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Corrigendum to “Structural Stability, Transitions, and Interactions within SoxYZCD-Thiosulphate from Sulfurimonas denitrificans: An In Silico Molecular Outlook for Maintaining Environmental Sulphur Cycle” 《反硝化硫单胞菌soxyzcd -硫代硫酸盐的结构稳定性、跃迁和相互作用:维持环境硫循环的硅分子展望》的勘误
Pub Date : 2016-12-20 DOI: 10.1155/2016/7905302
Sujay Ray, A. Banerjee
[This corrects the article DOI: 10.1155/2016/8683713.].
[这更正了文章DOI: 10.1155/2016/8683713.]。
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引用次数: 0
Detection of Gait Modes Using an Artificial Neural Network during Walking with a Powered Ankle-Foot Orthosis 利用人工神经网络检测动力踝足矫形器行走时的步态模式
Pub Date : 2016-12-13 DOI: 10.1155/2016/7984157
Mazharul Islam, E. Hsiao-Wecksler
This paper presents an algorithm, for use with a Portable Powered Ankle-Foot Orthosis (i.e., PPAFO) that can automatically detect changes in gait modes (level ground, ascent and descent of stairs or ramps), thus allowing for appropriate ankle actuation control during swing phase. An artificial neural network (ANN) algorithm used input signals from an inertial measurement unit and foot switches, that is, vertical velocity and segment angle of the foot. Output from the ANN was filtered and adjusted to generate a final data set used to classify different gait modes. Five healthy male subjects walked with the PPAFO on the right leg for two test scenarios (walking over level ground and up and down stairs or a ramp; three trials per scenario). Success rate was quantified by the number of correctly classified steps with respect to the total number of steps. The results indicated that the proposed algorithm's success rate was high (99.3%, 100%, and 98.3% for level, ascent, and descent modes in the stairs scenario, respectively; 98.9%, 97.8%, and 100% in the ramp scenario). The proposed algorithm continuously detected each step's gait mode with faster timing and higher accuracy compared to a previous algorithm that used a decision tree based on maximizing the reliability of the mode recognition.
本文提出了一种用于便携式供电踝足矫形器(即PPAFO)的算法,该算法可以自动检测步态模式的变化(平地,楼梯或坡道的上升和下降),从而允许在摆动阶段进行适当的踝关节驱动控制。人工神经网络(ANN)算法利用惯性测量单元和足部开关的输入信号,即足部的垂直速度和分段角。对人工神经网络的输出进行过滤和调整,以生成用于对不同步态模式进行分类的最终数据集。五名健康男性受试者在两种测试场景中右腿佩戴PPAFO行走(在平地上行走,上下楼梯或斜坡;每个场景三次试验)。成功率通过正确分类的步骤数相对于总步骤数来量化。结果表明,该算法在楼梯场景下的水平模式、上升模式和下降模式下的成功率分别为99.3%、100%和98.3%;98.9%、97.8%和100%(斜坡场景)。与以往基于模式识别可靠性最大化的决策树算法相比,该算法以更快的时序和更高的精度连续检测每步的步态模式。
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引用次数: 22
Structural Stability, Transitions, and Interactions within SoxYZCD-Thiosulphate from Sulfurimonas denitrificans: An In Silico Molecular Outlook for Maintaining Environmental Sulphur Cycle 反硝化硫单胞菌soxyzcd -硫代硫酸盐的结构稳定性、跃迁和相互作用:维持环境硫循环的硅分子前景
Pub Date : 2016-09-29 DOI: 10.1155/2016/8683713
Sujay Ray, A. Banerjee
Thiosulphate oxidation (an essential mechanism) serves to maintain the global sulphur cycle. Earlier experimental and computational studies dealt with environmental thiosulphate oxidation but none dealt with thiosulphate oxidation from deep ocean belts. Wet-laboratory experimental research shows that epsilon-proteobacteria Sulfurimonas denitrificans possess sox (sulphur-oxidizing) operon and perform thiosulphate oxidation efficiently underneath the oceans. From this specific sox operon, SoxCD complex recycles the thiosulphate-bound SoxY from SoxYZ complex to balance the environmental sulphur cycle. So, four chief proteins were variedly modeled and relevant simulated interactive structures were obtained. The final simulated tetraprotein complex (SoxYZCD) from docked SoxYZ and SoxCD complexes was disclosed to be a highly interactive one with predominant ionic residues. Free energy of folding, solvent accessibility, and conformational shifts (coil-like conformation to helices and sheets) were observed in SoxYZ complex after interacting with SoxCD. The stability of the complex (SoxYZCD) after simulation was also observed through the electrostatic surface potential values. These evaluations were rationalized via biostatistics. This aids SoxCD for recycling SoxY along with thiosulphate, which remains interconnected by four H-bonds with SoxY. Therefore, this novel exploration is endowed with the detailed molecular viewpoint for maintaining the sulphur cycle (globally) including the ocean belts.
