• Title/Summary/Keyword: 510(k)

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STUDY ON THE ANATOMICAL POSITION OF MANDIBULAR CANAL USING COMPUTED TOMOGRAPHY IN MANDIBULAR PROGNATHISM PATIENTS (하악 전돌증 환자에서 전산화 단층 촬영을 이용한 하악관의 해부학적 위치에 관한 연구)

  • Lee, Dong-Hyun;Kim, Jae-Won;Lee, Su-Youn;Kim, Jae-Hyun;An, Sang-Heon;Lee, Sang-Han;Jang, Hyun-Jung
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.31 no.6
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    • pp.510-518
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    • 2009
  • Purpose: In this study, we analyzed and compared the anatomical position of the mandibular canal in normal occlusion and mandibular prognathism patients. Patients and Methods: Computed tomography image from 58 patients were divided into normal occlusion group and mandibular prognathism group, and each measurement were taken in the each measuring points(2nd premolar, 1st molar, 2nd molar, 3rd molar, ramus). Measurements were statistically analyzed by student's t-test. Results: BC (Thickness of the buccal cortex) value was 2.3~2.7 mm, CB (Distance from the canal to the lingual aspect of the buccal cortex) value was 1.3~4.3 mm, MC (Diameter of the canal) value was 3.2~3.8 mm, LI (Distance from the canal to the lingual aspect of the lingual cortex) value was 2.0~3.7 mm, TM (Thickness of the total mandible) value was 9.5~12.9 mm and CM (Distance from the canal to the inferior border of the mandible) value was 6.9~17.5 mm. Conclusion: In the comparison between two groups, there was statistically significant difference in CB value of 2nd, 3rd molar between normal occlusion and mandibular prognathism, and other value in the rest of the measuring points didn't show statistically significant difference.

Synthesis of $TiO_2$ Powders by the Hydrolysis of Titanium n-Butoxide and Reaction Mechanism (Titanium n-Butoxide의 가수분해에 의한 $TiO_2$ 분말 합성과 반응 메커니즘)

  • Park, J.K.;Myung, J.J.;Chung, Y.S.;Kyong, J.B.;Kim, H.K.
    • Journal of the Korean Chemical Society
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    • v.43 no.5
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    • pp.505-510
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    • 1999
  • $TiO_2$ powders were prepared via hydrolysis of titanium n-butoxide in n-butanol and hydrolysis mechanism of titanium n-butoxide was studied using UV-Vis spectrometer. Hydrolysis reactions were controlled to proceed to pseudo-first order reaction in the presence of excess water. The phases of $TiO_2$ powders, prepared under the these conditions, were identified by XRD and reaction rates were calculated by Gugggenheim method. Prepared powders were noncrystalline states in their initial stage of formation but transformed to crystalline rutile structure by heating. Reaction mechanism of titanium n-butoxide was proposed as Interchange-Associative(Ia) mechanism, based on the data of n-value and termodynamic parameters which were determined from the rate constants.

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Inhibitory Effect of Fritillaria Verticillata Willd. var. Thunbergii Bak Ethanol Extract on Melanin Biosynthesis (절패모(浙貝母) 에탄올 추출물의 멜라닌 생성 억제 효과)

  • Ha, Tae-Kwang;Lee, Boo-Kyun;Yoon, Jeong-Rock;Mun, Yeun-Ja;Woo, Won-Hong;Park, Seong-Ha;Lee, Jang-Cheon
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.25 no.3
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    • pp.510-515
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    • 2011
  • This study was conducted to evaluate the depigmenting properties of ethanol extract from a Fritillaria verticillata Willd. (EFV) in B16F10 cells. Fritillaria verticillata Willd., a perennial herbaceous plant, has been used as a stimulator of mammary gland, expectorant, blood pressure depressant, antitussive agents in Korean herbal medicine. In the present study, we observed that melanin synthesis of B16F10 cells were significantly decreased by EFV without cytotoxicity. However, EFV could not suppress tyrosinase activity in B16F10 cells and mushroom tyrosinase activity. Furthermore, EFV did not effect the protein expression of tyrosinase, tyrosinase-related protein -1 (TRP-1), and TRP-2. These results suggest that EFV inhibited melanin synthesis and the hypopigmentary effect of EVF was not due to regulation of tyrosinase protein.

