PeerMD, a P2P molecular dynamics simulation frame-work based on Web services is proposed. It utilizes rich free CPU time and network bandwidth of P2P networks to provide enough resources for dynamics simulation of bio...PeerMD, a P2P molecular dynamics simulation frame-work based on Web services is proposed. It utilizes rich free CPU time and network bandwidth of P2P networks to provide enough resources for dynamics simulation of bio-macromolecule, and has resolved the problem that it is difficult to interoperate between heterogeneous peers in P2P environment through Web services. Structure of PeerMD is given. Function, input and output of molecular dynamics simulation Web service are defined. Processes of publishing, discovering and invoking of molecular dynamics simulation Web service based on multi-level SuperPeer are given. A protocol system of PeerMD is implemented on a basic P2P platform JXTA, and experimental simulations of tumor necrosis fact alpha （TNF-α） and two mutations of it are executed on the protocol system. Simulation results show that PeerMD can speed up molecular dynamics simulation perfectly.展开更多
To compare the anti-tumor effects of transmembrane TNF-α(TM-TNF)and secreted TNF-α(S-TNF)in vivo,mouse fibroblasts NIH3T3 were transfected separately with three types of retrovirus containing wild type TNF-α(Wt-TNF...To compare the anti-tumor effects of transmembrane TNF-α(TM-TNF)and secreted TNF-α(S-TNF)in vivo,mouse fibroblasts NIH3T3 were transfected separately with three types of retrovirus containing wild type TNF-α(Wt-TNF),TM-TNF mutant(TM-TNFm),S-TNF mutant(S-TNFm).Southern blot,RT-PCR,FACS and bioassay were used to investigate TNF-αgene integration,expression and its biological activity.It was found that both fixed cells and supernatant of NIH3T3/Wt-TNF,the fixed cells of NIH3T3/TM-TNFm and the supernatant of NIH3T3/S-TNFm could express high level of TNF-αor its mutants and effectively kill H22 in vitro.The transfected NIH3T3 were separately injected into the mice at the sites of H22 tumor cell inoculation according to a ratio of 5∶1 or 1∶1(effector/target cells,E/T)after the third day of H22 challenge,respectively.At the E/T=5∶1,the NIH3T3/TM-TNFm induced the highest tumor regression,while NIH3T3/S-TNFm exerted the strongest tumor depressing effect at the E/T=1∶1 in vivo.No obvious side effects were noted throughout the course of treatment.The results suggest that both TM-TNF and S-TNF could cause tumor regression.The anti-tumor effect of TM-TNF would be more powerful and safe than that of S-TNF at the proper E/T ratio.展开更多
An efficient Galerkin meshfree formulation for three dimensional simulation of large deformation failure evolution in soils is presented. This formulation utilizes the stabilized conforming nodal integration, where fo...An efficient Galerkin meshfree formulation for three dimensional simulation of large deformation failure evolution in soils is presented. This formulation utilizes the stabilized conforming nodal integration, where for the purpose of stability and efficiency a Lagrangian smoothing strain at nodal point is constructed and thereafter the internal energy is evaluated nodally. This formulation ensures the linear exactness, efficiency and spatial stability in a unified manner and it makes the conventional Galerkin meshfree method affordable for three dimensional simulation. The three dimensional implementation of stabilized conforming nodal integration is discussed in details. To model the failure evolution in soil medium a coupled elasto-plastic damage model is used and an objective stress integration algorithm in combination of elasto-damage predictor and plastic corrector method is employed for stress update. Two typical numerical examples are shown to demonstrate the effectiveness of the present method for modeling large deformation soil failure.展开更多
基金the National Natural Science Foundation of China(30670421,60773191).
文摘PeerMD, a P2P molecular dynamics simulation frame-work based on Web services is proposed. It utilizes rich free CPU time and network bandwidth of P2P networks to provide enough resources for dynamics simulation of bio-macromolecule, and has resolved the problem that it is difficult to interoperate between heterogeneous peers in P2P environment through Web services. Structure of PeerMD is given. Function, input and output of molecular dynamics simulation Web service are defined. Processes of publishing, discovering and invoking of molecular dynamics simulation Web service based on multi-level SuperPeer are given. A protocol system of PeerMD is implemented on a basic P2P platform JXTA, and experimental simulations of tumor necrosis fact alpha （TNF-α） and two mutations of it are executed on the protocol system. Simulation results show that PeerMD can speed up molecular dynamics simulation perfectly.
文摘To compare the anti-tumor effects of transmembrane TNF-α(TM-TNF)and secreted TNF-α(S-TNF)in vivo,mouse fibroblasts NIH3T3 were transfected separately with three types of retrovirus containing wild type TNF-α(Wt-TNF),TM-TNF mutant(TM-TNFm),S-TNF mutant(S-TNFm).Southern blot,RT-PCR,FACS and bioassay were used to investigate TNF-αgene integration,expression and its biological activity.It was found that both fixed cells and supernatant of NIH3T3/Wt-TNF,the fixed cells of NIH3T3/TM-TNFm and the supernatant of NIH3T3/S-TNFm could express high level of TNF-αor its mutants and effectively kill H22 in vitro.The transfected NIH3T3 were separately injected into the mice at the sites of H22 tumor cell inoculation according to a ratio of 5∶1 or 1∶1(effector/target cells,E/T)after the third day of H22 challenge,respectively.At the E/T=5∶1,the NIH3T3/TM-TNFm induced the highest tumor regression,while NIH3T3/S-TNFm exerted the strongest tumor depressing effect at the E/T=1∶1 in vivo.No obvious side effects were noted throughout the course of treatment.The results suggest that both TM-TNF and S-TNF could cause tumor regression.The anti-tumor effect of TM-TNF would be more powerful and safe than that of S-TNF at the proper E/T ratio.
基金supported by the National Natural Science Foundation of China (Grant Nos. 10972188, 10602049)the Program for New Century Excellent Talents in University from China Education Ministry (Grant No. NCET-09-0678)the Fundamental Research Funds for the Central Universities of China (Grant No. 2010121073)
文摘An efficient Galerkin meshfree formulation for three dimensional simulation of large deformation failure evolution in soils is presented. This formulation utilizes the stabilized conforming nodal integration, where for the purpose of stability and efficiency a Lagrangian smoothing strain at nodal point is constructed and thereafter the internal energy is evaluated nodally. This formulation ensures the linear exactness, efficiency and spatial stability in a unified manner and it makes the conventional Galerkin meshfree method affordable for three dimensional simulation. The three dimensional implementation of stabilized conforming nodal integration is discussed in details. To model the failure evolution in soil medium a coupled elasto-plastic damage model is used and an objective stress integration algorithm in combination of elasto-damage predictor and plastic corrector method is employed for stress update. Two typical numerical examples are shown to demonstrate the effectiveness of the present method for modeling large deformation soil failure.