硫代硫酸盐氧化(一种基本机制)有助于维持全球硫循环。早期的实验和计算研究涉及环境硫代硫酸盐氧化,但没有研究涉及深海带的硫代硫酸盐氧化。湿实验室实验研究表明,epsilon-proteobacteria硫单胞菌反硝化菌具有硫氧化操纵子,并在海洋下有效地进行硫硫酸盐氧化。SoxCD络合物通过这个特定的sox操纵子,从SoxYZ络合物中回收硫代硫酸盐结合的SoxY,以平衡环境硫循环。因此,对4种主要蛋白进行了不同的建模,得到了相应的模拟相互作用结构。由SoxYZ和SoxCD配合物对接得到的最终模拟四蛋白复合物(SoxYZCD)是一个具有优势离子残基的高度相互作用的复合物。SoxYZ配合物与SoxCD相互作用后,观察到自由折叠能、溶剂可及性和构象转变(螺旋状构象和片状构象)。通过静电表面电位值观察了模拟后配合物(SoxYZCD)的稳定性。这些评价是通过生物统计学来合理化的。这有助于SoxCD与硫代硫酸盐一起回收SoxY,硫代硫酸盐与SoxY通过四个氢键相互连接。因此,这一新颖的探索为维持包括海洋带在内的(全球)硫循环提供了详细的分子观点。
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引用次数: 2
A Coupled Phase-Temperature Model for Dynamics of Transient Neuronal Signal in Mammals Cold Receptor 哺乳动物冷感受器瞬态神经元信号动力学的相温耦合模型
Pub Date : 2016-09-28 DOI: 10.1155/2016/2754249
Firman Ahmad Kirana, H. Alatas, Irzaman Husein
We propose a theoretical model consisting of coupled differential equation of membrane potential phase and temperature for describing the neuronal signal in mammals cold receptor. Based on the results from previous work by Roper et al., we modified a nonstochastic phase model for cold receptor neuronal signaling dynamics in mammals. We introduce a new set of temperature adjusted functional parameters which allow saturation characteristic at high and low steady temperatures. The modified model also accommodates the transient neuronal signaling process from high to low temperature by introducing a nonlinear differential equation for the “effective temperature” changes which is coupled to the phase differential equation. This simple model can be considered as a candidate for describing qualitatively the physical mechanism of the corresponding transient process.
