• Title/Summary/Keyword: Magnetic Materials

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Comparison of the Patella Baja in Patients With and Without Anterior Cruciate Ligament Injury (전방 십자 인대 손상군과 정상군에서 슬개골 저위증의 비교)

  • Lee, Woo-Suk;Kim, Sung-Hun;Cho, Sung-Jin;Lim, Ji-Hyuk;Chung, Whan-Young;Hwang, Cheol-Mog
    • Journal of the Korean Arthroscopy Society
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    • v.10 no.1
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    • pp.39-44
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    • 2006
  • Purpose: The object of this study is to compare the Insall-Salvati ratio and Carton index between the patients who have an anterior cruciate ligament (ACL) tear and the patients who have no ACL tear. Materials and Methods: The study group included 114 patients who had an ACL tear and received arthroscopic reconstruction. The group I was acute ACL tear group, within 3 weeks after injury. The group II was chronic ACL tear group who had MRI was done after 3 weeks from injury. The group III was normal control group. We measured the Insall-Salvati ratio and Carton index on Magnetic Resonance Images (MRI) for all patients. Results: The Insall-Salvati ratio of control group was $1.02{\pm}0.12$ and Carton index of control group was $1.14{\pm}0.16$. The ACL-tear study group was $0.91{\pm}0.12\;and\;0.89{\pm}0.20$ respectively. The Insall-Salvati ratio and Caton index in ACL tear group was significantly less than those of control group. There were no significant differences in comparing with acute and chronic ACL tear group. Conclusion: Our study show that patella baja has an association with ACL tears, therefore in patients with an ACL tear who had patella baja, ideal graft for reconstruction was seriously considered.

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Clinical and genetic characteristics of Korean patients with IARS2-related disorders

  • Lee, Jin Sook;Kim, Man Jin;Kim, Soo Yeon;Lim, Byung Chan;Kim, Ki Joong;Choi, Murim;Seong, Moon-Woo;Chae, Jong-Hee
    • Journal of Genetic Medicine
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    • v.16 no.2
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    • pp.55-61
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    • 2019
  • Purpose: Genetic defects in the nuclear-encoded mitochondrial aminoacyl-tRNA synthetases were first identified as causes of various disorders in 2007. Variants in IARS2, which encodes a mitochondrial isoleucyl-tRNA synthetase, were first reported in 2014. These variants are associated with diverse phenotypes ranging from CAGSSS (CAtaracts, Growth hormone deficiency, Sensory neuropathy, Sensorineural hearing loss, and Skeletal dysplasia) and Leigh syndrome to isolated nonsyndromic cataracts. Here, we describe the phenotypic and genetic spectrum of Korean patients with IARS2-related disorders. Materials and Methods: Using whole-exome sequencing followed by Sanger sequencing, we identified five patients with IARS2 mutations. Their medical records and brain magnetic resonance images were reviewed retrospectively. Results: All five patients presented with developmental delay or regression before 18 months of age. Three patients had bilateral cataracts, but none had hearing loss or sensory neuropathy. No evidence of skeletal dysplasia was noted, but two had short stature. One patient had cardiomyopathy and another exhibited renal tubulopathy and hypoparathyroidism. Their brain imaging findings were consistent with Leigh syndrome. Interestingly, we found the recurrent mutations p.R817H and p.V105Dfs*7 in IARS2. Conclusion: To our knowledge, this is the first report of Korean patients with IARS2-related disorders. Our findings broaden the phenotypic and genotypic spectrum of IARS2-related disorders in Korea and will help to increase clinical awareness of IARS2-related neurodegenerative diseases.

Trajectory Simulation of ASR Particles in Induction Electrostatic Separation (유도형 정전선별에서 ASR 입자의 궤적모사)

  • Kim, Beom-uk;Park, Chul-hyun
    • Resources Recycling
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    • v.28 no.6
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    • pp.96-105
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    • 2019
  • Automobile shredder residue (ASR) is the final waste produced when end-of-life vehicles (ELVs) are shredded. ASR can be separated using mineral-processing operations such as comminution, air classification, magnetic separation, and/or electrostatic separation. In this work, trajectory analyses of conductors (copper) and non-conductors (glass) in the ASR have been carried out using induction electrostatic separator for predicting or improving the ASR-separation efficiency. From results of trajectory analysis for conductors, the trajectories of copper wire by observation versus simulation for coarse particles of 0.5 and 0.25 mm showed consistent congruity. The observed 0.06 mm fine-particles trajectory was deflected toward the (-) attractive electrode owing to the charge-density effects due to the particle characteristics and relative humidity. In the case of non-conductors, the actual trajectory of dielectric glass deflected toward the (-) electrode, showing characteristics similar to those of conductive particles. The analyses of stereoscopic microscope and SEM & EDS found heterologous materials (fine ferrous particles and conductive organics) on the glass surface. This demonstrates the glass decreasing separation efficiency for non-ferrous metals during electrostatic separation for the recycling of ASR. Future work will require a pretreatment process for eliminating impurities from the glass and advanced trajectory-simulation processes.

