• The Journal of the Acoustical Society of Korea
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• v.34 no.4
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• pp.288-294
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• 2015

The fiber optic Sagnac interferometer is well established as a sensor for detection of physical perturbations such as acoustic and vibration. In this paper acoustic signals generated in the cylindrical cavity submerged in transformer oil were measured by the fiber optic sensor array in one Sagnac loop. Two different external sound frequencies, $f_1$ and $f_2$, were applied to the sensor array simultaneously by using piezoelectric with frequency range from 5 kHz to 90 kHz. Based on the experimental results, fiber optic sensor detected harmonic series of applied sound frequency such as $f_1$, $f_2$, $2f_1$, $2f_2$, ${\mid}f_1-f_2{\mid}$, ${\mid}f_1+f_2{\mid}$. Suggested fiber optic sensor array can be applied to monitor physical quantities such as internal sound pressure and vibration due to partial discharge in the real electric transformer system.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.1
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• pp.134-145
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• 2021

In the case of excessively worn dentition, there is often insufficient space for the prosthesis, and if physiologically acceptable, the prosthesis can be fabricated by increasing the vertical dimension of occlusion. Various methods have been introduced to determine the vertical dimension of occlusion. Clinicians have to choose a method that can comfort the patient among several methods. A removable appliance can be used as a reversible method to ensure that the determined vertical dimension of occlusion does not cause physiological problems. When making impressions of many teeth, it is often difficult to make accurate impressions at once. In this case, after making an accurate impression of the individual teeth, a transfer coping was made and a pickup impression was taken in the oral cavity to create a master cast. In this case, a fixed partial denture was fabricated and full mouth rehabilitation was performed by increasing the vertical dimension of occlusion in a patient with excessively worn dentition and lack of space for restoration. As a result of follow-up of the patient for 7 years, satisfactory results were obtained both esthetically and functionally.

• Journal of the Korean Society of Radiology
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• v.82 no.3
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• pp.749-755
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• 2021

Congenital defects of the pericardium, which are generally asymptomatic, are rare disorders characterized by complete or partial absence of the pericardium. Here, we report a rare case of a 19-year-old male who was incidentally diagnosed with congenital absence of the left pericardium during examination for symptoms of pneumothorax. Chest radiography and CT revealed a collapsed left lung without any evidence of trauma, no unusual findings of free air spaces along the right side of the ascending aorta, heart shifted toward the left side of the thorax, and a shallow chest. Subsequent thoracoscopy confirmed the absence of the left pericardium and displacement of the heart toward the left thoracic cavity. We further discuss the correlation between radiologic images and surgical findings of a congenital pericardial defect associated with spontaneous pneumothorax.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.2
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• pp.344-356
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• 2005

There are normal inhabitants doing medically useful functions in the body. There are many kinds of bacteria performing specific functions in the oral cavity. Two strains of lactic acid bacteria were isolated from inhabitants of caries-free children's oral cavity, which inhibited the formation of artificial plaque by Streptococcus mutans and the production of volatile sulfur compounds by anaerobic bacteria. The isolates were identified by the test using API 50 CHL medium kit and 16S rDNA partial sequencing. 1. Two isolates were Gram-positive bacilli and produced hydrogen peroxide. 2. When Streptococcus mutans was cultured in the media, the mean weight of formed artificial plaque on the orthodontic wires was $124.4{\pm}30.4\;mg$, whereas being reduced to $5.2{\pm}2.0mg$ and $10.6{\pm}6.6mg$ in the media cultured with Streptococcus mutans and each isolate, respectively (p<0.05) 3. The number of viable cells of Streptococcus mutans was $3.4{\times}10^9$ per ml in the cultured solution, whereas those of Streptococcus mutans in the combined culture with each of isolates were $4.6{\times}10^8\;and\;2.4{\times}10^8$ per ml. 4. The optical density was 1.286 in the supernatant of Fusobacterium nucleatum after vortexing for 30minutes, whereas in the supernatant of combined Fusobacterium nucleatum and each isolate, they were reduced to 0.628 and 0.497, which the percentages of coaggregation between them were 29.4% and 57.8%, respectively 5. The optical density of Fusobacterium nucleatum precipitate was 1.794 in the culture media containing cysteine and $FeSO_4$, being reduced to 1.144 and 0.915 in the coaggregated precipitates of Fusobacterium nucleatum and each isolate. The optical density of Porphyromonas gingivalis precipitate was 1.932 in the culture media, being reduced to 1.170 and 1.266 in the coaggregated precipitates of Porphyromonas gingivalis and each isolate. 6. When two isolates were tested with API 50 CHL medium kit, those were identified Lactobaciallius salivarius and Lactobaciallius delbrueckii subsp. lactis. 7. The similarity values of 16S rDNA sequence between each of isolates and Lactobaciallius salivarius subsp. salicinius were 99.60% and 99.73%, respectively, meaning that isolates were Lactobaciallius salivarius subsp. salicinius. These results indicated that two strains isolated from caries-free children's saliva, which inhibited the formation of artificial plaque and the production of volatile sulfur compounds, were identified as Lactobaciallius salivarius subsp. salicinius.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1979.05a
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• pp.4.4-5
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• 1979

