• Title/Summary/Keyword: Magnetic array

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A case of Sotos syndrome presented with end-stage renal disease due to the posterior urethral valve

  • Cho, Won Im;Ko, Jung Min;Kang, Hee Gyung;Ha, Il-Soo;Cheong, Hae Il
    • Journal of Genetic Medicine
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    • v.11 no.2
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    • pp.74-78
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    • 2014
  • Sotos syndrome (SS, OMIM 117550) is characterized by prenatal and postnatal overgrowth with multiple congenital anomalies. However, there have been few cases of growth retardation caused by renal failure from infancy. We report a case of dysplasia of the bilateral kidneys with renal failure and poor postnatal growth. A 2-month-old boy visited the emergency room owing to poor oral intake and abdominal distension. He was born at the gestational age of 38 weeks with a birth weight of 4,180 g. After birth, he had feeding difficulty and abdominal distension. Upon physical examination, his height and weight were in less than the 3rd percentile, while his head circumference was in the 50th percentile on the growth curve. He also showed a broad and protruding forehead and high hairline. Blood laboratory tests showed severe azotemia; emergent hemodialysis was needed. Abdominal ultrasonography revealed bilateral renal dysplasia with multiple cysts and diffuse bladder wall thickening. A posterior urethral valve was suggested based on vesicoureterography and abdominal magnetic resonance findings. Results of a colon study to rule out congenital megacolon did not reveal any specific findings. The conventional karyotype of the patient was 46, XY. Array comparative genomic hybridization study revealed a chromosome 5q35 microdeletion including the NSD1 gene, based on which SS was diagnosed. We describe a case of SS presenting with end stage renal disease due to posterior urethral valve. The typical somatic overgrowth of SS in the postnatal period was not observed due to chronic renal failure that started in the neonatal period.

Analysis of Magnetic Isotropy Property using Magnetoresistance Curve of CoFe/Cu/CoFe/PtMn Multilayer Film (CoFe/Cu/CoFe/PtMn 다층박막의 자기저항 곡선을 이용한 자기 등방성 특성 분석)

  • Choi, Jong-Gu;Kim, Su-Hee;Choi, Sang-Heon;Lee, Sang-Suk;Rhee, Jang-Roh
    • Journal of the Korean Magnetics Society
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    • v.27 no.4
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    • pp.123-128
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    • 2017
  • The magnetic isotropy property from the magnetoresistance (MR) curve and magnetization (MH) loop for the PtMn based spin valve (SV) multilayer films fabricated with different the bottom structure after post-annealing treatment was investigated. The exchange biased coupling field ($H_{ex}$), coercivity ($H_c$), and MR ratio of Glass/Ta(10 nm)/CoFe(6 nm)/Cu(2.5 nm)/CoFe(3 nm)/Ta(4 nm) SV multilayer film without antiferromagnetic PtMn layer are 0 Oe, 25 Oe, and 3.3 %, respectively. MR curve for the Glass/Ta(10 nm)/CoFe(6 nm)/Cu(2.5 nm)/CoFe(3 nm)/PtMn(6 nm)/Ta(4 nm) SV multilayer film showed $H_{ex}=2Oe$, $H_c=316Oe$, and MR (%) = 4.4 % with one butterfly MR curve having by the effect of antiferromagnetic PtMn layer. MR curve for the dualtype Glass/Ta(10 nm)/CoFe(6 nm)/Cu(2.5 nm)/CoFe(3 nm)/PtMn(6 nm)/CoFe(3 nm)/Cu(2.5 nm)/CoFe(6 nm)/Ta(4 nm) SV multilayer film showed $H_c=37.5Oe$ and 386 Oe, MR = 3.5 % and 6.5 % with two butterfly MR curves and square-like hysteresis MH loops. The anisotropy property in CoFe spin valve-PtMn multilayer is neglected by the effects of a very small value of $H_{ex}$ and a very slightly shape magnetic anisotropy. This result is possible to explain the effect of magnetization configuration spin array of the bottom SV film and the top SV film of PtMn layer.

