Cytochrome P450 (CYP) superfamily is one of the membership largest and function most diverse protein superfamily recogniozed among living beings. Members of this superfamily were further assigned to different families...Cytochrome P450 (CYP) superfamily is one of the membership largest and function most diverse protein superfamily recogniozed among living beings. Members of this superfamily were further assigned to different families and subfamilies based on their amino acid similarities. According to their phylogenetic relationships, the CYP genes which likely diverged from common ancestor gene and may share common functions were grouped into one clan. Widely distributing scallops are a group of the most conspicuous bivalve; however the studies on their CYP is acarce. In this study, we searched the genome and expressed sequence tags of Zhikong scallop (Chlamys farreri) for CYP genes. In total, 88 non-redundant CYP were identified, which were homed in 13 CYPs gene families. Phylogenetic analysis divided these genes into 4 CYP clans. As in deuterostomes, Clan 2 was the largest, which contained 33 genes belonging to CYP1, CYP2, CYP17 and CYP356 families. Clan 3 contgained 19 genes belonging to CYP3, CYP5 and CYP30 families. Clan 4 contained 23 genes, all belonging to CYP4 family. The mitochondrial CYP clan contained 9 genes belonging to CYP10 and CYP24 families. In comparison, protostomes (C. farreri, D. pluex, D. melanogaster) contained more CYP genes than deuterostomes (S. purpuratus and vertebrates) in Clan 2 but less genes in Clan 3 and Clan 4. Our findings will aid to deciphering CYP function and evolution in scallops and bivalves.展开更多
The numerical models of liquid-filled straight pipe system with active silencers are established. The inffuence of the near field of secondary source in the active silencers and the elasticity of pipe wall on active n...The numerical models of liquid-filled straight pipe system with active silencers are established. The inffuence of the near field of secondary source in the active silencers and the elasticity of pipe wall on active noise control performance under sound excitation is analyzed.The results show that the near field of secondary source is non-uniform, and the active control effect of some frequencies is poor or even the sound pressure level will increase when the error points are located in this region. The noise reduction can be increased by more than 10 d B when the error points are in the region of uniform sound field. The noise reduction of most frequencies can be increased by more than 5 d B by increasing the number of error points. The coupling between secondary source and pipe wall is strong because of the elasticity of pipe wall. Asymmetrically distributed secondary sources tend to excite the pipe wall vibration,which causes the troughs of control effect. The symmetrically distributed secondary sources can significantly improve the control effect. Increasing the number of secondary sources can improve the active-passive hybrid control effect of the system. However, it makes the sound field in the pipe more complex, and the active silencing effect of the models with multiple secondary sources decreases with increasing frequency.展开更多
基金supported by National Natural Science Foundation of China (30972239)National High-Tech R&D Program (863 Program, 2012AA092204, 2012AA-10A401 and 2012AA10A402)+2 种基金Doctoral Fund of Ministry of Education of China (20100132110014)Earmarked Fund for Modern Agro-industry Technology Research System, Natural Science Foundation of Shandong Province (ZR2009DM019)Seed Improvement Project of Shandong Province
文摘Cytochrome P450 (CYP) superfamily is one of the membership largest and function most diverse protein superfamily recogniozed among living beings. Members of this superfamily were further assigned to different families and subfamilies based on their amino acid similarities. According to their phylogenetic relationships, the CYP genes which likely diverged from common ancestor gene and may share common functions were grouped into one clan. Widely distributing scallops are a group of the most conspicuous bivalve; however the studies on their CYP is acarce. In this study, we searched the genome and expressed sequence tags of Zhikong scallop (Chlamys farreri) for CYP genes. In total, 88 non-redundant CYP were identified, which were homed in 13 CYPs gene families. Phylogenetic analysis divided these genes into 4 CYP clans. As in deuterostomes, Clan 2 was the largest, which contained 33 genes belonging to CYP1, CYP2, CYP17 and CYP356 families. Clan 3 contgained 19 genes belonging to CYP3, CYP5 and CYP30 families. Clan 4 contained 23 genes, all belonging to CYP4 family. The mitochondrial CYP clan contained 9 genes belonging to CYP10 and CYP24 families. In comparison, protostomes (C. farreri, D. pluex, D. melanogaster) contained more CYP genes than deuterostomes (S. purpuratus and vertebrates) in Clan 2 but less genes in Clan 3 and Clan 4. Our findings will aid to deciphering CYP function and evolution in scallops and bivalves.
基金supported by the National Natural Science Foundation of China (12004412)。
文摘The numerical models of liquid-filled straight pipe system with active silencers are established. The inffuence of the near field of secondary source in the active silencers and the elasticity of pipe wall on active noise control performance under sound excitation is analyzed.The results show that the near field of secondary source is non-uniform, and the active control effect of some frequencies is poor or even the sound pressure level will increase when the error points are located in this region. The noise reduction can be increased by more than 10 d B when the error points are in the region of uniform sound field. The noise reduction of most frequencies can be increased by more than 5 d B by increasing the number of error points. The coupling between secondary source and pipe wall is strong because of the elasticity of pipe wall. Asymmetrically distributed secondary sources tend to excite the pipe wall vibration,which causes the troughs of control effect. The symmetrically distributed secondary sources can significantly improve the control effect. Increasing the number of secondary sources can improve the active-passive hybrid control effect of the system. However, it makes the sound field in the pipe more complex, and the active silencing effect of the models with multiple secondary sources decreases with increasing frequency.
