单细胞转录组学细胞动态分化数据模拟算法的比较与评估

对9种单细胞转录组学(single cell RNA sequencing, scRNA-seq)细胞动态分化数据模拟算法进行系统性地比较和评估,为算法的开发者和用户提供可靠的参考和帮助。利用多种评价指标对上述算法在准确性、可拓展性、适用性等3个方面进行全面评估,并对运行时间和内存消耗情况进行建模预测。结果显示：9种被评估的算法均不能在数据特征与拓扑结构这2个方面同时有完美的表现;算法Dyngen虽然能模拟与参考数据拓扑结构和细胞分化轨迹相似度较高的数据,但是它的运行时间较长且内存消耗过大;将近一半的算法还需要及时更新版本信息并维护相关功能。用户在使用scRNA-seq细胞动态分化数据模拟算法时应综合考虑不同的使用场景和特点来选择最适合的模拟算法。     

AMPA receptors: potential implications in development and disease

α-amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid (AMPA) receptors are one type of ionotropic glutamate receptor involved in rapid excitatory synaptic transmission. AMPA receptors have been increasingly implicated in long-term potentiation, and recent evidence suggests that they may play a role in disorders affecting the nervous system. The finding that early in postnatal development AMPA receptors are not expressed has lately been the focus of much attention. Resolving the factors involved in AMPA receptor expression suggests that their induction is a developmentally regulated process with the possibility that alterations in receptor expression may be correlated with pathology in neurological disorders. This paper provides an overview of factors involved in AMPA receptor induction as well as of their role in plasticity and neuronal pathologies. Received 5 December 2000; received after revision 12 January 2001; accepted 2 February 2001     

癌症单细胞数据拷贝数变异检测方法

随着单细胞测序数据的异质性优势在癌症研究中的逐渐体现，现有拷贝数变异检测方法在检测单细胞数据时效果差的问题亟待解决。提出一种新的单细胞数据拷贝数变异检测方法（FL-CNV），通过动态窗口划分及数据估算对变异区间进行范围估计和断点确定，以明确拷贝数变异的断点位置和变异类型。所提方法突破了现有检测方法在单细胞数据上的局限性，对其检测效果在模拟数据和真实数据上进行了实验验证。结果表明：与现有方法相比，本文所提方法能显著提高拷贝数变异检测的精度和敏感度，且所得结果与比较基因组杂交（array-based comparative genomic hybridization，aCGH）的拷贝数变异进行了相关性验证，具有更高的可信度。     

单细胞微米炭球的制备及其对盐酸四环素的吸附性能研究

以酵母菌为原料,通过预处理-炭化-活化工艺制备了单细胞微米炭球,并利用X射线衍射仪（XRD）、扫描电子显微镜（SEM）、傅里叶红外光谱（FT-IR）和氮气吸附脱附（BET）等手段对单细胞微米炭球的结构演变进行探究。结果表明：所制得的单细胞微米炭球为黑色粉末,系无定形炭结构;单细胞微米炭球保持了酵母细胞椭圆形的形貌,分散均匀且形貌一致,平均尺寸约为1.81 μm×1.03 μm,比表面积达到1.61×10⁴ cm²/g,孔径集中在0.9、29和36 nm附近,具有丰富的孔结构。通过进一步考察单细胞微米炭球对盐酸四环素的吸附行为,证实所获得的单细胞微米炭球对四环素具有较好的吸附去除效果,吸附容量可达23.73 mg/g,符合Freundlich等温吸附模型。     

微流控芯片在单细胞捕获中的应用

 单细胞捕获是单细胞水平研究的前提和重要组成部分。微流控芯片通常具有与细胞尺寸相当的微通道结构,并能操控纳升至皮升级的极小体积流体,非常适用于高通量的单细胞捕获,加上微流控芯片能够将其他多种操作单元集成在一起,为单细胞分析提供了一种效率高、消耗低的研究平台。概述并对比了多种涉及流体力学、光、电、磁、声等领域的微流控单细胞捕获技术的原理和应用,展望了其未来的研究方向。     

特发性房颤患者的心房电生理特性

用食管心房调搏技术，对１８例特发性房颤患和２０例健康成年人的心房电生理特性进行对照研究。结果显示：特发性房颤中层得的心房有效不应期缩短，相对不应期延长，早搏刺激的房间传导延缓显增加。这些电生理异常可能在房颤的发生上起着重要作用，特发性房颤患可能有隐匿性心房肌病变。     

基于拉曼镊子的发酵过程单细胞分析：应用与展望

微生物发酵是个复杂的过程,而细胞间的异质性对微生物发酵性能有重要的影响。通过单细胞分析了解微生物细胞的异质性,利于发酵环境的优化,从而减少细胞间的异质性,提高发酵性能。整合显微拉曼光谱和光学微操控的拉曼镊子是实时、无损、无须标记且快速灵敏的单细胞分析方法。本文重点回顾拉曼镊子在聚酯、类胡萝卜素、脂肪酸、生物乙醇以及重组蛋白等发酵生产过程中的应用,并分析其在应用上存在的不足。在克服自身不足、融合新的分析技术与数据处理方法后,拉曼镊子将是了解细胞异质性、认知复杂生物过程的有力手段。     

General anaesthetic actions on ligand-gated ion channels

The molecular mechanisms of general anaesthetics have remained largely obscure since their introduction into clinical practice just over 150 years ago. This review describes the actions of general anaesthetics on mammalian neurotransmitter-gated ion channels. As a result of research during the last several decades, ligand-gated ion channels have emerged as promising molecular targets for the central nervous system effects of general anaesthetics. The last 10 years have witnessed an explosion of studies of anaesthetic modulation of recombinant ligand-gated ion channels, including recent studies which utilize chimeric and mutated receptors to identify regions of ligand-gated ion channels important for the actions of general anaesthetics. Exciting future directions include structural biology and gene-targeting approaches to further the understanding of general anaesthetic molecular mechanisms. Received 10 December 1998; received after revision 22 February 1999; accepted 23 February 1999     

一种快速可靠的豚鼠心室肌细胞分离法

报道一种快速的豚鼠心室肌细胞分离方法。该方法可获得杆状、清晰边缘的耐Ca^2 的单个心室肌细胞。     

Pheromone behavioral responses in unusual male European corn borer hybrid progeny not correlated to electrophysiological phenotypes of their pheromone-specific antennal neurons

In genetic studies on the sex pheromone communication system of two races of European corn borer, which use opposite pheromone blends of the E and Z compounds, it was found that antennal olfactory cell response amplitudes to the two compounds were controlled by an autosomal factor, whereas behavioral responses to the blends were controlled by a sex-linked locus. Because of the difference in genetic controls, it was postulated that some unusual males would be produced in F₂ crosses between these two races. These unusual males would have antennal olfactory cells that respond as the Z-race males, but would respond behaviorally to the E blend. The present studies combined behavioral studies in a flight tunnel and single cell electrophysiological studies to show that these unusual males do indeed exist. These findings show that the spike amplitude of peripheral olfactory cells is not important in regulating species- or race-specific pheromone responses, as compared to some central nervous system factor assesses the spike frequencies from different pheromone-component-specific cells on the antenna. This factor seems to be essential in governing the pheromone-blend specific behavioral responses of male moths.