this research, we propose optical quantitative phase microscopy (QPM) as a new observation tool to study degranulation processes in a live mast cell without any fluorescence labeling. We measure the cell volumes and the cross sectional profiles (x-z plane) of an RBL-2H3 cell and a HeLa cell, before and after they are exposed to calcium ionophore A23187 and silver nanoparticles (AgNPs). We verify that the volume and the cross sectional line profile of the RBL-2H3 cell were changed significantly when it was exposed to A23187. When 50 microg/mL of AgNP is used instead of A23187, the measurements of cell volume and cross sectional profiles indicate that RBL-2H3 cells also follow degranulation processes. Degranulation processes for these cells are verified by monitoring the increase of intracellular calcium ([Ca(2+)](i)) and histamine with fluorescent methods.</P>

High-speed confocal fluorescence lifetime imaging microscopy (FLIM) with the analog mean delay (AMD) method.

Won, Youngjae,Moon, Sucbei,Yang, Wenzhong,Kim, Donguk,Han, Won-Taek,Kim, Dug Young Optical Society of America 2011 Optics express Vol.19 No.4

<P>We demonstrate a high-speed confocal fluorescence lifetime imaging microscopy (FLIM) whose accuracy and photon economy are as good as that of a time-correlated single photon counting (TCSPC). It is based on a new lifetime determination scheme, the analog mean delay (AMD) method. Due to the technical advantages of multiple fluorescence photon detection capability, accurate lifetime determination scheme and high photon detection efficiency, the AMD method can be the most effective method for high-speed confocal FLIM. The feasibility of real-time confocal FLIM with the AMD method has been demonstrated by observing the dynamic reaction of calcium channels in a RBL-2H3 cell with respect to 4관PDD stimulus. We have achieved the photon detection rate of 125 times faster than a conventional TCSPC based system in this experiment.</P>

Fabrication and characterization of polypyrrole coatings by embedding antimony modified SnO2 nanoparticles

Zhihao Chen,Yijie Jin,Wenzhong Yang,Bin Xu,Yun Chen,Xiaoshuang Yin,Ying Liu 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.75 No.-

Polypyrrole (PPy) coatings were successfully electrosynthesized on the carbon steel by embedding SnO2and Sb-SnO2 nanoparticles (NPs). The associated structural, morphology, hydrophobic, physicalproperties, anti-corrosion and self-healing performance of these coatings were systematically studiedby several tests. XRD results showed that SnO2 had a tetragonal rutile structure and the lattice parametersindicated that Sb ions were successful substituted into SnO2 lattice. The average size of SnO2 NPs wasdecreased by the incorporation of Sb-SnO2 NPs, which were found through TEM images. The contactangle test showed that the hydrophobic of PPy coatings was greatly enhanced by the incorporation of Sb-SnO2 NPs. SEM results revealed that Sb-SnO2/PPy coating exhibited a more compact and uniform surfacethan SnO2/PPy coating, hence the physical barrier effect was significantly strengthened. Theelectrochemical measurements confirmed the excellent anti-corrosion and self-healing ability of Sb-SnO2/PPy coating for a long immersion time in HCl solution. The superior anti-corrosion performance ofSb-SnO2/PPy coating was ascribed to the synergistic effects of the anodic protection combined with theself-healing effect, the excellent physical barrier effect with compact, smooth and hydrophobic coatingsurface as well as the formation of p-n junction with decreased charge transfer.

Autofocusing and edge detection schemes in cell volume measurements with quantitative phase microscopy

Lee, Seungrag,Lee, Ji Yong,Yang, Wenzhong,Kim, Dug Young The Optical Society 2009 Optics express Vol.17 No.8

<P>We have proposed and demonstrated a very sensitive volume measurement scheme for a live cell with a quantitative phase microscopy (QPM) utilizing auto-focusing and numerical edge detection schemes. An auto-focusing technique with two different focus measures is applied to find the focus dependent errors in our live cell volume measurement system. The volume of a polystyrene bead sample with 3 mum diameter has been measured for the validity test of our proposed method. We have shown that a small displacement of an object from its focusing position can cause a large volume error. A numerical edge detection technique is also used to accurately resolve the boundary between a cell and its suspension medium. We have applied this method to effectively suppress errors by the surrounding medium of a single red blood cell (RBC).</P>

