• Title/Summary/Keyword: resolved resonance

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Enterovirus 71 infection and neurological complications

  • Lee, Kyung Yeon
    • Clinical and Experimental Pediatrics
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    • v.59 no.10
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    • pp.395-401
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    • 2016
  • Since the outbreak of the enterovirus 71 (EV71) infection in Malaysia in 1997, large epidemics of EV71 have occurred in the Asia-Pacific region. Many children and infants have died from serious neurological complications during these epidemics, and EV71 infection has become a serious public health problem in these areas. EV71 infection causes hand, foot and mouth disease (HFMD) in children, and usually resolves spontaneously. However, EV71 occasionally involves the central nervous system (CNS), and induces diverse neurological complications such as brainstem encephalitis, aseptic meningitis, and acute flaccid paralysis. Among those complications, brainstem encephalitis is the most critical neurological manifestation because it can cause neurogenic pulmonary hemorrhage/edema leading to death. The characteristic clinical symptoms such as myoclonus and ataxia, cerebrospinal fluid (CSF) pleocytosis, and brainstem lesions on magnetic resonance imaging, in conjunction with the skin rash of HFMD and the isolation of EV71 from a stool, throat-swab, or CSF sample are typical findings indicating CNS involvement of EV71 infection. Treatment with intravenous immunoglobulin and milrinone are recommended in cases with severe neurological complications from EV71 infection, such as brainstem encephalitis. Despite the recent discovery of receptors for EV71 in human cells, such as the scavenger receptor B2 and P-selection glycoprotein ligand 1, it is not known why EV71 infection predominantly involves the brainstem. Recently, 3 companies in China have completed phase III clinical trials of EV71 vaccines. However, the promotion and approval of these vaccines in various countries are problems yet to be resolved.

14N Mines Pulsed-ENDOR of Proximal Histidine and Heme of Aquometmyoglobin and Fluormetmyoglobin

  • Lee, Hong-In
    • Bulletin of the Korean Chemical Society
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    • v.23 no.12
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    • pp.1769-1772
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    • 2002
  • Previous $^{19}F\;and\;^{1,2}H$ electron-nuclear double resonance (ENDOR) study of fluorometmyoglobin (MbF) in frozen-solution state provided sensitive tools sensing subtle structural changes of the heme that are not obtainable from X-ray. [Fann et al., J. Am. Chem. Soc. 1995, 117, 6019] Because of the intrinsic inhomogeneouse EPR line broadening effect of MbF in frozen-solution state, detection of the intrinsic inhomogeneouse EPR line broadening effect of MbF in frozen-solution state, detection of the electronic and geometrical changes of the heme ring itself and the proximal histidine by using $^{14}N$ CW ENDOR was interfered. In the present study, hyperfine-sensitive $^{14}N$ Mims ENDOR technique of pulsed-EPR was employed to probe the changes. With two different $\tau$ values of 128 and 196 ns, $^{14}N$ ENDOR signals of the heme and proximal histidine were completely resolved at $g'_{II}(=g_e=2)$. This study present that X-band $^{14}N$ Mims ENDOR sequence can sensitively detect the small changes of the spin densities and p orbital populations of the proximal and the heme nitrogens, caused by ligand and pH variation of the distal site.

27Al Solid-state NMR Structural Studies of Hydrotalcite Compounds Calcined at Different Temperatures

  • Park, Tae-Joon;Choi, Sung-Sub;Kim, Yong-Ae
    • Bulletin of the Korean Chemical Society
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    • v.30 no.1
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    • pp.149-152
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    • 2009
  • Hydrotalcites are anionic clays that are quite prevalent in nature and their importance is growing more and more because of their very wide range of potential applications and uses. Understanding the structural and compositional changes that occur on the molecular scale during the thermal decomposition of hydrotalcite compounds is essential for the basic prediction and comprehensive understanding of the behavior and technical application of these materials. In this study, several hydrotalcite compounds calcined at different temperatures for applications in a chlorine resistant textile were prepared and 27-Aluminm solid-state nuclear magnetic resonance (NMR) spectroscopy was used as a tool to study their local structure and behavior. The changes in the Al coordination of the hydrotalcite compounds were investigated with one dimensional (1D) solid-state magic angle spinning (MAS) NMR spectroscopy. The two broad resonances arising from the structurally different Al coordinations of these compounds were clearly resolved by two dimensional (2D) triple quantum magic angle spinning (3QMAS) NMR spectroscopy.