Detection and Characterization of Enteroviral RNA in Paraffin-embedded Heart Tissues from Patients with Dilated Cardiomyopathy

  • Chung, Kyung-Won;Nam, Jung-Hyun;Lee, Ho-Jung;Hong, Hae-Nam;Cho, Young-Keol;Chu, Chul-Hyun;Kim, Yoo-Kyum
    • The Journal of Korean Society of Virology
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    • v.30 no.1
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    • pp.29-37
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    • 2000
  • The aim of this study was to investigate viral etiology in dilated cardiomyopathy (DCM) by polymerase chain reaction (PCR) or nested reverse transcription PCR (RT-PCR), and characterize the enteroviral RNA presented in the clinical specimens. Twenty-eight paraffin-embedded heart tissue samples were assayed to detect cytomegalovirus, herpes simplex virus type 1, type 2, parvovirus, adenovirus, and enterovirus (EV) with each specific primer. Of these 28 patients (mean age: 27, M: 24, F: 4), 26 were histologically diagnosed as DCM and 2 as myocardial infarction (MI). Nested RT-PCR detected enteroviral RNA in 7 (26.9%) of 26 patients with DCM, and none of patients with MI. And none of DNA viruses tested were detected from the samples. Amplified products were also genotyped by single-strand conformation polymorphism (SSCP). Three subtypes can be differentiated from 7 clinical specimens. Furthermore, direct sequence analysis was performed to determine whether genetic variation of EV is present in the explanted heart tissues from patients with DCM. Although most of the sequences among the wild isolates have the greatest similarity to those of coxsackievirus B3, there are specific regions of variable sequences (no 490 - no 510). The data suggest that enterovirus may be a major viral pathogen for the DCM in Korea and nucleotide sequence data indicate that coxsackievirus B3 may be a leading etiologic agent of DCM.

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Flora of Vascular Plants in Deokjeokdo (Ongjin-gun) and Its Adjacent Regions, Korea (덕적도(옹진군) 및 인근 도서지역의 관속식물상)

  • Kim, Hyun-Jun;Ji, Seong-Jin;Jung, Su-Young;Park, Su Hyun;Lee, Sle-Gee;Lee, Chan-Woo;Chang, Kae Sun
    • Korean Journal of Plant Resources
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    • v.28 no.4
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    • pp.487-510
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    • 2015
  • This study was carried out to inventory the vascular plant flora in Deokjeokdo and its adjacent regions (Mungapdo, Soyado), Ongjin-gun, South Korea, from April to October 2014. Based on the voucher specimens, vascular plants in this area consisted of 108 families, 362 genera, 578 species, 5 subspecies, 66 varieties and 4 forms, totally 653 taxa. In the flora of this area, 5 taxa of Korean endemic plants were found distributed in the sites, including Hepatica insularis Nakai and Asarum glabrata (C.S.Yook & J.G.Kim) B.U.Oh. Korean rare and endangered plants found in this area were 1 taxa of Critical Endangered Species (CR) and 5 taxa of Vulnerable Species (VU). The floristic regional indicator plants found in this area were 67 taxa comprising 3 taxa of grade V, 2 taxa of grade IV, 12 taxa of grade III, 3 taxa of grade II and 47 taxa of grade I. Naturalized plants consisted of 67 taxa, such as Chenopodium album L. and Erigeron annuus (L.) Pers. were recognized widely distributed in the area.

Efficient Multicasting Mechanism for Mobile Computing Environment (AC Direct IC를 이용한 25W급 LED 조명기 설계에 관한 연구)

  • Jeong, Jae-hoon;Gam, Ji-hyeon;Jo, So-hyeon;Woo, Joo;Kim, Min;Kim, Gwan hyeong;Lee, Sung-min;Byun, Gi-sig
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2017.10a
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    • pp.510-511
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    • 2017
  • In this paper, we have studied to minimize the lifetime and fault occurrence of LED fixtures, which have a short lifetime and frequent faults. In the current LED chip, the lifetime is semi-permanent, but compared to the lifetime of the LED chip, Drivers do not last long. In recent years, low-priced LED illuminators such as those from China have entered the market, and many consumers are perceiving LED illuminators. In order to solve these problems, we designed an LED illuminator of 25W class by using AC Direct IC, which has a longer lifetime than the conventional driver, by removing the electrolytic capacitor in the LED driving driver which is the cause of the failure.

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Population Structure and Genetic Diversity of Garlic in Korea by ISSR Marker (산마늘의 지역적 변이와 종다양성 연구)

  • Huh Man-Kyu;Sung Jung-Sook;Choi Joo-Soo;Jeong Young-Kee;Rhu Eun-Ju;Chung Kyung-Tae
    • Journal of Life Science
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    • v.16 no.2 s.75
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    • pp.253-258
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    • 2006
  • Garlic is a perennial herb primarily distributed throughout the world. These plants are regarded as a medically and agricultural important crop in the world. The genetic relationships between cultivated and wild species were investigated at the population levels by constructing tree based on ISSR (inter-simple sequence repeats) markers. In addition, ISSR analysis was also conducted to estimate genetic diversity and population structure of these species. Three wild garlic populations in Korea were found to have more alleles per locus (mean 1.672 vs. 1.510) higher percent polymorphic locus (67.2 vs. 51.0), and higher diversity (0.250 vs. 0.198) than three cultivated populations. The cultivated and wild species in Korea are well separated from each other at phylogenetic trees. Although there is not direct evidence that A. victorialis is an ancestor of Korean A. sativum, there is a possibility that cultivated A. sativum in Korea has evolved from wild A. victorialis in Korea. Populations of A. victorialis may be useful in germ-plasm classification and evolutionary process.

Root Yields and Saikosaponin Contents Depending on Planting Time and Cultivated Regions of Bupleurum falcatum L.