An Efficient Routing in Urban Vehicular Ad Hoc Networks

Xu Liya,Deng Anyuan,Gao Guangyong,Yang Wenzhong,Cheng Yong 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.8

VANET is a highly mobile wireless ad hoc network that is targeted to support road safety, traffic monitoring and other applications. The node communication is easy to break due to the high mobility of vehicles and the road layout. In this paper, we propose an efficient routing based on static node assistance. The static nodes are fixed in each intersection. Each static node stores information of other static nodes in path. The routing takes static nodes as backbone nodes and vehicles as relay nodes between static nodes. The static nodes are selected dynamically and sequentially, and they are chosen according to the delay that packets are forwarded from the current static node to the candidate one. The vehicular relay selection between two static nodes considers the link stability as the parameter. Simulation results show performance improvement comparing with performance of other existing routing approaches.

Corrosion inhibition properties of two imidazolium ionic liquids with hydrophilic tetrafluoroborate and hydrophobic hexafluorophosphate anions in acid medium

Yangyang Guo,Bin Xu,Ying Liu,Wenzhong Yang,Xiaoshuang Yin,Yun Chen,Jinxun Le,Zhihao Chen 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.56 No.-

The ionic liquids, 1-vinyl-3-aminopropylimidazolium hexafluorophosphate ([VAIM][PF6]) and 1-vinyl-3-aminopropylimidazolium tetrafluoroborate ([VAIM][BF4]) acted as the corrosion inhibitors. Weight lossmeasurements showed the corrosion inhibition efficiencies of [VAIM][PF6] and [VAIM][BF4] were 90.53%and 54.01% at 45 C, respectively. The ILs were mix-type inhibitors. Raising the temperature can have adecreased inhibition efficiency of [VAIM][BF4], while [VAIM][PF6] presented an opposite trend. Inaddition, [VAIM][PF6] obeyed Langmuir monolayer adsorption isotherm, while [VAIM][BF4] obeyed EIAwadykinetic-thermodynamic adsorption for blocking active sites. Moreover, Molecular DynamicSimulations showed that [VAIM][PF6] owned a higher adsorption energy, which may be responsible forthe more adsorption groups of [VAIM][PF6].

Scale inhibition performance of calcium sulfate by 1,6-diaminohexanecontained polyaminoamide dendrimers: Static experiment and MD simulation

Yue Sun,Li Li,Zhihao Chen,Xiaoshuang Yin,Wenzhong Yang,Yun Chen,Ying Liu 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.115 No.-

The calcium sulfate scale is a common scale in the industrial water system, which is difficult to beremoved by common chemical cleaning methods. In this paper, a new phosphorous free of 1,6-Diaminohexane-contained polyaminoamide dendrimers (PAMAM) scale inhibitor with a threedimensional(3D) branched structure has been developed. The scale inhibition performances of differentgenerations of PAMAM dendrimers (PAMAM-mid, PAMAM-0G, PAMAM-0.5G and PAMAM-1G) are estimatedby the static scale inhibition method. Moreover, the effects of the scale inhibitor concentrationsand solution temperatures on the CaSO4 scale inhibition efficiency are thoroughly discussed. Results indicatethat the PAMAM-mid and PAMAM-0.5G) exhibit excellent inhibition performance on CaSO4 precipitation. Especially, the CaSO4 scale inhibition efficiency of PAMAM-0.5G is above 95% when the dose is10 mg/L, and the corresponding value is almost 100% when the inhibitor dose is 20 mg/L. In addition,the influence of descaling agents on the crystal and morphology of CaSO4 scales are studied by XRDand SEM tests. The results show that the scale inhibition ability of the PAMAM molecules mainly inhibitsthe growth of these crystal planes by adsorption on the surface of the growing crystal. Molecular dynamicssimulation results find that the PAMAM-0.5G dendrimer molecule can energetically interact well withthree crystal planes of calcium sulfate dihydrate. Finally, the simulation results provide a theoreticalguidance to judge the performance of scale inhibitors and synthesize new high-efficiency scale inhibitor.