Development of a fast reactor multigroup cross section generation code EXUS-F capable of direct processing of evaluated nuclear data files

  • Lim, Changhyun;Joo, Han Gyu;Yang, Won Sik
    • Nuclear Engineering and Technology
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    • v.50 no.3
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    • pp.340-355
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    • 2018
  • The methods and performance of a fast reactor multigroup cross section (XS) generation code EXUS-F are described that is capable of directly processing Evaluated Nuclear Data File format nuclear data files. RECONR of NJOY is used to generate pointwise XS data, and Doppler broadening is incorporated by the Gauss-Hermite quadrature method. The self-shielding effect is incorporated in the ultrafine group XSs in the resolved and unresolved resonance ranges. Functions to generate scattering transfer matrices and fission spectrum matrices are realized. The extended transport approximation is used in zero-dimensional calculations, whereas the collision probability method and the method of characteristics are used for one-dimensional cylindrical geometry and two-dimensional hexagonal geometry problems, respectively. Verification calculations are performed first for various homogeneous mixtures and cylindrical problems. It is confirmed that the spectrum calculations and the corresponding multigroup XS generations are performed adequately in that the reactivity errors are less than 50 pcm with the McCARD Monte Carlo solutions. The nTRACER core calculations are performed with the EXUS-F-generated 47 group XSs for the two-dimensional Advanced Burner Reactor 1000 benchmark problem. The reactivity error of 160 pcm and the root mean square error of the pin powers of 0.7% indicate that EXUF-F generates properly the broad-group XSs.

Velopharyngeal Insufficiency Accompanied with Hypertrophic Tonsils: A Case Report (편도비대를 동반한 구개인두부전 환자의 치험례)

  • Kim, Eun Key;Koh, Kyung Suck;Park, Mi Kyong
    • Archives of Plastic Surgery
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    • v.32 no.5
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    • pp.660-662
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    • 2005
  • It is well documented that adenoidectomy is attributed to hypernasality in certain cases, but not clear that the enlarged tonsils affect the quality of speech. Hypertrophied tonsils may cause and complicate the problem of velopharyngeal incompetency. The huge tonsils prevent lateral pharyngeal walls from a medial movement and interfere velar elevation, being hypernasality. Hyponasality developes as the tonsils encroach in nasopharyngeal space. Voluminous tonsils also interfere airflow in the oropharyneal passage and produce the phenomenon of cul-de-sac resonance or muffled sound. The authors and et al. present a case of velopharyngeal insufficiency accompanied with hypertrophic tonsils. Improving the lateral constricting pharyngeal wall and velar elevation after tonsillectomy minimized the velopharyngeal gap. Accordingly, the procedures of sphincter pharyngoplasty and palatal lengthening resolved the problem of hypernasality instead of pharyngeal flap. Tonsillectomy prior to pharyngeal flap surgery tends to reduce the postoperative airway problems. Sometimes, however, only tonsillectomy does without pharyngeal flap. Surgical approach by stages and intermittent evaluation are recommended at intervals of at least six weeks.

Pudendal nerve entrapment syndrome caused by ganglion cysts along the pudendal nerve

  • Kim, Young Je;Kim, Du Hwan
    • Journal of Yeungnam Medical Science
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    • v.38 no.2
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    • pp.148-151
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    • 2021
  • Pudendal nerve entrapment (PNE) syndrome refers to the condition in which the pudendal nerve is entrapped or compressed. Reported cases of PNE associated with ganglion cysts are rare. Deep gluteal syndrome (DGS) is defined as compression of the sciatic or pudendal nerve due to a non-discogenic pelvic lesion. We report a case of PNE caused by compression from ganglion cysts and treated with steroid injection; we discuss this case in the context of DGS. A 77-year-old woman presented with a 3-month history of tingling and burning sensations in the left buttock and perineal area. Ultrasonography showed ganglion cystic lesions at the subgluteal space. Magnetic resonance imaging revealed cystic lesions along the pudendal nerve from below the piriformis to the Alcock's canal and a full-thickness tear of the proximal hamstring tendon. Aspiration of the cysts did not yield any material. We then injected steroid into the cysts, which resolved her symptoms. Steroid injection into a ganglion cyst should be considered as a treatment option for PNE caused by ganglion cysts.

Neoadjuvant Chemotherapy and Subsequent Adjuvant Chemotherapy with Hydroxyurea after Craniotomy in a Cat with a Meningioma

  • Chae-Yeon Kim;Jin-Young Kim;Yoon-Ho Roh;Kun-Ho Song;Joong-Hyun Song
    • Journal of Veterinary Clinics
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    • v.40 no.5
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    • pp.341-348
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    • 2023
  • An 11-year-old neutered male domestic short-haired cat presented with neurological symptoms that developed over a three-month period. These included mental dullness, vocalization, ataxia, and visual impairment. The patient was diagnosed with a primary intracranial tumor at a local animal hospital. After the first diagnosis, the cat was administered hydroxyurea, prednisolone, omeprazole, and gabapentin for 3 months. After the initiation of medical treatment, the patient's clinical symptoms did not improve and the size of the tumor was static on the second magnetic resonance imaging (MRI). The dosage of hydroxyurea and prednisolone was increased for two weeks. The patient's clinical signs improved, and subsequently, a craniotomy was performed. The clinical signs completely resolved six days after surgery. Adjuvant chemotherapy with hydroxyurea was continuously administered after the craniotomy. The patient demonstrated a good clinical status during the nine-month follow-up period. Neoadjuvant chemotherapy has not yet been reported for meningiomas in cats. Further clinical trials with longer follow-up periods and larger patient cohorts will be required to confirm the effectiveness of neoadjuvant chemotherapy with hydroxyurea in feline meningioma.