我们提出了一个由膜电位相和温度耦合微分方程组成的理论模型来描述哺乳动物冷受体的神经元信号。基于Roper等人先前工作的结果,我们修改了哺乳动物冷受体神经元信号动力学的非随机相位模型。我们引入了一套新的温度调节功能参数,以允许在高和低稳定温度下的饱和特性。修正后的模型还通过引入与相位微分方程耦合的“有效温度”变化的非线性微分方程来适应从高温到低温的瞬态神经元信号传递过程。这个简单的模型可以作为定性描述相应瞬态过程的物理机制的候选模型。
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引用次数: 2
Data Acquisition System for In Situ Monitoring of Chemoelectrical Potential in Living Plant Fuel Cells 植物燃料电池化学电势原位监测数据采集系统
Pub Date : 2016-08-30 DOI: 10.1155/2016/6108056
F. Chee, Cheng-Ann Chen, Jackson Hian Wui Chang, Ying Ying Choo, J. Dayou
Photosynthesis process in plants generates numerous sources of bioenergy. However, only a small fraction is readily exploited for electrical energy. The impact of environmental factors is one of the significant physiological influences on the electrical potential of the plants. Hence, we developed a data acquisition (DAQ) system for instantaneous monitoring of electrical potential in plants and Aloe vera was used as a plant sample. The static response characterization, capability index (P/T), and Pearson's coefficient of correlation procedures were applied to assess the reliability of the obtained data. This developed system offers the capability of in situ monitoring and detecting gradual changes in the electrical potential of plants up to a correlational strength of greater than 0.7. Interpretation of the electrical signal mechanisms in the Aloe vera plant and the optimization of the electricity can be achieved through the application of this monitoring system. This system, therefore, can serve as a tool to measure and analyze the electrical signals in plants at different conditions.
植物的光合作用过程产生多种生物能源。然而,只有一小部分容易被开发为电能。环境因素的影响是影响植物电位的重要生理因素之一。因此,我们开发了一个数据采集(DAQ)系统,用于瞬时监测植物的电位,并使用芦荟作为植物样本。采用静态响应表征、能力指数(P/T)和Pearson相关系数等方法评估所得数据的可靠性。这种开发的系统提供了现场监测和检测植物电位逐渐变化的能力,相关强度大于0.7。通过该监测系统的应用,可以实现对芦荟植物电信号机制的解读和电的优化。因此,该系统可以作为测量和分析植物在不同条件下电信号的工具。
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引用次数: 4
Physical Non-Contact Communication between Microscopic Aquatic Species: Novel Experimental Evidences for an Interspecies Information Exchange 微观水生物种之间的物理非接触交流:物种间信息交换的新实验证据
Pub Date : 2016-03-02 DOI: 10.1155/2016/7406356
D. Fels
Previous experiments on physical non-contact communication within same species gave rise to test for this type of communication also across the species border, which was the aim of the present study. It was found that autotrophic unicellular organisms (Euglena viridis), separated by cuvettes, affected the proliferation rate of heterotrophic unicellular organisms (Paramecium caudatum). Further, the heterotrophic unicellular organism affected also the proliferation rate of a multicellular heterotrophic organism (Rotatoria sp.) and vice versa. In the case when populations (of Euglena viridis and Paramecium caudatum) were shielded against electromagnetic fields in the optical spectrum from each other, no effects were measured. The results may support the notion that the organisation of ecosystems relies also on the exchange of electromagnetic fields from their constituting biosystems.
先前对同一物种内部物理非接触交流的实验产生了对跨物种边界的这种类型交流的测试,这是本研究的目的。通过试管分离发现,自养单细胞生物(绿绿Euglena viridis)对异养单细胞生物(尾草履虫)的增殖速率有影响。此外,异养单细胞生物也影响多细胞异养生物(Rotatoria sp.)的增殖率,反之亦然。当绿绿草履虫和尾草履虫的种群在光谱中相互屏蔽电磁场时,没有测量到任何影响。这些结果可能支持这样一种观点,即生态系统的组织也依赖于其构成生物系统的电磁场的交换。
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引用次数: 5
Self-Optimized Biological Channels in Facilitating the Transmembrane Movement of Charged Molecules 促进带电分子跨膜运动的自优化生物通道
Pub Date : 2016-01-29 DOI: 10.1155/2016/1657679
V. T. N. Huyen, Le Bin Ho, V. Lap, V. L. Nguyen
We consider an anisotropically two-dimensional diffusion of a charged molecule (particle) through a large biological channel under an external voltage. The channel is modeled as a cylinder of three structure parameters: radius, length, and surface density of negative charges located at the channel interior-lining. These charges induce inside the channel a potential that plays a key role in controlling the particle current through the channel. It was shown that to facilitate the transmembrane particle movement the channel should be reasonably self-optimized so that its potential coincides with the resonant one, resulting in a large particle current across the channel. Observed facilitation appears to be an intrinsic property of biological channels, regardless of the external voltage or the particle concentration gradient. This facilitation is very selective in the sense that a channel of definite structure parameters can facilitate the transmembrane movement of only particles of proper valence at corresponding temperatures. Calculations also show that the modeled channel is nonohmic with the ion conductance which exhibits a resonance at the same channel potential as that identified in the current.
