• Title/Summary/Keyword: Resonance Type

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The Effect of KTX Vehicle Size Adjustment on High-Speed Railway Bridge Vibration : Numerical Study (수치해석을 통한 KTX 객차 길이 조정이 고속철도교량의 동적거동 특성에 미치는 영향 연구)

  • Shin, Jeong-Ryol;Kim, Hyun-Min;Sohn, Hoon;Yun, Chung-Bang
    • Proceedings of the KSR Conference
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    • 2008.11b
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    • pp.854-863
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    • 2008
  • A high attention has been paid on the running safety of Korean high-speed train, KTX. In running of KTX on bridge, the running unsafety problem issued from a resonance phenomenon of bridge, which was usually caused by the periodic wheel-loads of train. Therefore, many researches on this running safety of train on bridge have been conducted by domestic or foreign researchers. In this paper, for PSC box-girder bridge which is the representative high-speed railway bridge type, some numerical analyses on the dynamic characteristics of bridge with the non-periodic wheel-loads through vehicle size adjustment were performed. These numerical analyses shows the fact that the resonance phenomenon on bridge was mitigated through vehicle size adjustment. Additional numerical analyses on the vibration reduction of bridge in accordance with the location of size-adjusted vehicle were performed. From these results, it was represented that the adjustment of vehicle size has an effect on the running safety of train as well as the ride comfort.

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Assessment of the Purity of Emodin by Quantitative Nuclear Magnetic Resonance Spectroscopy and Mass Balance

  • Park, Sojung;Choi, Yu-Jin;Do, Giang Hoang;Seo, Eun Kyoung;Hyun, Seunghun;Lee, Dongho
    • Natural Product Sciences
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    • v.25 no.3
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    • pp.222-227
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    • 2019
  • Quantitative nuclear magnetic resonance (qNMR) is a well-established method adopted by international pharmacopoeia for quantitative and purity analyses. Emodin is a type of anthraquinone, well known as the main active component of Fabaceae, Polygonaceae and Rhamnaceae. Purity analysis of emodin is usually performed by using the high-performance liquid chromatography (HPLC)-UV method. However, it cannot detect impurities such as salts, volatile matter, and trace elements. Using the qNMR method, it is possible to determine the compound content as well as the nature of the impurities. Several experimental parameters were optimized for the quantification, such as relaxation delay, spectral width, number of scans, temperature, pulse width, and acquisition time. The method was validated, and the results of the qNMR method were compared with those obtained by the HPLC and mass balance analysis methods. The qNMR method is specific, rapid, simple, and therefore, a valuable and reliable method for the purity analysis of emodin.

NMR Hydrogen Exchange Study of DNA Duplex Containing the Consensus Binding Site for Human MEIS1

  • Choi, Seo-Ree;Jin, Ho-seong;Seo, Yeo-Jin;Lee, Joon-Hwa
    • Journal of the Korean Magnetic Resonance Society
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    • v.24 no.4
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    • pp.117-122
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    • 2020
  • Transcription factors are proteins that bind specific sites or elements in regulatory regions of DNA, known as promoters or enhancers, where they control the transcription or expression of target genes. MEIS1 protein is a DNA-binding domain present in human transcription factors and plays important roles in various biological functions. The hydrogen exchange rate constants of the imino protons were determined for the wild-type containing the consensus DNA-binding site for the MEIS1 and those of the mutant DNA duplexes using NMR spectroscopy. The G2A-, A3G- and C4T-mutant DNA duplexes lead to clear changes in thermal stabilities of these four consensus base pairs. These unique dynamic features of the four base pairs in the consensus 5'-TGAC-3' sequence might play crucial roles in the effective DNA binding of the MEIS1 protein.

Time-dependent changes of fruit metabolites studied by 1H NMR

  • Park, Sung Jean
    • Journal of the Korean Magnetic Resonance Society
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    • v.26 no.3
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    • pp.24-33
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    • 2022
  • The browning phenomenon of fruits can be easily observed when fruits or vegetables (apples, pears, bananas, potatoes, etc.) are cut with a knife and the part turns brown. When this browning occurs, changes in taste, color, and nutrients usually are introduced. The cause of this browning phenomenon has been well studied for a long time, but these studies have mainly focused on preventing deterioration of processed foods during food processing or storage. Resultantly, there are few studies on how much changes in nutrients (saccharides, amino acids, fats, water-soluble low molecular weight ammonium ions, etc.) are caused by browning. The purpose of this study is to determine the change in nutrients during browning using apple as a model fruit. We conducted a comparative study on how much the nutrient fluctuations differ depending on the presence or absence of pretreatment such as the application of heat. All analysis was conducted using 1H NMR. The ANOVA analysis showed that the concentrations of 4 amino acids (alanine, asparagine, isoleucine, and valine), 3 types of sugars (fructose, glucose, and xylose), 1 type of organic acid (lactate) and choline were significantly increased in samples showing browning. In addition, the groups before and after browning were clearly separated using multivariate statistical analysis methods (PCA, PLS-DA), which was greatly contributed by two sugar components (fructose and glucose) present in high concentrations in apples.