Transient Non-Regenerative Anemia in a Dog with Granulomatous Meningoencephalitis Following Leflunomide Treatment

  • Ga-Hyun Lim;Ju-Hyun An;Su-Min Park;Jeong-Hwa Lee;Ye-In Oh;Kyoung-Won Seo;Hwa-Young Youn
    • Journal of Veterinary Clinics
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    • v.41 no.3
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    • pp.165-169
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    • 2024
  • A 10-year-old, spayed female Maltese dog was tentatively diagnosed with granulomatous meningoencephalitis (GME) on magnetic resonance imaging. The meningoencephalitis was classified as aseptic GME because cerebral fluid analysis did not reveal an infectious aetiology. Two months after leflunomide treatment (Arava; Sanofi; 4 mg/kg/day), the patient developed non-regenerative, macrocytic, and normochromic anemia. As the patient's anaemia began after the administration of leflunomide, and other differentials for anaemia had been ruled out, the leflunomide was determined to be the cause and this treatment ended. After 15 days, the anaemia resolved spontaneously. This is the first report of reversible aplastic anaemia following treatment with leflunomide in a canine patient with GME.

Anatomical study to determine a new approach to treat benign masses located in the anterior condyle region: a case report

  • Sin Guen Kim;Sung Chul Bok;Suk In Choi;Jun Woo Park;Dong Ju Choi
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.50 no.2
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    • pp.110-115
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    • 2024
  • A 22-year-old male patient presented to the clinic with severe pain in the preauricular area with an inability to completely occlude the jaw. Facial computed tomography and magnetic resonance imaging revealed a well-defined lesion that was tentatively diagnosed as a benign tumor or cystic mass. Surgical approach of a lesion in the condyle is delicate and problematic as many vulnerable anatomical structures are present. There are several methods for surgery in this area. Typically, an extraoral approach is dangerous because of potential injuries to nerves and arteries. The intraoral approach also presents difficulties due to the lack of visibility and accessibility. On occasion, coronoidectomy may be performed. The goal here was to determine an easier and safer new surgical approach to the condyle. We reached the anterior part of the pterygoid plate in the same method as in Le Fort I surgery. From this point, through the external pterygoid muscle, approaching the anterior aspect of the condyle is relatively easy and safe, with minimal damage to the surrounding tissues. Pus was drained at the site, and the lesion was diagnosed as an abscess. Pain and inability to close the mouth resolved without recurrence.

Comparison of Proton T1 and T2 Relaxation Times of Cerebral Metabolites between 1.5T and 3.0T MRI using a Phantom (모형을 이용한 1.5T와 3.0T 자기공명에서의 뇌 대사물질들의 수소 T1과 T2 이완시간의 비교)

  • Kim, Ji-Hoon;Chang, Kee-Hyun;Song, In-Chan
    • Investigative Magnetic Resonance Imaging
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    • v.12 no.1
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    • pp.20-26
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    • 2008
  • Purpose : To present the T1 and T2 relaxation times of the major cerebral metabolites at 1.5T and 3.0T and compare those between 1.5T and 3.0T. Materials and Methods : Using the phantom containing N-acetyl aspartate (NAA), Choline (Cho), and Creatine (Cr) at both 1.5T and 3.0T MRI, the T1 relaxation times were calculated from the spectral data obtained with 5000 ms repetition time (TR), 20 ms echo time (TE), and 11 different mixing time (TM)s using STEAM (STimulated Echo-Acquisition Mode) method. The T2 relaxation times were obtained from the spectral data obtained with 3000 ms TR and 5 different TEs using PRESS (Point-RESolved Spectroscopy) method. The T1 and T2 relaxation times obtained at 1.5T were compared with those of 3.0T. Results : The T1 relaxation times of NAA were $2293\;{\pm}\;48\;ms$ at 1.5T and $2559\;{\pm}\;124\;ms$ at 3.0T (11.6% increase at 3.0T). The T1 relaxation times of Cho were $2540\;{\pm}\;57\;ms$ at 1.5T and $2644\;{\pm}\;76\;ms$ at 3.0T (4.1% increase at 3.0T). The T1 relaxation times of Cr were $2543\;{\pm}\;75\;ms$ at 1.5T and $2665\;{\pm}\;94\;ms$ at 3.0T (4.8% increase). The T2 relaxation times of NAA were $526\;{\pm}\;81\;ms$ at 1.5T and $468\;{\pm}\;74\;ms$ at 3.0T (11.0% decrease at 3.0T). The T2 relaxation times of Cho were $220\;{\pm}\;44ms$ at 1.5T and $182\;{\pm}\;35\;ms$ at 3.0T (17.3% decrease at 3.0T). The T2 relaxation times of Cr were $289\;{\pm}\;47\;ms$ at 1.5T and $275\;{\pm}\;57\;ms$ at 3.0T (4.8% decrease at 3.0T). Conclusion : The T1 relaxation times of the major cerebral metabolites (NAA, Cr, Cho), which were measured at the phantom, were 4.1%-11.6% longer at 3.0T than at 1.5T. The T2 relaxation times of them were 4.8%-17.3% shorter at 3.0T than at 1.5T. To optimize MR spectroscopy at 3.0T, TR should be lengthened and TE should be shortened.

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