Stereotactic radiosurgery for brain metastasis in non-small cell lung cancer

  • Won, Yong Kyun;Lee, Ja Young;Kang, Young Nam;Jang, Ji Sun;Kang, Jin-Hyoung;Jung, So-Lyoung;Sung, Soo Yoon;Jo, In Young;Park, Hee Hyun;Lee, Dong-Soo;Chang, Ji Hyun;Lee, Yun Hee;Kim, Yeon-Sil
    • Radiation Oncology Journal
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    • v.33 no.3
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    • pp.207-216
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    • 2015
  • Purpose: Stereotactic radiosurgery (SRS) has been introduced for small-sized single and oligo-metastases in the brain. The aim of this study is to assess treatment outcome, efficacy, and prognostic variables associated with survival and intracranial recurrence. Materials and Methods: This study retrospectively reviewed 123 targets in 64 patients with non-small cell lung cancer (NSCLC) treated with SRS between January 2006 and December 2012. Treatment responses were evaluated using magnetic resonance imaging. Overall survival (OS) and intracranial progression-free survival (IPFS) were determined. Results: The median follow-up was 13.9 months. The median OS and IPFS were 14.1 and 8.9 months, respectively. Fifty-seven patients died during the follow-up period. The 5-year local control rate was achieved in 85% of 108 evaluated targets. The 1- and 2-year OS rates were 55% and 28%, respectively. On univariate analysis, primary disease control (p < 0.001), the Eastern Cooperative Oncology Group (ECOG) performance status (0-1 vs. 2; p = 0.002), recursive partitioning analysis class (1 vs. 2; p = 0.001), and age (<65 vs. ${\geq}65$ years; p = 0.036) were significant predictive factors for OS. Primary disease control (p = 0.041) and ECOG status (p = 0.017) were the significant prognostic factors for IPFS. Four patients experienced radiation necrosis. Conclusion: SRS is a safe and effective local treatment for brain metastases in patients with NSCLC. Uncontrolled primary lung disease and ECOG status were significant predictors of OS and intracranial failure. SRS might be a tailored treatment option along with careful follow-up of the intracranial and primary lung disease status.

Clinical application of RapidArc volumetric modulated arc therapy as a component in whole brain radiation therapy for poor prognostic, four or more multiple brain metastases

  • Lee, Seung-Heon;Lee, Kyu-Chan;Choi, Jin-Ho;Kim, Hye-Young;Lee, Seok-Ho;Sung, Ki-Hoon;Kim, Yun-Mi
    • Radiation Oncology Journal
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    • v.30 no.2
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    • pp.53-61
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    • 2012
  • Purpose: To determine feasibility of RapidArc in sequential or simultaneous integrated tumor boost in whole brain radiation therapy (WBRT) for poor prognostic patients with four or more brain metastases. Materials and Methods: Nine patients with multiple (${\geq}4$) brain metastases were analyzed. Three patients were classified as class II in recursive partitioning analysis and 6 were class III. The class III patients presented with hemiparesis, cognitive deficit, or apraxia. The ratio of tumor to whole brain volume was 0.8-7.9%. Six patients received 2-dimensional bilateral WBRT, (30 Gy/10-12 fractions), followed by sequential RapidArc tumor boost (15-30 Gy/4-10 fractions). Three patients received RapidArc WBRT with simultaneous integrated boost to tumors (48-50 Gy) in 10-20 fractions. Results: The median biologically effective dose to metastatic tumors was 68.1 $Gy_{10}$ and 67.2 $Gy_{10}$ and the median brain volume irradiated more than 100 $Gy_3$ were 1.9% (24 $cm^3$) and 0.8% (13 $cm^3$) for each group. With less than 3 minutes of treatment time, RapidArc was easily applied to the patients with poor performance status. The follow-up period was 0.3-16.5 months. Tumor responses among the 6 patients who underwent follow-up magnetic resonance imaging were partial and stable in 3 and 3, respectively. Overall survival at 6 and 12 months were 66.7% and 41.7%, respectively. The local progression-free survival at 6 and 12 months were 100% and 62.5%, respectively. Conclusion: RapidArc as a component in whole brain radiation therapy for poor prognostic, multiple brain metastases is an effective and safe modality with easy application.