The degree of hearing impairment of chronic otitis media will indicate the nature and severity of middle ear pathology especially condition of ossicular chain, size of ear drum perforation and location of granulation tissue in the middle ear cavity. The subjects were 189 ears of tympanoplasty for chronic otitis media and divided into four groups as follows: Normal ossicular chain with only ear drum perforation (group I), normal ossicular chain with granulation tissue only around the ossicles regardless of any other region (group II), ossicular ankylosis or fixation of handle of malleus to promontory with or without granulation tissue around the ossicle (group III) and ossicular interruption by partial or complete destruction(groupf IV). The results were concluded as follows: 1) The average hearing threshold of chronic otitis media was 44.6 dB and hearing threshold was closely related to the condition of ossicular chain. Hearing threshold became greater in order of normal ossicular chain, ankylosis and interruption. 2) The average hearing threshold of ossicular interrupted group was 49.1 dB and it was greater in the cases of total destruction than that of partial destruction. 3) The hearing loss in the cases of normal ossicular chain with only tympanic membrane perforation was within 45 dB and this level was presumed to represent normal ossicular function. The degree of hearing loss was in proportion to the size of ear drum perforation and when over 45 dB, other middle ear pathology was suggested. 4) In the cases of small ear drum perforation with normal ossicular function, the hearing threshold was within 30 dB. 5) In the type of audiogram, flat type was 30.2% and ascending type 35.4%. Descending type was more frequent in the cases of normal ossicular mobility with granulation tissue around the ossicle and flat type was observed frequently in the cases of ossicular ankylosis. 6) Carhart's notch was seen in 14 cases (7.4%) and observed mainly in ossicular ankylosis. 7) There was no relation between hearing threshold and histopathological type of granulation tissue in chronic otitis media. However the degree of hearing impairment was related to the location of granulation tissue in the middle ear cavity. 8) Authors recognized the granulation tissue compensated the function of interrupted ossicular chain.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.3
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• pp.473-480
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• 2007

The dentigerous cyst originates through alteration of stellate reticulum after amelogenesis has completed, with accumulation of fluid between the layers of the reduced enamel epithelium or between this epithelium and the tooth crown. Its incidence is relatively high on 10s or 20s of age and it is always related to the unerupted crown. Generally, it has no symptom, however, if the cyst is large or accompanied with pus formation, swelling and pain may occur. In radiographic findings, it shows impacted crown surrounded by well defined unilocular radiolucent lesion and occasionally displacement of adjacent teeth or root resorption. The goal of treatment is complete elimination of abnormal tissue preserving the tooth involved in the cyst. Enucleation and marsupialization are commonly used for the treatment. Marsupialization is the procedure which removes the partial portion of the cystic wall and connects with the oral mucosa. As the pressure in the cyst decreases, bone regeneration takes place in the defect area and cystic wall converts into normal mucosa. This procedure, however, is the most conservative procedure which allows the protection of adjacent important structures. If the eruption space is sufficient, then inducing the eruption of the permanent tooth in the cyst is also possible. In following cases, dentigerous cyst was diaganosed after clinical and radiographic examination. Marsupialazation was done to remove the cyst and induce the tooth, which was in the cyst, to erupt into the oral cavity.