  • Kim, Choon-Shik;Seong, Jae-Duck;Park, Chung-Heon;Park, Chun-Gun;Cho, Yang-Hee;Kwak, Jun-Soo
    • Korean Journal of Medicinal Crop Science
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    • v.13 no.5
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    • pp.298-302
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    • 2005
  • In order to decide the optimum planting time for Bupleurum falcatum L. which is grown widely in Korea, some experiments were carried out in different regions such as mid-north area (Gangwon-do, Gyeonggi-do and Chungcheongnamdo), mid-south area (Jeollanam-do, Jeollabuk-do, Gyeongsangnam-do and Gyeongsangbuk-do). The mid-south area had the highest total saikosaponin contents of 1.001, which is the medicinal ingredients of Bupleurum falcatum L., in accordance with the different Bupleurum falcatum L. regions. Also this area has the highest extract contents of 24.3%. Average dry root yields in mid-north area (Gangwon-do) were $450{\sim}460$ kg/ha at planting time of March 20th to March 30th, 500 kg/ha at the time of March 30th to April 10th, and $470{\sim}480$ kg/ha at the time of March 10th to March 20th in Chungcheongnam-do. The optimum planting time in the mid-south area (Jeollabuk-do) was March 10th to March 30th with the average dry root yield of $490{\sim}550$ kg/ha. Average dry root yield in Euiseong, Gyeongsangbuk-do area was 470 kg/ha, and the optimum planting time was April 10th, which suggested that the yield increased as the planting time was delayed. At Jeju-do, the volcanic soil of farsouthern area, average dry root yield was 510 kg/ha at the time of March 10th, but the yield from non-volcanic soil was lower than from volcanic soil, which had a dry root yield of 470 kg/ha.

Application of Polycarbonate Diol Prepared with Carbon Dioxide in the Field of Waterborne Polyurethane (이산화탄소를 이용하여 제조된 폴리카보네이트 디올의 수분산 폴리우레탄에 응용)

  • Lim, Jae-Woo;Oh, Hyoung-Jin;Kim, Young-Jo;Jeong, Kwang-Eun;Yim, Jin-Heong;Ko, Young-Soo
    • Polymer(Korea)
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    • v.34 no.6
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    • pp.507-510
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    • 2010
  • Poly(cyclohexane carbonate) diol was synthesized by the alternating copolymerization of cyclohexene oxide and $CO_2$ over Cr based transition metal catalysts. The prepared PCCD was applied as a precursor for the preparation of waterborne polyurethane (PUD) in order to investigate an application field of carbon dioxide-based polycarbonate. The scratch resistance and thermal properties of PUDs, which was prepared with two kinds of polymeric diols (PCD and PCCD) were investigated. The scratch resistance and thermal decomposition temperature of PUD film prepared with PCCD is worse than those prepared with PCD, poly(hexamethylene carbonate) glycol. While, glass transition temperature of PUD film prepared with PCCD was higher than that prepared with PCD. It might be due to the rigid cyclohexane structure in the PCCD.

Effect of Pulsed Radiofrequency Neuromodulation on Clinical Improvements in the Patients of Chronic Intractable Shoulder Pain

  • Jang, Ji Su;Choi, Hyuk Jai;Kang, Suk Hyung;Yang, Jin Seo;Lee, Jae Jun;Hwang, Sung Mi
    • Journal of Korean Neurosurgical Society
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    • v.54 no.6
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    • pp.507-510
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    • 2013
  • Objective : The aim of this study was to evaluate effect of pulsed radiofrequency (PRF) neuromodulation of suprascpaular nerve (SSN) in patients with chronic shoulder pain due to adhesive capsulitis and/or rotator cuff tear. Methods : The study included 11 patients suffering from chronic shoulder pain for at least 6 months who were diagnosed with adhesive capsulitis (n=4), rotator cuff tear (n=5), or adhesive capsulitis+rotator cuff tear (n=2) using shoulder magnetic resonance imaging or extremity ultrasonography. After a favorable response to a diagnostic suprascapular nerve block twice a week (pain improvement >50%), PRF neuromodulation was performed. Shoulder pain and quality of life were assessed using a Visual Analogue Scale (VAS) and the Oxford Shoulder Score (OSS) before the diagnostic block and every month after PRF neuromodulation over a 9-month period. Results : The mean VAS score of 11 patients before PRF was $6.4{\pm}1.49$, and the scores at 6-month and 9 month follow-up were $1.0{\pm}0.73$ and $1.5{\pm}1.23$, respectively. A significant pain reduction (p<0.001) was observed. The mean OSS score of 11 patients before PRF was $22.7{\pm}8.1$, and the scores at 6-month and 9 month follow-up were $41.5{\pm}6.65$ and $41.0{\pm}6.67$, respectively. A significant OSS improvement (p<0.001) was observed. Conclusion : PRF neuromodulation of the suprascapular nerve is an effective treatment for chronic shoulder pain, and the effect was sustained over a relatively long period in patients with medically intractable shoulder pain.