A novel approach to quantitative ultrasonic naked gene delivery and its non-invasive assessment

The purpose of this study was to investigate practical, safe, easy-to-use, non-cytotoxic, and reliable parameters to apply to an ultrasound (US) naked gene therapy system. The ultrasound pressure at the point of cell exposure was measured using a calibrated hydrophone and the intensity calculated. An acoustic power meter calibrated using a hydrophone was used to measure the power of the transducer. Four cell types were exposed to US with different exposure times and intensities. Fluorescent microscopy, spectrophotometry, scanning electron microscope, laser scanning confocal microscopy, flow cytometry and histogram analysis were used to evaluate the results of the study. The plasmid of green fluorescent protein (GFP) served as the reporter gene. The energy accumulation E in US gene delivery for 90% cell survival was defined as the optimal parameters (E=3.56+/-0.06), and at 80% cell survival was defined as the damage threshold (E=59.67+/-3.54). US safely delivered GFP into S180 cells (35.1 kHz) at these optimal parameters without obvious damage or cytotoxity in vitro. Exposed cell function was proved normal in vivo. The transfection rate was 35.83+/-2.53% (n=6) in viable cells, corresponding to 90.17+/-1.47% (n=6) cell viability. The intensity of GFP expression showed a higher fluorescent peak in the group of adeno-associated virus GFP vector (AVV-GFP) than in the control group (P<0.001). The effect of US gene delivery and cell viability correlated as a fifth order polynomial with US intensity and exposure time. With optimal parameters, US can safely deliver naked a gene into a cell without damage to cell function. Both optimal uptake and expression of gene depend on the energy E at 90% cell survival. E can be applied as a control factor for bioeffects when combined with other parameters. Stable caviation results in optimal parameters for gene delivery and the transient caviation may cause cell damage, which will bring about a sharp rise of permeabilization. The results may be applied to the development of a novel clinical gene therapeutic system.     

一种超声石油固井质量检测回波信号识别的新方法

本文提出一种基于连续小波变换和傅里叶交换相结合的超声固井质量检测回波信号的识别方法。根据超声固并质量检测回波信号的非平稳特性,该方法先对回波信号进行连续小波变换;然后利用博里叶变换,计算其在特定刻度时间段的幅度谱作为模式特征对回波信号进行识别。分析研究表明:理论和实际回波信号的处理结果基本一致,该方法相对于仅基于频谱特征和仅基于离散小波变换的识别方法而言具有分析刻度精细、受回波信号的时间错位影响很小、识别率高的优点,非常适合对具有时变谱特性的超声回波信号的识别。     

A quantitative approach to ionic adsorption

Binding properties of multi-atomic systems with ionic bonds are calculated by using a recently developed method based on the density functional formalism. The charge density is obtained from a superposition of the respective atomic densities where the charge transfer between these atoms is chosen such that the total energy attains a minimum. The kinetic energy of the electrons can to a very good approximation be calculated by means of a modified Thomas-Fermi-v. Weizsäcker expression. The molecules NaCl and NaW and a NaW₄ cluster have been treated as model systems for ionic interaction. Moreover, we have computed the binding properties of a Na atom adsorbed on a W(100) surface. This particular problem is the primary subject of the present study. The calculations yield binding energies, binding distances, vibrational frequencies, and induced dipole moments.     

A quantitative approach to soliton instability

We present an approach for instabilities of solitons that is based on the spectrum of a fourth-order linearized operator. Unlike the standard approach which is based on the slope (Vakhitov-Kolokolov) condition, this approach provides the quantitative value of the instability rate and the qualitative nature of the instability dynamics.     

A quantitative approach to low-energy quantum chromodynamics

A general method for solving the low-energy spectrum of an infrared unstable field theory is presented. The method involves a strong coupling expansion of the lattice approximation to the theory. Ultimately the results must be continued to zero-coupling constant in accord with the asymptotic freedom of such theories. The method is applied to the pure gauge field (glueball) part of quantum chromodynamics. The spectrum of lowest-lying states consists of a scalar and tensor which are almost degenerate and an axial vector with mass ≈1.6 times the scalar mass.The same procedure applied to the Abelian gauge theory yields unstable results which may indicate the presence of a phase transition.     

近红外光谱定量分析的新方法:半监督最小二乘支持向量回归机

在近红外光谱定量分析中,样品化学值测定的准确度是运用数学模型进行定量分析精确度的理论极限。但能够准确获取化学值的样品数量比较少,许多模型在建模时只考虑这部分样品数据,而不考虑大量的无化学值的样品数据。针对该问题,本文在LS-SVR的基础上,提出了可以同时利用有化学值(标签)和无化学值样品数据的半监督LS-SVR(S2LS-SVR)模型。类似于LS-SVR,该模型也只需求解一个线性方程组。最后,以烤烟样品数据集为实验材料,建立了四种样品成分(总糖、还原糖、总氮和烟碱)的定量分析模型。四种样品成分的预测值与实际值的平均误差分别为6.62%,7.56%,6.11%和8.20%,相关系数分别为0.974 1,0.973 3,0.923 0和0.948 6。经分析比较发现S2LS-SVR模型优于PLS和LS-SVR,从而验证了S2LS-SVR模型的可行性和有效性。     

