Bursting synchronization in clustered neuronal networks

Neuronal networks in the brain exhibit the modular (clustered) property, i.e., they are composed of certain subnetworks with differential internal and external connectivity. We investigate bursting synchronization in a clustered neuronal network. A transition to mutual-phase synchronization takes place on the bursting time scale of coupled neurons, while on the spiking time scale, they behave asynchronously. This synchronization transition can be induced by the variations of inter- and intra- coupling strengths, as well as the probability of random links between different subnetworks. Considering that some pathological conditions are related with the synchronization of bursting neurons in the brain, we analyze the control of bursting synchronization by using a time-periodic external signal in the clustered neuronal network. Simulation results show a frequency locking tongue in the driving parameter plane, where bursting synchronization is maintained, even in the presence of external driving. Hence, effective synchronization suppression can be realized with the driving parameters outside the frequency locking region.     

Au／TS-1@Mesosilica双功能催化材料的制备及其催化丙烯直接环氧化性能

设计制备了一种新型微孔介孔复合核壳结构钛硅分子筛TS-1@Mesosilica（TS-l@Ms）,核为MFI结构钛硅分子筛TS-1,壳层为以非离子表面活性剂P123为模板剂组装形成的介孔氧化硅．壳层氧化硅具有三维蠕虫状孔道结构,有利于微孔和介孔部分的连通及反应物和产物的扩散．通过沉积沉淀法将金纳米粒子负载在壳层介孔孔道,和TS-1中的钛活性中心协同,形成适合于C3H6和H2、O2直接气相环氧化制备环氧丙烷（PO）的双功能催化材料．实验结果表明,Au／TS-1@MS在空速8000mLg-h、温度473K条件下连续反应132h,活性和选择性没有明显下降,丙烯转化率保持在3．7％左右,PO选择性87％以上．     

Characteristics analysis of acupuncture electroencephalograph based on mutual information Lempel-Ziv complexity

As a convenient approach to the characterization of cerebral cortex electrical information,electroencephalograph (EEG) has potential clinical application in monitoring the acupuncture effects.In this paper,a method composed of the mutual information method and Lempel-Ziv complexity method (MILZC) is proposed to investigate the effects of acupuncture on the complexity of information exchanges between different brain regions based on EEGs.In the experiments,eight subjects are manually acupunctured at ’Zusanli’ acupuncture point (ST-36) with different frequencies (i.e.,50,100,150,and 200 times/min) and the EEGs are recorded simultaneously.First,MILZC values are compared in general.Then average brain connections are used to quantify the effectiveness of acupuncture under the above four frequencies.Finally,significance index P values are used to study the spatiality of the acupuncture effect on the brain.Three main findings are obtained:(i) MILZC values increase during the acupuncture;(ii) manual acupunctures (MAs) with 100 times/min and 150 times/min are more effective than with 50 times/min and 200 times/min;(iii) contralateral hemisphere activation is more prominent than ipsilateral hemisphere’s.All these findings suggest that acupuncture contributes to the increase of brain information exchange complexity and the MILZC method can successfully describe these changes.     

一种黄酮衍生物的合成及其体外抗癌活性

以柚皮素为原料,通过对其结构进行修饰,合成了黄酮衍生物5-羟基-2-(4-羟基苯基)-7-(2-吗啉基乙氧基)-4H-苯骈吡喃-4-酮;利用核磁共振、元素分析及质谱确认了产物的结构,利用MTT法测定了其对人肝癌细胞(HepG2)、7721以及QSG7701正常肝细胞株的抑制率.结果表明,同槲皮素相对照,合成的黄酮衍生物对肝癌细胞具有良好的抑制活性.     

用快速低温冷冻和ESK方法分析兔脂肪栓塞脑组织中自由基

用快速低温冷冻-ESR实验方法研究兔脂肪栓塞模型脑组织自由基的变化,实验发现脂肪栓塞实验组自由基相对浓度是正常对照组的2-3倍。ESR检测到脂类过氧化自由基和以碳为中心的烷基类自由基的事实表明脂肪栓塞病变存在活性氧自由基作用过程。文中对快速冷冻法可行性进行评估。     

Ni(II)螯合物在氨基酸合成中的应用

Ni(II)螯合物诱导合成氨基酸是氨基酸合成方法中一类新颖且有工业生产价值的合成方法. 从合成方法学 、络合金属离子的优选、配体的改进、卤代片段的选择、合成氨基酸种类等方面介绍该合成方法的研究进 展.     

丹参脂溶性成分结构优化研究进展

丹参作为一种传统中药在临床上广泛应用于心脑血管疾病的治疗,对其有效成分及衍生物的研究一直是国内外的研究热点.丹参的有效成分主要分为脂溶性成分和水溶性成分,其脂溶性成分具有多种药理活性,但因其水溶性不足、生物利用度低的缺点限制了临床应用.为了能够推进丹参脂溶性成分的临床应用,研究人员以丹参脂溶性成分为先导化合物进行结构优化,以期能够提高其类药性.综述了近年来丹参主要脂溶性成分的结构优化及相关药理活性的研究进展,总结了主要脂溶性成分的成药性结构优化策略以及该类衍生物的合成方法,阐述了不同位置结构优化对药理活性的影响,旨在为丹参脂溶性成分创新药物的研发提供新的研究思路.     

无机及分析化学实验课“双轨型”教学模式改革与探索

针对无机及分析化学实验教学中存在的问题,探索"课内"实验与"课外"实践相结合的"双轨型"教学模式。介绍了"双轨型"实践教学模式改革的重要性、总体目标和架构;从改革教学方法、优化教学内容、倡导"绿色"化学等方面对"课内"实验教学进行改革;从教学内容、方法与组织等方面对"课外"实践教学进行探索;并对"双轨型"实践教学考核评价体系进行了优化,取得了较好的成效。     

The modulation of brain functional connectivity with manual acupuncture in healthy subjects:An electroencephalograph case study

Manual acupuncture is widely used for pain relief and stress control.Previous studies on acupuncture have shown its modulatory effects on the functional connectivity associated with one or a few preselected brain regions.To investigate how manual acupuncture modulates the organization of functional networks at a whole-brain level,we acupuncture at ST36 of a right leg to obtain electroencephalograph(EEG) signals.By coherence estimation,we determine the synchronizations between all pairwise combinations of EEG channels in three acupuncture states.The resulting synchronization matrices are converted into functional networks by applying a threshold,and the clustering coefficients and path lengths are computed as a function of threshold.The results show that acupuncture can increase functional connections and synchronizations between different brain areas.For a wide range of thresholds,the clustering coefficient during acupuncture and postacupuncture period is higher than that during the pre-acupuncture control period,whereas the characteristic path length is shorter.We provide further support for the presence of "small-world" network characteristics in functional networks by using acupuncture.These preliminary results highlight the beneficial modulations of functional connectivity by manual acupuncture,which could contribute to the understanding of the effects of acupuncture on the entire brain,as well as the neurophysiological mechanisms underlying acupuncture.Moreover,the proposed method may be a useful approach to the further investigation of the complexity of patterns of interrelations between EEG channels.     

最小神经元模型放电起始动态控制与分析

本文采用最小神经元模型,从生理学角度设计wash-out滤波器,实现了不同放电起始动态机理之间的转换,并证明wash-out滤波器控制通过影响阈下电流的竞争结果改变了神经元的放电起始动态机理. 关键词： 放电起始动态机理 阈下电流竞争 最小神经元模型 wash-out滤波器