• Journal of the Korean Magnetic Resonance Society
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• v.19 no.1
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• pp.29-35
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• 2015

The microscopic dynamics of $CsH_2PO_4$, with two distinct hydrogen bond lengths, are studied by static nuclear magnetic resonance (NMR) and magic angle spinning (MAS) NMR. The proton dynamics of the two crystallographically inequivalent hydrogen sites were discussed in terms of the $^1H$ NMR and $^1H$ MAS NMR spectra. Although the hydrogen bonds have two inequivalent sites, H(1) and H(2), distinct proton dynamics for the two sites were not found. Further, the $^{133}Cs$ spectrum is more or less continuous near $T_{C1}$ (=153 K). Finally, the phase transition mechanism of $T_{C1}$ in $CsH_2PO_4$ is related to the ordering of protons.

• Natural Product Sciences
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• v.22 no.1
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• pp.30-34
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• 2016

A simple and rapid method based on proton nuclear magnetic resonance spectroscopy was developed for determination of trans-anethole content in fennel essential oil. Spectra of pure trans-anethole, of the pure essential oil of fennel, and of the pure oil of fennel with thymol internal standard were recorded. The signal of $H-1^/$ was used for quantification of trans-anethole. This proton signal is well separated in the proton magnetic resonance spectrum of the compound. No reference compound is needed and cheap internal standard was used. The results obtained from spectroscopic analysis were compared with those obtained by gas chromatography. Additionally, the developed method was used for determination of the type of vegetable oil used as a carrier in commercial products, which cannot be quantified as such by gas chromatography. This study demonstrates the application of proton nuclear magnetic resonance spectroscopy as a quality control method for estimation of essential oil components.

• Journal of the Korean Magnetic Resonance Society
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• v.20 no.3
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• pp.82-86
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• 2016

Ginseng is used as a medicinal ingredient. The quality control of species, age, origin and manufacturing process is important. The metabolome of ginseng about quality was studied in many reports. Almost studies carried out the extract of ginseng, however, the reproducibility cannot be obtained using extracted sample. In this study, powdery ginseng samples were analyzed using high resolution-magic angle spinning nuclear magnetic resonance (HR-MAS NMR)-based metabolomics except extraction step. Sample was measured three times using 600 MHz NMR spectrometer equipped with nano probe. Reproducibility can be enhanced using this method and the metabolic profiles of ginseng were identified and quantified.

• Communications of the Korean Mathematical Society
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• v.16 no.3
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• pp.519-541
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• 2001

Magnetic Resonance Electrical Impedance Tomography(MREIT) is a new medical imaging technique for the cross-sectional conductivity distribution of a human body using both EIT(Electrical Impedance Tomography) and MRI(Magnetic Resonance Imaging) system. MREIT system was designed to enhance EIT imaging system which has inherent low sensitivity of boundary measurements to any changes of internal tissue conductivity values. MREIT utilizes a recent CDI (Current Density Imaging) technique of measuring the internal current density by means of MRI technique. In this paper, a mathematical modeling for MREIT and image reconstruction method called the alternating J-substitution algorithm are presented. Computer simulations show that the alternating J-substitution algorithm provides accurate high-resolution conductivity images.

• Journal of Magnetics
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• v.20 no.1
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• pp.57-61
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• 2015

In this paper wireless power transmission system based on magnetic resonance coupling circuit was carried out. With the research objectives based on the mutual coupling model, mathematical expressions of optimal coupling coefficients are examined. Equivalent circuit parameters are calculated by Maxwell software, and the equivalent circuit was solved by Matlab software. The power transfer efficiency of the system was derived by using the electrical parameters of the equivalent circuit. System efficiency was analyzed depending on the different air gap values for various characteristic impedances. Hence, magnetic resonance coupling involves creating a resonance and transferring the power without radiating electromagnetic waves. As the air gap between the coils increased the coupling between the coils were weakened. The impedance of circuit varied as the air gap changed, affecting the power transfer efficiency.

• Investigative Magnetic Resonance Imaging
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• v.23 no.1
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• pp.65-69
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• 2019

Ramsay Hunt syndrome with the complication of encephalitis or meningoencephalitis is rarely reported and uncommon in immunocompetent patients. The radiological manifestations of such cases usually involve the cerebellum and brainstem or exhibit the absence of any abnormality. We report a case of a 78-year-old immunocompetent man hospitalized with Ramsay Hunt syndrome, who later developed meningoencephalitis. The cerebrospinal fluid-study excluded other causes of meningoencephalitis, and the clinical diagnosis indicated varicella zoster virus meningoencephalitis. Magnetic resonance imaging revealed increased signal intensities in the bilateral temporal lobe, midbrain, and pons on T2-weighted imaging, and T2 fluid attenuated inversion recovery and contralateral asymmetric pachymeningeal enhancement. Contrast-enhanced T1-weighted imaging revealed ipsilateral facial nerve enhancement.

• Investigative Magnetic Resonance Imaging
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• v.23 no.1
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• pp.75-80
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• 2019

Metastasis of rhabdomysarcoma to the breast is a very rare manifestation in adult males. Herein, we report a case of metastasis from embryonal rhabdomyosarcoma in the left hypothenar muscle that presented as a breast mass in a 38-year-old man, who four months later expired because of multiple bone metastases related to pancytopenia. We describe the various imaging findings, including mammograms, ultrasonography, computerized tomography (CT), positron emission tomography-computed tomography (PET-CT), and magnetic resonance imaging (MRI) of this rare disease. The various imaging findings of this lesion could be helpful for future diagnosis of male breast lesions.

• Investigative Magnetic Resonance Imaging
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• v.23 no.3
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• pp.279-282
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• 2019

Neurosyphilis is an infection of the brain or spinal cord that is caused by the bacterium Treponema pallidum. Syphilitic myelitis, which involves the spinal cord, is a very rare form of neurosyphilis seen in patients with syphilis. It requires differentiation from other diseases of the spinal cord, including idiopathic transverse myelitis and spinal cord infarction. Herein, we describe the presentation and diagnosis of syphilitic myelitis in a 43-year-old woman, based on a flip-flop sign and candle guttering appearance depicted in magnetic resonance imaging and laboratory tests.

• Investigative Magnetic Resonance Imaging
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• v.25 no.2
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• pp.135-140
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• 2021

Breast angiosarcoma is a very rare manifestation. Herein, we report a case of breast angiosarcoma in a 21-year-old woman admitted to our hospital with a one-year history of a palpable mass with fullness and swelling of the right breast. The various imaging findings, including mammography, ultrasound (US), and magnetic resonance imaging (MRI), of this rare disease are described. The imaging findings of US and combined MRI of breast angiosarcoma were specific in this case. The imaging characteristics could be helpful in detecting and diagnosing breast angiosarcoma in young women with a palpable mass with fullness and swelling of the breast.

• Investigative Magnetic Resonance Imaging
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• v.25 no.2
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• pp.129-134
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• 2021

The prevalence of cheek lymphoma, especially a mucosa-associated lymphoid tissue lymphoma (MALT), is very rare. Non-specific symptoms and image findings of cheek lymphoma may mimic benign entities and make it difficult to diagnose. In this case report, we present a case of MALT lymphoma of the cheek mimicking benign entities on computed tomography and magnetic resonance imaging.