잠김 금속판을 이용한 경골 골절의 치료에 대한 임상적 경험 및 초기 결과

권영호,정구희,박영균 고신대학교의과대학 2008 고신대학교 의과대학 학술지 Vol.23 No.2

Background : By this study, we evaluated the efficacy of locking compression plate in the treatment of a fractured tibia. Materials and Methods : eighteen tibial fractures were treated by percutaneous plating with locking compression plate. They were composed of nine cases of proximal fracture, two cases of comminuted shaft fracture and seven cases of distal fracture. The results were retrospectively evaluated by the knee and ankle joint motion and walking ability. Results : All fractures were healed except one. The average time for fracture healing was 16.5 weeks(range, 8-24 weeks). Complications included a genu valgus case, but there was no complication of superficial or deep infection. All patients had the recovery of knee and ankle joint motion to the level of pre-injury and could walk without crutch. Conclusion : The locking compression plate(LCP) enables the minimally invasive percutaneous plating technique to fix the tibial fracture and can be selected for the tibial fixation, especially comminuted or metaphyseal fracture because the fixed angle stability of LCP is sufficient to maintain the fracture stability and early joint motion.

자가부식 프라이머 접착제의 적용방식이 법랑질의 결합강도에 미치는 영향

박재구,조권환,조영곤 大韓齒科保存學會 2008 Restorative Dentistry & Endodontics Vol.33 No.2

The purpose of this study was to evaluate the effect of passive or active application of primer and coat times of bond on the shear bond strength when a self-etching primer adhesive (Clearfil SE Bond) was applied to enamel surface. Crowns of sixteen human molars were selected. Buccal and lingual enamels of crowns were partially exposed and slabs of 1.2 mm thick were made. They were divided into one of four equal groups (n = 8). Group 1: passive application of Primer and 1 coat of Bond, Group 2: active application of Primer and 1 coat of Bond, Group 3: passive application of Primer and 2 coats of Bond, Group 4: active application of Primer and 2 coats of Bond. Clearfil AP-X was bonded to enamel suface of each group using Tygon tubes. The bonded specimens were subjected to microshear bond strength (uSBS) testing with a crosshead speed of 1 mm/min. The results of this study were as follows; 1. The uSBS of Group 1 was the lowest among groups and the uSBS of Group 4 was the highest. 2. There was not statistically significant interaction between enamel uSBS by application method of Primer and coat time of Bond (p > 0.05). 3. There was not statistically significant difference between enamel uSBS by passive and active application of Primer (p > 0.05). 4. There was statistically significant difference between enamel uSBS by one- and two-coat of Bond (p < 0.05). 이 연구는 Clearfil SE Bond를 거친 법랑질 표면에 적용할 때, 자가부식 프라이머의 적용방식 (능동적인 또는 수동적인)과 접착레진의 도포회수 (1회 또는 2회)가 법랑질의 결합강도에 미치는 영향을 알아보기 위하여 시행하였다. 16개의 발거된 대구치 치관의 협면이나 설면에서 법랑질 절편을 만들어 4개의 군으로 배정한 다음, 1군은 프라이머를 수동적으로 적용한 후 접착레진을 1회 도포하였고, 2군은 프라이머를 능동적으로 적용한 후 접착레진을 1회 도포하였고, 3군은 프라이머를 수동적으로 적용한 후 접착레진을 2회 도포하였고, 4군은 프라이머를 능동적으로 적용한 후 접착레진을 2회 도포하였다. 적용된 접착레진을 10초간 광조사한 후, 법랑질 표면에 2-3개의 Tygon tube를 위치시키고 Clearfil AP-X를 충전하고 40초간 광조사 하였다. Universal testing machine을 이용하여 법랑질 표면에서 복합레진이 파절될 까지 분당 1.0 mm의 cross-head speed로 전단하중을 가하고 통계적으로 분석하여 다음과 같은 결과를 얻었다. 거친 법랑질에 대한 Clearfil SE Bond의 미세전단 결합강도는 자가부식 프라이머의 적용방식 보다는 접착레진의 도포회수에 의해 증가할 수 있음을 알 수 있었다.

