• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.19 no.1
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• pp.11-15
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• 2008

Endoscopic laser cordectomy is known as an oncologically sound procedure for T1 and selected T2 glottic carcinoma ; it has comparable local control rate and better long-term laryngeal preservation rate when compared with those of radiotherapy. Even if results of the reported voice outcome studies after surgery or radiotherapy are diverse and controversial, resection deeper than the body layer of the vocal fold (type III, IV, V cordectomy) usually leads to aerodynamic insufficiency during phonation and results in poor voice quality. A keyhole defect or development of synechiae at the anterior commissure after type VI cordecomy may also result in unsatisfactory vocal outcome. However, many advances in phonosurgical techniques are reported to be successfully applied in the reconstruction of glottal defect that is subsequent to endoscopic laser cordectomy. In case of glottal insufficiency, voice restoration can be achieved by means of augmentation of the paraglottic space or medialization of the excavated vocal fold. Injection laryngoplasty with synthetic materials or autologous fat is gaining its popularity for restoring minor glottal volume defect because of its convenience. Laryngeal framework surgery, especially type I thyroplasty with premade implant systems or Gore-Tex, is most frequently used to correct larger glottic volume defect. In case of anterior commissural keyhole defect, additional procedure including laryngofissure may be required. For anterior commissural synechiae, laryngeal keel may be inserted for several weeks or mitomycin-C may be repeatedly applied after the division of adhesive scar to prevent restenosis. In this paper, current concepts and the authors' experiences of phonosurgical reconstruction of vocal function after endoscopic cordectomy will be introduced.

• Archives of Plastic Surgery
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• v.36 no.2
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• pp.205-210
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• 2009

Purpose: Corrugator supercilii muscle pulls eyebrow to inferomedial direction and produces the vertical component of the glabellar line formation. Current techniques for eliminating of glabellar frown include direct resection of corrugators and botulinum toxin injection. Muscle resection in endoscopic face lift procedure is relatively complex and has many disadvantages ranging from possible nerve injury, postoperative edema, pain and a long recovery period. The Botox treatment on the other hand is much more simple in technique but has a short duration of action. The authors have attempted new ways of finding improved treatment of the glabellar frown by selectively blocking of motor nerves innervating the corrugator supercili muscle by using radiofrequency ablation technique. Methods: A total of 80 patients were recruited in our study during the period between Feb. 2007 to June 2008. A probe was introduced from the supraorbital ridge and advanced to the corrugator supercilii muscle. Nerve stimulator was then used to locate the nerve innervating the corrugator and radiofrequency ablation of the nerve was done. Results: In all patients, there were marked improvement in glabellar frown after treatment. There were no reported cases of any relapses during the follow up period. No complication was noted such as facial nerve injury. No patient complained of any adverse symptoms other than slight discomfort due to swelling of the operation site. Conclusion: The treatment of glabellar frown lines using selective nerve block with radiofrequency ablation was not only less invasive but also excellent in surgical outcomes.

• Biomolecules & Therapeutics
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• v.23 no.5
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• pp.465-470
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• 2015

Chrysin is a 5,7-dihydroxyflavone and was recently shown to potently inhibit enterovirus 71 (EV71) by suppressing viral 3C protease ($3C^{pro}$ activity. In the current study, we investigated whether chrysin also shows antiviral activity against coxsackievirus B3 (CVB3), which belongs to the same genus (Enterovirus) as EV71, and assessed its ability to prevent the resulting acute pancreatitis and myocarditis. We found that chrysin showed antiviral activity against CVB3 at $10{\mu}M$, but exhibited mild cellular cytotoxicity at $50{\mu}M$, prompting us to synthesize derivatives of chrysin to increase the antiviral activity and reduce its cytotoxicity. Among four 4-substituted benzyl derivatives derived from C(5) benzyl-protected derivatives 7, 9-11 had significant antiviral activity and showed the most potent activity against CVB3 with low cytotoxicity in Vero cells. Intraperitoneal injection of CVB3 in BALB/c mice with $1{\times}10^6TCID_{50}$ (50% tissue culture infective dose) of CVB3 induced acute pancreatitis with ablation of acinar cells and increased serum CXCL1 levels, whereas the daily administration of 9 for 5 days significantly alleviated the pancreatic inflammation and reduced the elevation in serum CXCL1 levels. Collectively, we assessed the anti-CVB3 activities of chrysin and its derivatives, and found that among 4-substituted benzyl derivatives, 9 exhibited the highest activity against CVB3 in vivo, and protected mice from CVB3-induced pancreatic damage, simultaneously lowering serum CXCL1 levels.

