• Journal of The Korean Ophthalmological Society
• /
• v.55 no.1
• /
• pp.1-6
• /
• 2014

Purpose: To investigate the clinical manifestation of nasolacrimal duct obstruction after radioactive iodine therapy for thyroid cancer. Methods: The authors examined 622 patients who were treated with radioactive iodine therapy after the operation for thyroid cancer from January 2009 to December 2011. Fourteen patients (18 eyes) were diagnosed nasolacrimal duct obstruction based on the lacrimal irrigation test, lacrimal probing test and dacryocystography in our oculoplastic clinic. We analyzed the dose of radioactive iodine therapy, number of treatments, clinical manifestation and treatment type by retrospectively reviewing the patients' medical records. Results: The mean radioactive iodine dose ($215.7{\pm}23.1mCi$, p = 0.01) and the mean number of treatments ($1.36{\pm}0.50$, p < 0.001) were significantly greater in 14 patients who had nasolacrimal duct obstruction than in patients who did not. The average onset of tearing symptoms occurred 10.2 months after radioactive iodine therapy. The mean time between correct diagnosis and therapy was 18.4 months. Three patients (3 eyes) had occlusion at the common cannaliculus and 11 patients (15 eyes) had occlusion at the nasolacrimal duct. Ten patients (13 eyes) underwent endonasal dacryocystorhinostomy for complete obstruction and 4 patients (5 eyes) underwent silicone tube intubation for partial obstruction. Conclusions: Nasolacrimal duct obstruction is a rare complication associated with radioactive iodine therapy for thyroid cancer, thus, clinicians should be aware of this complication and refer patients with symptoms of epiphora to the oculoplastic department for specialized evaluation and treatment.

• The Korean Journal of Blood Transfusion
• /
• v.23 no.2
• /
• pp.162-168
• /
• 2012

Background: Potassium, the most common cation in the intracellular space, plays a critical role in our physiology. Potassium imbalance may cause life-threatening problems, ranging from general weakness to cardiac arrest due to ventricular fibrillation. For emergency physicians, detection of such derangement within a short period of time is of critical importance. In this study, we wanted to determine whether analysis of whole blood samples can be used as a screening tool for potassium imbalance by comparative analysis of whole blood and serum samples. Methods: Two samples were drawn from 227 patients. The whole blood sample was taken from the radial artery and contained in a commercially available arterial blood collection syringe with a lithium-heparin coating. The serum sample was contained in a commercially available vacuum bottle in a non-additive silicone coated tube and transported to the laboratory. The study population was divided into three groups, patients with normal whole blood potassium, patients with decreased whole blood potassium, and patients with elevated whole blood potassium. Potassium levels for each group were coupled with serum potassium levels and compared. Results: No significant difference in potassium values was observed between whole blood and serum samples (P<0.05). Strong associations were observed among the three groups (normal range, hypokalemia, and hyperkalemia group). Compared to the normal group (r=0.851), the hyperkalemia group showed a stronger association between variables (r=0.897), and the hypokalemia group showed a weaker association (r=0.760). Their correlation coefficients were highly significant (P<0.05). Conclusion: Our study illustrates that point-of-care testing using whole blood with whole blood can be a reliable screening tool when treating patients with suspicious potassium abnormality, especially in hyperkalemia patients.

• Journal of the Korean Magnetics Society
• /
• v.18 no.4
• /
• pp.136-141
• /
• 2008

In this study, the magnetic(static and high-frequency) and microwave absorbing properties have been investigated in Ru-Co substituted M-hexaferrites($BaFe_{12-2x}Ru_xCo_xO_{19}$). The powders and sintered specimens were prepared by conventional ceramic processing technique. With the calcined powders, the composite specimens were prepared using the silicone rubber as a matrix material. The substitution ratio of Ru-Co to obtain in-plane magnetic anisotropy, thus having the minimum coercivity, is much smaller (about x=0.3) than the previously reported Ti-Co substituted specimen. Owing to this low substitution, the specimen has a large value of saturation magnetization($M_s$=65 emu/g). Ferromagnetic resonance behavior and microwave absorbing frequency band is strongly influnced by the coercvity which can be controlled by Ru-Co substitution ratio. It is found that the M-hexaferrites with planar magnetic anisotropy by doping Ru-Co in both sintered and composite form have superior microwave absorbing properties in GHz frequency range.