기질성 뇌장애 환자의 구조적 뇌영상과 비교한 저해상 전자기 단층 촬영 영상

이승환,권구형,박영민,김 현,이강준,정영조 大韓神經精神醫學會 2006 신경정신의학 Vol.45 No.3

Objectives : Patients with organic brain lesion can produce unique slow waves (delta and theta) in the EEG. Basic assumption of this study was that the low resolution electro magnetic tomography (LORETA), an inverse source localization program, can provide functional images representing increased slow wave activity in these patients compared to normal subjects. Methods : The current study was performed by 18 channels digital EEG for 10 patients whose organic deficit have been Visually confirmed by CT or MRI. The source images of slow wave (1-7 Hz) frequency were produced by LORETA-key program. Results : We found that in eight out of ten subjects, LORETA successfully found out the source regions which were very closely matched to their original brain lesions. However in two subjects whose organic brain lesions were too small (<1cm) and located out of gray matter, we failed to find any increased slow wave activity compared with normal control. Conclusion : We can conclude that LORETA could be a useful method to provide functional imaging in patients with gray matter deficits in their brain. Its usefulness and limitations were discussed.

전경대원에서 발생한 결핵의 임상 양상

문창기,박상준,조민구,김영중,김소연,김윤권,정준오,안석진,김은실,서승오,김지훈,최원제,이윤영,박형기,최규영,김현근 대한감염학회 2006 감염과 화학요법 Vol.38 No.6

Background: The purpose of this study was to document the incidence and clinical characteristics of patients with tuberculosis (TB) in combat and auxiliary police, living in a group, in Korea where the incidence rate of active TB in a general population is higher than in Western countries. Materials and Methods:We retrospectively reviewed the medical records of all tuberculosis patients diagnosed at National Police Hospital from January 2002 through December 2004. Results:In 2002-2004, a total of 156 cases of tuberculosis were identified with the mean (Standard deviation) age of 20.6 (±1.0) years. Of these, 134 (85.9%) patients were registered as new cases, 11 (7.1%) as relapse, 2 (1.3%) as failure, 5 (3.1%) as treatment-after-default cases whereas 4 (2.6 %) patients were not included in any categories. Average annual new TB rate and smear-positive TB rate were 86.5/10^(5) and 17.4/10^(5) person-years, respectively. In 12 of 31 smear-positive cases, time from onset of symptoms to diagnosis was more than 30 days. Two multidrug-resistance TB cases were identified and two suspected outbreak episodes of TB had occurred during 3 years. Conclusion:There was no statistically significant difference in the incidence rate of new cases of TB between the general population aged 20 to 29 years and combat and auxiliary police in Korea. 배경 : 국내 결핵의 발생은 감소 추세에 있으나 여전히 후진국형 발생양상을 보이고 있다. 특히 집단생활을 하는 젊은이들에서 발생하는 결핵의 유행이 간헐적으로 알려지고 있어 우려를 낳고 있다. 이에 저자들은 최근 전경대원의 결핵 발병 양상에 대해 알아보고자 본 연구를 시행하였다. 재료 및 방법 : 2002년 1월부터 2004년 12월까지 3년간 경찰병원에서 결핵 진료를 받은 전경대원의 의무기록을 후향적으로 분석하여 연도별 결핵 신환발생률, 도말양성결핵 신환율, 진단 지연, 집단발병, 다제내성결핵을 조사하였다. 결과 : 연도별 결핵 신환자 수(10만명당 발생추정치)는 2002년 50명(83.6명), 2003년 42명(83.7명), 2004년 42명(93.5명)이었고 도말양성 폐결핵 신환자 수는 2002년 10명(16.7명), 2003년 11명(21.9명), 2004년 6명(13.4명)이었다. 3년간 도말양성 폐결핵 환자는 31명이 있었고 그 중 12명은 호흡기 증상 발생 30일이 지나서 진단을 받았다. 다제내성 결핵은 2명이 있었으며 결핵의 집단발병이 의심되는 사례는 2차례 있었다. 결론 : 전경대원과 20-29세 연령군 일반인의 결핵 신환발생률, 도말양성 폐결핵 발생률의 통계적으로 유의한 차이는 없었다.

