• Title/Summary/Keyword: and resonance

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Comparison of New AJCC Staging System with OId AJCC Staging System in Nasopharyngeal Carcinoma (비인강암에서의 AJCC의 새로운 병기 분류법과 기존 병기 분류법의 비교)

  • Hong Semie;Wu Hong-Gyun;Park Charn I1
    • Radiation Oncology Journal
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    • v.18 no.4
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    • pp.221-225
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    • 2000
  • Purpose : This study was designed to examine the reliability of the new version of the AJCC staging system (1997) of nasopharyngeal carcinoma in comparison with the AJCC staging system of 1992. Materials and Methods :Between 1983 and 1996, 185 patients with histologically proven nasopnaryngeal carcinoma were treated with radiation therapy at the Department of Therapeutic Radiology Seoul National University Hospital. For these patients, AJCC staging system of 1992 was compared with the 1997 version by reviewing hospital records, computed tomography (CT) and/or magnetic resonance imaging (MRI). Results :5-year overall suwival rates according to the 1992 and 1997 AJCC staging systems were 100$\%$, and 100$\%$ at stage 1: 100$\%$, and 68.8$\%$ at stage 11; 61.4$\%$, and 63.8$\%$ at stage 111; 61.1$\%$, and 63.2$\%$ at stage IV. S-year overall survival rates of each classification showed significant differences between stages (p=0.0049 for the old version, p=0.01 for the new), but no significant difference was found between the staging systems except at stage 11. Conclusion : The new AJCC staging system allows staging as reliably as the 1992 version, but the adequacy of the newly modified staging classification should be confirmed by further clinical examination.

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Behavioral Response of the Lacewing Chrysopa cognata to both Aphis gossypii-induced Plant Volatiles and Chrysopa cognata-derived Volatiles (목화진딧물 감염 식물 및 칠성풀잠자리 유래-휘발성물질들에 대한 칠성풀잠자리의 행동 반응)

  • Cho, Jum Rae;Lee, Min Ho;Park, Chang Gyu;Kim, Jeong Hwan;Hooper, Tony;Woodcock, Christine;Pickett, John
    • Korean journal of applied entomology
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    • v.53 no.1
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    • pp.7-13
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    • 2014
  • This study was performed to investigate the response of the lacewing Chrysopa cognata to both Aphis gossypii-induced plant volatiles and lacewing-derived volatiles. The results of a Y-tube olfactometer bioassay showed that more C. cognata males were attracted to green pepper plants infected with A. gossypii than to uninfected green pepper plants alone or clean air and C. cognata males were attractive to C. cognata females. Gas chromatography-electroantennographic detection (GC-EAD) analysis showed that the antennae of C. cognata females elicited EAD-active responses to the volatiles entrained from A. gossypii-infected green pepper plants. 4-Ethylacetophenone, 3-ethylbenzaldehyde, 3-ethylacetophenone, and 4-ethylbenzaldehyde from A. gossypii-induced green pepper volatiles, and (Z,Z)-4,7-tridecadiene, (Z)-4-tridecene, and (Z)-4-undecene from C. cognata female entrainment were elucidated by further analysis using GC coupled nuclear magnetic resonance spectroscopy. Of the A. gossypii-induced plant volatiles identified in this study, 4-ethylacetophenone and 3-ethylbenzaldehyde significantly increased the attraction of C. cognata males to nepetalactol, but (Z)-4-tridecene and (Z)-4-undecene did not. (Z,Z)-4,7-Tridecadiene significantly reduced the attractiveness of nepetalactol to C. cognata.

The Abnormality of Posterior Default Mode Network in Medication-Naïve Attention-Deficit Hyperactivity Disorder Children : Resting State fMRI Study (약물 복용력이 없는 주의력결핍 과잉행동장애 아동에서의 뒤쪽 내정상태회로 이상 : 휴식상태 기능적 뇌자기공명영상 연구)

