Lead exposure induces decreased hippocampal N-methyI-D-aspartic acid （NMDA） receptor gene and protein expressions, which influences the molecular mechanisms of learning and memory. However, lead poisoning-induced di...Lead exposure induces decreased hippocampal N-methyI-D-aspartic acid （NMDA） receptor gene and protein expressions, which influences the molecular mechanisms of learning and memory. However, lead poisoning-induced differences in NMDA subunit expression, and the correlation of lead poisoning with learning and memory, remain poorly understood. The present study measured differences in expression of NMDA receptor subunits NR1, NR2A, and NR2B in memory-related brain regions of rats who underwent different doses of lead exposure. Results demonstrated decreased NR1, NR2A, and NR2B subunit expressions in some memory-related brain areas. The inhibitory effect of 4.8 mmol/L lead exposure on hippocampal NR2B was most significant, although NR2A expression also significantly decreased following 14.4 mmol/L lead exposure. There was no difference in NR1 expression following exposure to 〈 4.8 mmol/L lead, although the inhibitory effect of 19.6 mmol/L lead exposure was strongest for NR1 expression in the hippocampus. Inhibitory avoidance test results revealed that greater concentrations of lead exposure resulted in decreased learning and memory. Therefore, lead toxicity was dependent on NMDA receptor subunit composition, and NR1, NR2A, and NR2B expressions were associated with time and concentration of lead exposure.展开更多
针对现有的内存相关漏洞检测方法中存在依赖指针数据流而导致大量误报漏报、缺乏漏洞特征的形式化描述以及漏洞特征描述不全面的问题,提出一种基于抽象内存模型的内存相关漏洞检测方法。对抽象内存模型进行相关定义;基于抽象内存模型,...针对现有的内存相关漏洞检测方法中存在依赖指针数据流而导致大量误报漏报、缺乏漏洞特征的形式化描述以及漏洞特征描述不全面的问题,提出一种基于抽象内存模型的内存相关漏洞检测方法。对抽象内存模型进行相关定义;基于抽象内存模型,对内存泄露、重复释放内存和读写释放后的内存这三种与内存相关的漏洞类型的特征进行形式化符号表示;基于代码的控制流图,利用可行路径求解算法得到代码的所有可行路径,并对所有可行路径上的抽象内存进行运行时状态判定,从而检测代码是否存在内存相关的漏洞;使用Juliet Test Suite中的CWE401、CWE415、CWE416三个内存相关漏洞的测试数据集对提出的检测方法进行验证,实验结果表明,相比依赖指针数据流的检测方法,该方法在内存相关漏洞检测的误报率和漏报率均降低。展开更多
基金the grant of Science and Technology Bureau of Liaoning Province,No. 20041033
文摘Lead exposure induces decreased hippocampal N-methyI-D-aspartic acid （NMDA） receptor gene and protein expressions, which influences the molecular mechanisms of learning and memory. However, lead poisoning-induced differences in NMDA subunit expression, and the correlation of lead poisoning with learning and memory, remain poorly understood. The present study measured differences in expression of NMDA receptor subunits NR1, NR2A, and NR2B in memory-related brain regions of rats who underwent different doses of lead exposure. Results demonstrated decreased NR1, NR2A, and NR2B subunit expressions in some memory-related brain areas. The inhibitory effect of 4.8 mmol/L lead exposure on hippocampal NR2B was most significant, although NR2A expression also significantly decreased following 14.4 mmol/L lead exposure. There was no difference in NR1 expression following exposure to 〈 4.8 mmol/L lead, although the inhibitory effect of 19.6 mmol/L lead exposure was strongest for NR1 expression in the hippocampus. Inhibitory avoidance test results revealed that greater concentrations of lead exposure resulted in decreased learning and memory. Therefore, lead toxicity was dependent on NMDA receptor subunit composition, and NR1, NR2A, and NR2B expressions were associated with time and concentration of lead exposure.
文摘针对现有的内存相关漏洞检测方法中存在依赖指针数据流而导致大量误报漏报、缺乏漏洞特征的形式化描述以及漏洞特征描述不全面的问题,提出一种基于抽象内存模型的内存相关漏洞检测方法。对抽象内存模型进行相关定义;基于抽象内存模型,对内存泄露、重复释放内存和读写释放后的内存这三种与内存相关的漏洞类型的特征进行形式化符号表示;基于代码的控制流图,利用可行路径求解算法得到代码的所有可行路径,并对所有可行路径上的抽象内存进行运行时状态判定,从而检测代码是否存在内存相关的漏洞;使用Juliet Test Suite中的CWE401、CWE415、CWE416三个内存相关漏洞的测试数据集对提出的检测方法进行验证,实验结果表明,相比依赖指针数据流的检测方法,该方法在内存相关漏洞检测的误报率和漏报率均降低。