중부지역 옥수수 파종기에 따른 생육단계 및 수량성 변화

서종호, 문중경, 정건호, 서민정, 구자환, 박장환, 배환희, 신성휴, 권영업 忠北大學校 農業科學硏究所 2014 農業科學硏究 Vol.30 No.2

Maize hybrids were planted on April 1, April 25, May 20 and June 15 in 2012, 2013 at the experimental paddy and upland fields in Suwon city , respectively to know changes of growth stage and yield according to different planting time. Maize planting on April 1 was not recommended because total growing days at planting on April 1 was not different with that at planting on April 25 due to many days from planting to emergence over 20 days at planting on April 1. Total growing days were not much different among three planting time after April 25 because days from silking to maturity was lengthened though days from planting to silking was shortened at later planting time. Stalk weight was decreased as planting time was delayed, particularly at planting times after May 20 at paddy field by excess water injury during early growth stage. But, grain yield was not low as in May and June. It is needed to introduce early maturity maize variety as Yanganok at late planting for higher grain yield and enough time for soil preparation for next winter crops

Study on the nanofiberization of the giant miscanthus (Miscanthus sacchariflorus)

Gu Joong Kwon,Min Young Kim,Ji Wook Yang,Dae Young Kim,Seung Hwan Lee 강원대학교 산림과학연구소 2018 강원대학교 산림과학연구소 학술대회 Vol.2018 No.09

As an alternative biomass, the giant miscanthus was introduced for raising the bio industry in Korea. Unlike the expectations, however, its application has been limited due to its low economical value. To utilize it as a high added value material, in this study, the feasibility of nanofiber production from giant miscanthus holocellulose treated with delignification by peracetic acid method and their properties were investigated. The yield of the cellulose nanofiber produced by the acid hydrolysis method using sulfuric acid was calculated on the base of percentage of moisture content of the obtained suspension. As results, the yields were affected by sulfuric acid concentration, reaction time and temperature. The higher the reaction temperature, the smaller the length and width of the fiber were observed by TEM analysis. In addition, TEMPO oxidized giant miscanthus cellulose fiber treated with ball mill was shorter in fiber length than that of by homogenizer treatment. Moreover, the particle size was manufactured with uniform size with increase of the ball mill and homogenizer processing speed and time. In the FT-IR analysis, the carboxylation reaction of cellulose was confirmed. It was confirmed by X-ray diffraction analysis that the intensity of 002 was shifted after the ball mill and homogenizer treatment of TEMPO oxidized giant miscanthus cellulose.

Offline Fault Localization Technique on HVDC Submarine Cable via Time–Frequency Domain Reflectometry

Kwon, Gu-Young,Lee, Chun-Kwon,Lee, Geon Seok,Lee, Yeong Ho,Chang, Seung Jin,Jung, Chae-Kyun,Kang, Ji-Won,Shin, Yong-June Institute of Electrical and Electronics Engineers 2017 IEEE transactions on power delivery Vol.32 No.3

<P>Fault localization is one of the most significant aspects in the maintenance of high-voltage direct current (HVdc) submarine cables that have unconventional installation characteristics, such as long cable lengths and underwater installation locations. In order to protect and diagnose the cable, an improved fault localization technique, that is, time-frequency domain reflectometry (TFDR) and tangent distance pattern recognition are proposed in this paper. The fault location information of the HVdc submarine cables can be obtained from the tangent distance, to support the results of TFDR. To verify the performance of the proposed method, a commercial HVdc submarine cable is used in the experiments. A test bed is constructed for creating a similar environment with that of the submarine cable and filled with sea water. Both low-and high-impedance faults are emulated in this experiment by local insulation faults with iron, sea water, and air. The theoretical concepts and experimental results of the proposed method are presented. It is expected that the proposed method can improve the reliability of real-world HVdc power systems.</P>

Identification and Characterization of Clevudine-Resistant Mutants of Hepatitis B Virus Isolated from Chronic Hepatitis B Patients

