The purpose of the study was to investigate the impact of rat cytomegalovirus （RCMV） infection on the development of the nervous system in rat embryos, and to evaluate the involvement of Wnt signaling pathway key mo...The purpose of the study was to investigate the impact of rat cytomegalovirus （RCMV） infection on the development of the nervous system in rat embryos, and to evaluate the involvement of Wnt signaling pathway key molecules and the downstream gene neurogenin 1 （Ngnl） in RCMV infected neural stem cells （NSCs）. Infection and control groups were established, each containing 20 pregnant Wistar rats. Rats in the infection group were inoculated with RCMV by intraperitoneal injection on the first day of pregnancy. Rat E20 embryos were taken to evaluate the teratogenic rate. NSCs were isolated from El3 embryos, and maintained in vitro. We found： 1） Poor fetal development was found in the infection group with low survival and high malformation rates. 2） The proliferation and differentiation of NSCs were affected. In the infection group, NSCs proliferated more slowly and had a lower neurosphere formation rate than the control. The differentiation ratio from NSCs to neurons and glial cells was significantly different from that of the control, showed by immunofluorescenee staining. 3） Ngnl mRNA expression and the nuclear p-catenin protein level were significantly lower than the control on day 2 when NSCs differentiated. 4） The Morris water maze test was performed on 4-week pups, and the infected rats were found worse in learning and memory ability. In a summary, RCMV infection caused abnormalities in the rat embryonic nervous system, significantly inhibited NSC proliferation and differentiation, and inhibited the expression of key molecules in the Wnt/β-catenin signaling pathway so as to affect NSCs differentiation. This may be an important mechanism by which RCMV causes embryonic nervous system abnormalities.展开更多
Ground vibration accelerations caused by the collapse of blasting demolition of urban viaducts was recorded in ordered to analyze the engineering characteristics and effects on the surrounding buildings. Through the a...Ground vibration accelerations caused by the collapse of blasting demolition of urban viaducts was recorded in ordered to analyze the engineering characteristics and effects on the surrounding buildings. Through the analysis of peak ground acceleration,peak frequency,duration and response spectra of the recorded vibrations in different acceleration arrays,some conclusions are drawn: the peak ground acceleration decreases with increasing distance, and the amplitude of vertical component is higher than that of the horizontal components,especially in near source region. The peak frequency of ground acceleration decreases with distance,and in near source region,it is larger than the natural frequency of the surrounding buildings,and thus it will not have much effect on the buildings. The duration of ground acceleration caused by collapse is longer than that caused by blasting itself. The vertical response spectrum is the largest of the three components,and it decreases rapidly in the near source region of about 30 m,but beyond that the distance decreases slowly.The horizontal components are smaller than the local seismic design spectrum,while the vertical component for natural period under 0.15 s exceeds the seismic design spectrum,but the natural periods of general buildings are usually beyond that domain,so this will not have much effect on the nearby buildings.展开更多
基金Shandong Province High-level Talent of Health 1020 Project Fund(No.2008-1)Science and Technology Creative Research of Weifang Medical University(No.K11TS1010)+1 种基金A Project of Shandong Province Higher Educational Science and Technology Program(No.J12LK04)National Natural Science Foundation of China(30900775)
文摘The purpose of the study was to investigate the impact of rat cytomegalovirus （RCMV） infection on the development of the nervous system in rat embryos, and to evaluate the involvement of Wnt signaling pathway key molecules and the downstream gene neurogenin 1 （Ngnl） in RCMV infected neural stem cells （NSCs）. Infection and control groups were established, each containing 20 pregnant Wistar rats. Rats in the infection group were inoculated with RCMV by intraperitoneal injection on the first day of pregnancy. Rat E20 embryos were taken to evaluate the teratogenic rate. NSCs were isolated from El3 embryos, and maintained in vitro. We found： 1） Poor fetal development was found in the infection group with low survival and high malformation rates. 2） The proliferation and differentiation of NSCs were affected. In the infection group, NSCs proliferated more slowly and had a lower neurosphere formation rate than the control. The differentiation ratio from NSCs to neurons and glial cells was significantly different from that of the control, showed by immunofluorescenee staining. 3） Ngnl mRNA expression and the nuclear p-catenin protein level were significantly lower than the control on day 2 when NSCs differentiated. 4） The Morris water maze test was performed on 4-week pups, and the infected rats were found worse in learning and memory ability. In a summary, RCMV infection caused abnormalities in the rat embryonic nervous system, significantly inhibited NSC proliferation and differentiation, and inhibited the expression of key molecules in the Wnt/β-catenin signaling pathway so as to affect NSCs differentiation. This may be an important mechanism by which RCMV causes embryonic nervous system abnormalities.
基金Sponsored by the National Natural Science Foundation of China(Grant No.51578516 and 51238012)the Basic Research Foundation of Institute of Engineering Mechanics,CEA(Grant No.2011B02)+1 种基金973 Program(Grant No.2011CB013601)the Wuhan Blasting Company
文摘Ground vibration accelerations caused by the collapse of blasting demolition of urban viaducts was recorded in ordered to analyze the engineering characteristics and effects on the surrounding buildings. Through the analysis of peak ground acceleration,peak frequency,duration and response spectra of the recorded vibrations in different acceleration arrays,some conclusions are drawn: the peak ground acceleration decreases with increasing distance, and the amplitude of vertical component is higher than that of the horizontal components,especially in near source region. The peak frequency of ground acceleration decreases with distance,and in near source region,it is larger than the natural frequency of the surrounding buildings,and thus it will not have much effect on the buildings. The duration of ground acceleration caused by collapse is longer than that caused by blasting itself. The vertical response spectrum is the largest of the three components,and it decreases rapidly in the near source region of about 30 m,but beyond that the distance decreases slowly.The horizontal components are smaller than the local seismic design spectrum,while the vertical component for natural period under 0.15 s exceeds the seismic design spectrum,but the natural periods of general buildings are usually beyond that domain,so this will not have much effect on the nearby buildings.