THE CURRENT STATUS OF BIOMEDICAL ENGINEERING IN THE USA

  • Webster, John G.
    • Proceedings of the KOSOMBE Conference
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    • v.1992 no.05
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    • pp.27-47
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    • 1992
  • Engineers have developed new instruments that aid in diagnosis and therapy Ultrasonic imaging has provided a nondamaging method of imaging internal organs. A complex transducer emits ultrasonic waves at many angles and reconstructs a map of internal anatomy and also velocities of blood in vessels. Fast computed tomography permits reconstruction of the 3-dimensional anatomy and perfusion of the heart at 20-Hz rates. Positron emission tomography uses certain isotopes that produce positrons that react with electrons to simultaneously emit two gamma rays in opposite directions. It locates the region of origin by using a ring of discrete scintillation detectors, each in electronic coincidence with an opposing detector. In magnetic resonance imaging, the patient is placed in a very strong magnetic field. The precessing of the hydrogen atoms is perturbed by an interrogating field to yield two-dimensional images of soft tissue having exceptional clarity. As an alternative to radiology image processing, film archiving, and retrieval, picture archiving and communication systems (PACS) are being implemented. Images from computed radiography, magnetic resonance imaging (MRI), nuclear medicine, and ultrasound are digitized, transmitted, and stored in computers for retrieval at distributed work stations. In electrical impedance tomography, electrodes are placed around the thorax. 50-kHz current is injected between two electrodes and voltages are measured on all other electrodes. A computer processes the data to yield an image of the resistivity of a 2-dimensional slice of the thorax. During fetal monitoring, a corkscrew electrode is screwed into the fetal scalp to measure the fetal electrocardiogram. Correlations with uterine contractions yield information on the status of the fetus during delivery To measure cardiac output by thermodilution, cold saline is injected into the right atrium. A thermistor in the right pulmonary artery yields temperature measurements, from which we can calculate cardiac output. In impedance cardiography, we measure the changes in electrical impedance as the heart ejects blood into the arteries. Motion artifacts are large, so signal averaging is useful during monitoring. An intraarterial blood gas monitoring system permits monitoring in real time. Light is sent down optical fibers inserted into the radial artery, where it is absorbed by dyes, which reemit the light at a different wavelength. The emitted light travels up optical fibers where an external instrument determines O2, CO2, and pH. Therapeutic devices include the electrosurgical unit. A high-frequency electric arc is drawn between the knife and the tissue. The arc cuts and the heat coagulates, thus preventing blood loss. Hyperthermia has demonstrated antitumor effects in patients in whom all conventional modes of therapy have failed. Methods of raising tumor temperature include focused ultrasound, radio-frequency power through needles, or microwaves. When the heart stops pumping, we use the defibrillator to restore normal pumping. A brief, high-current pulse through the heart synchronizes all cardiac fibers to restore normal rhythm. When the cardiac rhythm is too slow, we implant the cardiac pacemaker. An electrode within the heart stimulates the cardiac muscle to contract at the normal rate. When the cardiac valves are narrowed or leak, we implant an artificial valve. Silicone rubber and Teflon are used for biocompatibility. Artificial hearts powered by pneumatic hoses have been implanted in humans. However, the quality of life gradually degrades, and death ensues. When kidney stones develop, lithotripsy is used. A spark creates a pressure wave, which is focused on the stone and fragments it. The pieces pass out normally. When kidneys fail, the blood is cleansed during hemodialysis. Urea passes through a porous membrane to a dialysate bath to lower its concentration in the blood. The blind are able to read by scanning the Optacon with their fingertips. A camera scans letters and converts them to an array of vibrating pins. The deaf are able to hear using a cochlear implant. A microphone detects sound and divides it into frequency bands. 22 electrodes within the cochlea stimulate the acoustic the acoustic nerve to provide sound patterns. For those who have lost muscle function in the limbs, researchers are implanting electrodes to stimulate the muscle. Sensors in the legs and arms feed back signals to a computer that coordinates the stimulators to provide limb motion. For those with high spinal cord injury, a puff and sip switch can control a computer and permit the disabled person operate the computer and communicate with the outside world.