• Journal of the Mineralogical Society of Korea
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• v.29 no.2
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• pp.47-58
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• 2016

The Fe-component of pyrophyllite is an impurity that reduces its grade in the final product. In order to identify the amount of impurity in pyrophyllite and to remove the Fe from the ore using a dry method, microwave heating and magnetic separation were carried out. Pyrite and hematite were identified to contain pyrophyllite by microscopy, XRD, XRF, SEM/EDS and EPMA analysis. It is suggested that the euhedral pyrite in the pyrophyllite is formed by hydrothermal solution, and then the dissolution cavity structure is formed with a partial remainder of the pyrite which dissolved in acidic water. And the $Fe^{3+}$ ion contained in the acidic water precipitated out in the concentric structure of hematite as the origin of sedimentary structure. As a result of the microwave heating and magnetic separation experiments, the Fe removal rates obtained were 96% and 93% from pyrophyllite ore from the Sunsan mine and Wando mine, respectively. It is confirmed that the microwave heating and magnetic separation method was an environmentally friendly method to upgrade the low-grade pyrophyllite.

• Tuberculosis and Respiratory Diseases
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• v.56 no.2
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• pp.216-220
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• 2004

Because a cavitary pulmonary metastasis is rare, it may not be readily identified. However, various types of cancers can metastasize to the lung in the form of cavities. We report a case of a multiple cavitary metastases to the lung from a cholangiocarcinoma in a 60-year-old man. He complained of generalized weakness and a poor oral intake for 2 months. The plain chest radiography and the chest computed tomography showed multiple small thick-walled cavities and nodules the both lungs. A bronchoscopic examination revealed a focal irregularly elevated surface of the mucosa at the orifice of the superior segment of the right lower lobe and the biopsy demonstrated an infiltrative metastatic adenocarcinoma. The abdomen-pelvis computed tomography showed an ill-marginated and irregularly low-dense area in the right lobe of the liver and a diffuse dilatation of the peripheral intrahepatic bile ducts. The esophagogastroscopy and colonoscopy showed no abnormal findings. It was concluded that the cholangiocarcinoma of the liver metastasized to the lung in the form of cavities. Thereafter, the patient underwent six cycles of the systemic chemotherapy with gemcitabine and cisplatin, and the follow-up imaging studies showed a partial response.

• Restorative Dentistry and Endodontics
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• v.25 no.4
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• pp.575-586
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• 2000

In this study, adaptation of compomer to saliva contaminated dentin was evaluated with scanning electron microscope(SEM) and confocal laser scanning microscope(CLSM). For the SEM study, the occulusal surfaces of thirty two molar teeth were grounded to exposure dentin surfaces. The specimen were randomly assigned to control and three experimental groups with four samples in each group. In control group, Dyract and F-2000 compomer were bonded on the specimens according to the manufactures direction. Experimental groups were subdivided into three groups. They were contaminated with saliva on dentin surfaces ; Experimental group 1 : Saliva was dried with compressed air. Experimental group 2 : Saliva was rinsed with air-water spray and dried. Experimental group 3 : After polymerization of an adhesive, they were contaminated with saliva, and then saliva was rinsed with air-water spray and dried. Dyract and F-2000 compomer were bonded on saliva-treated dentin surfaces. The interfaces between dentin and compomer were observed with SEM. For the CLSM study, Class V cavities were prepared in buccal and ligual surfacess of thirty two molars. The specimens were divided into control and experimental groups. Class V cavities in experimental group were contaminated with saliva and those surfaces in each experimental groups received the same treatments as for the SEM study. Cavities were applied Prime & Bond 2.1 and F-2000 compomer primer/adhesive that were mixed with fluorescein, and then were filled with Dyract and F-2000 compomer. Specimens were embedded in transparent acrylic resin and sectioned buccolingual1y with diamond wheel saw, and then mounted on cover slide for CLSM study. The interface between cavity and compomer was observed by fluoresence imaging with a CLSM. The results were as follows : 1. In SEM exammination of Dyract group, control group, experimental group 2, 3 showed close adaptation to dentin and hybrid layer of $3{\sim}4{\mu}m$ diameter. Interfacial gap between compomer and dentin in experimental group 1 was wider than in control group. 2. In SEM examination of F-2000 group, adaptation to dentin of control group was closer than Dytact control group, but hybrid-like layer was not observed. Interfacial gap between compomer and dentin in experimental group 1 was wider than in Dyract experimental group 1. 3. In dissolution specimens of Dyract and F-2000 group, resin tags penetrated through dentinal tubules in control group and experimental group 1 and 3, but the penetration of resin tag was irregular and partial in experimental group 1. 4. In CLSM exammination of Dyract and F-2000 group, adhesive patterns of control and experimental groups showed same as in SEM. This result suggests the treatment methods, rinsing & drying, repeating all adhesive procedures, will produce good effect on adaptation of compomer to dentin if the dentin surface or polymerized adhesive is contaminated by saliva.