A poroelastic model for ultrasonic wave attenuation in partially frozen brines (부분 동결된 소금물에서의 초음파감쇠에 대한 다공성탄성 모델)

  • Matsushima, Jun;Nibe, Takao;Suzuki, Makoto;Kato, Yoshibumi;Rokugawa, Shuichi
    • Geophysics and Geophysical Exploration
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    • v.14 no.1
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    • pp.105-115
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    • 2011
  • Although there are many possible mechanisms for the intrinsic seismic attenuation in composite materials that include fluids, relative motion between solids and fluids during seismic wave propagation is one of the most important attenuation mechanisms. In our previous study, we conducted ultrasonic wave transmission measurements on an ice-brine coexisting system to examine the influence on ultrasonic waves of the unfrozen brine in the pore microstructure of ice. In order to elucidate the physical mechanism responsible for ultrasonic wave attenuation in the frequency range of 350.600 kHz, measured at different temperatures in partially frozen brines, we employed a poroelastic model based on the Biot theory to describe the propagation of ultrasonic waves through partially frozen brines. By assuming that the solid phase is ice and the liquid phase is the unfrozen brine, fluid properties measured by a pulsed nuclear magnetic resonance technique were used to calculate porosities at different temperatures. The computed intrinsic attenuation at 500 kHz cannot completely predict the measured attenuation results from the experimental study in an ice-brine coexisting system, which suggests that other attenuation mechanisms such as the squirt-flow mechanism and wave scattering effect should be taken into account.

Arthroscopic Management of the Triangular Fibrocartilage Complex Injuries (삼각 섬유 연골 복합체 손상의 관절경적 처치)

  • Moon Young Lae;You Jae Won;Oh Jong Ho;Jin Dae Sik
    • Journal of the Korean Arthroscopy Society
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    • v.5 no.1
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    • pp.32-35
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    • 2001
  • Purpose : To evaluate the efficacy of arthroscopic management of the triangular fibrocartilage complex(TFCC). Materials and Methods : Thirteen patients(14 wrists) with acute or chronic traumatic triangular fibrocartilage complex lesions were included in the study. The mean patients' age was 28.3 years, with a range of 21 to 45 years. All patients were diagnosed by physical examination, arthrographic or magnetic resonance imaging studies. Eight of the 14 wrists had central TFCC tear while 6 wrists had peripheral tear. Under arthroscopic control, injuries to the central portions were treated by debridement and excision of unstable tissue fragment while peripheral tears were repaired. The follow-up period averaged 28 months. The results were analyzed clinically using the Mayo modification of the Green and O' Brien wrist scoring system. Results : Nine of the 14 wrists were rated excellent,3 good and 2 fair Overall, 12 of the 14 patients rated as satisfactory and returned to sports or work activities. Conclusion : Arthroscopic treatment of TFCC resulted in a high degree of patient satisfaction and an increase in the ability to perform at workshop.

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Development of the Handy Non-contact Surface Roughness Measurement Device by using the Optical Fiber Sensor (광섬유센서에 의한 간이 비접촉 표면조도 측정기의 개발)

  • Hong, Jun-Hee
    • 대한공업교육학회지
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    • v.34 no.2
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    • pp.346-362
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    • 2009
  • The purpose of this study was to develop the handy non-contact measurement device of the surface roughness by using the optical fiber sensor. The advantages of fiber optic sensors are high-speed responsibility, non-effect of the magnetic, convenience of the product and high precision. The measurement theory for surface roughness of optical fiber sensor is one to one correspondence between the reflected light intensity based on the surface roughness of the object and the measurement value of previously known for surface roughness. The reflected light intensity was determined using the distance to the surface from the sensor probe and the limit reflection angle based on the surface roughness. Therefore, in this study, the sensor probe was produced for determining the value of surface roughness only using the limit reflection angle based on the surface roughness with the fixed distance from the surface. A prototype measurement system was composed of a transmitting part, a receiving part and a signal processing circuit. The materials of standard measurement which was used in this experiment were SM45C, STS303 and Al60. According to the results of this study, approximation surface roughness formulas which was deduced from the correlation of between the standard surface roughness and the sensing output were verified that they were effect against the surface roughness measurement value of the option sample. And handy optical fiber surface roughness measurement device which was produced by an order was verified that it was effect for measuring of the precision surface roughness.

