Field-focusing hyperthermia and magnetic resonance imaging (MRI) with a grounded probe and a commercial MRI scanner

A method for performing magnetic resonance imaging (MRI) and producing field-focusing hyperthermia sequentially in phantoms and rat tissues with a grounded hyperthermic probe and a commercial MRI scanner was demonstrated. In the treatment mode the MRI scanner was used as a radiofrequency (RF) power source, and an invasive, electrically grounded, tuned probe was used to produce hyperthermia in phantoms via induced eddy current convergence. Temperature increases of 4.5 degrees C/5 minutes in a dielectrically uniform phantom and 5.0 degrees C/6 minutes in the peritoneum of a rat were measured in the vicinity (3-5 mm) of the grounded probe with the transmitter of the MRI scanner working at 2 per cent duty cycle. The advantage of this combined diagnostic and therapeutic approach is that the position of the hyperthermic probe can be monitored before each treatment, with observation of the tumor during and after treatment, if desired. In addition, the total cost is significantly less than that of both an MRI scanner and an RF hyperthermia treatment system.     

Visualization of copper(II) in velvet mesquite (Prosopis Juliflora-Velutina) and soybeans (Glycine max) by earth field magnetic resonance imaging

The goal of this research was to visualize the uptake of copper by plants to promote phytoremediation. The hypothesis was that regions of the plant that contain more copper have enhanced nuclear magnetic resonance using copper as a paramagnetic contrast agent. Earth field magnetic resonance imaging (EFMRI) spectrometry uses a magnetic field 300,000 times weaker than a 600 MHz nuclear magnetic resonance spectrometer. As in conventional human MRI, this portable instrument is capable of recording one-, two-, and three-dimensional images, although the sample size is reduced. The enhancement of signal was first demonstrated recording the two dimensional images of different concentrations of aqueous copper sulfate. The study also focused on growing mesquite and soybean plants in hydroponic media containing 0.25 mM copper nitrate for four and three weeks, respectively, and recording their EFMRI images with plants grown without copper nitrate. The results showed that EFMRI allows the probing the plant absorption of copper without having to dissect the specimen and therefore requires less sample preparation and time than current techniques. This technique may be beneficial to phytoremediation by imaging plants to evaluate their copper accumulation.     

浅谈药品生产企业的厂址选择和厂区规划

厂址的选择与厂区的规划是药品生产企业实施GMP的第1个环节,现就药品生产企业厂址选择与厂区规划的GMP符合性进行了探讨,并提出了具体的方法与实施步骤。     

计算机辅助工艺规划综述(二)

通过对计算机辅助工艺规划（CAPP）系统发展过程进行总结，指出CAPP的发展方向及企业成功实施该系统的模式选择。     

Integrated setup planning and operation sequencing (ISOS) using genetic algorithm

Process planning is an essential component for linking design and manufacturing process. Setup planning and operation sequencing are two most important functions in the implementation of CAD/CAPP/CAM integration. Many researches solved these two problems separately. Considering the fact that the two functions are complementary, it is necessary to integrate them more tightly so that performance of a manufacturing system can be improved economically and competitively. This paper presents a generative system and genetic algorithm (GA) approach to process plan the given part. The proposed approach and optimization methodology analysis constraints such as TAD?(tool?approach?direction), tolerance relation between features and feature precedence relations to generate all possible setups and operations using workshop resource database. Tolerance relation analysis has a significant impact in setup planning for obtaining the part accuracy. Based on technological constraints, the GA algorithm approach, which adopts the feature-based representation, simultaneously optimizes the setup plan and sequence of operations using cost indices. Case studies show that the developed system can generate satisfactory results in optimizing the integrated setup planning and operation sequencing in feasible condition.     

Magnetic resonance butterfly coils: Design and application for hyperpolarized C studies

Hyperpolarized ¹³C magnetic resonance spectroscopy in pig models enables cardiac metabolism assessment and provides a powerful tool for heart physiology studies, although the low molar concentration of derivate metabolites gives rise to technological limitations in terms of data quality. The design of dedicated coils capable of providing large field of view with high Signal-to-Noise Ratio (SNR) data is of fundamental importance.     

Clear imaging of Förster resonance energy transfer (FRET) signals of Ras activation by a time-lapse three-dimensional deconvolution system

A procedure for a time series of three‐dimensional Förster resonance energy transfer observation of a cell has been established. It employs quantitative deconvolution and three‐dimensional views of intensity‐modulated displays. The development was done with Raichu, a synthetic Ras protein capable of producing Förster resonance energy transfer upon its activation, for which two‐dimensional imaging has been established. This method gave much clearer images of Förster resonance energy transfer than does the usual method without deconvolution, even though the signals were relatively weak. The results suggest that this procedure is compatible with weak fluorescent light, which is prone to photobleaching.     

