Evaluation of EEG Oscillatory Patterns and Cognitive Process during Simple and Compound Limb Motor Imagery

Motor imagery (MI), sharing similar neural representations to motor execution, is regarded as a window to investigate the cognitive motor processes. However, in comparison to simple limb motor imagery, significantly less work has been reported on brain oscillatory patterns induced by compound limb motor imagery which involves several parts of limbs. This study aims to investigate differences of the electroencephalogram (EEG) patterns as well as cognitive process between simple limb motor imagery and compound limb motor imagery. Ten subjects participated in the experiment involving three tasks of simple limb motor imagery (left hand, right hand, feet) and three tasks of compound limb motor imagery (both hands, left hand combined with right foot, right hand combined with left foot). Simultaneous imagination of different limbs contributes to the activation of larger cortical areas as well as two estimated sources located at corresponding motor areas within beta rhythm. Compared with simple limb motor imagery, compound limb motor imagery presents a network with more effective interactions overlying larger brain regions, additionally shows significantly larger causal flow over sensorimotor areas and larger causal density over both sensorimotor areas and neighboring regions. On the other hand, compound limb motor imagery also shows significantly larger 10–11 Hz alpha desynchronization at occipital areas and central theta synchronization. Furthermore, the phase-locking value (PLV) between central and occipital areas of left/right hand combined with contralateral foot imagery is significantly larger than that of simple limb motor imagery. All these findings imply that there exist apparent intrinsic distinctions of neural mechanism between simple and compound limb motor imagery, which presents a more complex effective connectivity network and may involve a more complex cognitive process during information processing.     

MAP3K2 augments Th1 cell differentiation via IL-18 to promote T cell-mediated colitis

T cell-mediated immunity in the intestine is stringently controlled to ensure proper immunity against pathogenic microbes and to prevent autoimmunity, a known cause of inflammatory bowel disease. However, precisely how T cells regulate intestine immunity remains to be fully understood. In this study, we found that mitogen-activated protein kinase kinase kinase 2(MAP3K2) is required for the CD4~+T cell-mediated inflammation in the intestine. Using a T cell transfer colitis model, we found that MAP3K2-deficient na?ve CD4~+T cells had a dramatically reduced ability to induce colitis compared to wild type T cells. In addition, significantly fewer IFN-γ-but more IL-17A-producing CD4~+T cells in the intestines of mice receiving MAP3K2-deficient T cells than in those from mice receiving wild type T cells was observed. Interestingly, under well-defined in vitro differentiation conditions, MAP3K2-deficient na?ve T cells were not impaired in their ability to differentiate into Th1, Th17 and Treg. Furthermore, the MAP3K2-regulated colitis severity was mediated by Th1 but not Th17 cells in the intestine. At the molecular level, we showed that MAP3K2-mediated Th1 cell differentiation in the intestine was regulated by IL-18 and required specific JNK activation. Together, our study reveals a novel regulatory role of MAP3K2 in intestinal T cell immunity via the IL-18-MAP3K2-JNK axis and may provide a novel target for intervention in T cell-mediated colitis.     

络石藤与地瓜藤抑制NO活性及差异性化学成分研究

络石藤为药典记载的常用中药，而地瓜藤在民间部分地区用作络石藤。为明确两种药材抗炎活性及相关化学成分间的差异，初步探讨其可能的药效物质基础，该研究通过检测不同浓度络石藤与地瓜藤醇提物对RAW264.7细胞存活率的影响，采用Griess试剂法测定LPS诱导的RAW264.7细胞上清液NO释放量，利用UPLC-Q-TOF-MS/MS技术对络石藤与地瓜藤醇提物中的化学成分进行分析，并结合多元统计学中的OPLS-DA模型鉴定两种药材的差异性化学成分。结果表明：(1)两种药材皆具有一定的NO抑制作用，络石藤粗提物的抑制作用稍强于地瓜藤。(2)络石藤与地瓜藤的化学成分存在明显差异，络石藤中的21个差异性成分主要为木脂素类，而地瓜藤中的10个差异性成分主要为黄酮类。综上认为，差异性化学成分可能是造成这两种药材抗炎活性差异的主要活性物质。该研究结果为络石藤与地瓜藤的抗炎药效物质基础和质量控制提供了理论依据。     

Time-locked and phase-locked features of P300 event-related potentials (ERPs) for brain–computer interface speller

The brain–computer interface P300 speller is aimed to help those patients unable to activate muscles to spell words by utilizing their brain activity. However, a problem associated with the use of this brain–computer interface paradigm is the generation mechanics of P300 related to responses to visual stimuli. Herein, we investigated the event-related potential (ERP) response for the P300-based brain–computer interface speller. A signal preprocessing method integrated coherent average, principal component analysis (PCA) and independent component analysis (ICA) to reduce the dimensions and noise in the raw data. The time–frequency analysis was based on wavelet and two characteristic parameters of event-related spectral perturbation (ERSP) and inter-trial coherence (ITC) were computed to indicate the evoked response (time-locked) and phase reset (phase-locked) activity, respectively. Results demonstrated that the proposed method was valid for the time-locked and phase-locked feature extraction and both the evoked response and phase reset contributed to the genesis of the P300 signal. These electrophysiological responses characteristics of ERPs would be used for BCI P300 speller design and its signal processing strategies.     