  • Choi, Jee-Wook;Go, Hyo-Jin;Woo, Young-Sup;Song, Seung-Hoon;Yang, Po-Song;Jeong, Bum-Seok
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.23 no.2
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    • pp.57-62
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    • 2012
  • Objectives : Characteristic symptoms, including hyperactivity and easy distractibility, in children with attention-deficit hyperactivity disorder (ADHD) suggest that their brain status, even at rest, might differ from that of healthy children. This study was conducted in order to determine whether resting state brain activity is compromised in medication-naive children with ADHD. Methods : Twenty medication-naive children with ADHD (mean age $10.3{\pm}2.5$) and 28 age- and gender-matched healthy volunteers (mean age $10.3{\pm}2.0$) underwent measurements for resting state brain activity using functional magnetic resonance imaging (fMRI). Among resting state related-independent components (RSICs) extracted from fMRI data using independent component analysis, a significant difference in RSICs was observed between groups, using a mixed Gaussian/gamma model. Results : Except for IQ, which was higher in the healthy control group, no demographic difference was observed between the two groups (p<.001). Significantly less activation of one RSIC, which includes the bilateral precuneus/posterior cingulate cortex, occipito-temporal junction, and anterior cingulate cortex, was observed in the ADHD group, compared with the control group (p<.05). Conclusion : An abnormal RSIC, posterior default mode network (DMN), was observed in the medication-naive ADHD group. Results of our study suggest that abnormality of posterior DMN is one of the main pathophysiologies of ADHD.

The Development of Signal Processing Software for Single-and Multi-Voxel MR Spectroscopy (단위용적 및 다용적 기법 자기공명분광 신호처리 분석 소프트웨어의 개발)

  • Paik, Moon-Young;Lee, Hyun-Yong;Shin, Oun-Jae;Eun, Choong-Ki;Mu, Chi-Woong
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.39 no.5
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    • pp.544-555
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    • 2002
  • The aim of this study is to develop the $^1H$-MRS data postprocessing software for both single-voxel and multi-voxel technique, which plays and important role as a diagnostic tool in clinical field. This software is based on graphical user interface(GUI) under windows operating system of personal computer(PC). In case of single-voxel MRS, both of raw data in time-domain and spectrum data in frequency-domain are simultaneously displayed in a screen. Several functions such as DC correction, zero filling, line broadening, Lorentz-Gauss filtering and phase correction, etc. are included to increase the quality of spectrum data. In case of multi-voxel analysis, spectroscopic image reconstructed by 3-D FFT was displayed as a spectral grid and overlapped over previously obtained T1- or T2-weighted image for the spectra to be spatially registered with the image. The analysis of MRS peaks were performed by obtaining the ratio of peak area. In single-voxel method, statistically processed peak-area ratios of MRS data obtained from normal human brain are presented. Using multi-voxel method, MR spectroscopic image and metabolite image acquired from brain tumor are demonstrated.

Highly sensitive and selective detection of cyanide in aqueous solutions using a surface acoustic wave chemical sensor (표면음향파 화학센서를 이용한 수용액 중 시안화이온의 선택적인 고감도 검출)

  • Lee, Soo Suk
    • The Journal of the Acoustical Society of Korea
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    • v.35 no.6
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    • pp.473-479
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    • 2016
  • We report a highly selective and sensitive 200 MHz Surface Acoustic Wave (SAW) sensor that can detect cyanide ion in aqueous solution using surface immobilized thioester molecules in combination with gold nanoparticles (AuNPs). To construct the sensor device, a monolayer of thioester compound was immobilized on the SAW sensor surface. At the sensor surface, hydrolysis of thioester group by nucleophilic addition of cyanide occurred and the resulting free thiol unit bound to AuNP to form thiol-AuNP conjugate. For the signal enhancement, gold staining signal amplification process was introduced subsequently with gold (III) chloride trihydrate and reducing agent, hydroxylamine hydrochloride. The SAW sensor showed a detection ability of $17.7{\mu}M$ for cyanide in aqueous solution and demonstrated a saturation behavior between the frequency shift and the concentration of cyanide ion. On the other hand, our SAW sensor had no activities for other anions such as fluoride ion, acetate ion and sulfate ion, moreover, no significant interference observed by other anions. Finally, all the experiments were carried out in-house developed sensor and fluidics modules to obtain highly reproducible results.

