TCR engagement of immature CD4+CD8+ thymocytes induces clonal maturation (positive selection) as well as clonal deletion (negative selection) in the thymus. However, the cell death execution events of thymocytes during the negative selection process remain obscure. Using a cell-free system, we identified two different DNase activities in the cytosol of in vivo anti-TCR-stimulated murine thymocytes: one that induced chromosomal DNA fragmentation, which was inhibited by an inhibitor of caspase-activated DNase, and another that induced plasmid DNA degradation, which was not inhibited by an inhibitor of caspase-activated DNase. We purified the protein to homogeneity that induced plasmid DNA degradation from the cytosol of anti-CD3-stimulated thymocytes and found that it is identical with cyclophilin B (Cyp B), which was reported to locate in endoplasmic reticulum. Ab against Cyp B specifically inhibited the DNA degradation activity in the cytosol of anti-CD3-stimulated thymocytes. Furthermore, recombinant Cyp B induced DNA degradation of naked nuclei, but did not induce internucleosomal DNA fragmentation. Finally, we demonstrated that TCR engagement of a murine T cell line (EL4) with anti-CD3/CD28 resulted in the release of Cyp B from the microsome fraction to the cytosol/nuclear fraction. Our data strongly suggest that both active caspase-activated DNase and Cyp B may participate in the induction of chromosomal DNA degradation during cell death execution of TCR-stimulated thymocytes.

With the continuous development of the computer network and popularization, the computer network has brought endless resources, but the resulting network security problem also becomes very important. The article mainly introduced based on WINDOWS system environment of small and medium-sized network security control and virus prevention and control strategies. In order to secure the safe and efficient operation of all work, to guarantee the network security and normal use of the system. Network security relative to our actual life is indispensable. At the same time, we must always pay heed to the construction of computer network security.

The water-based gravure ink contains no volatile organic solvents and makes little environmental pollution, so it will be used widely as one promising environment-protecting ink. The dryness of water-based ink is always one hard point, because the printing carrier plastic hasn’t absorbability. To improve the dryness speed, the use of shallow version reducing the transfer is a common way. In order to reach the quality requirements of the graver press, the ink with high pigment is necessary. In this text getting printable ink samples, the primary ink that is dispersed by high-speed grinding is maxed with good- compatible water-based resin, co-solvent and auxiliary in proportion. Then getting the proof of the ink using IGT F1, the viscosity, size distribution, color density were tested . The influence of pigment/binder ratio to the viscosity, dispersibility and adherence of the ink were discussed. The result indicates that with the pigment/binder ratio promoting, the viscosity of the primary ink is decreasing. The dispersibility of primary ink is influenced by the pigment/binder ratio, when the pigment/binder is 2:1 ,the size of ink is the smallest. The pigment/binder ratio in primary ink has a certain influence to the adherence and the apparent performances of the ink. And the color density and the gloss of the proof are also influenced.

Cam mechanisms are widely used in automated machines. Globoid cam has received widespread attention for its eminent kinematics and dynamic performance in research and application. As a commonly used cam mechanism in industry, especially in the field of industrial robots, Globoid Cam has the advantages of being highly efficient, highly accurate and relatively cheap. This study used ProEngineer to create a 3D model of the Globoid Cam mechanism. This paper describes the steps used to create a 3D model of the Globoid Cam, and the basic principles behind the parametric 3D modeling method.

Cam mechanisms are widely used in automated machines. Conjugate cams have become popular for its eminent kinematics and dynamic performance in research and in industry. As a commonly used cam mechanism in industry, especially in automatic pin insertion machines, conjugate cams have the advantages of being highly efficient, highly accurate and relatively cheap. A parametric simulation method was used to create a conjugate cam profile. This paper describes the steps used to create 3D models of the conjugate cam and the basic principles used to simulate the motion of cam mechanisms. The motion simulations were done with the parametric 3D modeling method using Creo Parametric Software.