Kwon, So Young,Park, Yong Kwang,Ahn, Sung Hyun,Cho, Eun Sook,Choe, Won Hyeok,Lee, Chang Hong,Kim, Byung Kook,Ko, Soon Young,Choi, Hyo Sun,Park, Eun-Sook,Shin, Gu Choul,Kim, Kyun-Hwan American Society for Microbiology 2010 Journal of virology Vol.84 No.9

<B>ABSTRACT</B><P>Clevudine (CLV) is a nucleoside analog with potent antiviral activity against chronic hepatitis B virus (HBV) infection. Viral resistance to CLV in patients receiving CLV therapy has not been reported. The aim of this study was to characterize CLV-resistant HBV in patients with viral breakthrough (BT) during long-term CLV therapy. The gene encoding HBV reverse transcriptase (RT) was analyzed from chronic hepatitis B patients with viral BT during CLV therapy. Sera collected from the patients at baseline and at the time of viral BT were studied. To characterize the mutations of HBV isolated from the patients, we subjected the HBV mutants to <I>in vitro</I> drug susceptibility assays. Several conserved mutations were identified in the RT domain during viral BT, with M204I being the most common. <I>In vitro</I> phenotypic analysis showed that the mutation M204I was predominantly associated with CLV resistance, whereas L229V was a compensatory mutation for the impaired replication of the M204I mutant. A quadruple mutant (L129M, V173L, M204I, and H337N) was identified that conferred greater replicative ability and strong resistance to both CLV and lamivudine. All of the CLV-resistant clones were lamivudine resistant. They were susceptible to adefovir, entecavir, and tenofovir, except for one mutant clone. In conclusion, the mutation M204I in HBV RT plays a major role in CLV resistance and leads to viral BT during long-term CLV treatment. Several conserved mutations may have a compensatory role in replication. Drug susceptibility assays reveal that adefovir and tenofovir are the most effective compounds against CLV-resistant mutants. These data may provide additional therapeutic options for CLV-resistant patients.</P>

Diagnosis of Shielded Cable Faults via Regression-Based Reflectometry

Kwon, Gu-Young,Lee, Chun-Kwon,Shin, Yong-June Institute of Electrical and Electronics Engineers 2019 IEEE transactions on industrial electronics Vol.66 No.3

<P>Fault diagnosis has been studied actively across the electrical industry to help maintain the stability of electrical equipment. Among this equipment, shielded cables, which are widely used in various industrial sectors, require careful and periodic diagnosis, owing to their poor installation environments and potential for creating huge economic losses. Reflectometry is a representative solution to locate the cable faults. However, conventional reflectometry techniques require prior knowledge about the cable under test, such as the reference wave velocity, total length of the cable, etc. Moreover, the degree of failure cannot be determined using conventional methods. In this paper, a novel reflectometry technique is proposed to locate and evaluate the faults in a cable, without requiring any prior knowledge. A general regression neural network based on the kernel density estimation is utilized with special feature extraction procedures. The proposed method is tested in an actual test bed with two types of emulated faults, and is found to estimate both the fault location and reflection coefficient successfully. It is expected that the proposed method can improve the stability of industrial equipment.</P>

Synthesis and electroluminescence of blue fluorescent diarylaminofluorene derivatives for organic light-emitting diodes.

Kwon, Young Soo,Lee, Kum Hee,Young Kim, Gu,Seo, Ji Hoon,Kim, Young Kwan,Yoont, Seung Soo American Scientific Publishers 2009 Journal of Nanoscience and Nanotechnology Vol.9 No.12

<P>A series of seven diarylaminofluorene-derived fluorescent molecules demonstrating a blue emission in organic light-emitting diodes (OLEDs) were synthesized via the Horner-Wadsworth-Emmons reaction and the Suzuki-cross coupling reaction. Among the molecules, one device exhibited blue emission with a maximum luminance of 28900 cd/m2 at 12 V. A luminous efficiency of 11.5 cd/A at 20 mA/cm2 was achieved. The peak wavelength of the electroluminescence (EL) was 459.5 nm with the CIE coordinates of (x = 0.173, y = 0.281) at 8 V. The device also showed a stable color chromaticity at various voltages.</P>