The circuit testable realization and its fault detection for logic functions with ESOP （EXOR-Sum-Of-Products） expressions are studied. First of all, for the testable realization by using XOR gate cascade, a test set...The circuit testable realization and its fault detection for logic functions with ESOP （EXOR-Sum-Of-Products） expressions are studied. First of all, for the testable realization by using XOR gate cascade, a test set with 2n ＋ m ＋ 1 vectors for the detections of AND bridging faults and a test set with 2n ＋ m vectors for the detections of OR bridging faults are presented. Secondly, for the testable realization by using ）（OR gate tree, a test set with 2n ＋ m vectors for the detections of AND bridging faults and a test set with 3n ＋ m ＋ 1 vectors for the detections of OR bridging faults are presented. Finally, a single fault test set with n ＋ 5 vectors for the XOR gate tree realization is presented. Where n is the number of input variables and m is the number of product terms in a logic function.展开更多
The insect spruce budworm(Choristoneura fumiferana) produces antifreeze protein(AFP) to assist in the protection of the over-wintering larval stage and contains multiple isoforms. Structures for two isoforms,known as ...The insect spruce budworm(Choristoneura fumiferana) produces antifreeze protein(AFP) to assist in the protection of the over-wintering larval stage and contains multiple isoforms. Structures for two isoforms,known as CfAFP-501 and CfAFP-337,show that both possess similar left-handed β-helical structure,although thermal hysteresis activity of the longer isoform CfAFP-501 is three times that of CfAFP-337. The markedly enhanced activity of CfAFP-501 is not proportional to,and cannot be simply accounted for,by the increased ice-binding site resulting from the two extra coils in CfAFP-501. In or-der to investigate the molecular basis for the activity difference and gain better understanding of AFPs in general,we have employed several different computational methods to systematically study the structural properties and ice interactions of the AFPs and their deletion models. In the context of intact AFPs,a majority of the coils in CfAFP-501 has better ice interaction and causes stronger ice lattice disruption than CfAFP-337,strongly suggesting a cooperative or synergistic effect among β-helical coils. The synergistic effect would play a critical role and make significant contributions to the anti-freeze activity β-helical antifreeze proteins. This is the first time that synergistic effect and its implica-tion for antifreeze activity are reported for β-helical antifreeze proteins.展开更多
Platinum-based antitumour drug ZD0473 was designed to reduce the cisplatin resistance to the tumor cells. In this paper, the mixed method of molecular mechanics and quantum chemistry, HF/lanl2dz// MM/uff and B3LYP/lan...Platinum-based antitumour drug ZD0473 was designed to reduce the cisplatin resistance to the tumor cells. In this paper, the mixed method of molecular mechanics and quantum chemistry, HF/lanl2dz// MM/uff and B3LYP/lanl2dz//6-31G*, are used to investigate the differences between four types of GG, 3′AG5′, 3′GA5′, and AA complexes, which are formed from four discrete DNA fragments recognized by ZD0473 and cisplatin. The results show that the binding interaction of both ZD0473 and cisplatin drugs with the GG base pair is much stronger than with other base pairs, namely the recognition capability of such drugs to the GG base pair is more considerable. Moreover, the interaction of four complexes of ZD0473 with DNA fragments is stronger than that of cisplatin with corresponding DNA fragments, which indicates the stronger binding capability of ZD0473 with DNA fragments and high antitumour activity of ZD0473. The main reason for easier forming of 3′GA5′ complex than the 3′AG5′ one is that the drug molecule prefers to bind with a single G base to form a monoligand compound firstly; then the con- figuration transformation from such monoligand compound to the bi-ligand one is limited.展开更多
Based on the computational simulation with the vacuum environment for the fish-type-II antifreeze protein-ice-solvent(water)system,the multi-complex system of the antifreeze protein-ice-water has been constructed and ...Based on the computational simulation with the vacuum environment for the fish-type-II antifreeze protein-ice-solvent(water)system,the multi-complex system of the antifreeze protein-ice-water has been constructed and calculated.We have studied the interaction of such proteinice system with water solvent through the dynamics simula-tion with 350 ps.By employing the Molecular Dynamics simulation and semi-empirical method calculation,we have further investigated the interface properties of the antifreeze protein and ice crystal combined system.Consequently,a water solvent affects significantly the properties of this combined system.展开更多
基金Supported by the National Natural Science Foundation of China (No.60006002)the Education Department of Guangdong Province of China (No.02019).