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Analysis of Image Distortion on Magnetic Resonance Diffusion Weighted Imaging

  • Cho, Ah Rang;Lee, Hae Kag;Yoo, Heung Joon;Park, Cheol-Soo
    • Journal of Magnetics
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    • v.20 no.4
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    • pp.381-386
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    • 2015
  • The purpose of this study is to improve diagnostic efficiency of clinical study by setting up guidelines for more precise examination with a comparative analysis of signal intensity and image distortion depending on the location of X axial of object when performing magnetic resonance diffusion weighted imaging (MR DWI) examination. We arranged the self-produced phantom with a 45 mm of interval from the core of 44 regent bottles that have a 16 mm of external diameter and 55 mm of height, and were placed in 4 rows and 11 columns in an acrylic box. We also filled up water and margarine to portrait the fat. We used 3T Skyra and 18 Channel Body array coil. We also obtained the coronal image with the direction of RL (right to left) by using scan slice thinkness 3 mm, slice gap: 0mm, field of view (FOV): $450{\times}450mm^2$, repetition time (TR): 5000 ms, echo time (TE): 73/118 ms, Matrix: $126{\times}126$, slice number: 15, scan time: 9 min 45sec, number of excitations (NEX): 3, phase encoding as a diffusion-weighted imaging parameter. In order to scan, we set b-value to $0s/mm^2$, $400s/mm^2$, and $1,400s/mm^2$, and obtained T2 fat saturation image. Then we did a comparative analysis on the differences between image distortion and signal intensity depending on the location of X axial based on iso-center of patient's table. We used "Image J" as a comparative analysis programme, and used SPSS v18.0 as a statistic programme. There was not much difference between image distortion and signal intensity on fat and water from T2 fat saturation image. But, the average value depends on the location of X axial was statistically significant (p < 0.05). From DWI image, when b-value was 0 and 400, there was no significant difference up to $2^{nd}$ columns right to left from the core of patient's table, however, there was a decline in signal intensity and image distortion from the $3^{rd}$ columns and they started to decrease rapidly at the $4^{th}$ columns. When b-value was 1,400, there was not much difference between the $1^{st}$ row right to left from the core of patient's table, however, image distortion started to appear from the $2^{nd}$ columns with no change in signal intensity, the signal was getting decreased from the $3^{rd}$ columns, and both signal intensity and image distortion started to get decreased rapidly. At this moment, the reagent bottles from outside out of 11 reagent bottles were not verified from the image, and only 9 reagent bottles were verified. However, it was not possible to verify anything from the $5^{th}$ columns. But, the average value depends on the location of X axial was statistically significant. On T2 FS image, there was a significant decline in image distortion and signal intensity over 180mm from the core of patient's table. On diffusion-weighted image, there was a significant decline in image distortion and signal intensity over 90 mm, and they became unverifiable over 180 mm. Therefore, we should make an image that has a diagnostic value from examinations that are hard to locate patient's position.

The Comparative Analysis Study and Usability Assessment of Fat Suppressed 3D T2* weighted Technique and Fat Suppressed 3D SPGR Technique when Examining MRI for Knee Joint Cartilage Assesment (슬관절 연골 평가를 위한 자기공명영상 검사 시 지방 신호 억제 3D T2* Weighted 기법과 지방 신호 억제 3D SPGR 기법의 비교 및 유용성 평가)

