• 제목/요약/키워드: Combination resonance

검색결과 222건 처리시간 0.032초

A case of suspected bacterial meningoencephalitis in a Miniature Pinscher dog

  • Jung, Dong-In;Park, Chul;Kang, Byeong-Teck;Yoo, Jong-Hyun;Park, Hee-Myung
    • 대한수의학회지
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    • 제46권4호
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    • pp.405-408
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    • 2006
  • A 4-year-old male Miniature Pinscher was referred because of head tilt, nystagmus, and ataxia. The hemogram revealed a moderate neutrophilic leukocytosis. On magnetic resonance imaging, cerebellar inflammation was detected. And cerebrospinal fluid analysis indicated marked neutrophilic pleocytosis. Based on these results, bacterial meningoencephalitis was suspected. The clinical signs were well controlled by a combination antibiotics therapy of the third generation cephalosporins (cefotaxime and cefixime) and metronidazole. We tentatively diagnosed this case as a bacterial meningoencephalitis because clinical signs were improved after only antibiotics therapy and relapsed when stopped antibiotics administrations, even though the result of bacterial culture on communication of cerebrospinal fluid (CSF) was negative.

측두하악관절 내장증 환자의 임상증상과 자기공명영상 소견의 비교 연구 (Comparison of MRI findings with clinical symptoms in temporomandibular joint internal derangement)

  • 권기정
    • Imaging Science in Dentistry
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    • 제35권2호
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    • pp.69-75
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    • 2005
  • Purpose : To determine the clinical correlation of magnetic resonance imaging (MRI) findings of temporomandibular joint internal derangements. Materials and Methods : The MR images of 150 TMJs in 75 patients were analyzed. The clinical symptoms were pain in the preauricular area and masticatory muscles and TMJ sounds. Results : There was a statistically significant relationship between the MRI diagnoses of different types of disc displacements and clinical findings of pain, clicking, and crepitus. The risk of TMJ pain was increased when the disc displacement without reduction occurred at the same time in combination with the osteoarthrosis and effusion. Conclusion : Regardless of the results, the data indicate that each of these MR imaging variables may not be regarded as the unique and dominant factor in defining TMJ pain occurrence.

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Characterization of Elastic, Dielectric and Piezoelectric Properties of piezoelectric Materials

  • Cao, Wenwu
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1999년도 추계학술대회 논문집
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    • pp.13-22
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    • 1999
  • Both the resonance and ultrasonic techniques are standard methods far characterizing the physical properties of piezoelectric materials. However, we found that each technique can only offer a few reliable measurements while the rest often have errors or impossible to implement because of the sample requirements. This paper show that one can use the combination of both techniques to achieve much better accuracy and be able to get the complete set of elastic, dielectric and piezoelectric coefficients using fewer samples. Using an ultrasonic spectroscopy we have also measure the dispersion of the ultrasonic velocity and the attenuation up to 65 MHz. Pb(Zr,Ti)O$_3$[PZT] ceramics were used as examples fur both studies.

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A new sesterterpenoid showing anti-inflammatory effect from the Marine Sponge Haliclona species

  • Lee, Kyung;Rho, Jung-Rae
    • 한국자기공명학회논문지
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    • 제19권1호
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    • pp.23-28
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    • 2015
  • Four spiroketal sestertepenoids (1 ~ 4) were isolated from the marine sponge Haliclona species. Their planar structures were completely determined from a combination of extensive 1D and 2D NMR experiments, and also the relative stereochemistry on the chiral centers were established by the ROESY experiment. Compounds 1 ~ 3 were determined as the same planar structures with different stereochemistry on the chiral centers C-11 and C-13. Of these, 1 was identified as a new stereoisomer. Four compounds showed the inhibition effect of nitric oxide (NO) production in LPS-stimulated RAW 264.7 cells (0.7~2.0 g/ml).

Sarcotrine G, a New Derivative Isolated from a Marine Sponge Sarcotragus Species

  • Hwang, Buyng-Su;Park, Su-Young;Park, Myung-Gil;Rho, Jung-Rae
    • 한국자기공명학회논문지
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    • 제12권1호
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    • pp.33-39
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    • 2008
  • Four sesterterpenoids were isolated from AMPK activity-guided fraction of marine sponge Sarcotragus species. Their planar structures were determined from combination of extensive 1D and 2D NMR experiments and MS data, and the configuration at the chiral centers were assigned by comparison with the $^1H$ and $^{13}C$ chemical shifts of the known compounds. Among four compounds, compound 2 was found to be a new sarcotrine derivative. Though not strong, compounds 1-4 moderately showed AMPK activation effect on L6 myoblast cell through Western Blot analysis.

Long-term Chemotherapy with Hydroxyurea in a Dog with Suspected Intracranial Meningioma

  • Jung, Dong-In;Lim, Chae-Young;Kang, Byeong-Teck;Kim, Ju-Won;Yoo, Jong-Hyun;Park, Hee-Myung
    • 한국임상수의학회지
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    • 제25권6호
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    • pp.514-517
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    • 2008
  • A 9-year-old female mixed breed dog was presented due to cluster seizure episode. A mass in the frontal lobe was noted on brain magnetic resonance imaging (MRI). The dural tail sign was identified on contrast MR images. Based on MRI findings, intracranial meningioma was suspected strongly. The patient's symptom was controlled well by a combination therapy of hydroxyurea and prednisolone, and survived for fourteen months after diagnosis. This case report demonstrated that the clinical findings, imaging characteristics of a dog with suspected intracranial meningioma and long-term survival after hydroxyurea plus prednisolone therapy.