• Journal of Technologic Dentistry
• /
• v.41 no.1
• /
• pp.21-27
• /
• 2019

Purpose: To evaluate 2D and 3D of occulsal, mesial-occlusal and mesial-occlusal-distal cavity of composite resin inlay. Methods: Abutment tooth 16, 36 of FDI system was selected for the study. Inlay prostheses classified as occlusal cavity (OC group), mesial-occlusal (MOC) and mesial-occlusal-distal cavity (MODC) were prepared using composite resin. Composite resin was injected with composite resin in prepared tooth cavity and then photopolymerized with UV light. Additional thermal polymerization was performed. Marginal gap of composite resin inlays were measured by digital microscope(x160) with silicone replica technique. The data was analyzed from statistical software for Kruskal-Wallis test (${\alpha}=0.05$). 3-dimensional analysis was analyzed through superimposition method. Results: The smallest 2D marginal fit measure of the three groups was $47.0{\pm}21.6{\mu}m$ in the MOC group. The largest 2D marginal was $69.1{\pm}33.8{\mu}m$ in the MODC group. In the trueness of the three groups, the most accurate figure was $14.4{\pm}2.3{\mu}m$ for the MODC group. In Precision, the most accurate figure was $14.5{\pm}4.3{\mu}m$ for the MODC group. Conclusion : In this study, 2D marginal fit of OC, MOC, and MODC cavities fabricated with composite resin was applicable to all clinical applications. In the 3D inner surface accuracy evaluation, the MODC group showed the accuracy results.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.8 no.4
• /
• pp.553-561
• /
• 2020

Water-soluble rubber asphalt-based waterproofing material, which is one of the waterproofing materials for building structures, is mainly used indoors (toilet, kitchen, balcony, etc.). In general, asphalt-based materials are used for non-exposed installation, rather than as exposed type as they do not deviate from their usual basic black pigmentation, and water-soluble rubber asphalt-based coating waterproofing materials are basically limited to indoors because of their low physical properties. Accordingly, in order to improve the tensile and elongation properties, a silane coupling agent, an inorganic filler, and a processor oil w ere added to improve the physical properties, and accordingly, the basic physical properties of the outdoor coating waterproofing material quality standard were analyzed. As a result, the water-soluble rubber asphalt coating waterproofing material compared with the exposure quality standard showed a result that exceeded the basic physical property quality standard of silicone rubber in all items under test evaluation, but the tensile strength and tear strength of the first class of urethane rubber were chloroprene. It was found that the performance compared to the quality standards of rubber-based tear strength was about 34.2% to about 40.8%.

• Korean Chemical Engineering Research
• /
• v.60 no.1
• /
• pp.132-138
• /
• 2022

In this study, a basic study was performed to systematically compare the changes in surface properties according to the post-processing method of the stereolithography (SLA) printing method, which is a photocuring 3D printing method, and to provide information on the post-processing method suitable for the application. Although it was possible to improve some of the transparency of the SLA-type output by regularly changing the irregular microstructure of the surface through polishing, it was difficult to secure sufficient transparency like glass. The change in contact angle characteristics due to grinding showed a tendency to slightly increase as the grinding time increased and the particle size of the sandpaper used was small, but the variation between samples was large and the average contact angle was 77~90°, showing no statistically significant difference. Surface treatment methods other than polishing were tried, and it was confirmed that it was possible to easily and simply improve the transparency by applying a commercially available vehicle scratch remover or silicone oil. In addition, a method for securing high transparency such as glass by using a scratch remover after sequential grinding while reducing the particle size of the sandpaper was proposed. Finally, even after surface treatment through polishing and various methods, it was difficult to secure a contact angle of 90° or more.