Cross-Sectional and Skeletal Anatomy of Long-tailed Gorals (Naemorhedus caudatus) Using Imaging Evaluations

  • Sangjin Ahn;Woojin Shin;Yujin Han;Sohwon Bae;Cheaun Cho ;Sooyoung Choi;Jong-Taek Kim
    • Journal of Veterinary Science
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    • v.24 no.4
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    • pp.60.1-60.8
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    • 2023
  • Background: Accurate diagnosis of diseases in animals is crucial for their treatment, and imaging evaluations such as radiographs, computed tomography (CT), and magnetic resonance imaging (MRI) are important tools for this purpose. However, a cross-sectional anatomical atlas of normal skeletal and internal organs of long-tailed gorals (Naemorhedus caudatus) has not yet been prepared for diagnosing their diseases. Objectives: The objective of this study was to create an anatomical atlas of gorals using CT and MRI, which are imaging techniques that have not been extensively studied in this type of wild animal in Korea. Methods: The researchers used CT and MRI to create an anatomical atlas of gorals, and selected 37 cross-sections from the head, thoracic, lumbar, and sacrum parts of gorals to produce an average cross-sectional anatomy atlas. Results: This study successfully created an anatomical atlas of gorals using CT and MRI. Conclusions: The atlas provides valuable information for the diagnosis of diseases in gorals, which can improve their treatment and welfare. The study highlights the importance of developing cross-sectional anatomical atlases of gorals to diagnose and treat their diseases effectively.

Bilateral Stress Fracture of Femur Neck, Fatigue Type of Non-Athlete Young Adult (젊은 비운동선수인 성인에서 발생한 양측 대퇴 목의 피로골절)

  • Yun, Yeo Joon;Na, Yong Jae;Jung, Ji Won;Lee, Kyu Hoon
    • Clinical Pain
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    • v.18 no.2
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    • pp.126-129
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    • 2019
  • Bilateral femoral neck stress fractures have been rarely reported. When diagnosed, they are usually limited to athletes or military personnel. A 35-year-old man, previously healthy, visited the emergency department for right inguinal pain. On physical examination, no external wound, tenderness or limitation of motion were found in either lower extremity. Plain radiography showed normal findings but an magnetic resonance image showed a linear fracture in the femoral neck. In this case, bilateral femoral neck stress fractures were found in a young non-athlete adult with no prior medical history of related injuries. Surgery is generally not performed for stress fractures but considering the patient's early mobilization and the need for quick reintegration into society, surgery was done in this case.

Classification system for partial distal biceps tendon tears: a descriptive 3-Tesla magnetic resonance imaging study of tear morphology

  • Alex B Boyle;Simon BM MacLean
    • Clinics in Shoulder and Elbow
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    • v.26 no.4
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    • pp.366-372
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    • 2023
  • Background: There is minimal literature on the morphology of partial distal biceps tendon (DBT) tears. We sought to investigate tear morphology by retrospectively reviewing 3-Tesla magnetic resonance imaging (3T MRI) scans of elbows with partial DBT tears and to propose a basic classification system. Methods: 3T MRI scans of elbows with partial DBT tears were retrospectively reviewed by two experienced observers. Basic demographic data were collected. Tear morphology was recorded including type, presence of retraction (>5 mm), and presence of discrete long-head and short-head tendons at the DBT insertion. Results: For analysis, 44 3T MRI scans of 44 elbows with partial DBT tears were included. There were 9 isolated long-head tears (20%), 13 isolated short-head tears (30%), 2 complete long-head tears with a partial short-head tear (5%), 5 complete short-head tears with a partial long-head tear (11%), and 15 peel-off tears (34%). Retraction was seen in 5 or 44 partial tears (11%), and 13 of the 44 DBTs were bifid tendons at the insertion (30%). Conclusions: Partial DBT tears can be classified into five sub-types: long-head isolated tears, short-head isolated tears, complete long-head tears with partial short-head involvement, complete short-head tears with partial long-head involvement, and peel-off tears. Classification of tears may have implications for operative and non-operative management. Level of evidence: III.