  • Kang, Sung-Jin
    • Journal of the Korean Magnetics Society
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    • v.26 no.6
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    • pp.219-225
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    • 2016
  • In this study, for assessment of degenerative knee joint cartilage disease we acquired images by fat suppressed 3D spoiled gradient recalled (SPGR) and fat suppressed 3D $T2^*$ weighted imaging techniques. To do a quantitative evaluation, the knee joint cartilage was divided into medial femoral cartilage (MFC), medial tibial cartilage (MTC), lateral femoral cartilage (LFC), lateral femoral cartilage (LFC) and patella cartilage (Pat) to measure their respective signal intensity values, signal-to-noise ratio, and contrast-to-noise ratio. As for the measured values, statistical significance between two techniques was verified by using Mann-Whitney U-Test. To do a qualitative evaluation, two radiologists have examined images by techniques after which image artifact, cartilage surface, tissue contrast, and depiction of lesion distinguishing were evaluated based on 4-point scaling (1: bad, 2: appropriate, 3: good, 4: excellent), and based on the result, statistical significance was verified by using Kappa-value Test. 3.0T MR system and HD T/R 8ch knee array coil were used to acquire images. As a result of a quantitative analysis, based on SNR values measured by using two imaging techniques, MFC, LFC, LTC, and Pat showed statistical significance (p < 0.05), but MTC did not (p > 0.05). As a result of verifying statistical significance for measured CNR value, MFC, LFC, and Pat showed statistical significance (p < 0.05), while MTC and LTC did not show statistical significance (p > 0.05). As a result of a qualitative analysis, by comparing mean values for evaluated image items, 3D $T2^*$ weighted Image has indicated a slightly higher value. As for conformance verification between the two observers by using Kappa-value test, all evaluated items have indicated statistically significant results (p < 0.05). 3D $T2^*$ weighted technique holds a clinical value equal to or superior to 3D SPGR technique with respect to evaluating images, such as distinguishing knee joint cartilages, comparing nearby tissues contrast, and distinguishing lesions.

No asymmetric outflows from Sagittarius A* during the pericenter passage of the gas cloud G2

  • Park, Jong-Ho;Trippe, Sascha;Krichbaum, Thomas;Kim, Jae-Young;Kino, Motoki;Bertarini, Alessandra;Bremer, Michael;de Vicente, Pablo
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.1
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    • pp.73.2-74
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    • 2015
  • The gas cloud G2 falling toward Sagittarius A* (Sgr A*), the supermassive black hole at the center of the Milky Way, is supposed to provide valuable information on the physics of accretion flows and the environment of the black hole. We observed Sgr A* with four European stations of the Global Millimeter Very Long Baseline Interferometry Array (GMVA) at 86 GHz on 1 October 2013 when parts of G2 had already passed the pericenter. We searched for possible transient asymmetric structure - such as jets or winds from hot accretion flows - around Sgr A* caused by accretion of material from G2. The interferometric closure phases (which are zero if the spatial brightness distribution of the target is symmetric, and deviate from zero otherwise) remained zero within errors during the observation time. We thus conclude that Sgr A* did not show significant asymmetric (in the observer frame) outflows in late 2013. Using simulations, we constrain the size of the outflows that we could have missed to ${\approx}2.5$ mas along the major axis, ${\approx}0.4$ mas along the minor axis of the beam, corresponding to approximately 232 and 35 Schwarzschild radii, respectively; we thus probe spatial scales on which the jets of radio galaxies are suspected to convert magnetic into kinetic energy. As probably less than 0.2 Jy of the flux from Sgr A* can be attributed to accretion from G2, one finds an effective accretion rate ${\eta}M{\leq}1.5{\times}10^9kg/s{\approx}7.7{\times}10^{-9}M_{earth}/yr$ for material from G2. Exploiting the kinetic jet power-accretion power relation of radio galaxies, one finds that the rate of accretion of matter that ends up in jets is limited to $M{\leq}10^{17}kg/s{\approx}0.5M_{Earth}/yr$ less than about 20% of the mass of G2. Accordingly, G2 appears to be largely stable against loss of angular momentum and subsequent (partial) accretion at least on time scales ${\leq}1$ year.

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USE OF NEAR-INFRARED SPECTROSCOPY TO PREDICT OIL CONTENT COMPONENTS AND FATTY ACID COMPOSITION IN OLIVE FRUIT