Kinetics and Mechanism of the Pyridinolysis of Benzyl Bromides in Dimethyl Sulfoxide

  • 홍성완;고한중;이혜황;이익춘
    • Bulletin of the Korean Chemical Society
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    • 제20권10호
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    • pp.1172-1176
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    • 1999
  • Nucleophilic substitution reaction of Y-benzyl bromide with X-pyridines are investigated in DMSO at 45.0℃. Biphasic rate dependence is observed on varying the substituents in the substrate (Y) as well as in the nucleophile (X). The two well-defined straight lines in the Hammett (ρy) and Bronsted ( βx) plots are interpreted to indicate the changes in transition-state structure, a decrease in bond cleavage as the substituent on the substrate is changed from electron-donors ( ρy < 0) to electron-acceptors ( ρy > 0), and an increase in the extent of bond formation with the corresponding changes of the substituent on the pyridine. A Jencks' type analysis of separate polar (ρ) and resonance (ρr) effects can also be accounted for by the change of the transition-state structure, not by the variable combination of polar and resonance effects.

인체 중간엽 줄기세포의 표지를 위한 상용화 된 Superparamagnetic Iron Oxide Nanoparticle과 Tansfection Agent의 적절한 병용을 위한 연구 (Evaluation of Optimal Combination of Commercially Available Superparamagnetic Iron Oxide Nanoparticles and Transfection Agents for Labelling of Human Mesenchymal Stem Cells)

  • 김성헌;오순남;박윤희;강원경;안국진;정수교
    • Investigative Magnetic Resonance Imaging
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    • 제16권1호
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    • pp.31-39
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    • 2012
  • 목적: 상용화 된 superparamagnetic iron oxide (SPIO) nanoparticles과 transfection agent (TA)의 최적의 병용 용량을 알아보고자 하였다. 대상과 방법: Protamine sulfate (Pro), poly-L-lysin (PLL)과 ferumoxide, ferucarbotran을 다양한 농도에서 인체 중간엽 줄기세포에서 배양하여 세포 생존능을 알아보았다. 세포 철 섭취율은 정성적으로, 정량적으로 분석하였다. 결과: Ferumoxide 처리군의 생존능과 철 섭취율은 ferucarbotrn 처리군보다 통계적으로 의미있게 높았다 (p < 0.05). T2 이완시간은 ferumoxide 처리군에서 짧았다 (p < 0.05). 25 ${\mu}g$/ml ferumoxide와 3.0 ${\mu}g$/ml Pro 또는 PLL 병용군이 최적의 조건이었다. 결론: Ferumoxide 처리군의 세포 생존능과 철 섭취율은 ferucarbotrn 처리군보다 높았다. 25 ${\mu}g$/ml ferumoxide와 3.0 ${\mu}g$/ml TA는 줄기세포 표지에 적합하다.

비선형 부하의 운전시 유도전동기의 특성 해석 (Characteristics Analysis of Induction Motor by Operation of Non-lineal Loads)

  • 김종겸;박영진;이은웅
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 학술대회 논문집 전문대학교육위원
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    • pp.147-153
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    • 2006
  • Voltage unbalance will be generated by the load unbalance operation such as combination operation of single & three phase load and current unbalance will be more severe by the deteriorated voltage quality. Under the these unbalance conditions, all power electronic converters used in different types of electronic systems can increase harmonic disturbances by injecting harmonic currents directly into the feeder grid of three phase 4-wire. Harmonic current may cause torque to decrease. it may also overheat or become noisy and torque oscillation in the rotor can lead to mechanical resonance and vibration. This paper presents a scheme on the characteristics of induction motor under the combination of linear & non-linear loads at the three phase 4-wire power distribution system by the unbalance and harmonic components. It was able to confirm that the number of torque pulsation decreased and torque ripple values increased by the harmonics that reduction was difficult by five harmonics filters at additional driving time of single-phase non-linear load.

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훅조인트로 연결된 축계의 비선형 비틀림 진동의 분기해석 :2-자유도계 모델 (Nonlinear Torsional Oscillations of a System incorporating a Hooke's Joint : 2-DOF Model)

  • 장서일
    • 한국소음진동공학회논문집
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    • 제13권4호
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    • pp.317-322
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    • 2003
  • Torsional oscillations of a system incorporating a Hooke's joint are investigated by adopting a nonlinear 2-degree-of-freedom model. Linear and Van der Pol transformations are applied to obtain the equations of motion to which the method of averaging can be readily applied. Various subharmonic and combination resonances are identified with the conditions of their occurrences. Applying the method of averaging leads to the reduced amplitude- and phase-equations of motion, of which constant and periodic solutions are obtained numerically. The periodic solution which emerges from Hopf bifurcation point experiences period doubling bifurcation leading to infinite solution rather than chaotic solution.