Objective: Neurological evaluation is commonly applied to identify ischemia in focal cerebral ischemia model though it might not be sensitive. In present study, we hired sleeping time to assess ischemia occurrence. Me...Objective: Neurological evaluation is commonly applied to identify ischemia in focal cerebral ischemia model though it might not be sensitive. In present study, we hired sleeping time to assess ischemia occurrence. Methods: Permanent middle cerebral artery occlusion was induced in Sprague-Dawley rats under pentobarbital and ketamine anesthesia respectively. Sleeping time was recorded. Neurological evaluation was conducted by modified Bederson’s scoring system at 4 h and histopathological evaluation was performed at 3 d after middle cerebral artery occlusion. Results: Slices of brain stained by TTC, H&E and hoechst 33258 revealed extensive lesion in the two ischemic groups. The sensitivity to identify ischemia by neurological evaluation was 62.5%, but it was 81.3% and 80% respectively when evaluating by sleeping time (pentobarbital: ≥90.7 min, ketamine: ≥36.1 min). The sensitivity to identify ischemia by sleeping time was significantly higher than that by neurological evaluation (P<0.05). Conclusion: Our results suggested that to identify ischemia by sleeping time is a simple and sensitive method in the setting of focal cerebral ischemia in rat.展开更多
The issue of CCF （common cause failure） in digital I ＆ C （instrumentation and control） systems is of great interest because an increasing number of such systems are implemented in nuclear power plants. For the mi...The issue of CCF （common cause failure） in digital I ＆ C （instrumentation and control） systems is of great interest because an increasing number of such systems are implemented in nuclear power plants. For the mitigation of ATWS （anticipated transients without scram） as well as CCF within the PPS （plant protection system） and the ESF-CCS （engineered safety feature-component control system）, the ADPS （advanced diverse protection system） has been developed by KEPCO E ＆ C （KEPCO Engineering and Construction） Company for new nuclear units in Korea. As compared to the DPS （diverse protection system） design of APR1400, the ADPS has a diverse safety injection function considering a LBLOCA （large break loss of coolant accident） concurrent with the CCF of the PPS and ESF-CCS. Besides the function of SIAS （safety injection actuation signal） initiation, several CCF avoidance features, such as the changes of software design classification, communication methods, equipment platform, and man-machine interfaces, are introduced to enhance the reliability of the ADPS. In addition, the ADPS has recently incorporated four redundant channels with 2-out-of-4 voting logics to enhance its fault tolerant capability. Therefore, it is expected that the ADPS can provide an enhanced reliability regarding possible CCFs in the safety-grade digital I ＆ C systems as well as the ADPS itself.展开更多
Objective：There are a great number of modified models based on the four-vessel occlusion（4VO）model of Pulsinelli and Brierley which has been used worldwide for brain ischemia research.However,up to now the problems...Objective：There are a great number of modified models based on the four-vessel occlusion（4VO）model of Pulsinelli and Brierley which has been used worldwide for brain ischemia research.However,up to now the problems of collateral circulations of 4VO and the difficulty in arranging a surgery to occlude the basilar artery in other models are not satisfactorily solved yet.In this study,an improved 4-vessel occlusion（I4VO）rat model which is easy to handle and able to decrease the effect of collateral circulation is reported.Methods：The common carotid arteries and the beginning of the subclavical arteries of rats were occluded for different time by one-stage apertura thoracis superior approach.Neurological deficit scores defined by the modified Garcia scoring system and histopathological method were used to evaluate the effects of this model up to 7 days after reperfusion.Results：The neurological scores in the 15-min and 25-min groups decreased significantly at 24,48 and 72 hours after reperfusion（P〈0.05）,and the histopathologic study showed that there were stable,symmetrical changes of lesions in bilateral hippocampus in all the ischemia samples from two ischemia groups compared with sham operated group（P〈0.05）.Conclusion：This modified model is safe,easy,reliable,stable,mini-invasive as well as time-saving in making bilateral hemispheric ischemia,which can effectively decrease collateral circulations and meanwhile lead to stable lesions in hippocampus and cortex.展开更多
文摘Objective: Neurological evaluation is commonly applied to identify ischemia in focal cerebral ischemia model though it might not be sensitive. In present study, we hired sleeping time to assess ischemia occurrence. Methods: Permanent middle cerebral artery occlusion was induced in Sprague-Dawley rats under pentobarbital and ketamine anesthesia respectively. Sleeping time was recorded. Neurological evaluation was conducted by modified Bederson’s scoring system at 4 h and histopathological evaluation was performed at 3 d after middle cerebral artery occlusion. Results: Slices of brain stained by TTC, H&E and hoechst 33258 revealed extensive lesion in the two ischemic groups. The sensitivity to identify ischemia by neurological evaluation was 62.5%, but it was 81.3% and 80% respectively when evaluating by sleeping time (pentobarbital: ≥90.7 min, ketamine: ≥36.1 min). The sensitivity to identify ischemia by sleeping time was significantly higher than that by neurological evaluation (P<0.05). Conclusion: Our results suggested that to identify ischemia by sleeping time is a simple and sensitive method in the setting of focal cerebral ischemia in rat.
文摘The issue of CCF （common cause failure） in digital I ＆ C （instrumentation and control） systems is of great interest because an increasing number of such systems are implemented in nuclear power plants. For the mitigation of ATWS （anticipated transients without scram） as well as CCF within the PPS （plant protection system） and the ESF-CCS （engineered safety feature-component control system）, the ADPS （advanced diverse protection system） has been developed by KEPCO E ＆ C （KEPCO Engineering and Construction） Company for new nuclear units in Korea. As compared to the DPS （diverse protection system） design of APR1400, the ADPS has a diverse safety injection function considering a LBLOCA （large break loss of coolant accident） concurrent with the CCF of the PPS and ESF-CCS. Besides the function of SIAS （safety injection actuation signal） initiation, several CCF avoidance features, such as the changes of software design classification, communication methods, equipment platform, and man-machine interfaces, are introduced to enhance the reliability of the ADPS. In addition, the ADPS has recently incorporated four redundant channels with 2-out-of-4 voting logics to enhance its fault tolerant capability. Therefore, it is expected that the ADPS can provide an enhanced reliability regarding possible CCFs in the safety-grade digital I ＆ C systems as well as the ADPS itself.
文摘Objective：There are a great number of modified models based on the four-vessel occlusion（4VO）model of Pulsinelli and Brierley which has been used worldwide for brain ischemia research.However,up to now the problems of collateral circulations of 4VO and the difficulty in arranging a surgery to occlude the basilar artery in other models are not satisfactorily solved yet.In this study,an improved 4-vessel occlusion（I4VO）rat model which is easy to handle and able to decrease the effect of collateral circulation is reported.Methods：The common carotid arteries and the beginning of the subclavical arteries of rats were occluded for different time by one-stage apertura thoracis superior approach.Neurological deficit scores defined by the modified Garcia scoring system and histopathological method were used to evaluate the effects of this model up to 7 days after reperfusion.Results：The neurological scores in the 15-min and 25-min groups decreased significantly at 24,48 and 72 hours after reperfusion（P〈0.05）,and the histopathologic study showed that there were stable,symmetrical changes of lesions in bilateral hippocampus in all the ischemia samples from two ischemia groups compared with sham operated group（P〈0.05）.Conclusion：This modified model is safe,easy,reliable,stable,mini-invasive as well as time-saving in making bilateral hemispheric ischemia,which can effectively decrease collateral circulations and meanwhile lead to stable lesions in hippocampus and cortex.