我们考虑带电分子(粒子)在外部电压下通过一个大生物通道的各向异性二维扩散。该通道被建模为具有三个结构参数的圆柱体:半径、长度和位于通道内壁的负电荷的表面密度。这些电荷在通道内产生电势,电势在控制通过通道的粒子电流方面起着关键作用。结果表明,为了促进粒子跨膜运动,通道应合理自优化,使通道电位与共振电位重合,从而使通道上的粒子电流较大。观察到的易化似乎是生物通道的固有特性,无论外部电压或颗粒浓度梯度如何。从某种意义上说,这种促进是非常选择性的,即具有确定结构参数的通道只能在相应温度下促进具有适当价态的粒子的跨膜运动。计算还表明,模拟的通道是非欧姆的,离子电导在与电流中确定的通道电势相同的情况下表现出共振。
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引用次数: 0
Efficiency Enhancement of Cocktail Dye of Ixora coccinea and Tradescantia spathacea in DSSC 鸡尾草和鸡翅草鸡尾酒染料在DSSC中的增效作用
Pub Date : 2015-12-17 DOI: 10.1155/2015/582091
Zularif Zolkepli, Andery Lim, P. Ekanayake, K. Tennakoon
The use of anthocyanin dyes extracted from epidermal leaves of Tradescantia spathacea (Trant) and petals of Ixora coccinea (IX) was evaluated in the application of dye-sensitized solar cells (DSSCs). Subsequently, cocktail anthocyanin dyes from these dyes were prepared and how they enhanced the cell's overall performance was assessed using five different volume-to-volume ratios. Cocktail dyes absorbed a wider range of light in the visible region, thus increasing the cell efficiencies of the cocktail dyes when compared to the DSSC sensitized by individual dyes. The surface charge (zeta-potential), average size of aggregated anthocyanin molecules (zetasizer), and anthocyanin stability in different storage temperatures were analyzed and recorded. Lower size of aggregated dye molecules as revealed from the cocktail dyes ensured better adsorption onto the TiO2 film. Tradescantia/Ixora pigments mixed in 1 : 4 ratio showed the highest cell efficiency of η = 0.80%, under the irradiance of 100 mW cm−2, with a short-circuit current density 4.185 mA/cm2, open-circuit voltage of 0.346 V, and fill factor of 0.499. It was found that the desired storage temperature for these cocktail dyes to be stable over time was −20°C, in which the anthocyanin half-life was about approximately 1727 days.
研究了从spathacea (Trant)的表皮叶和Ixora coccinea (IX)的花瓣中提取的花青素染料在染料敏化太阳能电池(DSSCs)中的应用。随后,从这些染料中制备鸡尾酒花青素染料,并使用五种不同的体积比评估它们如何增强细胞的整体性能。鸡尾酒染料在可见光区域吸收了更大范围的光,因此,与单个染料敏化的DSSC相比,鸡尾酒染料提高了细胞效率。分析并记录了花青素在不同贮藏温度下的表面电荷(ζ电位)、聚集分子的平均大小(ζ诱变剂)和稳定性。从鸡尾酒染料中可以看出,较小尺寸的聚集染料分子确保了TiO2膜上更好的吸附。在辐照度为100 mW cm−2、短路电流密度为4.185 mA/cm2、开路电压为0.346 V、填充系数为0.499的条件下,以1:4比例混合的Tradescantia/Ixora颜料的电池效率最高,η = 0.80%。结果表明,在- 20℃的贮存温度下,这些鸡尾酒染料的花青素半衰期约为1727天。
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引用次数: 19
Flexural Stiffness of Myosin Va Subdomains as Measured from Tethered Particle Motion 从栓系粒子运动测量肌球蛋白Va亚域的弯曲刚度
Pub Date : 2015-11-30 DOI: 10.1155/2015/465693
A. Michalek, G. Kennedy, D. Warshaw, M. Y. Ali