• Korean Journal of Head & Neck Oncology
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• v.14 no.2
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• pp.151-155
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• 1998

Background and Objectives: Numerous studies were conducted to develop radiosensitizers to increase antitumor effect and decrease systemic toxicity of ionizing radiation. In current study, the authors tested the synergistic effect of mutant $TNF-{\alpha}(M_3S)$ with radiation therapy on heterotransplanted hypoparyngeal squamous cell carcinoma. Materials and Method: SNU-1041 cell line was heterotransplanted to nude mice. When the tumors grew up to $70mm^3$ or more, the animals were randomly placed into 4 groups(n=10/group). Group I : 0.1ml of normal saline injected intraperitoneally once a day for 5 days. Group II : 10ug of $TNF-{\alpha}$ injected intraperitoneally once a day for 5 days. Group III : a single radiation dose of 10 Gy per animal delivered. Group IV : single radiation dose of 10 Gy was delivered 1 hour after intraperitoneal injection of $TNF-{\alpha}$ 10 ug. Results: Four weeks after treatment, group IV showed the least tumor growth during the 4 weeks follow up and the relative tumor growth rate(RTG) of each groups after 4 weeks were 31, 5.8, 10, and 3.2 respectively(p<0.05). Conclusion: These study suggests that pretreatment with $TNF-{\alpha}$ can significantly enhance the effects of radiation therapy and further studies may be needed for clinical trials of combination treatment of $TNF-{\alpha}$ and radiation.

• Reproductive and Developmental Biology
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• v.34 no.2
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• pp.81-88
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• 2010

Our objective of current study was to investigate the development of bone and heart in association with diabetes mellitus (DM). DM was induced by administering an intraperitoneal injection of streptozotocin (STZ; 60 mg/kg) to 4-week-old Sprague-Dawley rats. Body weight and blood glucose were monitored, and rats were sacrificed after 2 or 5 weeks. The left ventricle (LV), including the interventricular septum, was weighed, and body weight and tibial bone length were assessed. Young diabetic rats showed reduced growth in terms of tibial length and body weight compared to controls. Moreover, diabetic males showed more significant growth suppression and reduced LV size than diabetic females. Morphometric analysis of tibiae from diabetic rats revealed suppressed bone growth at 2 and 5 weeks, with no difference between genders. STZ-induced diabetes decreased bone growth and retarded pre-pubertal heart development. As a result, diabetes may increase cardiovascular risk factors and lead to eventual heart failure. Therefore, new therapeutic approaches are required for diabetic children exhibiting growth retardation. Heart growth factor, exercise, and cardiopulmonary physical therapy may be required to promote heart development and physiological function.

• Journal of Pharmacopuncture
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• v.20 no.3
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• pp.220-226
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• 2017

Objectives: The currently available agents for use against toxoplasmosis have serious limitations. Thus, the aim of the present study was to investigate the anti-Toxoplasma gondii (T. gondii) activities of methanol extracts of Feijoa sellowiana (F. sellowiana) (leaves and fruits), Quercus castaneifolia (Q. castaneifolia) (fruits), and Allium paradoxum (A. paradoxum) (leaves) in vitro and in vivo. Methods: Vero cells were treated with different concentrations (from 0 to $400{\mu}g/mL$) of the above extracts or with pyrimethamine at a dose of 50 mg/mL (positive control). Then, the viabilities of the T. gondii-infected cells were measured by using colorimetric MTT (3-(4, 5-dimethylthiazol-2-yl) 2, 5-diphenyltetrazolium bromide) assays. In addition, the survival rates of mice acutely infected with $2{\times}10^4$ RH strain tachyzoites of T. gondii were examined in vivo after intraperitoneal injection of the extracts at doses of 100 and 200 mg/kg/day for 5 days. Results: In the in vitro anti- T. gondii assay, the $IC_{50}$ values were 12.77, 180.2, 74.73, 213.2 and $163.8{\mu}g/mL$, and the selectivity indices were 6.05, 1.31, 0.35, 0.69 and 1.30 for the F. sellowiana (leaves and fruits), Q. castaneifolia, and A. paradoxum extracts and pyrimethamine, respectively. Moreover, the mice treated with F. sellowiana (leaves and fruits) achieved better results in terms of survival than the others (P < 0.05). Conclusion: The results of the current study indicate that methanol extract of F. sellowiana has significant anti-Toxoplasma activity. Further study should be conducted to investigate the potential bioactivity of this extract through bioactivity-guided fractionation.