The Usefulness of Diffusion-weighted MR Imaging for Differentiation between Degenerative Spines and Infectious Spondylitis (퇴행성 척추와 감염성 척추염의 감별에 있어서 확산강조영상의 유용성)

  • 박원규;변우목;최준혁
    • Investigative Magnetic Resonance Imaging
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    • v.6 no.2
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    • pp.152-157
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    • 2002
  • Purpose : The differential diagnosis between Modic type I degenerative spine and infectious spondylitis sometimes is difficult, because the affected bone marrows in both disease show similar signal intensity on conventional MR imaging. We evaluate the usefulness of diffusion-wighted MR imaging for differential diagnosis between Modic type I degenerative spine and infectious spondylitis. Materials and methods : The spin-echo and diffusion-weighted MR images of eight patients with Modic type I degenerative spines and 14 patients with infectious spondylitis diagnosed by clinical findings or CT-guided biopsies we re analyzed. The diffusion-weighted imaging sequence was based on reversed fast imaging with steady-state precession (PSIF). Signal intensity changes of the vertebral bone marrow on conventional spin-echo and diffusion-weighted MR imaging were compared between degenerative spine and infectious spondylitis. Results : On T1-weighte d images, the affeted bone marrow in both disease showed hypointense signals. On T 2-weighted images, all of type I degenerative spine and 11 of infectious spondylitis showed hyperintensity, and three of infectious spondylitis showed heterogeneo us mixed signal intensity. On diffusion-weighted MR images, all of type I degenerative spine were hypointense with peripheral high signal intensity to normal vertebral body, but infectious spondylitis was hyperintense (n = 11) and hypointense (n=3). Conclusion : Diffusion-weighted MR imaging is useful to differentiate Modic type I degenerative spine from infectious spondylitis. On diffusion-weighted images, the high singal intensity of bone marrow suggests infectious spondylitis, whereas the low signal intensity of bone marrow with peripheral focal high signal intensity suggests type I degenerative spine.

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Statistical Study of Conservative Treated Herniated Intervertebral Lumbar Disc (요추 추간판탈출증 환자의 보존적 치료에 대한 통계적 연구)

  • Kim, Su-Jang;Kim, Yong;Kim, Sung-Yong;Lee, Jeong-Hun
    • The Journal of Korea CHUNA Manual Medicine
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    • v.3 no.1
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    • pp.43-53
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    • 2002
  • Objectives : The object is to study a clinical effect regarding the conservative treatment of the patient who was diagnosed as the herniated Intervertebral lumbar disc(HIVD) and hospitalized in the oriental medical hospital and clinical study about the type of the HIVD. Methods. The clinical studies were done on 65 cases (hospitalized in Dept. of Oriental Rehabilitation Medicine, jaseng on oriental medical hospital from June 2001 to May 2002) who complained of low back pain or sciatica and diagnosed as HIVD on CT(computerized tomography) or MRI(magnetic resonance imaging). They were given both oriental conservative treatment and exercise during the hospitalization period. We investigated and observed 20 items about sex, age, weight, height, occupation, smoking. obesity, duration of disease, clinical symptom and treatment duration in basis of medical recording which was drawn up at patient hospitalization. We classified HIVD with 4 types(Bulging. Protruded. Extruded, Sequestered) and decided the case which simultaneously had 2 overs with Mixed type. The treatment evaluation standard was classified with 4 branches; Excellent. Good, Fair and Poor. Results & Conclusions : The treatment result of over 'fair' is bulging type 85%, protruded type 92.7%, extruded type 100% and the mixed type was 85.1 %. The effect was good in order of bulging, mixed, protruded and extruded type. It appeared most plentifully with 30 people in L4-5 and L5-S 1 disc herniation type.

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Relation between shape of the articular eminence and disc displacement in the temporomandibular joint (측두하악관절에서 관절융기 형태와 관절원판 변위와의 연관성 연구)

  • Lee Heung-Ki;Hwang Eui-Hwan;Lee Sang-Rae
    • Imaging Science in Dentistry
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    • v.31 no.3
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    • pp.145-151
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    • 2001
  • Purpose : To investigate the hypothesis that the morphology of the articular eminence of the temporomandibular joint is a predisposing factor for disc displacement. Materials and Methods: MR images of 126 temporomandibular joints in 94 patients were analyzed to assess for morphology of the articular eminence and disc displacement. The displaced disc was further categorized as disc displacement with reduction (DDWR) and disc displacement without reduction (DDWOR). The morphology of the articular eminence was classified into four types; box, sigmoid, flattened, and deformed. The relationship between the four types of shape of the articular eminence and the two types of disc position was assessed. Results: In the DDWR and DDWOR groups, the morphology of articular eminence were a box type in 40.5%, a sigmoid type in 30.2%, a flattened type in 24.6%, and a deformed type in 4.7%. The box type of the articular eminence were 34.3% in the DDWR group and 42.9% in the DDWOR group. The sigmoid type of the articular eminence were 34.3% in the DDWR group and 28.6% in the DDWOR group. The flattened type of the articular eminence were 28.6% in the DDWR group and 23.1 % in the DDWOR group. The deformed type of articular eminence were 2.9% in the DDWR group and 5.5% in the DDWOR group. Conclusion: Disc displacement is more likely to be found in the temporomandibular joints with a box-shaped articular eminence. It can be considered that shape of the articular eminence is related to the development of disc displacement.

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