• Korean Journal of Acupuncture
• /
• v.38 no.4
• /
• pp.282-289
• /
• 2021

Objectives : The purpose of this study is to construct a model of the possible thermal runaway of electronic moxibustion and to implement an appropriate risk management method. Methods : To reproduce the system error situation of the electronic moxibustion circuit equipped with microcontroller unit, temperature sensor and heater, a code was set to disable the signal input to temperature sensor and maintain "high" heating signal to heater. The temperature change of electronic moxibustion was compared between 3 types of heater module; module 1 consisting of a combination of heater+0 ohm+0 ohm resistance, module 2 consisting of a combination of heater+Polymeric Positive Temperature Coefficient (PPTC)+0 ohm resistance, and module 3 consisting of a combination of heater+PPTC+10 ohm resistance. The temperature change was measured using a polydimethylsiloxane (PDMS) silicone phantom. After maintaining surface temperature of the phantom at 31~32℃ for 20 seconds, electronic moxibustion was applied. After operating electronic moxibustion, the temperature change was measured for 660 seconds on the surface and 900 seconds at 2 mm depth. Results : Regardless of the module type, the time-dependent change in temperature showed a rapid rise followed by a gentle curve, and a sharp drop in temperature after reaching the maximum temperature about 10 minutes after the switching the moxibustion on. Temperature measured at the depth of 2 mm below the surface increased slower and to a lesser extent. Module 1 reached highest peak temperature with largest change of temperature at both depths followed by module 2, and 3. Conclusions : Through the combination of PPTC+resistance with the heater of electronic moxibustion, it is possible to limit the rise in temperature even with the software error. Thus, this setting can be used as an independent safety measure for the electronic moxibustion control unit.

• Korean Journal of Mineralogy and Petrology
• /
• v.35 no.4
• /
• pp.423-430
• /
• 2022

Pressure-dependent elastic behavior and chemical reaction of natural sepiolite (Mg₈Si₁₂O₃₀(OH)₄·12H₂O) was studied under two different pressure-transmitting medium (PTM) conditions using synchrotron X-ray powder diffraction. Under non pore-penetrating silicone oil PTM, we observed that the b-axis length increases up to ca. 3.6 GPa, marking an anisotropic compression region with negative linear compressibility of β^b= -0.0012 GPa^-1, which then decreases at 7.7 GPa. Under pore-penetrating water PTM, the anisotropic compression behavior is enhanced with doubled negative linear compressibility of β^b= -0.0025 GPa^-1 up to 3.2 GPa, where transformation into stevensite is observed upon ex-situ temperature treatment at 280 ℃ as confirmed via XRD and SEM. Derived bulk moduli (K₀) and linear compressibilities (β) were compared to other structurally and chemically related minerals.

• The Journal of Korean Academy of Prosthodontics
• /
• v.61 no.1
• /
• pp.18-25
• /
• 2023

We present the case of a 65-year-old man with maxillary and mandibular complete dentures prepared using neutral zone technique after undergoing mandibulotomy due to tonsil cancer 10 years ago. The patient had a short edentulous period; hence, there was minimal absorption of the alveolar ridge and no abnormality in the motor function of the tongue. However, the retromolar pad was located inside the hamular notch, and the posterior alveolar ridge was relatively turned inward. If the artificial teeth would have been aligned conventionally, the functional space of the tongue would have been invaded, which would have moved the tongue posteriorly thereby reducing the stability of the denture. Therefore, applying the concept of the neutral zone can be a good reference point in such cases. The neutral zone was registered using tissue conditioner, and tooth alignment was performed by making a silicone putty index. The biggest advantage of using neutral zone concept is denture stability. In this case, the neutral zone technique was applied to obtain the lingual alignment limit of the posterior teeth to avoid invasion of the tongue space by the left posterior part of the mandible. Particularly, in case of a patient in which denture stability is difficult to obtain due to absorption of the alveolar ridge, it is believed that better results can be obtained using neutral zone technique.

• Journal of Industrial Convergence
• /
• v.20 no.12
• /
• pp.79-85
• /
• 2022

Recently, a smartphone manufactured on a flexible substrate has been released as an electronic device, and research on a stretchable electronic device is in progress. In this paper, a silicon-based stretchable material is made and used as a substrate to implement and evaluate an optical sensor device using oxide semiconductor. To this end, a substrate that stretches well at room temperature was made using a silicone-based solution rubber, and the elongation of 350% of the material was confirmed, and optical properties such as reflectivity, transmittance, and absorbance were measured. Next, since the surface of these materials is hydrophobic, oxygen-based plasma surface treatment was performed to clean the surface and change the surface to hydrophilicity. After depositing an AZO-based oxide film with vacuum equipment, an Ag electrode was formed using a cotton swab or a metal mast to complete the photosensor. The optoelectronic device analyzed the change in current according to the voltage when light was irradiated and when it was not, and the photocurrent caused by light was observed. In addition, the effect of the optical sensor according to the folding was additionally tested using a bending machine. In the future, we plan to intensively study folding (bending) and stretching optical devices by forming stretchable semiconductor materials and electrodes on stretchable substrates.