对一个私钥保护方案的分析与改造

在公开密钥密码系统中,用户必须使用私钥才能阅读加密的相关信息,因此私钥的安全有效管理非常重要。《电讯技术》2004年第1期《一种私钥管理实现技术》一文中提出了一种基于PKI的私钥管理实现方案,但在实现过程中不经意让CA无条件解密了"用户"送来的数据,并且返回用户,造成安全隐患。针对这个问题,分析并修改了这个方案,避免直接返回接受数据的"解密"值,保证了系统安全性。     

Predication of plasma concentration of remifentanil based on Elman neural network

Due to the nature of ultra-short-acting opioid remifentanil of high time-varying, complex compartment model and low-accuracy of plasma concentration prediction, the traditional estimation method of population pharmacokinetics parameters, nonlinear mixed effects model （NONMEM）, has the abuses of tedious work and plenty of man-made jamming factors. The Elman feedback neural network was built. The relationships between the patients＇ plasma concentration of remifentanil and time, patient＇ age, gender, lean body mass, height, body surface area, sampling time, total dose, and injection rate through network training were obtained to predict the plasma concentration of remifentanil, and after that, it was compared with the results of NONMEM algorithm. In conclusion, the average error of Elman network is -6.34%, while that of NONMEM is 18.99%. The absolute average error of Elman network is 27.07%, while that of NONMEM is 38.09%. The experimental results indicate that Elman neural network could predict the plasma concentration of remifentanil rapidly and stably, with high accuracy and low error. For the characteristics of simple principle and fast computing speed, this method is suitable to data analysis of short-acting anesthesia drug population pharmacokinetic and pharmacodynamics.     

兰地洛尔治疗手术期心动过速性心律失常的多中心疗效和安全性评价

目的: 评价注射用兰地洛尔治疗手术期心动过速性心律失常的疗效与安全性。方法: 采用随机、双盲、安慰剂平行对照、多中心的临床试验方法,将240例患者随机分为治疗组和对照组（1:1）,治疗组采用注射用兰地洛尔治疗,对照组采用安慰剂治疗,治疗后比较疗效。结果: 共有239例患者完成试验,其中治疗组120例,对照组119例。治疗组的心动过速控制率为87.5%,对照组的心动过速控制率为4.2%,治疗组优于对照组（P<0.05）。治疗组起效时间中位数为 1 min,安慰剂组起效时间中位数为大于 2 min,治疗组优于对照组（P<0.05）。治疗组在治疗期及访视期心率收缩压乘积与治疗前相比显著下降,差异有统计学意义（P<0.05）;安慰剂组在治疗 2 min 时心率收缩压乘积与治疗前相比未见显著下降,差异无统计学意义（P＞0.05）。结论: 注射用兰地洛尔治疗手术期心动过速性心律失常安全、有效。     

水泥混凝土路面裂缝的预防及处理

结合工程实践，对水泥混凝土路面裂缝的形成原因进行了分析，对水泥混凝土路面各种裂缝的防治进行了简单的探讨，并结合实际施工提出了防治裂缝的措施，从而确保水泥混凝土路面的工程质量。