• Bulletin of the Korean Chemical Society
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• v.35 no.10
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• pp.3052-3058
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• 2014

In this article, we have designed and synthesized a novel donor-${\pi}$-acceptor (D-${\pi}$-A) type porphyrin-based sensitizer (denoted UI-5), in which a carboxyl anchoring group and a 9,9-dimethyl fluorene were introduced at the meso-positions of porphyrin ring via phenylethynyl and ethynyl bridging units, respectively. Long alkoxy chains in ortho-positions of the phenyls were supposed to reduce the degree of dye aggregation, which tends to affect electron injection yield in a photovoltaic cell. The cyclic voltammetry was employed to determine the band gap of UI-5 to be 1.41 eV based on the HOMO and LUMO energy levels, which were estimated by the onset oxidation and reduction potentials. The incident monochromatic photon-to-current conversion efficiency of the UI-5 DSSC assembled with double-layer (20 nm-sized $TiO_2$/400 nm-sized $TiO_2$) film electrodes appeared lower upon overall ranges of the excitation wavelengths, but exhibited a higher value over the NIR ranges (${\lambda}$ = 650-700 nm) compared to the common reference sensitizer N719. The UI-5-sensitized cell yielded a relatively poor device performance with an overall conversion efficiency of 0.74% with a short circuit photocurrent density of $3.05mA/cm^2$, an open circuit voltage of 0.54 mV and a fill factor of 0.44 under the standard global air mass (AM 1.5) solar conditions. However, our report about the synthesis and the photovoltaic characteristics of a porphyrin-based sensitizer in a D-${\pi}$-A structure demonstrated a significant complex relationship between the sensitizer structure and the cell performance.

• Korean Journal of Optics and Photonics
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• v.17 no.3
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• pp.223-230
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• 2006

We demonstrate a distributed fiber sensor system based on spatially-selective Brillouin scattering, using a single laser diode as a light source whose optical frequency is directly modulated by the injection current. The pump and the counter-propagating probe lights, which are sinusoidally frequency-modulated, are superposed in the fiber so that stimulated Brillouin scattering takes places only at a specific location along the fiber. Brillouin gain peak position is controlled by varying the modulation frequency. Distributions of Brillouin shift frequency are measured for the case of concatenated optical fibers of two different kinds and also for the case of temperature distribution. The temperature coefficient of the Brillouin shift frequency is measured to be $1.33MHz/^{\circ}C$.

• Journal of the Korean Magnetics Society
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• v.25 no.1
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• pp.1-3
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• 2015

We demonstrate here an optical measurement technique to quantify the spin-orbit torques. The magnetization dynamics induced by the spin-orbit torques with a sinusoidal current injection is measured by use of polar magneto-optical Kerr effect. The measured signal is then analyzed based on the Landau-Lifhshitz-Gilbert equation with consideration of the spin-orbit torques. The present measurement technique is applied to Pd/Co/Pt films and then, the longitudinal and transverse components of the spin-orbit torques are successfully quantified. The present optical technique provides an alternative way to quantify the spin-orbit torques.

• ETRI Journal
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• v.31 no.6
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• pp.660-666
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• 2009

We investigate the effects of interfacial dielectric layers (IDLs) on the electrical properties of top-gate In-Ga-Zn-oxide (IGZO) thin film transistors (TFTs) fabricated at low temperatures below $200^{\circ}C$, using a target composition of In:Ga:Zn = 2:1:2 (atomic ratio). Using four types of TFT structures combined with such dielectric materials as $Si_3N_4$ and $Al_2O_3$, the electrical properties are analyzed. After post-annealing at $200^{\circ}C$ for 1 hour in an $O_2$ ambient, the sub-threshold swing is improved in all TFT types, which indicates a reduction of the interfacial trap sites. During negative-bias stress tests on TFTs with a $Si_3N_4$ IDL, the degradation sources are closely related to unstable bond states, such as Si-based broken bonds and hydrogen-based bonds. From constant-current stress tests of $I_d$ = 3 ${\mu}A$, an IGZO-TFT with heat-treated $Si_3N_4$ IDL shows a good stability performance, which is attributed to the compensation effect of the original charge-injection and electron-trapping behavior.