文摘The circuit testable realization and its fault detection for logic functions with ESOP （EXOR-Sum-Of-Products） expressions are studied. First of all, for the testable realization by using XOR gate cascade, a test set with 2n ＋ m ＋ 1 vectors for the detections of AND bridging faults and a test set with 2n ＋ m vectors for the detections of OR bridging faults are presented. Secondly, for the testable realization by using ）（OR gate tree, a test set with 2n ＋ m vectors for the detections of AND bridging faults and a test set with 3n ＋ m ＋ 1 vectors for the detections of OR bridging faults are presented. Finally, a single fault test set with n ＋ 5 vectors for the XOR gate tree realization is presented. Where n is the number of input variables and m is the number of product terms in a logic function.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 26073011, 20231010, 20503002 and 20631020)the Major State Basic Research Development Programs (Grant No. G2004CB719900)
文摘The insect spruce budworm(Choristoneura fumiferana) produces antifreeze protein(AFP) to assist in the protection of the over-wintering larval stage and contains multiple isoforms. Structures for two isoforms,known as CfAFP-501 and CfAFP-337,show that both possess similar left-handed β-helical structure,although thermal hysteresis activity of the longer isoform CfAFP-501 is three times that of CfAFP-337. The markedly enhanced activity of CfAFP-501 is not proportional to,and cannot be simply accounted for,by the increased ice-binding site resulting from the two extra coils in CfAFP-501. In or-der to investigate the molecular basis for the activity difference and gain better understanding of AFPs in general,we have employed several different computational methods to systematically study the structural properties and ice interactions of the AFPs and their deletion models. In the context of intact AFPs,a majority of the coils in CfAFP-501 has better ice interaction and causes stronger ice lattice disruption than CfAFP-337,strongly suggesting a cooperative or synergistic effect among β-helical coils. The synergistic effect would play a critical role and make significant contributions to the anti-freeze activity β-helical antifreeze proteins. This is the first time that synergistic effect and its implica-tion for antifreeze activity are reported for β-helical antifreeze proteins.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 20673011, 20231010, 20631020)the Major State Basic Research Development Programs (Grant No. G2004CB719900)
文摘Platinum-based antitumour drug ZD0473 was designed to reduce the cisplatin resistance to the tumor cells. In this paper, the mixed method of molecular mechanics and quantum chemistry, HF/lanl2dz// MM/uff and B3LYP/lanl2dz//6-31G*, are used to investigate the differences between four types of GG, 3′AG5′, 3′GA5′, and AA complexes, which are formed from four discrete DNA fragments recognized by ZD0473 and cisplatin. The results show that the binding interaction of both ZD0473 and cisplatin drugs with the GG base pair is much stronger than with other base pairs, namely the recognition capability of such drugs to the GG base pair is more considerable. Moreover, the interaction of four complexes of ZD0473 with DNA fragments is stronger than that of cisplatin with corresponding DNA fragments, which indicates the stronger binding capability of ZD0473 with DNA fragments and high antitumour activity of ZD0473. The main reason for easier forming of 3′GA5′ complex than the 3′AG5′ one is that the drug molecule prefers to bind with a single G base to form a monoligand compound firstly; then the con- figuration transformation from such monoligand compound to the bi-ligand one is limited.
基金This work was supported by the National Natural Science Foundation of China(No.20271009,20231010,20403003,20503002)the Major State Basic Research Development Program(No.G2004CB719900).
文摘Based on the computational simulation with the vacuum environment for the fish-type-II antifreeze protein-ice-solvent(water)system,the multi-complex system of the antifreeze protein-ice-water has been constructed and calculated.We have studied the interaction of such proteinice system with water solvent through the dynamics simula-tion with 350 ps.By employing the Molecular Dynamics simulation and semi-empirical method calculation,we have further investigated the interface properties of the antifreeze protein and ice crystal combined system.Consequently,a water solvent affects significantly the properties of this combined system.
