Reliable detection of bilateral activation in human primary somatosensory cortex by unilateral median nerve stimulation

In non-human primates, a bilateral representation of unilaterally presented somatosensory information can be found at the lowest level of cortical processing as indicated by the presence of neurons with bilateral receptive fields in the hand region of primary somatosensory (SI) cortex. In humans, such bilateral activation of SI is considered controversial due to highly variable detection rates for the much weaker ipsilateral response across different studies (ranging from 3% to 100%). Second-order blind identification (SOBI) is a blind source separation algorithm that has been successfully used to isolate neuronal signals from functionally distinct brain regions, including the left- and right-SI. SOBI-aided extraction of left- and right-SI responses to median nerve stimulation from high-density EEG has been previously validated against the fMRI and MEG literature. Here, we applied SOBI to EEG data and examined whether relatively weaker ipsilateral activations could be reliably detected across subjects. In single subject analysis, statistically significant somatosensory evoked potentials (SEPs) in response to unilateral stimulation were detected from both SI contralateral to and SI ipsilateral to the side of stimulation. Furthermore, these ipsilateral responses were observed in both the left and right hemispheres of all 10 subjects studied. Together these results demonstrate that unilateral stimulation of the median nerve, whether applied to the left or right wrist, can activate both the left- and right-SI, raising the possibility that in humans, unilateral sensory input may be bilaterally represented at the lowest level of cortical processing.     

Performance enhancement for audio-visual speaker identification using dynamic facial muscle model

Science of human identification using physiological characteristics or biometry has been of great concern in security systems. However, robust multimodal identification systems based on audio-visual information has not been thoroughly investigated yet. Therefore, the aim of this work to propose a model-based feature extraction method which employs physiological characteristics of facial muscles producing lip movements. This approach adopts the intrinsic properties of muscles such as viscosity, elasticity, and mass which are extracted from the dynamic lip model. These parameters are exclusively dependent on the neuro-muscular properties of speaker; consequently, imitation of valid speakers could be reduced to a large extent. These parameters are applied to a hidden Markov model (HMM) audio-visual identification system. In this work, a combination of audio and video features has been employed by adopting a multistream pseudo-synchronized HMM training method. Noise robust audio features such as Mel-frequency cepstral coefficients (MFCC), spectral subtraction (SS), and relative spectra perceptual linear prediction (J-RASTA-PLP) have been used to evaluate the performance of the multimodal system once efficient audio feature extraction methods have been utilized. The superior performance of the proposed system is demonstrated on a large multispeaker database of continuously spoken digits, along with a sentence that is phonetically rich. To evaluate the robustness of algorithms, some experiments were performed on genetically identical twins. Furthermore, changes in speaker voice were simulated with drug inhalation tests. In 3 dB signal to noise ratio (SNR), the dynamic muscle model improved the identification rate of the audio-visual system from 91 to 98%. Results on identical twins revealed that there was an apparent improvement on the performance for the dynamic muscle model-based system, in which the identification rate of the audio-visual system was enhanced from 87 to 96%.     

珍稀铁皮石斛SSR标记的开发及种质纯度鉴定

本研究利用磁珠富集法开发了60对铁皮石斛的SSR引物,从中筛选出15对多态性位点丰富、带型清晰、重复性好的引物。利用筛选出的SSR引物对铁皮石斛野生居群材料进行了遗传分析,共鉴定出等位变异92个,平均每个SSR位点等位变异数为6.1个;表观杂合度(HO)范围是0.60～0.85,平均值为0.72;期望杂合度(HE)范围是0.49～0.85,平均值为0.74。平均每个SSR位点多态信息含量(PIC)为0.702,变化范围为0.437～0.829。利用15对SSR引物对20种石斛试验材料进行跨种扩增,检测出有13对SSR引物具有种间通用性。此外,还利用所筛选的4对SSR引物检测了集约化种植过程中的铁皮石斛组培苗的种质纯度,结果显示:所开发的SSR标记可用于铁皮石斛组培苗的品种纯度鉴别。     

Online identification of the antioxidant constituents of traditional Chinese medicine formula Chaihu-Shu-Gan-San by LC–LTQ-Orbitrap mass spectrometry and microplate spectrophotometer

