• 한국재료학회지
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• 제23권3호
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• pp.155-160
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• 2013

ZnO thin films co-doped with Mg and Ga (MxGyZzO, x + y + z = 1, x = 0.05, y = 0.02 and z = 0.93) were prepared on glass substrates by RF magnetron sputtering with different sputtering powers ranging from 100W to 200W at a substrate temperature of $350^{\circ}C$. The effects of the sputtering power on the structural, morphological, electrical, and optical properties of MGZO thin films were investigated. The X-ray diffraction patterns showed that all the MGZO thin films were grown as a hexagonal wurtzite phase with the preferred orientation on the c-axis without secondary phases such as MgO, $Ga_2O_3$, or $ZnGa_2O_4$. The intensity of the diffraction peak from the (0002) plane of the MGZO thin films was enhanced as the sputtering power increased. The (0002) peak positions of the MGZO thin films was shifted toward, a high diffraction angle as the sputtering power increased. Cross-sectional field emission scanning electron microscopy images of the MGZO thin films showed that all of these films had a columnar structure and their thickness increased with an increase in the sputtering power. MGZO thin film deposited at the sputtering power of 200W showed the best electrical characteristics in terms of the carrier concentration ($4.71{\times}10^{20}cm^{-3}$), charge carrier mobility ($10.2cm^2V^{-1}s^{-1}$) and a minimum resistivity ($1.3{\times}10^{-3}{\Omega}cm$). A UV-visible spectroscopy assessment showed that the MGZO thin films had high transmittance of more than 80 % in the visible region and that the absorption edges of MGZO thin films were very sharp and shifted toward the higher wavelength side, from 270 nm to 340 nm, with an increase in the sputtering power. The band-gap energy of MGZO thin films was widened from 3.74 eV to 3.92 eV with the change in the sputtering power.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제29권4호
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• pp.245-248
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• 2003

The retraction of anterior teeth could be performed more easier by inducing of skeletal anchorage system rather than by conventional method on orthodontic treatment. But, we wonder how effective the system draws well without anchorage loss and draws anterior teeth aside posteriorly, and if the system can reduce the time, in comparison with the anchorage of posterior teeth. For that reason we have studied on the subject of patients, who were required the maximum anchorage on orthodontic treatment and the cases without crowding. The subjects of the experimental group are 35 areas of 20 people who were inserted miniscrews after Mx or Mn 1st premolar extracted. Also, the subjects of the control group are 81 areas of 45 people who were not inserted miniscrews. Compared the anchorage loss of experimental group with control one, we could get the result that the anchorage loss of experimental group is $1.034{\pm}0.891mm$ and control group is $2.790{\pm}1.882mm$(P<0.01). Compared the space closing time of experimental group with control one, we could get the result that the space closing time of experimental group is $369.40{\pm}110.81$days and control group is $406.56{\pm}231.63$days. But the result of comparing space closing time has no significance in statistics. We recognized that the experimental group is more faster than the control group in the canine retraction velocity from the result ; the speed of a experimental group has as much as $0.60{\pm}0.23mm/30days$ while the speed of a control group has $0.44{\pm}0.35mm/30days$(P<0.05). So, we could convince that orthodontic miniscrew is used effectively in the cases required the maximum anchorage.

• 한국운동역학회지
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• 제21권1호
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• pp.31-38
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• 2011

This study aimed to determine the effects of the blockage of visual feedback on joint dynamics of the lower extremity. Fifteen healthy male subjects(age: $24.1{\pm}2.3\;yr$, height: $178.7{\pm}5.2\;cm$, weight: $73.6{\pm}6.6\;kg$) participated in this study. Each subject performed single-legged landing from a 45 cm-platform with the eyes open or closed. During the landing performance, three-dimensional kinematics of the lower extremity and ground reaction force(GRF) were recorded using a 8 infrared camera motion analysis system (Vicon MX-F20, Oxford Metric Ltd, Oxford, UK) with a force platform(ORG-6, AMTI, Watertown, MA). The results showed that at 50 ms prior to foot contact and at the time of foot contact, ankle plantar-flexion angle was smaller(p<.05) but the knee joint valgus and the hip flexion angles were greater with the eyes closed as compared to with the eyes open(p<.05). An increase in anterior GRF was observed during single-legged landing with the eyes closed as compared to with the eyes open(p<.05). Time to peak GRF in the medial, vertical and posterior directions occurred significantly earlier when the eyes were closed as compared to when the eyes were open(p<.05). Landing with the eyes closed resulted in a higher peak vertical loading rate(p<.05). In addition, the shock-absorbing power decreased at the ankle joint(p<.05) but increased at the hip joints when landing with the eyes closed(p<.05). When the eyes were closed, landing could be characterized by a less plantarflexed ankle joint and more flexed hip joint, with a faster time to peak GRF. These results imply that subjects are able to adapt the control of landing to different feedback conditions. Therefore, we suggest that training programs be introduced to reduce these injury risk factors.

