목 적：복부 자기공명영상 검사는 호흡에 의한 움직임으로 인하여 최적의 영상 구현에 어려움이 많았다. 이에 본 연구에서는 복부자기공명검사 시 일정한 호흡을 돕는 메트로놈(Metronome)을 이용한 효과적인 검사 방법을 제시 하고자 한다. 대상 및 방법：2017년 1월 1일부터 2018년 1월 31일 까지 본원에서 검사한 복부 자기공명영상 검사를 받은 총60명(남자:여자 =44:16)의 환자를 대상으로 최적의 복부 자기공명영상 검사방법에 대하여 연구를 하였다. 장비는 General Electronics(GETM)의 Signa 1.5 Tesla 장비를 사용하였고, 연구는 호흡 유도하 스캔(RTr)의 Sequence중 T2 Single Shot Fast Spin Echo Axial Scan(T2 SSFSE), T2 Fast Spin Echo Propeller Axial Scan(이하 T2 Propeller)으로 하였다. 메트로놈(Metronome)을 사용하지 않고 검사한 그룹을 A그룹, 메트로놈(Metronome)을 사용하여 검사한 그룹은 B그룹 (BPM30=15회/분당)으로 나누었다. 결과는 SPSS 20.0을 사용하여 통계 분석하였다. 결 과：메트로놈 사용유무는 인공물 발생 정도와 영상의 화질에는 차이가 없었지만 메트로놈을 사용한 그룹이 검사시간 (485s:439s)과 검사 중 문제점(과호흡, 검사 중 수면, 재검사) 발생률(23%:3%)이 현저히 저감되었다(P<.05*). 결 론：복부 자기공명영상 검사 시 메트로놈(Metronome)을 사용하여 검사한 그룹이 사용하지 않은 그룹에 비하여 영상의 화질은 차이가 없었지만, 검사시간 단축 효과와 검사중 문제점 발생률 저감 효과는 통계학적으로 유의미 하였다(P<.05*). 따라서 호흡 유도하(RTr Scan) 복부 자기공명영상 검사 시 환자의 호흡수를 조절하는 메트로놈을 사용하면 더 효과적이라 할 수 있겠다.

We report the structural, morphological and magnetic properties of the Ni70Mn30 alloy prepared by Planetary Ball Mill method. Keeping the milling time constant for 30 h, the effect of different ball milling speeds on the synthesis and magnetic properties of the samples was thoroughly investigated. A remarkable variation in the morphology and average particle size was observed with the increase in milling speed. For the samples ball milled at 200 and 300 rpm, the average particle size and hence magnetization were decreased due to the increased lattice strain, distortion and surface effects which became prominent due to the increase in the thickness of the outer magnetically dead layer. For the samples ball milled at 400, 500 and 600 rpm however, the average particle size and hence magnetization were increased. This increased magnetization was attributed to the reduced surface area to volume ratio that ultimately led to the enhanced ferromagnetic interactions. The maximum saturation magnetization (75 emu/g at 1 T applied field) observed for the sample ball milled at 600 rpm and the low value of coercivity makes this material useful as soft magnetic material.

We report the structural, magnetic and magnetocaloric properties of Sr1.8Pr0.2FeMo1-xWxO6(0.0 ≤ x ≤ 0.4) samples prepared by the conventional solid state reaction method. The X-ray diffraction analysis confirms the formation of the tetragonal double perovskite structure with a I4/mmm space group in all the synthesized samples. The temperature dependent magnetization measurements reveal that all the samples go through a ferromagnetic to paramagnetic phase transition with an increasing temperature. The Arrott plot obtained for each synthesized sample demonstrates the second order nature of the magnetic phase transition. A magnetic entropy change is obtained from the magnetic isotherms. The values of maximum magnetic entropy change and relative cooling power at an applied field of 2.5 T are found to be 0.40 Jkg−1K−1 and 69 Jkg−1 respectively for the Sr1.8Pr0.2FeMoO6 sample. The tunability of magnetization and excellent magnetocaloric features at low applied magnetic field make these materials attractive for use in magnetic refrigeration technology.

Microalgae produce not only lipids for biodiesel production but also valuable biochemicals which are often accumulated under cellular stress mediated by certain chemicals. While the microcarriers for the application of drug delivery systems for animal cells are widely studied, their applications into microalgal research or biorefinery are rarely investigated. Here we develope dual-functional magnetic microcapsules which work not only as flocculants for microalgal harvesting but also potentially as microcarriers for the controlled release of target chemicals stimulating microalgae to enhance the accumulation of valuable chemicals. Magnetic microcapsules are synthesized by layer-by-layer(LbL) coating of PSS-PDDA on Fe3O4 nanoparticle-embedded CaCO3 microparticles followed by removing CaCO3 sacrificial templates. The positively charged magnetic microcapsules flocculate microalgae by electrostatic interaction which are sequentially collected by the magnetophoretic separation. The microcapsules with a polycationic outer layer provide efficient binding sites for negatively charged microalgae and by that means are further utilized as a chemical-delivery and flocculation system for microalgal research and biorefineries.

