基于熵算法的股票指数高频数据复杂度测算与评价

在日内高频环境下检验基于兼容法的柯尔莫哥洛夫熵、样本熵和模糊熵等复杂度测算方法对我国沪深300股票指数的测算效率，并运用筛选后的有效算法分阶段研究和比较了序列复杂度的变化过程与变化幅度.结果表明，模糊熵算法是一种更适用于我国沪深300股票指数的有效复杂度测算方法，其对相似容忍度的敏感性更低，测度值连续性更好.随时间推移，我国沪深300股票指数复杂度整体呈上升趋势,而相较于发达市场甚至周边新兴市场其复杂度偏低.     

Brain monitoring in dogs using the cerebral state index during the induction of anaesthesia via target-controlled infusion of propofol

The aim of this study was to evaluate the correlation between the cerebral state index (CSI) and the estimated propofol plasma concentrations in dogs during induction of anaesthesia. Fifteen healthy dogs undergoing scheduled routine surgical procedures were enrolled in this study. Target controlled infusion (TCI) software, based on the pharmacokinetic model for propofol, was used to control the syringe pump and to estimate plasma propofol concentrations (PropCp) and the CSI values every five-seconds. Three electrodes placed in the centre of the forehead, on the left side of the forehead and on the left mastoid were used to collect the electroencephalographic (EEG) signal converted by the cerebral state monitor into the CSI. The cerebral electrical changes induced by increasing propofol concentrations appear to be detected by CSI monitoring in dogs. The negative correlation between CSI and PropCp demonstrates that the CSI could be used to assess electrical brain activity in dogs during the induction of anaesthesia with propofol.     

银杏不同品种生长及耐旱性的比较

对6个银杏品种7 a生幼树的树高、干径、1 a生枝长及离体叶片的相对含水量(RWC)和叶绿素稳定指数(CSI)进行研究,结果表明,不同品种的干径和1 a生枝长度的差异达到了极显著水平,干径以大佛手最粗,为2.0824 cm,马铃最细,仅为1.5378 cm;1 a生枝长度最长的是大圆铃达22.9773 cm,最短的是郯城9号,仅为12.0889 cm;马铃的耐旱性最强,CSI为20.67,RWC损失率为65.07%。     

Correlation between clinical signs of depth of anaesthesia and cerebral state index responses in dogs during induction of anaesthesia with propofol

The cerebral state index (CSI) is used for monitoring EEG and depth of anaesthesia. The objective of this study was to analyse the correlation between ocular reflexes, CSI and estimated propofol plasma concentrations (PropCP) in dogs during induction of anaesthesia with propofol.Fourteen dogs were premedicated with acepromazine 0.05 mg kg⁻¹ IM. Anaesthesia was induced with a 200 ml h⁻¹ propofol 1% constant infusion rate until loss of corneal reflex using RugLoop II software with Beths’ pharmacokinetic model to estimate PropCp.Palpebral reflex (PR) and the corneal reflex (CR) were tested every 30 s and classified as present (+) or absent (−), and eyeball position was registered as rotated ventromedialy (ERV) or centred (EC).Heart rate (HR), mean arterial pressure (MAP) and CSI values were analyzed from baseline before the beginning of propofol infusion (T0) until loss of CR; CSI and PropCp, CSI and anaesthetic planes, and PropCp and anaesthetic planes were compared using correlation analysis.PropCp reached 7.65 ± 2.1 μg ml⁻¹ at the end of the study. CSI values at T0 were 89.2 ± 3.8. Based on the observation of ocular reflexes and eyeball position, it was possible to define five anaesthetic planes: A (superficial) to E (deep), being A (PR+/CR+/EC), B (PR+/ERV/CR+), C (PR−/ERV/CR+), D (PR−/EC/CR+) and E (PR−/EC/CR−). There was a significant correlation between PropCp and the anaesthetic planes (R = 0,861; P < 0.01). No significant correlation was observed between CSI and the anaesthetic planes or between CSI and PropCp. MAP decreased significantly from T0 until loss of corneal reflex (from 98 ± 14 mmHg to 82 ± 12 mmHg); HR did not change significantly (from 101 ± 30 bpm to 113 ± 16 bpm).The CSI monitoring was not consistent with the clinical observations observed in the different stages of depth anaesthesia. This could limit the use of CSI for monitoring depth of anaesthesia with propofol.