Chaihu-Shu-Gan-San (CSGS), a traditional Chinese medicine (TCM) formula containing seven herbal medicines, has been used in treatment of gastritis, peptic ulcer, irritable bowel syndrome and depression clinically. However, the chemical constituents in CSGS had not been studied so far. To quickly identify the chemical constituents of CSGS and to understand the chemical profiles related to antioxidant activity of CSGS, liquid chromatography coupled with electrospray ionization hybrid linear trap quadrupole orbitrap (LC–LTQ-Orbitrap) mass spectrometry has been applied for online identification of chemical constituents in complex system, meanwhile, antioxidant profile of CSGS was investigated by the fraction collecting and microplate reading system. As a result, 33 chemical constituents in CSGS were identified. Among them, 13 components could be detected both in positive and in negative ion modes, 20 constituents were determined only in positive ion mode and 2 components were only detected in negative ion mode. Meanwhile, the potential antioxidant profile of CSGS was also characterized by combination of 96-well plate collection of elutes from HPLC analysis and microplate spectrophotometer, in which the scavenging activities of free radical produced by DPPH of each fraction could be directly investigated by the analysis of microplate reader. This study quickly screened the contribution of CSGS fractions to the antioxidant activity and online identified the corresponding active constituents. The results indicated that the combination of LC–MSⁿ and 96-well plate assay system established in this paper would be a useful strategy for correlating the chemical profile of TCMs with their bioactivities without isolation and purification.     

穿心草的生药学鉴别

目的:对穿心草进行生药学鉴别。方法:分别对穿心草进行原植物形态鉴别、药材性状鉴别和显微鉴别。结果:穿心草药材茎多分枝,中空,淡棕黄色;叶多数穿茎。显微结构根外皮层、内皮层细胞巨大,常被径向分隔成多个子细胞,偶见石细胞;茎中空,双韧形,皮部有裂隙;叶上下表皮均有不等式气孔,细胞内常见砂晶、小针晶和小方晶等。结论:以上特征可为鉴别穿心草提供参考依据。     

红吹风的生药学鉴别

目的:对红吹风药材进行生药学鉴别。方法:分别对红吹风药材进行性状、显微及理化鉴别。结果:红吹风根的韧皮部有纤维束成群散在,木质部纤维束径向排列;茎中柱鞘纤维含大量草酸钙簇晶与针晶;叶中草酸钙簇晶多见,有外韧型维管束;理化鉴别提示有黄酮类成分。结论:以上特征可为红吹风药材的鉴别研究和开发利用提供参考依据。     

近红外光谱法建立防己药材的定性模型

目的建立防己药材的近红外模型,准确快速地筛查出伪品防己。方法采用近红外漫反射光谱法,通过一阶导数加矢量归一化,采用OPUS软件中的标准算法建立模型。结果模型能准确的区分正品和伪品防己。结论该模型可以用于快检车筛查。     

大理地区市售玉竹药材鉴定

目的建立玉竹及其混淆品的鉴别方法。方法对大理地区市售玉竹类药材进行调查、收集、鉴别。结果 21种药材来源于百合科,其余来源于兰科和菊科;其性状、显微、薄层色谱和紫外光谱特征有差异。结论为玉竹与其混淆品种的鉴别提供了依据。     

金银忍冬果实中化学成分的研究

目的 研究金银忍冬[Lonicera macckii (Rupr.) Maxim.]果实中的化学成分。方法 采用大孔树脂、硅胶、ODS柱色谱分离纯化,经理化常数及波谱学分析鉴定结构。结果 分离得到了6个化合物,鉴定了其中的4个,分别为裂马钱素二甲基缩醛（1）、裂环马钱素（2）、裂环马钱素酸（3）、苯甲基-O-β-D-吡喃木糖-(1→ 6)-β-D-吡喃葡萄糖苷（4）。结论 化合物1~4均为首次从金银忍冬果实中分离得到。     

祖师麻化学成分研究

目的 研究祖师麻的化学成分。方法 采用硅胶柱色谱、Pre-TLC、Pre-HPLC等方法进行分离纯化,根据理化常数和波谱数据鉴定结构。结果 从祖师麻提取物中分离得到7个已知化合物,分别鉴定为1-(4-羟基-3,5-二甲氧基苯基)-1,2-丙二酮（1）、4-羟基-3,5-二甲氧基苯甲醛（2）、4-甲基-7-羟基香豆素（3）、伞形花内酯（4）、7-羟基-8-甲氧基香豆素（5）、祖师麻甲素（6）和 α-D-吡喃果糖（7）。结论 化合物1为新天然产物,化合物2、3、7是首次从该属植物中分离得到。