<Emphasis Type="Italic">Pasteurella multocida</Emphasis> CMP-sialic acid synthetase and mutants of <Emphasis Type="Italic">Neisseria meningitidis</Emphasis> CMP-sialic acid synthetase with improved substrate promiscuity

Cytidine 5′-monophosphate (CMP)-sialic acid synthetases (CSSs) catalyze the formation of CMP-sialic acid from CTP and sialic acid, a key step for sialyltransferase-catalyzed biosynthesis of sialic acid-containing oligosaccharides and glycoconjugates. More than 50 different sialic acid forms have been identified in nature. To facilitate the enzymatic synthesis of sialosides with diverse naturally occurring sialic acid forms and their non-natural derivatives, CMP-sialic acid synthetases with promiscuous substrate specificity are needed. Herein we report the cloning, characterization, and substrate specificity studies of a new CSS from Pasteurella multocida strain P-1059 (PmCSS) and a CSS from Haemophillus ducreyi (HdCSS). Based on protein sequence alignment and substrate specificity studies of these two CSSs and a Neisseria meningitidis CSS (NmCSS), as well as crystal structure modeling and analysis of NmCSS, NmCSS mutants (NmCSS_S81R and NmCSS_Q163A) with improved substrate promiscuity were generated. The strategy of combining substrate specificity studies of enzymes from different sources and protein crystal structure studies can be a general approach for designing enzyme mutants with improved activity and substrate promiscuity.     

Genome Sequence of the Thermophile Bacillus coagulans Hammer,the Type Strain of the Species

Here we announce a 3.0-Mb assembly of the Bacillus coagulans Hammer strain, which is the type strain of the species within the genus Bacillus. Genomic analyses based on the sequence may provide insights into the phylogeny of the species and help to elucidate characteristics of the poorly studied strains of Bacillus coagulans.     

Enhanced 2,3-butanediol production by <Emphasis Type="Italic">Klebsiella pneumoniae</Emphasis> SDM

Enhanced 2,3-butanediol (BD) production was carried out by Klebsiella pneumoniae SDM. The nutritional requirements for BD production by K. pneumoniae SDM were optimized statistically in shake flask fermentations. Corn steep liquor powder and (NH₄)₂HPO₄ were identified as the most significant factors by the two-level Plackett–Burman design. Steepest ascent experiments were applied to approach the optimal region of the two factors and a central composite design was employed to determine their optimal levels. The optimal medium was used to perform fed-batch fermentations with K. pneumoniae SDM. BD production was then studied in a 5-l bioreactor applying different fed-batch strategies, including pulse fed batch, constant feed rate fed batch, constant residual glucose concentration fed batch, and exponential fed batch. The maximum BD concentration of 150 g/l at 38 h with a diol productivity of 4.21 g/l h was obtained by the constant residual glucose concentration feeding strategy. To the best of our knowledge, these results were new records on BD fermentation. Cuiqing Ma and Ailong Wang contributed equally to this work.     

Sensitive determination of protein based on the fluorescence enhancement effect of terbium (III)–epinephrine–protein–sodium dodecylsulfate system

It was found that the fluorescence of Tb³⁺–epinephrine (E) complex can be enhanced by both bovine serum albumin (BSA) and sodium dodecylsulfate (SDS), and stabilized by ascorbic acid (AA). It is considered that the fluorescence enhancement of the Tb³⁺–E–BSA–AA–SDS system originates not only from the hydrophobic microenvironment provided by BSA–SDS, but also from the energy transfer from BSA to Tb³⁺ in this system. Therefore, a new fluorescence method for the determination of protein concentrations as low as 1.3 × 10^?9 g mL^?1 BSA is established using Tb³⁺–epinephrine complex as probe. The method has been applied for the determination of BSA and human serum albumin in actual samples, and the results obtained are satisfactory. Compared with other fluorescence methods, this method is simpler and more sensitive for the determination of protein. The mechanism of the fluorescence enhancement of the system is studied in detail. Copyright © 2009 John Wiley & Sons, Ltd.