A practical approach to ultrasonic imaging using diffraction tomography

A technique for ultrasonic imaging based on the theory of diffraction tomography is presented. The method utilizes a fixed, circular configuration of transmitters and detectors. This configuration was selected because it avoids many practical limitations associated with the design of a medical imaging device. Practical considerations also motivated the inclusion of effects associated with the transmitter beam pattern rather than pursuing the more conventional approach in which plane-wave illumination is required. In addition, the problem of separately imaging both density and compressibility variations is considered.     

A novel approach to Ising problems

In 2000 Istrail suggested that calculating the partition function of non‐planar Ising models is an NP‐complete problem, implying that these problems are intractable and thus essentially unsolvable. In this note we discuss the validity of this suggestion and introduce the idea of gauging on an exact equation. We illustrate how this method works by applying it to two non‐planar Ising models, namely the 2D model with nearest and weak next nearest neighbor interactions and the anisotropic 3D model.     

Characterisation of colloidal drug delivery systems from the naked eye to Cryo-FESEM

Poly(ethylcyanoacrylate) nanoparticles prepared by interfacial polymerisation on the basis of microemulsions were prepared in this study and both colloidal systems, nanoparticles and microemulsions, were analysed by visual observation and several microscopic techniques. Phase boundaries for the microemulsions of the two pseudoternary systems ethyloleate, polyoxyethylene 20 sorbitan mono-oleate/sorbitan monolaurate and water with and without butanol as a cosurfactant were determined by visual observation of the samples. Microemulsions containing liquid crystals were determined by polarisation light microscopy. Using freeze-fracture transmission electron microscopy and Cryo-field emission scanning electron microscopy the type of microemulsion (w/o droplet, bicontinuous, solution) was characterised. Nanoparticles prepared from the different types of microemulsion were additionally observed by conventional scanning electron microscopy. The size of the nanoparticles obtained from electron microscopy was in good agreement with particle sizing techniques (photon correlation spectroscopy) from earlier studies and no morphological differences could be observed in particles prepared from the different types of microemulsions. Cryo-field emission scanning electron microscopy proved to be a most valuable technique in the visualisation of the colloidal systems as samples could be observed close to their natural state.     

A novel enzyme-assisted ultrasonic approach for highly efficient extraction of resveratrol from Polygonum cuspidatum

Resveratrol is a promising multi-biofunctional phytochemical, which is abundant in Polygonum cuspidatum. Several methods for resveratrol extraction have been reported, while they often take a long extraction time accompanying with poor extraction yield. In this study, a novel enzyme-assisted ultrasonic approach for highly efficient extraction of resveratrol from P. cuspidatum was developed. According to results, the resveratrol yield significantly increased after glycosidases (Pectinex® or Viscozyme®) were applied in the process of extraction, and better extraction efficacy was found in the Pectinex®-assisted extraction compared to Viscozyme®-assisted extraction. Following, a 5-level-4-factor central composite rotatable design with response surface methodology (RSM) and artificial neural network (ANN) was selected to model and optimize the Pectinex®-assisted ultrasonic extraction. Based on the coefficient of determination (R²) calculated from the design data, ANN model displayed much more accurate in data fitting as compared to RSM model. The optimum conditions for the extraction determined by ANN model were substrate concentration of 5%, acoustic power of 150 W, pH of 5.4, temperature of 55 °C, the ratio of enzyme to substrate of 3950 polygalacturonase units (PGNU)/g of P. cuspidatum, and reaction time of 5 h, which can lead to a significantly high resveratrol yield of 11.88 mg/g.     

一种新的蔡氏电路设计方法与硬件实现

提出了一种基于蔡氏无量纲状态方程新的电路设计方法.首先对蔡氏无量纲状态方程各变量进行比例压缩变换、微分-积分转换和时间尺度变换.其次根据变换后的方程设计出各模块电路，再将各模块按方程中各状态变量的对应关系联结起来.整个电路只由反相加法器、积分器和反相器三大模块构成，电路结构对称.与现有其他的混沌电路设计相比，该方法具有三个主要特点：(1)直观性强，实现了电路的模块化设计，并总结出了这类混沌电路更一般的设计原理，具有普适性，可用于其他无量纲连续状态方程的电路设计；(2)由于采用了反相加法器，各个电路参数独立 关键词： 蔡氏电路 多项式 模块化设计 硬件实验     

A novel approach to high-sensitivity grating interferometry

The authors propose a new approach for obtaining information about in-plane and out-of-plane displacements of an object tested using high-sensitivity grating interferometry. The interferences of each of the specimen grating diffraction orders with a reference beam are recorded separately. Computer addition and subtraction of the phase functions calculated from the interferograms give the in-plane and out-of-plane displacement values, respectively. The authors present their experimental work, and then compare their results with those obtained using a conventional grating interferometry approach.     

