Research of Effect of ^60Co γ-ray Irradiation on Cell Cycle of SMMC, 7721 Tumor Cell with Flow Cytometery

The resultsMost researchof cell cycle play an important role in resear, ching tumor occurrence, development and treatment. results show that malignant grade and pharmic sensitivity of tumor are relative to cell cycle. The sensitivity of medications is different to different phases of cell cycle of tumor. In general, the cell of M are more sensitivity. On the side, different medications have different action in different cell cycle. The irradiation can change cell cycle proccss and can induce the pattern of changes in cell cycle. For cxamplc, G1 arrest, G2 arrest and S arrest. So, thc research rcsults of tumor cell cycle in different irradiation have not only biological means but also realistic means for selecting chemical therapy medication after radiotherapy.     

Comparison of One and Two Fractional Irradiation by X-rays on Fibroblasts

In order to investigate the fractional effect, normal human fibroblasts GM5758 were irradiated with oneand two fractional X-rays. After irradiation, cell survival was performed by standard methods. Cell terminal differentiation pattern was determined as mitotic fibroblasts (MF) Ⅰ, Ⅱ and Ⅲ, post mitotic fibroblasts (PMF) Ⅳ, Ⅴ and Ⅵ, according to cellular morphology, as described by C. Fournier. As show in Fig.l, the survival fraction of two-fraction irradiation is higher than that of one-fraction irradiation. This result suggests that sub-lethal damage induced by radiation can be repaired efficiently for fractional irradiation. As for differentiation     

An Approach to Biochemical Imaging of Heterogeneity in the Bio—tissue Simultaneously Using the Data of Reflectance and Transmittance of Diffuse—Photon Density Waves

An algorithm for the biochemical imaging of heterogeneity in the bio-tissue with finite parallel-plane geometry simultaneously using the data of reflectance and transmittance of diffuse-photon density waves is presented.In this algorithm,the priori knowledge of heterogeneity is not needed,This algorithm is suitable for the imaging of heterogeneity in the large volume tissue and is small organs.To reduce the errors produced by the algorithm,it is suggested that the experiment should be performed in two steps,at first step the light source should be placed at one boundary to measure the data of reflectance and transmittance,and these data are used to construct the heterogeneous function in the half space close to the light source;at the second step the light source should be placed at another boundary to measure the data of reflectance and transmittance,these data are used to construct the heterogeneous function in another half space closed to the light source;after taking above two steps the heterogeneous function in the whole space is constructed.     

Active Control of Cellular Orientation through In-Situ Stress in the Substrate

We investigate the orientation of cells on substrates to find possible methods for controlling the cellular orientation. The force dipole model is employed in our modelling and simulation. The elastic interaction between cells as well as the elastic interaction between the cell and in-situ stress field in the substrate are found to be the two main physical mechanisms to control the cellular orientation. The former interaction dominates the cellular orientation when the in-situ stress is small, while the later dominates when the in-situ stress is large enough. Two cells tend to align perpendicularly on a free substrate, but the cellular orientation varies with the increasing in-situ stress. Two cells tendto align in parallel when the normal stress is large enough. Their direction is perpendicular to the extension stress direction or parallel to the compression stress direction. When the positive in-situ shear stress is large enough, the two cells tend to align at -45°. Based on this theoretical simulation, it is believed that the cellular orientation on substrates can be controlled by thein-situ stresses.     

Applications of Oblique-Incidence Reflectivity Difference Method in Primary Study of Protein Biomolecules

Oblique-incidence reflectivity difference （OI-RD） analysis is applied to detect the immunoglobulin-G and cytochrome biomolecules on standard glass substrates without fluorescence labelling. The OI-RD intensities not only depend on the protein structure, but also vary with the protein concentration. The results indicate that this method should have potential applications in detection of biochemical processes.     

Chalcogenide Random Access Memory Cell with Structure of W Sub-Microtube Heater Electrode

In order to reduce the reset current of cllalcogenide random access memory; a W sub-microtube heater electrode with outer/inner diameter of 260/100nm, which was fabricated with standard 0.184-μm technology, is proposed for the first time to achieve a reset current of about 0.5 mA. The reasons may be that sub-microtube increases the number of electrode edge and thermal efficiency is improved greatly because the thermal density on the edge of sub-microtube electrode is generally the highest.     

A Coarse Estimation of Cell Size Region from a Mesoscopic Stochastic Cell Cycle Model

Based on a deterministic cell cycle model of fission yeast, the effects of the finite cell size on the cell cycle regulation in wee1- cdc25△ double mutant type are numerically studied by using of the chemical Langevin equations. It is found that at a certain region of cell size, our numerical results from the chemical Langevin equations are in good qualitative agreement with the experimental observations. The two resettings to the G2 phase from early stages of mitosis can be induced under the moderate cell size. The quantized cycle times can be observed during such a cell size region. Therefore, a coarse estimation of cell size is obtained from the mesoscopic stochastic cell cycle model.     

Numerical Investigation of Surface Plasmons Associated Subwavelength Optical Single-Pass Effect

Surface plasmons （SPs） associated optical single-pass effect has been investigated in novel subwavelength metallic structures, including single slit and grating structures. With influence of SPs, these metallic structures can enhance transmission in incident direction and suppress it in the opposite direction, exhibiting a single-pass effect. The finite difference time domain method is employed to study the influences of structure parameters on far-field transmission, near-field electric field distribution and extinction ratio of the single-pass transmission effect. A maximal extinction ratio of 47.83dB is achieved in the grating structure.     

Instrumentation of coherent X-ray imaging and the primary experimental results

Coherent X-ray microscopy has advanced towards higher-energy, more brilliant sources over the past decade since its demonstrations, and many advancements have been made towards optimizing this imaging technique. Here we present both the experimental instrument for obtaining diffraction patterns and the primary reconstruction of yeast cell 2D projection. In addition, the characteristics of the existing optics at BL29XUL of SPring-8 Facility and the method of image reconstruction are discussed.     

Three-dimensional particle-in-cell method of simulating high power terahertz gyrotrons with planar structure

Based on analyzing the large-signal theory of the planar gyrotron, it is suggested that a simplified structure of the device is used for simulating this kind of device, with the working characteristics of the device kept unchanged, i.e., the same as those of the device with the original structure. Thus, the computational burden can be significantly reduced. Using the proposed method, we simulate a planar gyrotron with its simplified parameters by using the UNIPIC-3D code. Numerical results show that the working frequency, output power, and electron efficiency are respectively about 0.813 THz, 14 kW, and 21%.     

Finite Size Effect for the First-Order Phase Transition of the Three-Dimensional Blume-Capel Model on a Cellular Automaton

The first-order phase transition of the three-dimensional Blume-Capel model is investigated using the cooling algorithm which is improved from Creutz Cellular Automaton at D/J = 2.9, i.e. a ratio of single-ion anisotropy constant to bilinear interaction energy. We test the efficiency of the algorithm and obtain the finite-size effects at the first-order phase transition point. The transition temperature is estimated using the probability distributions of the order parameter and the energy. The analysis of data at the transition point indicates that the magnetic susceptibility and the specific heat maxima increase with the system value （L^d）.