Fluorescence Anisotropy of Cellular NADH as a Tool to Study Different Metabolic Properties of Human Melanocytes and Melanoma Cells

In this study, we wanted to see if fluorescence anisotropy could be used to detect changes in metabolism in cells with significant light scattering and absorption properties. Fluorescence anisotropy measurements of nicotinamide adenine dinucleotide (NADH) were performed with human melanocytes and melanoma cell lines. To demonstrate the feasibility of using fluorescence anisotropy for detecting metabolic changes, the electron transport chain was blocked using rotenone, inducing an accumulation of intracellular NADH. Total fluorescence increased in all cells as a result of rotenone treatment. Fluorescence anisotropy decreased in the rotenone-treated cells relative to the controls, suggesting an increased ratio of free to protein-bound NADH in the treated cells. In general, the fluorescence anisotropy of the melanocytes was significantly higher than that of the melanoma cell lines. Reflectance spectroscopy showed that the differences in fluorescence anisotropy between the cell types were not due to differences in scattering and absorption properties. Intrinsic cellular NADH fluorescence was experimentally extracted by ratioing polarized fluorescence to polarized reflectance. NADH binding, measured as the ratio of fluorescence intensity at 430 and 465 nm, showed more protein-bound NADH in the melanocytes than in the melanoma cells, consistent with the fluorescence anisotropy measurements.     

微电网储能系统调度日SOC初值确定方法

新能源微电网孤岛运行时,微电网的经济性和可靠性依赖于储能系统ESS（energy storage system）的功能发挥。在以天为单位的调度中,对ESS功能的需求转化为在综合考虑多天微电网能量需求的情况下对每日ESS的能量调度,其中含电池荷电状态SOC（state of charge）每天初值的确定。通过分析微电网多日供用电典型工况对调度日ESS的SOC初值的不同需求,基于多时间尺度预测和调度方法,提出了一种ESS调度日SOC初值的确定方法。设计了调度模型,引入每日SOC终值下限约束,根据多日工况对ESS的能量需求给出该下限值,进而以该调度模型进行多时间尺度调度确定下一日SOC初值,并作为下一日调度的输入。日调度和确定SOC初值滚动递进,使得基于该ESS的调度计划能够满足微电网多日能量需求。分析和算例说明了该方法的有效性。     

A biosensor that monitors cell morphology with electrical fields

Describes a “whole cell” biosensor that is very useful in the field of animal cell tissue culture and in many ways is akin to the canary in a coal mine. The heart of this method, called ECIS for electric cell-substrate impedance sensing, is a small gold electrode immersed in tissue culture medium. When cells attach and spread on this electrode, the measured electrical impedance changes because the cells constrain the current flow. This changing impedance can be interpreted to reveal useful information about cell behaviors. Since these behaviors, such as spreading and locomotion, involve the coordination of many biochemical reactions, they are extremely sensitive to most external parameters such as temperature, pH, and a myriad of chemical compounds. This broad response to changes in the environment allows this method to serve as a general biosensor. The measurements are easily automated, and the general conditions of the cells can be monitored by a personal computer controlling the necessary instrumentation     

A Real-Time Multi-Channel Monitoring System for Stem Cell Culture Process

A novel, up to 128 channels, multi-parametric physiological measurement system suitable for monitoring hematopoietic stem cell culture processes and cell cultures in general is presented in this paper. The system aims to measure in real-time the most important physical and chemical culture parameters of hematopoietic stem cells, including physicochemical parameters, nutrients, and metabolites, in a long-term culture process. The overarching scope of this research effort is to control and optimize the whole bioprocess by means of the acquisition of real-time quantitative physiological information from the culture. The system is designed in a modular manner. Each hardware module can operate as an independent gain programmable, level shift adjustable, 16 channel data acquisition system specific to a sensor type. Up to eight such data acquisition modules can be combined and connected to the host PC to realize the whole system hardware. The control of data acquisition and the subsequent management of data is performed by the system's software which is coded in LabVIEW. Preliminary experimental results presented here show that the system not only has the ability to interface to various types of sensors allowing the monitoring of different types of culture parameters. Moreover, it can capture dynamic variations of culture parameters by means of real-time multi-channel measurements thus providing additional information on both temporal and spatial profiles of these parameters within a bioreactor. The system is by no means constrained in the hematopoietic stem cell culture field only. It is suitable for cell growth monitoring applications in general.      