• Archives of Pharmacal Research
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• 제21권5호
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• pp.581-590
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• 1998

We developed a novel water-soluble camptothecin analobue, CKD602, and evaluated the inhibition of topoisomerase I and the antitumor activities against mammalian tumor cells and human tumor xenografts. CKD602 was a nanomolar inhibitor of the topoisomerase I enzyme in the cleavable complex assay. CKD602 was found to be 3 times and slightly more potent than topotecan and camptothecin as inhibitors of topoisomerase, respecitively. In tumor cell cytotoxicity, CKD602 was more potent than topotecan in 14 out of 26 human cancer cell lines tested, while it was comparable to camptothecin. CKD602 was tested for the in vivo antitumor activity against the human tumor xenograft models. CKD602 was able to imduce regression of established HT-29, WIDR and CX-1 colon tumors, LX-1 lung tumor, MX-1 breast tumor and SKOV-3 ovarian tumor as much as 80, 94, 76, 67, 87% and 88%, respectively, with comparable body weight changes to those of topotecan. Also the therapeutic margin (R/Emax: maximum tolerance dose/$ED-{58}$) of CKD602 was significantly higher than that of topotecan by 4 times. Efficacy was determined at the maximal tolerated dose levels using schedule dependent i.p. administration in mice bearing L1210 leukemia. On a Q4dx4 (every 4 day for 4 doses) schedule, the maximum tolerated dose (MTD) was 25 mg/kg per administration, which caused great weight loss and lethality in <5% tumor bearing mouse. this schedule brought significant increase in life span (ILS), 212%, with 33% of long-term survivals. The ex vivo antitumor activity of CKD602 was compared with that of topotecan and the mean antitumor index (ATI) values recorded for CKD602 were significantly higher than that noted for topotecan. From these results, CKD602 warrants further clinical investigations as a potent inhibitor of topoisomerase I.

• 임산에너지
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• 제22권3호
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• pp.1-10
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• 2003

본 연구는 점봉산 일대 천연활엽수림에서 산림 천이 경향과 잠재 산림 식생을 검토 분석한 것이다. 106개의 20m×20m 정방형 표본구를 설치하여 중ㆍ상층목의 아래에서 생육하는 하ㆍ중층목에 의해서 세대 교체되는 과정을 바탕으로 천이 경향을 평가하였다. 조사 대상 산림의 천이 경향분석은 Markov chain의 수학적 이론에서 변형된 추이 행렬 모델을 사용하였다. 본 연구 결과가 시사하는 바는 조사 산림은 천이의 중간 단계에 있으며, 수종 구성상 극성상림에 도달하려면 500년 이상의 기간이 소요될 것으로 나타났다. 현재 42.6%와 8.1%의 높은 상대밀도를 유지하고 있는 신갈나무와 음나무는 극성상의 안정상태가 되면 각각 13.3%와 0.5% 이하로 수종 구성비율이 감소하리라 예상된다. 반면에 전나무, 고로쇠나무, 물푸레나무, 피나무, 당단풍의 구성 비율은 증가할 것으로 사료된다. 미래 수종 구성 비율의 증감은 내음성 지수를 바탕으로 연구 모델을 검토한 결과와 대체로 일치하였다. 추이행렬 모델의 실제 상황에 대한 적용성을 평가하기 위하여 연구 모델의 가정과 민감도 역시 고찰하였다. 전반적인 연구 결과가 지적하는 바에 의하면 조사 산림의 현재 생태적 동태는 인간에 의한 방해와 교란이 있은 후 천이가 진행 중임을 반영한다.

• 대한치과기공학회지
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• 제11권1호
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• pp.35-45
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• 1989