Software development for the visualization of brain fiber tract by using 24-bit color coding in diffusion tensor image

  • Oh, Jung-Su;Song, In-Chan;Ik hwan Cho;Kim, Jong-Hyo;Chang, Kee-Hyun;Park, Kwang-Suk
    • Proceedings of the KSMRM Conference
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    • 2002.11a
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    • pp.133-133
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    • 2002
  • Purpose: The purpose of paper is to implement software to visualize brain fiber tract using a 24-bit color coding scheme and to test its feasibility. Materials and Methods: MR imaging was performed on GE 1.5 T Signa scanner. For diffusion tensor image, we used a single shot spin-echo EPI sequence with 7 non-colinear pulsed-field gradient directions: (x, y, z):(1,1,0),(-1,1,0),(1,0,1),(-1,0,1),(0,1,1),(0,1,-1) and without diffusion gradient. B-factor was 500 sec/$\textrm{mm}^2$. Acquisition parameters are as follows: TUTE=10000ms/99ms, FOV=240mm, matrix=128${\times}$128, slice thickness/gap=6mm/0mm, total slice number=30. Subjects consisted of 10 normal young volunteers (age:21∼26 yrs, 5 men, 5 women). All DTI images were smoothed with Gaussian kernel with the FWHM of 2 pixels. Color coding schemes for visualization of directional information was as follows. HSV(Hue, Saturation, Value) color system is appropriate for assigning RGB(Red, Green, and Blue) value for every different directions because of its volumetric directional expression. Each of HSV are assigned due to (r,$\theta$,${\Phi}$) in spherical coordinate. HSV calculated by this way can be transformed into RGB color system by general HSV to RGB conversion formula. Symmetry schemes: It is natural to code the antipodal direction to be same color(antipodal symmetry). So even with no symmetry scheme, the antipodal symmetry must be included. With no symmetry scheme, we can assign every different colors for every different orientation.(H =${\Phi}$, S=2$\theta$/$\pi$, V=λw, where λw is anisotropy). But that may assign very discontinuous color even between adjacent yokels. On the other hand, Full symmetry or absolute value scheme includes symmetry for 180$^{\circ}$ rotation about xy-plane of color coordinate (rotational symmetry) and for both hemisphere (mirror symmetry). In absolute value scheme, each of RGB value can be expressed as follows. R=λw|Vx|, G=λw|Vy|, B=λw|Vz|, where (Vx, Vy, Vz) is eigenvector corresponding to the largest eigenvalue of diffusion tensor. With applying full symmetry or absolute value scheme, we can get more continuous color coding at the expense of coding same color for symmetric direction. For better visualization of fiber tract directions, Gamma and brightness correction had done. All of these implementations were done on the IDL 5.4 platform.

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Control of Short-period and Solitary Waves Using Two-rowed Impermeable Rectangular Submerged Dike (2열 불투과성 사각형 잠제를 이용한 단주기파랑 및 고립파의 제어)

  • Lee, Kwang-Ho;Jung, Sung-Ho;Ha, Sun-Wook;Kim, Do-Sam
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.22 no.4
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    • pp.203-214
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    • 2010
  • This study numerically investigates the wave control of 2-rowed Impermeable Rectangular Submerged Dike(IRSD) with an object of how to control short-period and solitary waves simultaneously based on the Bragg resonance phenomenon that elevates the wave control performance. The boundary integral method using Green formula and the 3-D one-field Model for immiscible TWO-Phase flows (TWOPM-3D) by 3-D numerical wave flume have been used for the numerical predictions for short-period and solitary waves, respectively. These numerical models were verified through the comparisons with the previously published numerical results by other researchers. Through the parametric tests of numerical experiments for short-period waves, an optimum model of 2-rowed IRSD of a lowest transmission coefficient has been found. Furthermore, the performances of 3-D wave control for solitary waves were evaluated for the various free board, crown widths and gap distance between dikes, and have been compared with those of a single-rowed IRSD. Numerical results show that a 2-rowed IRSD with a less cross sectional area than 1-rowed one improves the wave attenuation performances when it is compared to that of single-rowed IRSD. Within the test frequency ranges of the numerical simulations conducted in this study, 2-rowed IRSD with an optimum gap distance shows an outstanding improvement of the wave attenuation up to 58% compared to that of single-rowed IRSD.

