The effects of three different typical resistivity models(Spitzer, Z&L and M&G) on the performance of pulsed inductive acceleration plasma are studied. Numerical results show that their influences decrease with th...The effects of three different typical resistivity models(Spitzer, Z&L and M&G) on the performance of pulsed inductive acceleration plasma are studied. Numerical results show that their influences decrease with the increase of the plasma temperature. The significant discriminations among them appear at the plasma temperature lower than 2.5 eV, and the maximum gap of the pulsed inductive plasma accelerated efficiency is approximately 2.5%.Moreover, the pulsed inductive plasma accelerated efficiency is absolutely related to the dynamic impedance parameters, such as voltage, inductance, capacitance and flow rate. However, the distribution of the efficiency as a function of plasma temperature with three resistivity models has nothing to do with the dynamic impedance parameter.展开更多
DNA polymerases are an essential class of enzymes or molecular motors that catalyze processive DNA syntheses during DNA replications. A critical issue for DNA polymerases is their molecular mechanism of processive DNA...DNA polymerases are an essential class of enzymes or molecular motors that catalyze processive DNA syntheses during DNA replications. A critical issue for DNA polymerases is their molecular mechanism of processive DNA replication. We have proposed a model for chemomechanical coupling of DNA polymerases before, based on which the predicted results have been provided about the dependence of DNA replication velocity upon the external force on Klenow fragment of DNA polymerase I. Here, we performed single molecule measurements of the replication velocity of Klenow fragment under the external force by using magnetic tweezers. The single molecule data verified quantitatively the previous theoretical predictions, which is critical to the chemomechanical coupling mechanism of DNA polymerases. A prominent characteristic for the Klenow fragment is that the replication velocity is independent of the assisting force whereas the velocity increases largely with the increase of the resisting force,attains the maximum velocity at about 3.8 pN and then decreases with the further increase of the resisting force.展开更多
Objective To observe the effects of bak gene on killing MDR bladder cancer cells and to study its mechanisms. Methods Bak gene was transfected into MDR bladder cancer cells by liposome. The mRNA of bak and bcl-2 were ...Objective To observe the effects of bak gene on killing MDR bladder cancer cells and to study its mechanisms. Methods Bak gene was transfected into MDR bladder cancer cells by liposome. The mRNA of bak and bcl-2 were detected by in situ hybridization. The protein of bak and bcl-2 were detected by SABC immunohistochemistry. The growth rate of human bladder cancer cells was studied by constructing the growth curve, cell apoptosis being observed by flow cytometry, and the outline of cells observed by fluorescence stain. Results The expression of bak mRNA was positive in EJ/bak cells (64% ,P【0.05).Bak protein expression of EJ/bak cells was positive (60 % ) and bcl-2 protein expression was de creased (P【0.05). The growth of MDR bladder cancer cells was significantly inhibited by 32% after bak gene was transfected (P 【 0. 05 ). Apoptosis cells increased significantly. The apoptosis rate was 35 %. Apoptotic bodies can be found in these cells on fluorescence stain. Conclusion Bak gene could inhibit the growth展开更多
基金Supported by the Fund of Science and Technology on Vacuum Technology and Physics Laboratory of Lanzhou Institute of Physics under Grant No YSC0715the National Natural Science Foundation of China under Grant No 62601210the Civil Aerospace Technology Research Project under Grant No D010509
文摘The effects of three different typical resistivity models(Spitzer, Z&L and M&G) on the performance of pulsed inductive acceleration plasma are studied. Numerical results show that their influences decrease with the increase of the plasma temperature. The significant discriminations among them appear at the plasma temperature lower than 2.5 eV, and the maximum gap of the pulsed inductive plasma accelerated efficiency is approximately 2.5%.Moreover, the pulsed inductive plasma accelerated efficiency is absolutely related to the dynamic impedance parameters, such as voltage, inductance, capacitance and flow rate. However, the distribution of the efficiency as a function of plasma temperature with three resistivity models has nothing to do with the dynamic impedance parameter.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 11674381, 21991133, 11774407, 11874415, 1187441431770812)+3 种基金the Key Research Program on Frontier Science (Grant No. QYZDB-SSWSLH045)the National Key Research and Development Program of China (Grant No. 2016YFA0301500)the CAS Strategic Priority Research Program (Grant No. XDB37010100)the National Laboratory of Biomacromolecules (Grant No. 2020kf02)。
文摘DNA polymerases are an essential class of enzymes or molecular motors that catalyze processive DNA syntheses during DNA replications. A critical issue for DNA polymerases is their molecular mechanism of processive DNA replication. We have proposed a model for chemomechanical coupling of DNA polymerases before, based on which the predicted results have been provided about the dependence of DNA replication velocity upon the external force on Klenow fragment of DNA polymerase I. Here, we performed single molecule measurements of the replication velocity of Klenow fragment under the external force by using magnetic tweezers. The single molecule data verified quantitatively the previous theoretical predictions, which is critical to the chemomechanical coupling mechanism of DNA polymerases. A prominent characteristic for the Klenow fragment is that the replication velocity is independent of the assisting force whereas the velocity increases largely with the increase of the resisting force,attains the maximum velocity at about 3.8 pN and then decreases with the further increase of the resisting force.
文摘Objective To observe the effects of bak gene on killing MDR bladder cancer cells and to study its mechanisms. Methods Bak gene was transfected into MDR bladder cancer cells by liposome. The mRNA of bak and bcl-2 were detected by in situ hybridization. The protein of bak and bcl-2 were detected by SABC immunohistochemistry. The growth rate of human bladder cancer cells was studied by constructing the growth curve, cell apoptosis being observed by flow cytometry, and the outline of cells observed by fluorescence stain. Results The expression of bak mRNA was positive in EJ/bak cells (64% ,P【0.05).Bak protein expression of EJ/bak cells was positive (60 % ) and bcl-2 protein expression was de creased (P【0.05). The growth of MDR bladder cancer cells was significantly inhibited by 32% after bak gene was transfected (P 【 0. 05 ). Apoptosis cells increased significantly. The apoptosis rate was 35 %. Apoptotic bodies can be found in these cells on fluorescence stain. Conclusion Bak gene could inhibit the growth