Opposite Neurophysiological Findings Induced by Sideritis scardica and Sideritis euboa Extract in the Rat

Psychophysiological effects of Sideritis herba extracts depend on biologically active ingredients, which might be different for several botanical types of this plant. The present investigation aimed at the characterization of extracts from Sideritis scardica and Sideritis euboa in vivo and in vitro. Construction of electropharmacograms on the base of recording of electrical field potentials from four different brain regions was used to compare the possible pharmacological effects to a database of reference drugs with known clinical indications. Whereas Sideritis scardica produced decreases of spectral power in line with stimulatory frequency patterns as observed in the presence of Ginkgo biloba extract, administration of Sideritis euboa produced opposite effects. Electrical stimulation of the Schaffer Collaterals was used to elicit a pyramidal cell response called population spike in vitro. The amplitude of this spike was determined in the presence of single as well as theta burst stimuli. Direct exposure of brain matter to Sideritis scardica extract led to concentration dependent increases of the population spike amplitude under both stimulation patterns in the range from 12.5 to 100 mg/L. On the opposite, extract from Sideritis euboa did not change the electric response up to 50 mg/L. Higher concentrations of this extract attenuated the signal amplitude. A 1:1 blend of both gave intermediate results. The in vitro results are in line with the in vivo EEG recordings, where both extracts induced opposite changes of the electric power with respect to electric frequency patterns. The results from both models suggest a stimulatory and/or memory-enhancing action for the extract from Sideritis scardica but not for Sideritis euboa extract, where a more tranquillizing effect like that observed in the presence of Humulus cone extract may be expected.

Psychophysiological Effects of Sideritis and Bacopa Extract and Three Combinations Thereof—A Quantitative EEG Study in Subjects Suffering from Mild Cognitive Impairment (MCI)

Mild cognitive impairment (MCI) is regarded as a transitional stage during the development of Alzheimer’s disease. Diagnosis of MCI can be obtained by the questionnaire “DemTect” in German speaking countries. Quantitative assessment has been successfully performed using psychometric testing concomitantly with quantitative EEG recording. The present investigation aimed at the possible treatment of MCI with two botanicals, namely extracts from Sideritis scardica (500 mg) or Bacopa monnieri (320 mg) and three combinations thereof using this method in order to find a new treatment. The performance of the d2-test, an arithmetic calculation test (CPT) and a memory-test revealed better performance for the d2-test only in the presence of Sideritis extract or the combinations with Bacopa extract. Quantitative EEG assessment during the different experimental conditions showed massive differences between both extracts. Whereas Sideritis extract and its combination with a low amount of Bacopa extract (160 mg) induced increases of spectral power in fronto-temporal brain areas, Bacopa and the combination of Sideritis with high amounts of Bacopa extract produced attenuation of all waves except for delta in fronto-temporal brain areas. These differences were also documented by quantitative EEG maps in comparison to Placebo. A different action of both extracts was confirmed by discriminant analysis, where Sideritis extract and its combination with low Bacopa grouped together quite at distance to Bacopa and the combination of Sideritis with high Bacopa. A combination of Sideritis extract with a low amount of Bacopa should be tested with daily repetitive dosing for at least 4 weeks as a consequence.

Psychophysiological Effects of a Combination of Sideritis and Bacopa Extract (memoLoges®) in 32 Subjects Suffering from Mild Cognitive Impairment. A Double-Blind, Randomized, Placebo-Controlled, 2-Armed Study with Parallel Design

Mild cognitive impairment (MCI) can be regarded as a non-demented transitional stage during the development of Alzheimer’s disease. Early recognition of this stage might increase the chance of prevention by early treatment. Within a pilot study, two plant-derived preparations and mixtures thereof were tested successfully in subjects suffering from MCI. A combination of Sideritis scardica and Bacopa monnieri extract (memoLoges®) was chosen now for a repetitive dosing during 4 weeks. Thirty-two subjects aged 50 to 80 years and suffering from MCI (having a DemTect questionnaire score between 8 and 13) were recruited for intake of 2 capsules of the preparation per day. Quantitative EEG recording during relaxation and concomitant performance of three 5 minutes lasting psychometric tests (d2-concentration test, arithmetic calculation test and memory test) was achieved at the first day and one day after the last repetitive intake. Seventeen channels of EEG and one channel EOG (for artefact rejection) were recorded. After frequency analysis (FFT) current source density was calculated as reported earlier. One, two and three hours after intake of the herbal extract or placebo the whole procedure was repeated. Brain imaging was achieved by conversion of numerical values of spectral EEG power into spectral colors and additive color mixture according to RGB as used in TV settings. Intake of memoLoges® induced a trend of improvement of performance in psychometric testing (all three tests). During relaxation quantitative assessment of EEG data revealed attenuation of delta and theta spectral power in frontal brain as likewise reported in the presence of the Alzheimer drug rivastigmine, bringing the spectrum back to “normality”. During mental work memoLoges® induced statistically significant increases of beta power. Since MCI subjects produce less beta power in comparison to healthy subjects, this increase must likewise be seen as a positive effect pointing to a healthier spectrum.