The application of nanoparticles in gene therapy and magnetic resonance imaging

The combination of nanoparticles, gene therapy, and medical imaging has given rise to a new field known as gene theranostics, in which a nanobioconjugate is used to diagnose and treat the disease. The process generally involves binding between a vector carrying the genetic information and a nanoparticle, which provides the signal for imaging. The synthesis of this probe generates a synergic effect, enhancing the efficiency of gene transduction and imaging contrast. We discuss the latest approaches in the synthesis of nanoparticles for magnetic resonance imaging, gene therapy strategies, and their conjugation and in vivo application.     

New imaging modalities: positron emission tomography and nuclear magnetic resonance

Positron emission tomography and nuclear magnetic resonance represent two new imaging modalities that utilize computer technology to provide tomographic images of the body. Positron emission tomography uses special metabolic imaging agents, which are positron emitters, to provide information on the metabolic processes that take place within the liver, kidney, and brain, and to allow study of physiologic changing systems such as blood flow. Nuclear magnetic resonance is used to evaluate the chemical constituents and the chemical composition of select tomographic areas within organs of interest. Both methods show great promise for the diagnosis and management of disease.     

径向磁化的双筒永磁轴承轴向磁力研究

为了解决径向磁化的双筒永磁轴承轴向磁力数值计算复杂及缺乏计算轴向磁力的工程化解析模型等问题,该文在分析磁筒气隙磁导的基础上,结合磁通连续性原理和稀土永磁材料特性,通过电磁场理论中的虚位移法得到了该型轴承工程化轴向磁力解析数学模型。模型表明:该型轴承轴向磁力与磁筒剩磁的平方成正比;轴向磁力随磁筒间隙半径、轴向长度及磁路总磁导的增大而增大,随磁筒间隙的增大而减小。在轴承正常轴向工作范围内,该模型计算值与实验值相当吻合。     

磁流变液阻尼器的磁路设计方法

磁流变阻尼器因其优越的性能，在汽车制造业、建筑业都具有潜在的巨大商业应用价值。在对磁流变阻尼器的磁路设计进行理论分析的基础上，建立一套比较完善且有效的磁流变阻尼器的磁路设计方法。本文所涉及的磁流变液阻尼器主要应用于车辆悬架的半主动振动控制。     

Direct detection and time-locked subsampling applied to pulsed electron paramagnetic resonance imaging

The application of direct time-locked subsampling (TLSS) to Fourier transform electron paramagnetic resonance (FT-EPR) spectroscopy at radio frequencies (rf) is described. With conventional FT-EPR spectroscopy, the high Larmor frequencies (L(f)) often necessitate the use of intermediate frequency (IF) stages to down convert the received free induction decay (FID) signal to a frequency that can be acquired with common data acquisition technology. However, our research focuses on in vivo studies, and consequently utilizes a FT-EPR system with a L(f) of 300 MHz. This relatively low frequency L(f), in conjunction with the advent of bandpass sampling analog-to-digital conversion and signal processing technologies, has enabled us to omit the IF stage in our FT-EPR system. With this in mind, TLSS techniques have been developed to directly sample the 300 MHz FID signal at a sampling rate of 80 MHz providing a signal bandwidth of 20 MHz. The required modifications to the data acquisition and processing system specific to this application are described. Custom software developed to control the EPR system setup, acquire the signals, and post process the data, is outlined. Data was acquired applying both coherent averaging and stochastic excitation sequences. The results of these experiments demonstrate digital down conversion of the 300 MHz FID signal to quadrature baseband. Direct FID TLSS eliminates many noise sources common in EPR systems employing traditional analog receiver techniques, such as the IF mixer stage in single channel systems, and the quadrature baseband mixer stage in dual channel systems.     

Multiphase flow and mixing quantification using computational fluid dynamics and magnetic resonance imaging