Electromagnetic interference (EMI) shielding is an important issue in modern daily life due to the increasing prevalence of electronic devices and their compact design. This study estimated EMI-shielding effect (EMI-SE) of small (8–14×17 mm) Hanji (Korean traditional paper) doped with carbon nanotubes (CNTs) and compared to Hanji without CNT using 2H (92.1 MHz) and 23Na (158.7 MHz) nuclear magnetic resonance (NMR) peak area data obtained from 1 M NaCl in D2O samples in capillary tubes that were wrapped in the Hanji samples. The simpler method of using the variation of reflected power and tuning frequency by inserting the sample into an NMR coil was also tested at 242.9, 158.7, and 92.1 MHz. Overall, EMI shielding was relatively more effective at the higher frequencies. Our results validated that NMR methods to be useful to evaluate EMI-SE, particularly for small, flexible shielding materials, and demonstrated that EMI shielding by absorption is dominant in Hanji mixed with CNT.

Functional magnetic resonance imaging (fMRI) is one of the best available devices that can record the activities of living human brain non-invasively. Its precision and high spatial resolution is matched by none other methodology. The entry barrier to fMRI research is exceptionally high. fMRI has widely been used in medical and scientific research, but its application to marketing research has been limited because of two important reasons. First, the cost problem. The MR scanning devices often cost multi-million dollars and using fMRI for marketing research can be costly. Second, analyzing data from fMRI study is another formidable task. fMRI measures the brain’s hemodynamic activities using voxel as a measuring unit; Voxels are often a cubic with 2 to 3 millimeters on one side. Since a typical adult brain represents over one million voxels in one scan volume, and each scan generally has 2 to 3 seconds of interval time, one experimental block of 40 seconds, for example, will create over 40 million data points. Compared to a typical marketing research data which in general have two dimensions (2d) of rows and columns, fMRI data is inherently 4d with added dimensions of voxel and time. Furthermore, the fMRI signal is sensitive to various sources of noises. In this talk, we offer support for marketing researchers who want to explore fMRI method for their research in the future. First, we discuss issues related to experimental design for fMRI experiments. We explain preprocessing steps that are recommended for fMRI data and show how to apply statistical methods to make inferences that can increase internal validity. Then, we will explicate how to apply big data analytics to fMRI data during this talk to find deep insights into customer’s brains. A real neuromarketing fMRI data will be used to break down the steps for fMRI research and data analytics. Finally, we will open a discussion to discover future research opportunities for marketing research using fMRI. The purpose of this talk is to lower the entry barrier of fMRI method in neuromarketing research so that more people in the marketing field can benefit from the most advanced scientific achievement of our time and discover deepest insights into our customers.

Magnetic resonance imaging (MRI) technique has recently been applied in agriculture and food science. It has potential to visualize internal structure of foods in nondestructive way and provides spatial information which could make reconstruct of three-dimension. MRI system also has great advantage for tracking water in beans or seeds. This study intends to analyze the changes of water distribution of coffee beans during water up-taking process. Samples used in the experiment were ‘Robusta’ coffee beans (Vietnam G1, Scr18 polish). A 30mm diameter plastic disposable test tube was used to hold bean during water up-take process. The oil column was placed next to the tube to get and to use as a reference signal. The magnetic resonance imaging system which installed at Institution for Agricultural Machinery & ICT Convergence in Chonbuk National University was used to obtain magnetic resonance (MR) image data sets. 30 images are included in each image data sets with ‘Axial’ image plane direction. In experiment, we used ‘Gradient Echo 3D’ pulse sequence. The water uptake process was performed for 150 minutes and acquired image data sets in every 10 minutes. This study showed some coffee beans which extracted as region of interest (ROI) from each images to study the water uptake process.