考虑多重分时电价和效益潜力的电力储能系统调度策略

电力储能系统接入电网在保证电力系统安全稳定运行方面具有诸多优势,执行储能系统调度策略能够实现削峰填谷,并从中获得经济效益.在不同的分时电价下,储能系统调度策略获得的经济效益往往具有差异性,因此定量研究不同分时电价下储能系统调度策略的效益潜力,对提高电力系统的整体经济效益具有重要意义.建立了考虑多重分时电价的储能系统调度策略效益潜力评估模型,量化储能系统调度策略在多重分时电价下的经济效益.以2018年某地的实际负荷数据为分析对象,采用改进粒子群优化算法验证所提储能系统调度策略的有效性,分析结果表明,所提储能系统调度策略效益潜力评估模型对提高电力系统的经济效益具有实用价值.     

基于谱分解动态散射成像的细胞无标记 检测与分类方法

细胞成像及检测技术在医学研究及临床诊断领域具有重要的研究意义和应用价值,而无标记与高通量检测尤其具有挑 战。 本研究基于动态散射理论的细胞成像方法,搭建了动态散射成像系统,提出了基于谱分解的动态信号提取算法,结合机器 学习算法实现了无标记、高通量的细胞分类。 采用血细胞、EG7-OVA 肿瘤细胞、A549 肺癌肿瘤细胞进行实验验证,结果表明本 文提出的方法对血细胞与肿瘤细胞识别准确率可达 98%以上,对于血细胞、EG7-OVA 细胞和 A549 细胞之间的三分类识别率约 为 91%。 本文实现的细胞检测和分类方法具有临床应用前景。     

平滑可再生能源发电系统输出波动的储能系统容量优化方法

光伏、风力发电等可再生能源(renewable energysources,RESs)具有随机性、间歇性等特点。为了抑制RESs输出波动对电网的不利影响,提出了用于平滑RESs发电系统功率输出的储能系统(energy storage system,ESS)容量优化确定方法。利用离散傅里叶变换(discrete Fouriertransform,DFT)对RESs输出功率进行频谱分析,基于频谱分析结果,考虑ESS充放电效率、荷电状态(state of charge,SOC)及RESs发电系统目标功率输出波动率的约束,确定所需ESS最小容量。采用美国华盛顿州实际观测风速数据及日本东北电力公司风电场接入电网20min有功功率波动规范(最大波动率为10%),在一风力发电系统中对该方法进行了验证。算例结果表明采用该方法能够以较小的容量将风机输出最大波动率由61.7%降到9.9%。     

Robustness of damping control implemented by Energy Storage Systems installed in power systems

An Energy Storage System (ESS) installed in a power system can effectively damp power system oscillations through controlling exchange of either active or reactive power between the ESS and power system. This paper investigates the robustness of damping control implemented by the ESS to the variations of power system operating conditions. It proposes a new analytical method based on the well-known equal-area criterion and small-signal stability analysis. By using the proposed method, it is concluded in the paper that damping control implemented by the ESS through controlling its active power exchange with the power system is robust to the changes of power system operating conditions. While if the ESS damping control is realized by controlling its reactive power exchange with the power system, effectiveness of damping control changes with variations of power system operating condition. In the paper, an example of power system installed with a battery ESS (BESS) is presented. Simulation results confirm the analytical conclusions made in the paper about the robustness of ESS damping control. Laboratory experiment of a physical power system installed with a 35 kJ/7 kW Superconducting Magnetic Energy Storage (SMES) was carried out to evaluate theoretical study. Results are given in the paper, which demonstrate that effectiveness of SMES damping control realized through regulating active power is robust to changes of load conditions of the physical power system.     

In vitro imaging of single living human umbilical vein endothelial cells with a clinical 3.0-T MRI scanner

Iron oxide-labelled, single, living human umbilical vein endothelial cells (HUVECs) were imaged over time in vitro using a clinical 3.0-T magnetic resonance (MR) microscopy system. Labelling efficiency, toxicity, cell viability, proliferation and differentiation were assessed using flow cytometry, magnetic cell sorting and a phenanthroline assay. MR images were compared with normal light and fluorescence microscopy. Efficient uptake of iron oxide into HUVECs was shown, although with higher label uptake dose-dependent cytotoxic effects were observed, affecting cell viability. For MR imaging, a T2* weighted three-dimensional protocol was used with in-plane resolution of 39×48μm² and 100-μm slices with a scan time of 13 min. MRI could detect living cells in standard culture dishes at single-cell resolution, although label loss was observed that corresponded with the intracellular iron measurements. MR microscopy using iron oxide labels is a promising tool for studying HUVEC migration and cell biology in vitro and in vivo, but possible toxic effects of label uptake and loss of label over time should be taken into account.     