This paper investigates the current challenges and practices of quality measurement in the oil & gas industry. It particularly focuses on automatic pipeline sampling of petroleum liquids according to ISO 3171. The problem is tackled using innovative diagnostic techniques, advanced design optimisation tools and a new mixing system that uses a Liquid Jet In Cross Flow (LJICF) configuration. First, a 2.5″ diameter small multiphase flow loop (SMPFL) was developed and magnetic resonance (MR) was utilised to characterise the mechanistic behaviour of mixing and the mixing efficiency of various nozzles. Second, a computational fluid dynamics (CFD) model was developed and validated using MR measurements on the SMPFL. The CFD model was then used to optimise the nozzle design as well as the design of a 10” nominal diameter large multiphase flow loop (LMPFL). The LMPFL is a well instrumented facility and was used to conduct mixing experiments on low velocity, low density and low viscosity fluids flowing in a horizontal pipe, which constitute challenging conditions for a mixing device to create homogeneous mixture. To quantify the homogeneity of the mixture created by the new mixing system on the LMPFL, a multiport profile proving (MPP) technique was developed and used to conduct water injection testing in compliance with ISO 3171 and API 8.2 standards. The water volume fraction (WVF) determined by the MPP had low relative error when compared to the mean WVF measured by the water cut meters and samples analysed using Coulometric Karl-Fischer (KF). Additionally, in an earlier study [1], the MPP measurement was able to detect a density gradient across the diameter of the pipe, making it an appropriate method to judge the homogeneity of the mixture. Therefore, the new mixing system together with the MPP technology shows real promise as an effective sampling and proving system for the petrochemical industry.     

基于PM的ERP实施模式研究

文章通过对现有ERP实施模式的分析,提出将项目管理（PM）思想运用到ERP实施中,将ERP的实施过程作为项目,按照PM方法进行有效的、动态的管理与控制,以指导ERP项目的实施,提升ERP实施的水平和效能。应用案例对比证实了基于PM的ERP实施模式的可行性和科学性。     

钕铁硼永磁体微型机器人转矩的分析

研制了一种外磁场控制的永磁体式微型管内机器人,提出了基于等效磁荷法中的磁矩传递力矩对永磁体式微型机器人传递力矩进行了分析计算,建立了传递力矩的数学模型,这将对永磁体式微型机器人的理论研究与实际应用具有指导作用。     

Optical characterization of elastohydrodynamic lubricated (EHL) contacts using surface plasmon resonance (SPR) effect

In this paper we report a novel optical technique based on the surface plasmon resonance (SPR) phenomenon for studying elastohydrodynamic lubricated (EHL) dimple. While it is well known that the refractive index (RI) variation in the lubricant may provide direct information on the pressure distribution inside a highly pressurized EHL dimple, one can obtain the pressure in the spectral SPR absorption curve, which corresponds to a unique color complexion in the SPR image.We have performed experiments to compare our SPR imaging technique with the one based on conventional optical interferometry. The new SPR technique provides an improvement of over 180 times in measurement accuracy. More importantly, SPR measures the RI directly and does not require any information on the lubricant film thickness. In light of these advantages, the SPR detection approach reported herein should be an attractive technique for studying EHL contacts.     

计算机辅助成组工艺过程设计(YDGAPP)系统

论述了木工机械行业的YDCAPP系统的功能及其特点,该系统是基于成组技术的半创成式CAPP系统。     

一种新的编码方法解决路径规划问题

提出了一种在极坐标环境下应用遗传算法求解机器人路径规划问题的方法.该方法采用简洁有效的路径染色体编码方法和快速的个体适应度计算方法,并对生成的初始路径点集进行提炼处理,以剔除其中含有的不必要拐点;仿真结果表明该方法可以解决大范围、多障碍环境的机器人路径规划问题.     

Multiparametric high-resolution imaging of barley embryos by multiphoton microscopy and magnetic resonance micro-imaging

Nonlinear optical microscopy and magnetic resonance imaging (MRI) address different properties of the sample and operate on different geometrical scales. MRI maps density and mobility of molecules tracking specific molecular signatures. Multiphoton imaging profits from the nonlinear absorption of light in the focus of a femtosecond laser source stimulating the autofluorescence of biomolecules. As this effect relies on a high light intensity, the accessible field of view is limited, but the resolution is very high (a few hundred nanometers). Here, we aim to link the different accessible scales and properties addressed in the different techniques to obtain a synoptic view. As model specimen we studied embryos of barley. Multiphoton stimulated autofluorescence images and images of second harmonic generation are achieved even down to low magnification (10x), low numerical aperture (N.A. 0.25) conditions. The overview images allowed morphological assignments and fluorescence lifetime imaging provides further information to identify accumulation of endogenous fluorophores. The second, complementary contribution from high-resolution MR images provides a 3D model and shows the embedding of the embryo in the grain. Images of the proton density were acquired using a standard 3D spin-echo imaging pulse sequence. Details directly comparable to the low magnification optical data are visible. Eventually, passing from the MR images of the whole grain via low magnification to high resolution autofluorescence data bridges the scale barrier, and might provide the possibility to trace transport and accumulation of, e.g., nutrients from large structure of the plant to the (sub-) cellular level.