The forward-backward multiplicity and correlations of a target evaporated fragment （black track particle） and target recoiled proton （grey track particle） emitted from 150 A MeV 4He, 290 A MeV ^12C, 400 A MeV ^12C...The forward-backward multiplicity and correlations of a target evaporated fragment （black track particle） and target recoiled proton （grey track particle） emitted from 150 A MeV 4He, 290 A MeV ^12C, 400 A MeV ^12C, 400 A MeV ^20Ne and 500 A MeV ^56Fe induced different types of nuclear emulsion target interactions are investigated. It is found that the forward and backward averaged multiplicity of a grey, black and heavily ionized track particle increases with the increase of the target size. The averaged multiplicity of a forward black track particle, backward black track particle, and backward grey track particle do not depend on the projectile size and energy, but the averaged multiplicity of a forward grey track particle increases with an increase of projectile size and energy. The backward grey track particle multiplicity distribution follows an exponential decay law and the decay constant decreases with an increase of target size. The backward-forward multiplicity correlations follow linear law which is independent of the projectile size and energy, and the saturation effect is observed in some heavy target data sets.展开更多
A study of intermittency of target associated fragments produced in the interactions of ^16O- AgBr at 4.5 AGeV/c with nuclear emulsion using the method of factorial moments, F4, has been performed. The dependence of t...A study of intermittency of target associated fragments produced in the interactions of ^16O- AgBr at 4.5 AGeV/c with nuclear emulsion using the method of factorial moments, F4, has been performed. The dependence of the moments on the number of bins M is found to follow a power law behavior for the experimental data in terms of new scaled variable Х（Z） suggested by Bialas and Gazdzicki. The anomalous dimensions, dq, increase linearly with the order of moments, q. This observation indicates the association of multifractility with production mechanism of target associated fragments.展开更多
Multiplicity fluctuation of the target residues emitted in the interactions in a wide range of projectile energies from 500 A MeV to 60 A GeV is investigated in the framework of two-dimensional scaled factorial moment...Multiplicity fluctuation of the target residues emitted in the interactions in a wide range of projectile energies from 500 A MeV to 60 A GeV is investigated in the framework of two-dimensional scaled factorial moment methodology. The evidence of non-statistical multiplicity fluctuation is found in 160-AgBr collisions at 60 A GeV, but not in 56Fe-AgBr collisions at 500 A MeV, 84Kr-AgBr collisions at 1.7 A GeV, 16O-AgBr collisions at 3.7 A GeV and 197Au-AgBr collisions at 10.7 A GeV.展开更多
An enhanced neutron production and an enhanced nuclear destruction due to secondary fragments have been observed in very thick targets irradiated with high energy ions. This enhancement is beyond theoretical calculati...An enhanced neutron production and an enhanced nuclear destruction due to secondary fragments have been observed in very thick targets irradiated with high energy ions. This enhancement is beyond theoretical calculations and it is an unresolved problem. It is observed only when primary ion interactions exceed an energy threshold (ECM/u ≈ 150 MeV). Investigations using nuclear emulsions for very high-energy nuclear reactions suggest that two distinctly different classes of relativistic projectile-like fragments are emitted in primary interactions: a “cool” channel with a temperature of (T(p)cool ≈ 10 MeV), and a “hot” channel with (T(p)hot ≈ 40 MeV. This second reaction class may induce the above mentioned enhanced reactions of secondary fragments, thus being responsible for unresolved problems. This assumption should be studied in further experiments. Nuclear interactions of secondary particles in thick targets are of interest, in particular in view of radiation protection needs for high energy and high intensity heavy ion accelerators. Many basic ideas of this paper go back to the late Professor E. Schopper (Frankfurt).展开更多
There were 6 target DNA fragments of the three parental strains existing in the cell of GEMs(genetically engineered microorganism strain) Fhhh measured in this research by PCR(polymerase chain reaction). The determina...There were 6 target DNA fragments of the three parental strains existing in the cell of GEMs(genetically engineered microorganism strain) Fhhh measured in this research by PCR(polymerase chain reaction). The determination showed that GEMs Fhhh contained all the 6 target DNA fragments, mnp 1, mnp 2、 lip 1、 lip 2, FLO 1 and 16S rDNA, and had the molecular genetic stability. Meanwhile the PCR production of each parental strain could only had its target DNA fragments and was different from each other. It may illustrate that the technique of the inter kingdom protoplast fusion for the construction of GEMs Fhhh through the process of intercellular gene recombination could be used as a reliable bioengineering technique to create the specific functional stain for the pollution control.展开更多
Abnormal expression or mutations in Ras proteins has been found in up to 30% of cancer cell types, making them excellent protein models to probe structure-function relationships of cell-signaling processes that mediat...Abnormal expression or mutations in Ras proteins has been found in up to 30% of cancer cell types, making them excellent protein models to probe structure-function relationships of cell-signaling processes that mediate cell transformtion. Yet, there has been very little development of therapies to help tackle Ras-related diseased states. The development of small molecules to target Ras proteins to potentially inhibit abnormal Ras-stimulated cell signaling has been conceptualized and some progress has been made over the last 16 or so years. Here, we briefly review studies characterizing Ras protein-small molecule interactions to show the importance and potential that these small molecules may have for Ras-related drug discovery. We summarize recent results, highlighting small molecules that can be directly targeted to Ras using Structure-Based Drug Design (SBDD) and Fragment-Based Lead Discovery (FBLD) methods. The inactivation of Ras oncogenic signaling in vitro by small molecules is currently an attractive hurdle to try to and leap over in order to attack the oncogenic state. In this regard, important features of previously characterized properties of small molecule Ras targets, as well as a current understanding of conformational and dynamics changes seen for Ras-related mutants, relative to wild type, must be taken into account as newer small molecule design strategies towards Ras are developed.展开更多
基金Supported by National Science Foundation of China(11075100)Natural Science Foundation of Shanxi Province,China(20110110012)Shanxi Provincial Foundation for Returned Overseas Chinese Scholars,China(2011-058)
文摘The forward-backward multiplicity and correlations of a target evaporated fragment （black track particle） and target recoiled proton （grey track particle） emitted from 150 A MeV 4He, 290 A MeV ^12C, 400 A MeV ^12C, 400 A MeV ^20Ne and 500 A MeV ^56Fe induced different types of nuclear emulsion target interactions are investigated. It is found that the forward and backward averaged multiplicity of a grey, black and heavily ionized track particle increases with the increase of the target size. The averaged multiplicity of a forward black track particle, backward black track particle, and backward grey track particle do not depend on the projectile size and energy, but the averaged multiplicity of a forward grey track particle increases with an increase of projectile size and energy. The backward grey track particle multiplicity distribution follows an exponential decay law and the decay constant decreases with an increase of target size. The backward-forward multiplicity correlations follow linear law which is independent of the projectile size and energy, and the saturation effect is observed in some heavy target data sets.