Servo motor adaptive speed control under angle-dependent disturbances using an RBF network

It is well known that the angle-dependent disturbance in a servo motor caused by nonuniformity of field windings, armature cogging, rotor imbalance, nonuniform load and so on, may influence the speed control performance greatly. This often leads to large speed fluctuations which are undesired in practical situations. Therefore speed fluctuation reduction techniques in the presence of angle-dependent disturbances are strongly required and have been studied by many researchers. In this paper, the authors propose a new approach to this problem via adaptive control with the aid of a radial basis function (RBF) network composed of Gaussian basis functions. The angle-dependent disturbance, viewed as a periodic non-linear function with a period of 2π radians in the angular domain, is approximated by an RBF network in (0, 2π) radians. Then an adaptive linearization control system employing the RBF network which compensates for the disturbance is proposed. The RBF network has the advantage that it is linear in the parameters and hence parameter adaption is very fast and easy to implement. It is proved through theoretical analysis that the stability of adaptive control is guaranteed by Lyapunov stability theory. Finally, simulation and experimental results are included in the paper to show the excellent performance of the proposed method. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 119(4): 77–86, 1997     

风-光电站中储能系统混合最优配置及其经济性研究

储能是解决大规模可再生能源并网问题的重要手段,然而,储能系统的投资成本高、运维损耗大,且不同类型储能系统的技术经济参数存在差异。因此,研究不同类型储能系统的混合优化配置及其经济性具有十分重要的意义。提出风光电站内容量型和功率型储能系统混合配置优化方法,以储能系统全生命周期净收益最大为目标,采用遗传算法进行求解;以张家口地区风光电站实际运行数据和当前3种主流储能电池实际参数为例,分析不同敏感性因素对储能系统选型及容量配置的影响。算例结果表明：容量型储能系统的经济性对电池价格变化更为敏感;液流电池及超级电容混合配置的经济性最佳。     

风-光电站中储能系统混合最优配置及其经济性研究

储能是解决大规模可再生能源并网问题的重要手段,然而,储能系统的投资成本高、运维损耗大,且不同类型储能系统的技术经济参数存在差异。因此,研究不同类型储能系统的混合优化配置及其经济性具有十分重要的意义。提出风光电站内容量型和功率型储能系统混合配置优化方法,以储能系统全生命周期净收益最大为目标,采用遗传算法进行求解;以张家口地区风光电站实际运行数据和当前3种主流储能电池实际参数为例,分析不同敏感性因素对储能系统选型及容量配置的影响。算例结果表明：容量型储能系统的经济性对电池价格变化更为敏感;液流电池及超级电容混合配置的经济性最佳。     

陡脉冲不可逆性电击穿治疗肿瘤的研究

为寻求更为有效的肿瘤治疗策略,通过对陡脉冲治疗肿瘤的电穿孔效应和内处理效应的国内外研究现状的分析,提出了陡脉冲不可逆性电击穿效应调控肿瘤细胞死亡和凋亡的创新思路。实验中肉眼和组织学、超微结构的观察首次证实陡脉冲能有效地杀伤肿瘤细胞,明显抑制了肿瘤的生长、增殖,延长了的生存期。基于重庆大学的最新研究提出了不同窗口参数的陡脉冲具有不同的生物电效应的设想,总结了利用陡脉冲不可逆性电击穿效应治疗肿瘤的新方法及目前的研究进展并提出了该技术走向临床需重点研究的内容及关键技术。     

纳秒脉冲电场诱导肿瘤细胞凋亡的内质网信号通路分析

ns脉冲电场在诱导肿瘤细胞凋亡方面展现出诱人的应用前景。由于ns脉冲电场诱导肿瘤细胞凋亡的机制尚未明确,严重阻碍了ns脉冲电场肿瘤治疗的临床进程。为进一步揭示其诱导凋亡的机制,将参数组合(电压幅值9kV,脉宽100ns,脉冲30个,频率1Hz)作用于人卵巢浆液性囊腺癌(SKOV3)细胞。首先检测了半胱氨酸天冬氨酸蛋白酶-12(cysteine aspartic acid specific protease-12,Caspase-12)蛋白的释放水平,其次用浓度分别为0、25、50、100μmol/L的钙螯合剂(BAPTA-AM)螯合细胞内的游离Ca2+,用Hoechst 33342荧光染色检测细胞凋亡率,最后采用蛋白质印迹(western blot)技术检测了Caspase-12蛋白释放的变化。试验结果表明:ns脉冲诱导SK-OV3凋亡时引起了细胞内Ca2+升高,从而介导内质网凋亡信号通路。该研究结果将进一步揭示ns脉冲诱导凋亡的机制。     

电力需求侧规模储能容量优化和经济性分析

储能系统由于具备对功率和能量的时间迁移能力,是实施电力需求侧管理、控制负荷变动的一种有效手段。分析并建立由储能系统初始投资成本、运行维护成本、设备更换成本和资金收益构成的储能系统净现值目标函数,为准确估算储能在频繁不规则循环下的寿命周期,提出了一种基于等效寿命损耗的电池寿命计算模型;为确定储能充放电起止时刻,提出了一种改进的储能充放电策略。在容量优化计算中,采用量子编码结合自适应遗传算法,并引入灾变思想以提高计算速度达到全局最优。最后基于某电力需求侧一典型日的数据,分别对锂离子、钠硫、铅酸储能系统容量进行优化,通过基于净现值的经济性分析,对比三种储能应用于电力需求侧的经济性,结果表明,基于文中设置的边界条件,钠硫储能较另外两种储能更具经济性。     