Quantitative approach to ultrasonic emulsion separation

Ultrasound of 2MHz was irradiated to the emulsion prepared from canola oil and water and flocculation of the oil droplets occurred immediately. By putting the emulsion sample in a thin glass cell and setting it in bath type irradiation equipment, the progress of the separation was quantitatively monitored with the optical absorbance. The use of the cell enables visual observation of the behavior of oil droplets. Pictures show the formation of flocks of the dispersed phase and the appearance of checkered pattern consisting of flocks at a regular interval. The observation indicates that the action of radiation forces on oil droplets, which causes the flocculation. The flocks started to rise after stopping irradiation with holding their shape. The rising rate of the flocks was significantly greater than that of oil droplets in the original emulsion. Ultrasonic irradiation caused a rapid decrease in the absorbance, which expresses a progress of the separation. Effects of two major operation parameters, power and time on the separation degree were examined. The degree improved with increasing power input and irradiation time. The dataset was arranged in a plot of normalized separation degree against the input energy. The plot suggests that effective separation was attained with a lower power input and a longer irradiation time. The plot provides a guide for setting condition for the separation.     

A novel approach to confront electroweak data and theory

A novel approach to study electroweak physics at one-loop level in generic SU(2)_L×U(1)_Y theories is introduced. It separates the 1-loop corrections into two pieces: process specific ones from vertex and box contributions, and universal ones from contributions to the gauge boson propagators. The latter are parametrized in terms of four effective form factors $\bar e^2 (q^2 ), \bar s^2 (q^2 ), \bar g_Z^2 (q^2 )$ and $\bar g_W^2 (q^2 )$ corresponding to the γγ, γZ,ZZ andWW propagators. Under the assumption that only the Standard Model contributes to the process specific corrections, the magnitudes of the four form factors are determined atq ²=0 and atq ²=m _Z ² by fitting to all available precision experiments. These values are then compared systematically with predictions of SU(2)_L×U(1)_Y theories. In all fits α _s (m _Z ) and $\bar \alpha (m_Z^2 )$ are treated as external parameters in order to keep the interpretation as flexible as possible. The treatment of the electroweak data is presented in detail together with the relevant theoretical formulae used to interpret the data. No deviation from the Standard Model has been identified. Ranges of the top quark and Higgs boson masses are derived as functions of α _s (m _Z ) and $\bar \alpha (m_Z^2 )$ . Also discussed are consequences of the recent precision measurement of the left-right asymmetry at SLC as well as the impact of a top quark mass and an improvedW mass measurement.     

Magnetizable implants and functionalized magnetic carriers: A novel approach for noninvasive yet targeted drug delivery

We describe a targeted drug delivery system consisting of two steps: first, intravenous injection and circulation of biocompatible, magnetic nanospheres encapsulated with a drug; and second, focal concentration and release of the drug at the target site utilizing an implanted, magnetizable intraluminal stent or seed. We introduce the system concept, outline the biomedical feasibility, and discuss potential clinical advantages.     

A constructive approach to gene expression dynamics

Recently, experiments on mRNA abundance (gene expression) have revealed that gene expression shows a stationary organization described by a scale-free distribution. Here we propose a constructive approach to gene expression dynamics which restores the scale-free exponent and describes the intermediate state dynamics. This approach requires only one assumption: Markov property.     

A novel multiple blade ultrasonic cutting device

In ultrasonic devices consisting of serially coupled tuned components, components whose tuned length dimension is large compared to other dimensions, or components with profiles designed for high gain, the response of the device during operation is often characterised by modal interactions, and especially the excitation of combination resonances. The effects on ultrasonic devices are high noise levels, component failures and poor operating performance. In this paper, energy exchanges between modes are characterised to illustrate the adverse effects of combination resonances. Design solutions are proposed to eliminate these effects which concentrate on reducing the number of modes. In particular, a novel half-wavelength three-blade cutting system tuned to the first longitudinal mode has been designed by finite element modelling. An experimental investigation demonstrates that the measured response does not show evidence of modal interactions.     

A novel ultrasonic micro-dissection technique for biomedicine

Molecular techniques are transforming our understanding of cellular function and disease. However, accurate molecular analysis methods will be limited if the input DNA, RNA, or protein is not derived from pure population of cells or is contaminated by the wrong cells. A novel Ultrasonic Vibration Micro-dissection (UVM) method was proposed to procure pure population of targeted cells from tissue sections for subsequent analysis. The principle of the ultrasonic vibration cutting is analyzed, and a novel micro-tool is designed. A multilayer piezoelectric actuator is used to actuate a sharp needle vibrating with high frequency and low amplitude (approx. 16-50 kHz, and 0-3 microm) to cut the tissue. Contrast experiment was done to test the feasibility of UVM method. Experimental results show that the embedded tissue can be quickly and precisely cut with the ultrasonic vibration micro-dissection method.