Degradation Characteristics of Cross-linked Hyaluronic Acid Membrane (가교된 히아루론산 막의 분해 특성)

  • Cheong, Seong-Ihl;Cho, Gu-Hyun
    • Membrane Journal
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    • v.19 no.4
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    • pp.310-316
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    • 2009
  • The degradation characteristics of cross-linked lactide/hyaluronic acid (LA/HA) membranes were investigated for purpose of applying to tissue engineering. The lactide/hyaluronic acid cross-linked with 1,3-butadiene diepoxide (BD) and 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC) was degradated in deionized water in water bath at $37^{\circ}C$. As the LA/HA mole ratio or crosslinking agent concentration decreased, the degradation rate of the crosslinked membranes increased. In order to investigate the structure change of the membrane in the degradation process, the control sample and 3, 6, 9 days-degradated samples were analysed by the nuclear magnetic resonance spectroscopy. In case of the membranes crosslinked with EDC, the HA-EDC bonding structure was degradated slowly whereas the HA-LA bonding structure was degradated quickly and dissappeared completely after 6 days. In case of the membranes crosslinked with BD, all the crosslinked bonding structure degradated slowly. The HA-BD bonding structure maintained its original state about 89, 83% in case of 3, 6 days-degardated samples respectively whereas the HA-LA bonding structure maintained its original state about 83, 65%. The scanning electron microscopy of the degradated membranes showed that the pore density in the surface, and the structure in the surface and cross section, of the before and after-degradation membranes did not change greatly, so the membranes was shown to be applied to materials for tissue engineering.

MRI of Hydrosyringomyelia Combined to Hydrocephalus and Occipital Dysplasia in a Dog (개에서 뇌수두증과 후두골 이형성증을 동반한 척수공동증의 자기공명영상학적 평가 1례)

  • Choi Chi-Bong;Bae Chun-Sik;Kim Hwi-Yool
    • Journal of Life Science
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    • v.15 no.4 s.71
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    • pp.664-667
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    • 2005
  • Hydrosyringomyelia is a dilation of the spinal cord central canal. In human it may be caused by congenital malformations such as Dandy-Walker syndrome and Chiari malformations or may be acquired as a result of infection, trauma or neoplasia. Hydrocephalus is an excessive accumulation of cerebrospinal fluid within the ventricles and occipital dysplasia is the dorsal extension of the foramen magnum. Hydrosyringomyelia and hydrocephalus can be confirmed by computed tomography or magnetic resonance imaging (MRI). A 3-year-old male maltese was presented with a history of long-term seizure. Blood examination was all unremarkable. On rostrodorsal-caudoventral oblique radiograph of the skull showed severe occipital dysplasia. On brain sonography through the persistent fontanelle, severe lateral ventriculomegaly was revealed. MRI examination revealed hydrocephalus and hydrosyringomyelia. Diuretic therapy didn't reduce clinical symptoms and surgical decompression was conducted. The dog responded well with ventriculo-peritoneal shunting. MRI is the most superior modality to diagnose hydrocephalus and hydrosyringomyelia, to plan therapy and to determine the prognosis.

Operation Analysis of Resonant DC/DC Converter able to Harvest Thermoelectric Energy (열전에너지 수확이 가능한 공진형 DC/DC 컨버터의 동작 해석)

  • Kim, Hyeok-Jin;Chung, Gyo-Bum;Cho, Kwan-Youl;Choi, Jae-Ho
    • The Transactions of the Korean Institute of Power Electronics
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    • v.15 no.2
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    • pp.150-158
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    • 2010
  • The operational characteristics of a resonant DC/DC converter, which can harvest thermoelectric energy, is analyzed, depending on the relative magnitudes of the input voltage and the load voltage. The resonant converter consists of LC resonant circuit connected to DC input source and a resonant pulse converter in which the input energy is transferred to the load as the resonant capacitor voltage is peak. The resonant capacitor doubles the input voltage by the resonance phenomenon. By the relative magnitude between the input voltage and the output voltage, the resonant DC/DC converter operates in three different modes. For boost mode, the peak voltage of the resonant capacitor is smaller than the load voltage. For hybrid mode, the peak voltage of the resonant capacitor is bigger than the load voltage and every switching period has both the boost mode and the direct mode. For the direct mode, the input voltage is bigger than the load voltage and the converter transfers directly the input energy to the load without the switching operation. Operation principles and the feasibility of the converter for the thermoelectric energy harvesting are verified with PSPICE simulation and experiment.