Improvement of instantaneous positioning by spatial stacking and modified sidereal filtering methods with application to the 2008 Ms8.0 Wenchuan earthquake

We obtained several displacement time series from the Sichuan permanent GPS net and processed the 1-Hz data observed during a few days before the 2008 Ms8.0 Wenchuan earthquake by double-difference instantaneous positioning technique. We filtered the data by the spatial stacking and the modified sidereal filte- ring methods to reduce correlation bias in space and time. The results indicate that these methods can improve the precision significantly.

Ex Vivo Characterization of the Action of Sideritis Extract Using Electrical Activity in the Rat Hippocampus Slice Preparation

A hydroethanolic extract (20% V/V) from Herba Sideritis scardica has been recognized to positively influence cognition. The present investigation aimed at the question if this extract would be able to modify intra-hippocampal communication after oral administration of 100 mg/kg daily for one week. The glutamatergic synapse between Schaffer Collaterals and pyramidal cells can be tested by electric stimulation using single pulses or theta burst stimulation. The resulting population spike is modulated by compounds acting at the central nervous system or other preparations directly or as ex vivo approach. In this case the effect of the special extract was tested in vitro the next day after repetitive in vitro administration. Conventional recording technique in the in vitro hippocampus slice revealed an increase of the population spike in the presence of single stimuli and theta burst stimuli resulting in increased long-term potentiation. This effect was tried to modulate by several glutamate receptor antagonists, among them compounds targeting at the ionic NMDA receptor (CGS19755), AMPA receptor (NBQX), Kainate receptor (UBP301) and targeting at three metabotropic glutamate receptors (mGluR I (YM298198), mGluRII ((RS)-APICA)) and mGluRIII (MSOP). Only NBQX was able to prevent the action of the Sideritis scardica extract. Since the AMPA receptor has been related to cognition in several reports in the literature, it is concluded from this result that the positive action of Sideritis scardica extract on brain function involves a modulation of AMPA receptor dependent neurotransmission.

一种顾及时空变化的BDS PPP多路径误差建模方法

根据BDS GEO、IGSO、MEO三种星座卫星轨道运行特性,使用多路径误差半天球格网点模型(multi-point hemispherical grid model,MHGM)和恒星日滤波(sidereal filtering,SF)方法建立BDS混合星座的多路径误差改正模型。使用该模型改正多路径误差后,BDS精密单点定位(precise point positioning,PPP)的载波相位验后残差显著减小,E、N、U方向定位精度分别提升41%、37%、38%,收敛速度整体提升31%。

基于时间卷积模型的GNSS多路径误差削弱

多路径误差是全球导航卫星系统(Global Navigation Satellite System,GNSS)短基线的主要误差源,考虑到GNSS多系统条件下,经典的恒星日滤波方法(Sidereal Filtering,SF)卫星的重访周期难以获取以及半天球模型(Multipath Hemispherical Map,MHM)需要大量数据支持的问题,引入了时间卷积网络模型(Time Convolutional Network,TCN),充分利用其对海量数据的深度挖掘能力,建立GNSS坐标序列中的多路径误差模型,并进行多路径误差的实时削弱。通过连续15 d的实验数据测试,结果表明,新方法克服了经典SF方法难以适用于多系统GNSS多路径误差的削弱,且仅需要1 d的训练样本,即可实现后续多天的多路径误差的实时削弱,其削弱效果明显优于MHM模型,表现出了良好的泛化能力。

基于正则化与恒星日滤波的BDS多路径误差削减方法

在重构的载波相位单差残差基础上,利用分段思想估计北斗卫星的多路径重复时间,分别采用正则化方法和经典小波滤波方法提取载波相位单差残差的多路径信号,得到“干净”的单差残差序列。实验结果表明,利用Tikhonov正则化方法正确提取多路径信号是可行的,多路径信号比原始测量残差更具平滑性,并进一步优化了正则化参数的估计方法。利用优化后的Tikhonov正则化方法与恒星日滤波后,载波相位单差残差平均改进40.5%;坐标残差E、N、U方向分别改进24.8%、26.3%和42.7%。无论是观测值域还是坐标域,优化后的Tikhonov正则化方法较传统的小波滤波方法更具优越性。