Amylose is carbohydrate polymer defined as a linear natural polysaccharide composed of α(1→4) bound glucose units. Due to its abundance, renewable nature, low cost, and biodegradability, this polymer is regarded as a promising green material for producing crystals and particles of different sizes ranging from the nanometer scale to the micrometer scale. Herein, short amylose chains and dextran-coated iron oxide magnetic nanoparticles (Dex@IONPs) were introduced to fabricate well-dispersed starch magnetic microbeads (SMMBs), which have a well-defined spherical shape and a uniform size of about 1 μm. We found that the aggregation of SMMBs can be mediated by the introduced Dex@IONPs in a concentration-dependent manner, indicating that Dex@MNPs, as the seed crystals, play an important role in self-assembly of SMMBSs. By using streptococcal protein G tagged with maltose binding protein (MBP-SPG), specific antibody against Escherichia coli O157:H7 was successfully immobilized on the surface of SMMBs. The Ab-functionalized SMMBs showed a high capture efficiency (>90%) comparable to the commercial immunomagnetic microparticles regardless of suspending agents (1X PBS and milk). Moreover, SMMBs exhibited excellent recyclability, in which the Ab immobilized on the surface of SMMBs can be refreshed by using the maltose elution buffer along with the unchanged capture efficiency. In addition, SMMBSs were assembled into the linear rod-shape microstructure by the introduced magnetic field during the amylose-mediated precipitation process. The convenient self-assembly of SMMBs with the well-defined size and shape, biocompatibility, tolerance to environmental variances, high magnetic response behavior, and excellent recyclability in the functionalization make these magnetic microparticles promising for many potential applications such as bio-sensing, labeling, and smart delivery of active compounds.

The outbreaks of foodborne diseases associated with bacterial contamination are still critical issues all over the world. To ensure food safety, the diagnosis of pathogenic bacteria on site at early state of contamination are required. Escherichia coli O157:H7 (E. Coli O157:H7) is one of the major factor causing foodborne diseases. We introduce a sandwich type colorimetric detection method integrated with chitosan-coated starch magnetic polymer beads(CS@SMBs) that can separate and concentrate bacteria in aqueous environment. For signal amplification, horseradish peroxidase-conjugated antibody (HRP-Antibody) and 3,3',5,5'- tetramethylbenzidine (TMB) were employed as enzyme label and chromogenic substrate, respectively. We demonstrate that CS@SMBs not only show a good magnetic sensitivity, but also can capture a variety of bacteria regardless of Gram-negative and Gram-positive, which offer possibility for separation of the broad range of bacteria from food matrix. Our approach successfully captures E. coli O157:H7 with detection limit of 101 CFU/mL through naked eye, making promise of fast, on-site, and sensitive detection of pathogenic bacteria.

Purpose：Recently, studies have been conducted to improve the signal intensities by increasing the filling factor, which is the volume ratio of the subject in the coil using a compensating material that does not appear as a magnetic resonance signal. Previous studies note that the magnetic susceptibility difference between the air and the compensation material should be minimized. Therefore, in this study, we tried to investigate and compare the materials that can reduce the susceptibility differences most effectively among various materials similar to human tissue density. Materials and Methods：The customized phantom was constructed using 7 different compound(borax powder, saline solution, sulfur powder, silicon power, graphite powder, wheat flour and silicon pad). A Bland-Altman plot was used to measure the magnetic susceptibility difference between the air and the phantom compound. Image acquisition was performed using a 3.0 T magnetic resonance imaging system (Skyra, Siemens, Germany) and a 15-channel head coil. Validation of a quantitative susceptibility mapping acquisitionw were carried out on T2 and T2* apping using Matlab (Ver.7.10, Mathworks, USA) and Image J (Ver.1.47v, NIH, USA) program. Results：The mean values of graphite (upper: -88.4, center: -100.5, lower: -101.6) and silicone (upper: -74.0, center: -37.1, lower: -96.6) were appeared negative which meant the susceptibility differences were higher than air. In contrast, wheat flour(Upper: 9.0, center: 0.3, lower: 11.3), silicon pad (upper: 13.9, center: -0.7, lower: 13.5), saline (upper: 11.9 , center: 1.0, lower: 16.3), borax (upper: 19.1, center: 1.2, lower: 13.6)and sulfur (upper: 19.0, center: 1.1, lower: 13.9)showed positive value which meant lower susceptibility difference compared to air. As a compensating material to overcome difference in susceptibility uniform performance and less deviation were observed in the compounds other than the graphite and silicon regardless of their position. Conclusion：The magnetic susceptibility is the intrinsic physical quantity of the elements in the periodic table such as mass and spin. In other words, when an element is exposed to an external magnetic field, it is a measure of how much the element is magnetized. Therefore, in selection of the magnetic susceptibility compensating material, it is important to select one the with the small magnetic susceptibility difference compared to air. In this study, the differences of susceptibility among wheat flour, silicon pad, physiological saline, borax and sulfur were observed to be appropriate. Increasing the filling factor with magnetic susceptibility compensating materials proposed in this study can improve the signal intensities.