  • Lorenzo, Leon-Moreno;Ana, Garrido-Varo;Luis, Rallo-Romero
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.1512-1512
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    • 2001
  • The University of Cordoba conducts since 1991 a breeding program to obtain new olive cultivars from intraspecific crosses. The objective is to obtain new early bearing and high-quality cultivars. In plant breeding, many seedlings must be tested to increased the chance of getting desirable genotypes. Therefore, fast, cheap and accurate methods of analysis are necessary. The conventional laboratory techniques are costly and time-consuming. Near Infrared Spectroscopy (NIRS) can satisfy the characteristics requested by plant breeders and offers many advantages such as the simultaneous analysis of many traits and cheap cost. The objective of this work was to asses the performance of NIRS to estimate oil fruit components (fruit weight, flesh moisture, flesh/stone ratio and oil flesh content in dry weight basis) and fatty acid composition in olive fruit. Genotypes from reciprocal crosses between ‘Arbequina’, ‘Frantoio’ and ‘Picual’ cultivars have been used in this study. A total of 287 samples, each from a single plant, were scanned using a DA-7000 Diode Array VIS/NIR Analysis System (Perten Instruments), which covers the visible and NIR range from 400-1700 nm. All samples were analysed for fatty acid composition (gas chromatography) and 220 for oil fruit components (oil content by nuclear magnetic resonance), 70% and 30% of samples were randomly assign for the calibration and validation sets respectively. The preliminary results shows that calibration for palmitic, oleic and linoleic acids were highly accurate with calibration and validation values of $r^2$ from 0.85 to 0.95 and 0.76 to 0.91 respectively. Calibration for palmitoleic and estearic acids were less accurate, probably because of the narrow range of variability available for these fatty acids. For the oil fruit components, calibration were high accurate for flesh moisture and oil flesh content in dry weight basis ($r^2$ higher than 0.90 in both calibration and validation sets) and less accurate for the other characteristics evaluated. The first results obtained indicate that NIRS analysis could be an ideal technique to reduce the cost, time and chemical wasted necessary to evaluate a large number of genotypes and it is accurate enough to use for pre-selecting genotypes in a breeding program.

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REPLACEMENT OF A PHOTOMULTIPLIER TUBE IN A 2-INCH THALLIUM-DOPED SODIUM IODIDE GAMMA SPECTROMETER WITH SILICON PHOTOMULTIPLIERS AND A LIGHT GUIDE

  • KIM, CHANKYU;KIM, HYOUNGTAEK;KIM, JONGYUL;LEE, CHAEHUN;YOO, HYUNJUN;KANG, DONG UK;CHO, MINSIK;KIM, MYUNG SOO;LEE, DAEHEE;KIM, YEWON;LIM, KYUNG TAEK;YANG, SHIYOUNG;CHO, GYUSEONG
    • Nuclear Engineering and Technology
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    • v.47 no.4
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    • pp.479-487
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    • 2015
  • The thallium-doped sodium iodide [NaI(Tl)] scintillation detector is preferred as a gamma spectrometer in many fields because of its general advantages. A silicon photomultiplier (SiPM) has recently been developed and its application area has been expanded as an alternative to photomultiplier tubes (PMTs). It has merits such as a low operating voltage, compact size, cheap production cost, and magnetic resonance compatibility. In this study, an array of SiPMs is used to develop an NaI(Tl) gamma spectrometer. To maintain detection efficiency, a commercial NaI(Tl) $2^{\prime}{\times}2^{\prime}$ scintillator is used, and a light guide is used for the transport and collection of generated photons from the scintillator to the SiPMs without loss. The test light guides were fabricated with polymethyl methacrylate and reflective materials. The gamma spectrometer systems were set up and included light guides. Through a series of measurements, the characteristics of the light guides and the proposed gamma spectrometer were evaluated. Simulation of the light collection was accomplished using the DETECT 97 code (A. Levin, E. Hoskinson, and C. Moison, University of Michigan, USA) to analyze the measurement results. The system, which included SiPMs and the light guide, achieved 14.11% full width at half maximum energy resolution at 662 keV.