观测值域恒星日滤波方法在高铁路基变形监测中的应用

针对高铁环境下对多路径误差削弱方法分析不足的问题,提出一种高铁路基变形监测方法:利用哈佳铁路路基实测北斗卫星导航系统(BDS)观测数据,采用双差、单差和非差观测值域恒星日滤波方法,提取变形监测中多路径相关的周期性误差,以消除多路径误差对变形监测结果的影响。实验结果表明:3种方法在东方向上的定位精度分别提高了26.90%、36.82%和27.41%,北方向提高了37.31%、46.10%和37.50%,高程方向提高了40.41%、42.52%和40.20%;单差方法对多路径效应改正的效果最好,更适用于高铁路基变形监测中多路径效应的削弱。

利用恒星日滤波削减油田井架BDS多路径效应

针对油田井架全球导航卫星系统(global navigation satellite system, GNSS)动态变形监测中存在的多路径效应,限制了变形监测的精度,提出一种BDS(Beidou navigation satellite system),双频单历元恒星日滤波方法削减多路径效应。该方法针对北斗导航卫星系统BDS不同类型卫星,通过单差残差序列提取多路径误差,并基于观测值域对各颗卫星单差残差序列进行改正,再利用LAMBDA方法固定模糊度,解算坐标。通过油田井架模拟及实际监测数据,对多路径误差改正前后的单差残差以及基线解进行分析。结果表明:该方法可以有效削弱油田井架环境的多路径效应,提高定位精度。在模拟试验中,东北天方向精度较改正前提升46.4%、35.5%、42.7%;实际工程监测试验中,东北天方向精度较改正前提升14.7%、11.4%、19.2%。

经皮穿刺股静脉和股动脉介入治疗动脉导管未闭

目的 :探讨非开胸经皮穿刺股静脉和股动脉治疗动脉导管未闭 (PDA)的疗效和安全性。方法 :对 16例PDA患者 ,应用 Siders纽扣补片和 Amplatzer蘑菇伞堵闭方法进行治疗 ,随访 1～ 5 2个月。结果 :16例堵闭均成功 ,术后心前区杂音消失或明显减轻 ,主动脉弓降部造影 16例完全堵闭 ,无残余分流 ,或少量残余分流 ;临床症状消失 ;X线示肺充血明显减轻和消失 ,心胸比例不同程度减小和恢复正常 ,堵闭装置无移位 ,无再通。结论 :介入治疗 PDA操作安全简便 ,适应证范围广 ,疗效可靠。

火箭飞行中天球系到星敏系的姿态转换方法

在远程火箭飞行过程中,通过计算天球系到星敏系的旋转四元数,可作为星图模拟的输入数据。本文从坐标系定义出发,首先,完善了基于北京时间的格林尼治恒星时角在工程上的实用算法,根据多次旋转原理,给出了天球系到发射惯性系的姿态转换方法;其次,探讨了发射惯性系到箭体系以及箭体系到星敏系的姿态转换方法;最后,给出算例,通过仿真计算得出结果,验证了方法的可行性。该方法容易理解,根据推导思路也可举一反三,对于星图模拟中姿态的转换具有一定参考意义。

北方典型内陆盆地高砷地下水的水化学特征及处理技术

我国高砷地下水分布广泛,是受砷污染最严重的地区之一,严重危害居民身体健康,开发经济、高效、环境友好的高砷地下水修复治理技术极具必要性。以大同盆地、呼包平原、河套平原和银川平原为代表性研究区域,归纳总结了北方干旱、半干旱地区典型高砷地下水区水化学特征。通常情况下,高砷地下水的p H值较高,共存阴离子(HCO-3、SO2-4和Cl-)浓度较大,溶解性有机碳含量较高,并且As(Ⅲ)为主要砷形态。开展了针对北方典型高砷地下水特定水化学环境特点(如p H值、共存阴阳离子以及溶解性有机物等)的改性天然菱铁矿除砷性能研究。结果表明,改性天然菱铁矿对溶液p H值具有良好的缓冲能力,其除砷性能基本不受p H值、共存阴离子、Ca/Mg阳离子及以腐殖酸为代表的溶解性有机物等典型高砷地下水水化学特征因素的影响,表明吸附剂对砷具有良好的吸附选择性。另外,改性天然菱铁矿对As(Ⅲ)的去除效果优于对As(V)的去除效果,因此,利用改性天然菱铁矿作为反应介质材料,将其应用于处理主要以As(Ⅲ)形式存在的高砷地下水具备良好的发展前景。