基金National Natural Science Foundation of China(10675077,10475054)Shanxi Provincial Natural Science Foundation(2007011005)Shanxi Provincial Science Foundation for Youths(20051002)
文摘A study of intermittency of target associated fragments produced in the interactions of ^16O- AgBr at 4.5 AGeV/c with nuclear emulsion using the method of factorial moments, F4, has been performed. The dependence of the moments on the number of bins M is found to follow a power law behavior for the experimental data in terms of new scaled variable Х（Z） suggested by Bialas and Gazdzicki. The anomalous dimensions, dq, increase linearly with the order of moments, q. This observation indicates the association of multifractility with production mechanism of target associated fragments.
基金supported by the National Natural Science Foundation of China(Grant No. 10475054)the Natural Science Foundation of Shanxi Province,China(Grant No. 2008011005)the Shanxi Provincial Foundation for Returned Scholars of China
文摘Multiplicity fluctuation of the target residues emitted in the interactions in a wide range of projectile energies from 500 A MeV to 60 A GeV is investigated in the framework of two-dimensional scaled factorial moment methodology. The evidence of non-statistical multiplicity fluctuation is found in 160-AgBr collisions at 60 A GeV, but not in 56Fe-AgBr collisions at 500 A MeV, 84Kr-AgBr collisions at 1.7 A GeV, 16O-AgBr collisions at 3.7 A GeV and 197Au-AgBr collisions at 10.7 A GeV.
文摘An enhanced neutron production and an enhanced nuclear destruction due to secondary fragments have been observed in very thick targets irradiated with high energy ions. This enhancement is beyond theoretical calculations and it is an unresolved problem. It is observed only when primary ion interactions exceed an energy threshold (ECM/u ≈ 150 MeV). Investigations using nuclear emulsions for very high-energy nuclear reactions suggest that two distinctly different classes of relativistic projectile-like fragments are emitted in primary interactions: a “cool” channel with a temperature of (T(p)cool ≈ 10 MeV), and a “hot” channel with (T(p)hot ≈ 40 MeV. This second reaction class may induce the above mentioned enhanced reactions of secondary fragments, thus being responsible for unresolved problems. This assumption should be studied in further experiments. Nuclear interactions of secondary particles in thick targets are of interest, in particular in view of radiation protection needs for high energy and high intensity heavy ion accelerators. Many basic ideas of this paper go back to the late Professor E. Schopper (Frankfurt).
文摘There were 6 target DNA fragments of the three parental strains existing in the cell of GEMs(genetically engineered microorganism strain) Fhhh measured in this research by PCR(polymerase chain reaction). The determination showed that GEMs Fhhh contained all the 6 target DNA fragments, mnp 1, mnp 2、 lip 1、 lip 2, FLO 1 and 16S rDNA, and had the molecular genetic stability. Meanwhile the PCR production of each parental strain could only had its target DNA fragments and was different from each other. It may illustrate that the technique of the inter kingdom protoplast fusion for the construction of GEMs Fhhh through the process of intercellular gene recombination could be used as a reliable bioengineering technique to create the specific functional stain for the pollution control.
文摘Abnormal expression or mutations in Ras proteins has been found in up to 30% of cancer cell types, making them excellent protein models to probe structure-function relationships of cell-signaling processes that mediate cell transformtion. Yet, there has been very little development of therapies to help tackle Ras-related diseased states. The development of small molecules to target Ras proteins to potentially inhibit abnormal Ras-stimulated cell signaling has been conceptualized and some progress has been made over the last 16 or so years. Here, we briefly review studies characterizing Ras protein-small molecule interactions to show the importance and potential that these small molecules may have for Ras-related drug discovery. We summarize recent results, highlighting small molecules that can be directly targeted to Ras using Structure-Based Drug Design (SBDD) and Fragment-Based Lead Discovery (FBLD) methods. The inactivation of Ras oncogenic signaling in vitro by small molecules is currently an attractive hurdle to try to and leap over in order to attack the oncogenic state. In this regard, important features of previously characterized properties of small molecule Ras targets, as well as a current understanding of conformational and dynamics changes seen for Ras-related mutants, relative to wild type, must be taken into account as newer small molecule design strategies towards Ras are developed.
