BACKGROUND Perioperative shivering is clinically common during cesarean sections under neuraxial anesthesia,and several neuraxial adjuvants are reported to have preventive effects on it.However,the results of current ...BACKGROUND Perioperative shivering is clinically common during cesarean sections under neuraxial anesthesia,and several neuraxial adjuvants are reported to have preventive effects on it.However,the results of current studies are controversial and the effects of these neuraxial adjuvants remain unclear.AIM To evaluate the effects of neuraxial adjuvants on perioperative shivering during cesarean sections,thus providing an optimal choice for clinical application.METHODS A systematic review and network meta-analysis were conducted following the PRISMA (Preferred Reported Items for Systematic Review and Meta-analysis) guidelines.Analyses were performed using Review Manager 5.3 and Stata 14.0.We searched PubMed,EMBASE,Web of Science,and Cochrane Central databases for eligible clinical trials assessing the effects of neuraxial adjuvants on perioperative shivering and other adverse events during cesarean sections.Perioperative shivering was defined as the primary endpoint,and nausea,vomiting,pruritus,hypotension,and bradycardia were the secondary outcomes.RESULTS Twenty-six studies using 9 neuraxial adjuvants for obstetric anesthesia during caesarean sections were included.The results showed that,compared with placebo,pethidine,fentanyl,dexmedetomidine,and sufentanil significantly reduced the incidence of perioperative shivering.Among the four neuraxial adjuvants,pethidine was the most effective one for shivering prevention (OR = 0.15,95%CI: 0.07-0.35,surface under the cumulative ranking curve 83.9),but with a high incidence of nausea (OR = 3.15,95%CI: 1.04-9.57) and vomiting (OR = 3.71,95%CI: 1.81-7.58).The efficacy of fentanyl for shivering prevention was slightly inferior to pethidine (OR = 0.20,95%CI: 0.09-0.43),however,it significantly decreased the incidence of nausea (OR = 0.34,95%CI: 0.15-0.79) and vomiting (OR = 0.25,95%CI: 0.11-0.56).In addition,compared with sufentanil,fentanyl showed no impact on haemodynamic stability and the incidence of pruritus.CONCLUSION Pethidine,fentanyl,dexmedetomidine,and sufentanil appear to be effective for preventing perioperative shivering in puerperae undergoing cesarean sections.Considering the risk-benefit profiles of the included neuraxial adjuvants,fentanyl is probably the optimal choice.展开更多
The samples obtained by Finite Element Method (FEM) simulation for section extrusion process have been trained on BP Neural Networks. The mapping relationsbetween die's geometrical parameters and energetic paramet...The samples obtained by Finite Element Method (FEM) simulation for section extrusion process have been trained on BP Neural Networks. The mapping relationsbetween die's geometrical parameters and energetic parameters, such as stress and strain generated in the die are established. The extrusion process model and its expert system are also determined. The excellent expansibility this system possesses provides a new prospect for the future development of expert system for section extrusion dies.展开更多
This paper studies the short-term prediction methods of sectional passenger flow, and selects BP neural network combined with the characteristics of sectional passenger flow itself. With a case study, we design three ...This paper studies the short-term prediction methods of sectional passenger flow, and selects BP neural network combined with the characteristics of sectional passenger flow itself. With a case study, we design three different schemes. We use Matlab to realize the prediction of the sectional passenger flow of the Beijing subway Line 2 and make comparative analysis. The empirical research shows that combining data characteristics of sectional passenger flow with the BP neural network have good prediction accuracy.展开更多