比较两种根管预备器械分离率及特征的实验研究

目的:比较Safesiders机用器械和Protaper机用器械在根管预备中的器械分离率及特征,以期为临床根管治疗寻求更为安全可靠的治疗器械。方法:收集因正畸、牙周病、外伤等拔除的离体恒牙510颗,共计根管861例。随机分为两组,A组441例,B组420例,分别使用Safesiders机用器械和Protaper机用器械预备根管,比较两组器械的分离率及特征。结果:Safesiders机用器械预备组分离率低于Protaper机用器械预备组(P<0.05),Safesiders机用器械组只有20#分离,分离率最高(P<0.05);Protaper机用器械组S1分离率最高(P<0.05)。Safesiders机用器械平均分离长度大于Protaper机用器械(P<0.05)。结论:safesdiers机用器械较Protaper机用器械更为安全。

顾及分段相似性的同震形变时间序列恒星日滤波优化算法

在常规恒星日滤波的基础上,提出一种顾及分段相似性的恒星日滤波优化算法。在构建滤波算子之前,首先确定用于构建滤波的坐标残差时间序列与地震当天坐标残差时间序列的分段相似性,然后根据相似性度量指标的大小确定权重后再进行滤波。研究结果表明:利用本文提出的顾及分段相似性的恒星日滤波优化方法能够显著改善单历元定位的精度和可靠性,克服常规滤波方法存在的缺陷,有利于恒星日滤波的无人工干预批处理。尤其是通用影像质量评价指数UIQI方法顾及了时间序列间的相关系数以及序列自身的均值和方差,比其他相似性度量更加科学合理,建议采用UIQI作为恒星日滤波优化算法的相似性度量。

基于恒星日滤波的PPP多径误差消除研究

基于PPP的数学模型,分析多径误差对PPP定位结果的影响。研究表明,对PPP应用恒星日滤波时解算区间、数据采样率等定位参数应保持一致。通过对定位偏差序列的拉格朗日插值,可以将恒星日滤波应用到低采样率的观测数据中,拓宽恒星日滤波的应用范围,降低处理计算量。针对IGS跟踪站的数据,应用恒星日滤波多径误差修正后,PPP动态定位的精度有了明显改善,东、北、天3方向的精度分别提高了69.2%、72.3%、27.6%。

内部人控制视角的“知识失业”

当前我国面临着较为严重的“知识失业”现象,“知识失业”与我国目前很多企事业单位存在着严重的内部人控制现象有很大的关系。内部人控制不仅加剧了“知识失业”的严重程度,同时使教育丧失了应有的的信号功能,造成了效率的损失。因此,从制度上对内部人控制进行约束已势在必行。

体验取样法在情绪研究中的应用优势

情绪研究的难题在于其具有动态变化性、情境依存性和个体差异性三大特征,这亟需研究者在对情绪及其相关变量测查时做特别的考量,而传统的情绪研究方法在这些方面存在欠缺。在这种情况下,体验取样法在情绪研究中具有得天独厚的优势:首先,它可以在一定时间跨度内对情绪事件进行即时、连续、重复地测量,降低了潜在记忆偏差和个人偏好的影响;其次,它把情绪事件置于真实的社会环境中,增强了研究的生态效度;另外,它丰富庞大的数据采集量能够从多水平、多角度、多变量分析个体情绪的整个变化过程。随着情绪研究的不断深入,体验取样法将会得到越来越多的运用。

2011年日本Mw9.0地震的高频GPS动态形变研究

以相对稳定的上海站(SHAO)为参考站,利用GAMIT/GLOBK的TRACK运动学分析模块对日本周边8个连续观测站的1 Hz GPS数据进行处理,获取并分析了2011年日本Mw9.0地震引起的动态地壳形变。结果表明,震时上盘各GPS站点主运动方向为东南方向,其中距震中较近的MIZU站和USUD站水平最大振幅分别达到3.11 m和0.67 m。为了削弱定位结果中与测站环境有关的系统误差,采用改进的恒星日滤波法对USUD站南北向动态时序进行滤波处理。经过滤波处理后,USUD站南北向动态时序离散度RMS由1.65 cm降低至0.82 cm。