Myosin Va (MyoVa) is a processive molecular motor involved in intracellular cargo transport on the actin cytoskeleton. The motor's processivity and ability to navigate actin intersections are believed to be governed by the stiffness of various parts of the motor's structure. Specifically, changes in calcium may regulate motor processivity by altering the motor's lever arm stiffness and thus its interhead communication. In order to measure the flexural stiffness of MyoVa subdomains, we use tethered particle microscopy, which relates the Brownian motion of fluorescent quantum dots, which are attached to various single- and double-headed MyoVa constructs bound to actin in rigor, to the motor's flexural stiffness. Based on these measurements, the MyoVa lever arm and coiled-coil rod domain have comparable flexural stiffness (0.034 pN/nm). Upon addition of calcium, the lever arm stiffness is reduced 40% as a result of calmodulins potentially dissociating from the lever arm. In addition, the flexural stiffness of the full-length MyoVa construct is an order of magnitude less stiff than both a single lever arm and the coiled-coil rod. This suggests that the MyoVa lever arm-rod junction provides a flexible hinge that would allow the motor to maneuver cargo through the complex intracellular actin network.
肌凝蛋白Va (MyoVa)是一种参与肌动蛋白细胞骨架细胞内货物运输的进行性分子马达。马达的加工能力和在肌动蛋白交叉点上导航的能力被认为是由马达结构各部分的刚度决定的。具体来说,钙的变化可能通过改变运动杠杆臂的刚度来调节运动进程,从而改变其头部间的通信。为了测量MyoVa子结构域的弯曲刚度,我们使用系缚粒子显微镜,将荧光量子点的布朗运动与电机的弯曲刚度联系起来,荧光量子点附着在与肌动蛋白结合的各种单头和双头MyoVa结构上。根据这些测量结果,MyoVa杠杆臂和线圈杆具有相当的抗弯刚度(0.034 pN/nm)。在加入钙后,由于钙调素可能与杠杆臂分离,杠杆臂的刚度降低了40%。此外,全长MyoVa结构的抗弯刚度比单杠杆臂和盘绕杆都要小一个数量级。这表明MyoVa杠杆臂杆连接处提供了一个灵活的铰链,允许马达通过复杂的细胞内肌动蛋白网络操纵货物。
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引用次数: 2
The Review of Nuclear Microscopy Techniques: An Approach for Nondestructive Trace Elemental Analysis and Mapping of Biological Materials 核显微技术:一种无损痕量元素分析和生物材料制图的方法
Pub Date : 2015-11-18 DOI: 10.1155/2015/740751
Stephen Juma Mulware
The properties of many biological materials often depend on the spatial distribution and concentration of the trace elements present in a matrix. Scientists have over the years tried various techniques including classical physical and chemical analyzing techniques each with relative level of accuracy. However, with the development of spatially sensitive submicron beams, the nuclear microprobe techniques using focused proton beams for the elemental analysis of biological materials have yielded significant success. In this paper, the basic principles of the commonly used microprobe techniques of STIM, RBS, and PIXE for trace elemental analysis are discussed. The details for sample preparation, the detection, and data collection and analysis are discussed. Finally, an application of the techniques to analysis of corn roots for elemental distribution and concentration is presented.
许多生物材料的特性往往取决于存在于基质中的微量元素的空间分布和浓度。多年来,科学家们尝试了各种各样的技术,包括经典的物理和化学分析技术,每种技术都有相对的准确性。然而,随着空间敏感亚微米光束的发展,利用聚焦质子束进行生物材料元素分析的核微探针技术取得了显著的成功。本文讨论了微量元素分析常用的微量探针技术STIM、RBS和PIXE的基本原理。讨论了样品制备、检测、数据收集和分析的细节。最后,介绍了该技术在玉米根系元素分布和浓度分析中的应用。
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引用次数: 18
期刊
Journal of Biophysics
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