储能与间歇式DG的容量配比关系以及实用估算方法

随着分布式电源在配电网中渗透率逐步提高,其间歇性和波动性等特点给电网带来了一定的冲击。储能是解决间歇式分布式电源（DG）接入问题的关键,现有的研究尚未明确储能与DG的容量配比关系。基于DG频谱分析结果对平滑输出场景下储能DG容量配比问题展开了研究,并提出了一种实用的储能容量配置估算方法。首先,介绍了储能容量优化的原理和算法。其次,利用某地各项目的实际间歇式DG数据,使用频谱分析的方法得到容量优化结果,并分析得到DG最大波动值与最优储能功率容量的关系、储能功率容量与能量容量的关系。实际工程较易得到的为DG的额定功率,因此还补充分析了DG额定功率与最大波动值之间的关系,最终得到储能容量与DG额定功率之间的关系,即储能与DG的配比规律。据此可无需要储能优化算法而通过简单手工计算得到近似优化的储能功率容量和能量容量。最后,通过算例对比了储能容量优化算法和实用方法,结果表明该实用方法简单有效。     

On discrete scattering Hurwitz polynomials

Discrete scattering Hurwitz polynomials play for discrete systems a similar role as scattering Hurwitz polynomials do for classical systems. A number of properties of discrete scattering Hurwitz polynomials are presented. These properties are obtained by deriving them from the corresponding properties of scattering Hurwitz polynomials. This is achieved by considering polynomials associated in a proper way to given polynomials and by examining the nature of the corresponding transformations.     

ns级陡脉冲诱导肿瘤细胞凋亡的实验研究

为进一步研究ns级陡脉冲诱导细胞的凋亡效应,以人卵巢腺癌SKOV3细胞为对象,进行了电场强度为10 kV/cm、脉宽为100 ns的陡脉冲实验研究。结果表明,通过流式细胞术观测发现早期凋亡率约22%;通过AO/EB荧光染色检测显示,早期凋亡细胞表现为细胞体积缩小,胞膜完整,浓聚成颗粒状,位于细胞的一侧,胞质浓缩,呈黄绿色荧光;晚期凋亡细胞体积缩小,胞膜完整,细胞核呈橙红色或红色荧光;细胞坏死时,细胞体积增大,呈不均匀的橙红色荧光,轮廓不清,已解体或接近解体。医学统计学和形态学特征表明ns级陡脉冲能诱导SKOV3肿瘤细胞发生凋亡。     

A novel scheme for global scattering center modeling of radar targets

A novel scheme for extracting the global scattering center model of radar targets is proposed in this paper. The 2D/3D scattering center models can be reconstructed based on the wideband measurements at different viewing angles. The sphere spreading of the 1D scattering center projections is exploited. The 1D-2D/3D scatterer map (OTSM) is designed to manifest the high dimensional scattering characteristic of radar targets. The Hough transform and the least squares method are used to extract the stable scattering centers and their scattering coefficients. This modeling method does not need a high density of the spatial grid, which greatly cuts down the necessary original data. The model built in this way describes the stable point scattering mechanisms in a large spatial extent and can be extrapolated to other frequencies in the optical region. Examples verify the validity of both the model and the method. __________ Translated from Chinese Journal of Radio Science, 2007, 22(3): 436–441 [译自: 电波科学学报]     

Effects of compression on soft tissue optical properties

Tissue optical properties are necessary parameters for prescribing light dosimetry in photomedicine. In many diagnostic or therapeutic applications where optical fiber probes are used, pressure is often applied to the tissue to reduce index mismatch and increase light transmittance. In this paper, we have measured in vitro optical properties as a function of pressure with a visible-IR spectrophotometer. A spectral range of 400-1800 mm with a spectral resolution of 5 nm was used for all measurements. Skin specimens of a Hispanic donor and two Caucasian donors were obtained from the tissue bank. Bovine aorta and sclera, and porcine sclera came from a local slaughter house. Each specimen, sandwiched between microscope slides, was compressed by a spring-loaded apparatus. Then diffuse reflectance and transmittance of each sample were measured at no load and at approximately 0.1, 1, and 2 kgf/cm². Under compression, tissue thicknesses were reduced up to 78%. Generally speaking, the reflectance decreased while the overall transmittance increased under compression. The absorption and reduced scattering coefficients were calculated using the inverse adding doubling method. Compared with the no-load controls, there was an increase in absorption and scattering coefficients among most of the compressed specimens