• The Journal of Pediatrics of Korean Medicine
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• v.13 no.2
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• pp.187-224
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• 1999

Background: In recent years, pediatric chronic sinusitis patients who don't respond with antibiotics are increasing, but there are a few reports on the herbal medicine therapy treating pediatric chronic sinusitis, so this report was studied. Objective: To demonstrate the effect of herbal medicine therapy in the chronic sinusitis before and after treatment using computed tomograpy (CT) and plain radiograpy. Materials and methods: Ninty patients (45 mail and 45 femail) treated in our hospital between February 1998 and August 1999 were studied. Ages ranged from 3 to 13 years (mean age :6.5 years). Sixty two patients had a underlyiing family history (allergy or sinusitis of parents or brothers), In the past history, 68 patients had asthma, allergy of milk, atopic dermatitis, bronchiollitis and irritable bowel syndrom. Illness period was from 10 days to 96 months (mean period:12.4 month). Duration of treatment were from 25 days to 200days (mean:96 days). To ascertain the efficacy of treatment, CT in the 42 and plain radiopgrapy in the 48 patients were checked out. In the CT, three images were obtained 2cm interval on the coronal and axial plan. CT findings of the chronic sinusitis were analyzed for mucoperiostal thickening before and after treatment using 4 grades;(normal, mild, moderate, severe). Normal was defined as below 3mm thickening of mucoperiosteum; mild was 3-5mm thickening; moderate was 5mm-1cm thickening; severe was above 1cm thickening. Plain radiograpy using Water's view provided maxillary sinus, anterior ethmoid sinus, frontal sinus. Normal was defined as simillar to density between sinus and oronasal cavity; mild was defined as generally increased density with no significant mucoperiosteal thickning; moderate was partial mucosal thickening without bony hypertropy; severe was total haziness with mucoperiosteal thickening. Gamihyunggyeyungyo-tang was administered mainly. Gamigwaghyangjeungki-san, Gamizwakwi-eum and Gamihyangso-san were administered for through oral route additional symptoms Results: Of the 90 patients, 84 patients showed complete recovery (93%), 4 patients showed no significant interval change(4%) and 2 patients were aggrevated (2%). Sixty patients were severe(67%) and 26 patients were moderate (29%), 4 patients were mild(4%) The duration of treatment was varied with patient conditions (91 days in average); severe were 101.7 days, moderate were 70 days and mild were 63 days. Fifty three patients with maxillary and ethmoid sinusitis were 114 days, 35 patients with maxillary sinusitis only were 71.5 days. Fifty eight patients with both maxillary sinusitis were 94.6 days, 26 patients with either maxillary sinusitis were 65 days. The symtoms of chronic sinusitis were nasal obstruction(75%), cough(69%), purulunt or mucosal discharge(62%), lymphoid follicle(54%), postnasal dripping(49%), headache(23%) and nose bleeding(22%). Conclusion: We know that herbal medicine therapy is the effective treatment of pediatric chronic sinusitis using plain radiograpy and CT. The duration of treatment may be significant assosiation with the location and degree of chronic sinusitis.