A Study on Discriminative Criteria of 6 Kinds of Achyranthis Radix Using HPLC/DAD;Isolation and Identification of 20-hydroxyecdysone from Aclryranthes japonica $N-{AKAI}$ and Comparison of Patterns of Achyranthis Radix from Different Locations by HPLC (HPLC/DAD를 이용한 6종(種) 우슬(牛膝)의 분류기준 연구;우슬(牛膝)(쇠무릎, Achyranthes japonica $N_{AKAI}$)로부터 20-hydroxyecdysone 분리.동정 및 산지별 우슬의 HPLC 패턴 비교)

  • Kim, Jeong-Hi;Kim, Jong-Mun;Kang, Dae-Hoon
    • The Korea Journal of Herbology
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    • v.23 no.1
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    • pp.109-116
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    • 2008
  • Objectives : This study was performed to investigate the discriminative criteria of 6 kinds of Achyranthis Radix by HPLC/DAD. Methods : 20-hydroxyecdysone is isolated by silica gel column chromatography ($CHCl_3$:MeOH, 7:1-1:1 v/v) and identified by nuclear magnetic resonance, A high-performance liquid chromatographic method with diode array detection was used to identify 20-hydroxyecdysone in A. japonica. The analysis was performed using $C_{18}$ column with isocratic elution consisted of 18% acetonitrile and 82% water and the detection was carried out by DAD at 254 nm. 6 kinds of Achyranthis Radix from different locations were extracted in MeOH. Each extracts was analyzed by HPLC in same condition as used in analysis of 20-hydroxyecdysone. The identities of each extracts were determined by comparing the retention time and UV spectrum with that of reference compound. Results : 1. A. japonica and A. bidentata showed the similar patterns of HPLC chromatogram and 20-hydroxycedysone was present in both of them because the peaks having the same retention time and UV spectrum as 20-hydroxyecdysone were shown in the HPLC chromatograms of A. japonica and A. bidentata 2. Cyathula officinalis and C. capitata showed the similar patterns of HPLC chromatogram. The peak having the same retention time and UV spectrum as 20-hydroxyecdysone was shown in the HPLC chromatogram of C. capitata but not shown in the HPLC chromatogram of C. officinalis. 3. Two species of medicinal drugs from Sacheon province showed similar patterns of HPLC chromatogram. Achyranthis Radix from Sacheon(wild) did not have 20-hydroxycedysone but Achyranthis Radix from Sacheon(cultivated) showed the peak having the same retention time as 20-hydroxyecdysone but UV spectrum of the peak was different from that of 20-hydroxyecdysone. Conclusions : These results suggested that 20-hydroxyecdysone could be the discriminative criteria for Achyranthis Radix contain 20-hydroxyecdysone though they belong to different genus and species. And the patterns of HPLC chromatogram also could be the discriminative criteria as the different species of Achyranthis Radix belonging to the same genus showed similar patterns of HPLC chromatogram.

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Magnetoresistance of Single-type and Dual-type GMR-SV Multilayer Thin Films with Top and Bottom IrMn Layer (상부와 하부 IrMn층을 갖는 단일구조 및 이중구조 거대자기저항-스핀밸브 다층박막의 자기적 특성 비교 분석)

  • Choi, Jong-Gu;Kim, Su-Hee;Choi, Sang-Heon;Lee, Sang-Suk
    • Journal of the Korean Magnetics Society
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    • v.27 no.4
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    • pp.115-122
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    • 2017
  • The antiferromagnet IrMn based four different GMR-SV multilayers on Corning glass were prepared by using ion beam deposition and DC magnetron sputtering system. The magnetoresistance (MR) properties for single-type and dual-type GMR-SV multilayer films were investigated through the measured major and minor MR curves. The exchange bias coupling field ($H_{ex}$) and coercivity ($H_c$) of pinned layer, the $H_c$ and interlayer exchange coupling field ($H_{int}$) of free layer for the dual-type structure GMR-SV multilayer films consisted of top IrMn layer were 410 Oe, 60 Oe, 1.6 Oe, and 7.0 Oe, respectively. The minor MR curve of two free layers was performed the squarelike feature having a MR ratio of 8.7 % as the sum of 3.7 % and 5.0 %. The value of average magnetic field sensitivity (MS) was maintained at 2.0 %/Oe. Also, the magnetoresistance properties of the single-type and dual-type structure GMR-SV multilayer films consisted of bottom IrMn layer were decreased more than those of top IrMn layer. Two antiparallel states of magnetization spin arrays of the pinned and free layers in the dual-type GMR-SV multilayer films occurred the maximum MR value by the effect of spin dependence scattering.