近期提出的单体相移深度神经网络(single phase-shift deep neural network,SPDNN),因其网络规模小、学习精度高,成为首个复杂中子共振截面拟合与评价的实用深度学习工具。在SPDNN学习共振截面的过程中,诸多因素显著影响网络的训练效果...近期提出的单体相移深度神经网络(single phase-shift deep neural network,SPDNN),因其网络规模小、学习精度高,成为首个复杂中子共振截面拟合与评价的实用深度学习工具。在SPDNN学习共振截面的过程中,诸多因素显著影响网络的训练效果、训练效率以及训练模型的泛化性。这些因素包括:决定网络相移层大小的共振截面频谱范围与频段宽度、隐藏层的数目、每层神经元的数目、激活函数、损失函数、训练步数和训练数据的预处理等。为了进一步提升SPDNN在共振截面研究中的实用性,详细考察了这些因素对网络拟合性能的影响。通过考察,确定了SPDNN在共振截面研究中适宜的网络构建和训练方法,助力推动SPDNN的广泛应用。展开更多
基金Supported by The Science and Technology Development Fund,Macao SAR,No.130/2017/A3 and No.0099/2018/A3
文摘BACKGROUND Perioperative shivering is clinically common during cesarean sections under neuraxial anesthesia,and several neuraxial adjuvants are reported to have preventive effects on it.However,the results of current studies are controversial and the effects of these neuraxial adjuvants remain unclear.AIM To evaluate the effects of neuraxial adjuvants on perioperative shivering during cesarean sections,thus providing an optimal choice for clinical application.METHODS A systematic review and network meta-analysis were conducted following the PRISMA (Preferred Reported Items for Systematic Review and Meta-analysis) guidelines.Analyses were performed using Review Manager 5.3 and Stata 14.0.We searched PubMed,EMBASE,Web of Science,and Cochrane Central databases for eligible clinical trials assessing the effects of neuraxial adjuvants on perioperative shivering and other adverse events during cesarean sections.Perioperative shivering was defined as the primary endpoint,and nausea,vomiting,pruritus,hypotension,and bradycardia were the secondary outcomes.RESULTS Twenty-six studies using 9 neuraxial adjuvants for obstetric anesthesia during caesarean sections were included.The results showed that,compared with placebo,pethidine,fentanyl,dexmedetomidine,and sufentanil significantly reduced the incidence of perioperative shivering.Among the four neuraxial adjuvants,pethidine was the most effective one for shivering prevention (OR = 0.15,95%CI: 0.07-0.35,surface under the cumulative ranking curve 83.9),but with a high incidence of nausea (OR = 3.15,95%CI: 1.04-9.57) and vomiting (OR = 3.71,95%CI: 1.81-7.58).The efficacy of fentanyl for shivering prevention was slightly inferior to pethidine (OR = 0.20,95%CI: 0.09-0.43),however,it significantly decreased the incidence of nausea (OR = 0.34,95%CI: 0.15-0.79) and vomiting (OR = 0.25,95%CI: 0.11-0.56).In addition,compared with sufentanil,fentanyl showed no impact on haemodynamic stability and the incidence of pruritus.CONCLUSION Pethidine,fentanyl,dexmedetomidine,and sufentanil appear to be effective for preventing perioperative shivering in puerperae undergoing cesarean sections.Considering the risk-benefit profiles of the included neuraxial adjuvants,fentanyl is probably the optimal choice.
文摘The samples obtained by Finite Element Method (FEM) simulation for section extrusion process have been trained on BP Neural Networks. The mapping relationsbetween die's geometrical parameters and energetic parameters, such as stress and strain generated in the die are established. The extrusion process model and its expert system are also determined. The excellent expansibility this system possesses provides a new prospect for the future development of expert system for section extrusion dies.
文摘This paper studies the short-term prediction methods of sectional passenger flow, and selects BP neural network combined with the characteristics of sectional passenger flow itself. With a case study, we design three different schemes. We use Matlab to realize the prediction of the sectional passenger flow of the Beijing subway Line 2 and make comparative analysis. The empirical research shows that combining data characteristics of sectional passenger flow with the BP neural network have good prediction accuracy.
文摘近期提出的单体相移深度神经网络(single phase-shift deep neural network,SPDNN),因其网络规模小、学习精度高,成为首个复杂中子共振截面拟合与评价的实用深度学习工具。在SPDNN学习共振截面的过程中,诸多因素显著影响网络的训练效果、训练效率以及训练模型的泛化性。这些因素包括:决定网络相移层大小的共振截面频谱范围与频段宽度、隐藏层的数目、每层神经元的数目、激活函数、损失函数、训练步数和训练数据的预处理等。为了进一步提升SPDNN在共振截面研究中的实用性,详细考察了这些因素对网络拟合性能的影响。通过考察,确定了SPDNN在共振截面研究中适宜的网络构建和训练方法,助力推动SPDNN的广泛应用。
