Background： CYP11A1, a gene belonging to the family 11 of cytochrome P450, encodes a crucial steroidogenic enzyme that catalyzes the initial step in the production of all classes of steroids. Many studies show that C...Background： CYP11A1, a gene belonging to the family 11 of cytochrome P450, encodes a crucial steroidogenic enzyme that catalyzes the initial step in the production of all classes of steroids. Many studies show that CYP11A1 plays a role in ovary function. However, the role of CYP11A1 in goose reproductive cycle remains largely unknown.Results： In this study, full-length CYP11A1 c DNA of Zhedong goose was obtained using reverse transcription polymerase chain reaction（RT-PCR） and rapid amplification of c DNA ends（RACE）. The c DNA consisted of a 96-base pair（bp） 5′untranslated region（UTR）, a 179-bp 3′UTR and a 1509-bp open reading frame. The open reading frame encodes a putative 503 amino acid protein that shares high homology with CYP11A1 of other birds. The amino acid sequence possesses conserved domains of the P450 superfamily, which include the steroid-binding domain and the heme-binding region. Real-time quantitative polymerase chain reaction（q PCR） analysis revealed CYP11A1 mR NA was expressed ubiquitously in every Zhedong goose tissue analyzed, including the heart, liver, glandular stomach,lung, spleen, kidney, intestinum tenue, intestinum crassum, cerebrum, cerebellum, muscle, oviduct, pituitary,hypothalamus and ovary.. The relatively low levels of CYP11A1 m RNA were detected in pituitary, ovary and oviduct tissues at ovulation when compared with levels at oviposition. Interestingly, higher expression was observed in ovary and oviduct tissues during brooding. Lastly, higher m RNA expression of Yangzhou geese was detected during the ovulation period than that of Zhedong geese.Conclusions： Our findings reveal the sequence characterization and expression patterns of the CYP11A1 gene during the goose reproductive cycle, which may provides correlative evidence that CYP11A1 expression is important in reproduction activity.展开更多
This paper puts forward a high-speed train bogie active stability method,based on frame lateral vibration control,for improving the stability and critical speed of railway vehicles at high speeds.Two inertial actuator...This paper puts forward a high-speed train bogie active stability method,based on frame lateral vibration control,for improving the stability and critical speed of railway vehicles at high speeds.Two inertial actuators apply active control forces to the front and rear end beams of the bogie frame.A scale model of bogie lateral dynamics is established,as well as the state space equation of the control system.Also,the multi-objective optimization is used to construct state feedback parameters,which take hunting stability and control effort into account.Furthermore,the effects of time-delay in the control system and suspension parameters on bogie hunting stability are studied.The dynamic behaviors and the stability mechanism of the bogie control system are analyzed.Finally,a 1:5 scale test rig is used to conduct a bogie active stability experiment.The results reveal that active control of frame lateral vibration can effectively improve the bogie system's hunting stability margin at high speeds,but time-delay in the control system cannot be ignored.展开更多
基金the earmarked fund for Modern Agro-industry Technology Research System (CARS-43-3)the Agricultural Science and Technology Independent Innovation Fund of Jiangsu Province (CX(13)2034)the Priority Academic Program Development of Jiangsu Higher Education Institutions (2011–137)
文摘Background： CYP11A1, a gene belonging to the family 11 of cytochrome P450, encodes a crucial steroidogenic enzyme that catalyzes the initial step in the production of all classes of steroids. Many studies show that CYP11A1 plays a role in ovary function. However, the role of CYP11A1 in goose reproductive cycle remains largely unknown.Results： In this study, full-length CYP11A1 c DNA of Zhedong goose was obtained using reverse transcription polymerase chain reaction（RT-PCR） and rapid amplification of c DNA ends（RACE）. The c DNA consisted of a 96-base pair（bp） 5′untranslated region（UTR）, a 179-bp 3′UTR and a 1509-bp open reading frame. The open reading frame encodes a putative 503 amino acid protein that shares high homology with CYP11A1 of other birds. The amino acid sequence possesses conserved domains of the P450 superfamily, which include the steroid-binding domain and the heme-binding region. Real-time quantitative polymerase chain reaction（q PCR） analysis revealed CYP11A1 mR NA was expressed ubiquitously in every Zhedong goose tissue analyzed, including the heart, liver, glandular stomach,lung, spleen, kidney, intestinum tenue, intestinum crassum, cerebrum, cerebellum, muscle, oviduct, pituitary,hypothalamus and ovary.. The relatively low levels of CYP11A1 m RNA were detected in pituitary, ovary and oviduct tissues at ovulation when compared with levels at oviposition. Interestingly, higher expression was observed in ovary and oviduct tissues during brooding. Lastly, higher m RNA expression of Yangzhou geese was detected during the ovulation period than that of Zhedong geese.Conclusions： Our findings reveal the sequence characterization and expression patterns of the CYP11A1 gene during the goose reproductive cycle, which may provides correlative evidence that CYP11A1 expression is important in reproduction activity.
基金supported by the National Railway Group Science and Technology Program(Nos.N2020J026 and N2021J028)the Independent Research and Development Projects of Traction Power State Key Laboratory(No.2022TPL-T02),China。
文摘This paper puts forward a high-speed train bogie active stability method,based on frame lateral vibration control,for improving the stability and critical speed of railway vehicles at high speeds.Two inertial actuators apply active control forces to the front and rear end beams of the bogie frame.A scale model of bogie lateral dynamics is established,as well as the state space equation of the control system.Also,the multi-objective optimization is used to construct state feedback parameters,which take hunting stability and control effort into account.Furthermore,the effects of time-delay in the control system and suspension parameters on bogie hunting stability are studied.The dynamic behaviors and the stability mechanism of the bogie control system are analyzed.Finally,a 1:5 scale test rig is used to conduct a bogie active stability experiment.The results reveal that active control of frame lateral vibration can effectively improve the bogie system's hunting stability margin at high speeds,but time-delay in the control system cannot be ignored.