Vitis amurensis Ruprecht root inhibited ${\alpha}$-melanocyte stimulating hormone-induced melanogenesis in B16F10 cells

  • Jin, Kyong-Suk;Oh, You Na;Hyun, Sook Kyung;Kwon, Hyun Ju;Kim, Byung Woo
    • Nutrition Research and Practice
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    • v.8 no.5
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    • pp.509-515
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    • 2014
  • BACKGROUND/OBJECTIVES: The root of Vitis amurensis Ruprecht, a sort of wild-growing grape, has been used in oriental medicine for treatment of skin ailments; however, its dermatological activity is not sufficiently understood. The aim of this study was to investigate tyrosinase inhibitory and anti-melanogenic activities of V. amurensis Ruprecht root methanol extract (VARM) in B16F10 mouse melanoma cells and to attempt to isolate and identify the active compound issued from VARM. MATERIALS/METHODS: Anti-melanogenic activity of VARM was analyzed in ${\alpha}$-melanocyte stimulating hormone (MSH)-stimulated B16F10 cells through evaluation of antioxidative activity as well as inhibited tyrosinase activity and melanin contents compared with those of kojic acid and arbutin. After anti-melanogenic analysis of VARM, serial fractionation, nuclear magnetic resonance (NMR), and thin layer chromatorgraphy (TLC) were applied for identification of active compounds contained in VARM. RESULTS: VARM significantly inhibited oxidative stress and tyrosinase activity and attenuated ${\alpha}$-MSH-induced melanin production in B16F10 cells. For isolation of active compounds, VARM was fractionated using a series of organic solvents, including dichloromethane ($CH_2Cl_2$), ethyl acetate (EtOAc), and n-butanol (n-BuOH). Among fractions showing anti-melanogenic activity, the CH2Cl2 fraction induced the most potent attenuation of melanogenesis without cytotoxicity and the major compound in the $CH_2Cl_2$ fraction was identified as betulinic acid. Betulinic acid isolated from the $CH_2Cl_2$ fraction of VARM significantly attenuated ${\alpha}$-MSH-induced melanogenesis in a dose dependent manner, which was stronger than that of arbutin used as a positive control. CONCLUSIONS: These results indicate that VARM inhibits oxidative stress, tyrosinase activity, and ${\alpha}$-MSH-induced melanogenesis in B16F10 cells, due primarily to the active compound, betulinic acid, in the $CH_2Cl_2$ fraction.

Power Loss and Electro-Magnetic Characteristics of Ni-Cu-Zn Ferrites (Ni-Cu-Zn페라이트의 損失과 磁性 特性)

  • Otsuki, E.;Kim, Jeong-Su
    • Resources Recycling
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    • v.13 no.6
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    • pp.37-42
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    • 2004
  • The power loss analysis was carried out for Ni-Cu-Zn ferrite sample with different content of NiO and ZnO. The power loss, Pcv decreases monotonically with increasing temperature and attains to a certain value at around 100~120 degrees Celsius. The frequency dependence of Pcv can be explained by Pcv~f$^n$, and n is independent of the frequency, f up to 1 MHz. The Pcv decreases with an increase in ZnO/NiO. The Pcv was separated to hysteresis loss(Ph) and residual loss(Pcv-Ph). The temperature characteristics and compositional dependence of Pcv can be attributed to the Ph, while Pcv-Ph is not affected by both temperature and ZnO/NiO. By analyzing temperature and composition dependence of Ph and initial permeability, ${\mu}_i$ like following equations could be formularized. ${\mu}_i{\mu}_0=I_s^2/(K_I+b{\sigma}_0{\lambda}_s)$ Wh=13.5(I$_s^2/{\mu}_i{\mu}_0)$ Where ${\mu}_0$ is permeability of vacuum, I$_s$ is saturation magnetization, K$_I$ is anisotropy constant, $s_0$ is internal heterogeneous stress, ${\lambda}_s$ is magnetostriction constant, b is unknown constant, and Wh is hysteresis loss per one cycle of excitation (Ph=Wh${\times}$f). Steinmetz constant of Ni-Cu-Zn ferrite, m=1.64~2.2 is smaller than that of Mn-Zn ferrites, which suggests the difference of loss mechanisms between these materials.