Super-resolution morphological dissemination of intercalating dye in single DNA molecules via binding activated localization microscopy

Fluorescent dye （YOYO-I） intercalated with single DNA molecules were investigated via bindingactivated localization microscopy （BALM） at sub-diffraction limit resolutions. Various dye-to-DNA base pair （bp） ratios were imaged using the blinking property of YOYO-1 dye under optimum BALM switching buffer conditions. Individual DNA molecules exhibited regular/irregular intercalating phenomena with respect to dye-to-DNA bp ratio. The acquired images were reconstructed into super-resolution images by applying a Gaussian fit to the centroid of the point spread function. The YOYO-1 intercalated with λ-DNA possessed a non-homogeneous region due to the different binding modes of YOYO-1 with λ-DNA. Each binding mode was imaged at the sub-diffraction limit super-resolution. The distance between homogenously localized intercalating dyes within the DNA molecules was measured to be 34nm （n= 10; dye：DNAbp= 1：100） without photocleavage in 50mmol/L β-mercaptoethylamine buffer. The results were similar to those of the theoretical values without photocleavage in the base pairs of single DNA molecules below the diffraction limit. The results paved the way for an in-depth microscopic analysis of molecular variation with single λ-DNA molecules. With this method, it should be possible to analyze the exact base pair breakdown during various stages of cell apoptosis.

Research of data transmission security in videoconference system

Many coal enterprises have built the videoconference systems on their LAN （Local Area Network）. As the development of these enterprises, their organizations are distributed over our country and even over the world. Therefore, the videoconference systems have to run over WAN （Wide Area Network）. Normally, the structure of a videoconference system is center_division including MCU （multi control unit）and participants. No QoS and security assurance are available now because all videoconference system is based on TCP/IP. Therefore, the system stability is absolutely depended on the Network. This paper discussed how to anti ARP attacking. The method discussed in this paper is based on TCP/IP.

Lorentz Force Velocimetry for Local Velocity Measurement

Standard flow measurement techniques fail for liquid metals due to their high temperatures,opaqueness and aggressiveness.However,recent developments in the measurement of volumetric fluxes of industrially relevant metal melts have been made.One of these methods,Lorentz Force Velocimetry(LFV)is based on the measurement of Lorentz forces generated when an electrically conducting fluid moves through a magnetic field.Our aim is to extend the working range of this method to the measurement of local flow velocities.To resolve local velocity fluctuations we reduce the size of the permanent magnet that produces the magnetic field.We use the fundamental setup of a square duct filled with the eutectic alloy GaInSn and having a cross-section of 5 cm by 5 cm.The magnet cube employed has an edge length of 1 cm.For this setup,we investigate both experimentally and numerically the interaction between the liquid metal flow and the non-uniform magnetic field.The results help in understanding the effect of flow dynamics on the total Lorentz force.