This study was carried out from June, 20, to October 22, 1988, for the purpose of researching on the complaint ratio of Respiratory symptoms of the dental laboratory technicians in Seoul. In this study, aiming to find out complaint ratio of respiratory symptoms of the dental laboratory, SNU-81-AL were applied, at random, to 193 dental laboratory technicians at 39 dental laboratories, as the research group, and to 178 clinical laboratory technicians at 10 general hospitals, as the control group, and above two groups were compared with each other. The following results were obtained from this research. 1. The quantity of respirable dust under 5$\mu$m measured at the dental laborartories was, on an average as well, 5$mg/m^3$-minimum 1.56$mg/m^3$), and the density of CO was, on an average as well, 5.0ppm(Mx 7.0-Mn 3.0). 2. The complaint ratio of five main respiratory symptoms(cough, phlegm, wheezing, nasal catarrh & cold, breathlessness) was, on an average, 44.3% at the dental laboratory technicians, phlegm was the major symptom complained by the greatest number of the technicians. 22.4% of the clinical laboratory technicians complained above 5 main respiratory symptoms, nassal catarrh & cold was the mostly complained symptoms among them. There showed a consideraly significant difference at the complaint ratio between the above 2 occupations(P<0.005). 3. There showed no paticular significant difference between male and female, at the complaint ratio of the dental laboratory technicians. However, there showed a considerable significant difference according to their sexuality, in case of the clinical laboratory technicians. 4. Considered from th view point of age, the highest age group was 20-29 with its average 48.5%, in case of dental laboratory technicians. The highest age group among the clinical laboratory technicians was over 40 age with its 28.7%. There showed no particular significant differences between to tow occupations. 5. Considered from the view point of work period, the highest work period group was 0-3 years with average 47.8%, in case of dental laboratory The highest work period group among the clinical laboratory technicians was 16 years with its 25.2%. There showed no particuar significant differences between the two occupations. 6. Considered from the view point of smoking, phlegm was complained by much more smokers than non-smokers, in both occupations. In case of non-smokers, many complained about nassal catarrh & cold. There showed no particular significant differences between the smokers and the non-smokers.

• 대한치과교정학회지
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• 제29권3호
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• pp.303-315
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• 1999

골격성 III급 부정교합자의 하악골 회전성장 양상이 하악이부 및 상하악절치부의 형태와 어떠한 관련이 있는지 알아보고자 본 연구를 시행하였다. 하악 전돌의 악골부조화를 보이며 교정치료의 경험이 없는 골격성 III급 부정교합자 성인 남녀 86명을 Skieller등이 하악골 회전성장 양상을 파악하기 위해 제안한 방법을 통해 전방회전성장군과 후방회전성장군으로 분류하여, 골격성 III급 부정 교합자에서 하악골 회전성장 양상에 따른 골격관계, 하악이부의 형태와 상하악절치의 위치에 관하여 분석한 결과 다음과 같은 결론을 얻었다. 1. 전방회전성장군에서 후방회전성장군에 비해 수평적인 두개안면 골격관계에서 SNA, SNB가 모두 유의성 있게 크게 나타났다. 또한 수직적인 두개안면 골격관계에 대해서는 모든 항목에서 차이가 있었다. 2. 하악이부 및 상하악절치부 형태와 하악골의 회전성장 양상 사이의 관계에서는 후방회전성장군에서 하악절치가 더 설측경사되고, 하악절치의 치조부 순설폭경이 좁으며 상악절치의 치조부에서 구개평면까지의 거리가 더 증가되었다. 3. 하악평면을 기준으로 계측한 symphysis ratio는 전방회전성장군과 후방회전성장군 사이에 유의한 차이가 없었다. 4. 하악골의 회전성장 양상과 하악이부 및 상하악절치부 형태에 대한 계측항목과의 상관분석에서, 후방회전성장 양상으로 성장할수록 overbite의 감소, 하악절치의 설측경사, 하악절치의 치조부 순설폭경 및 symphysis width의 감소가 나타났다.

• 한국임상수의학회지
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• 제19권2호
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• pp.186-190
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• 2002

아토피성 피부염은 면역계재성 피부질환으로 소양증이 주요 증상이며 이의 치료가 필수적이다. 따라서 개에서 제2세대 항히스타민제의 임상적용을 위해 피부에 히스타민에 의해 유발된 팽진과 발적에 대한 loratadine, cetirizine과 terfenadine의억제 효과를 비교하였다. 3종의 항히스타민제는 대조군에 비해 매우 유의하게 발적반응을 억제하였으며(p<0.01) cetirizine이 다른 제제에 비해 높은 억제효과를 보였다. 3종의 항히스타민제는 팽진 반응을 억제하는 효과를 보였으며 loratadine의 억제효과가 일정하며 지속적이었다. 따라서 제 2세대 항히스타민제인 loratadine과 cetirizine은 개에서 아토피성 피부염의 소양증 치료에 적용할 수 있는 항히스타민제로 사료된다. 특히 스테로이드제제를 대체할 수 있는 치료효과를 보일 것으로 판단된다.

• Journal of Periodontal and Implant Science
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• 제36권3호
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• pp.673-682
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• 2006

Recent study shows that implant design has a great impact on initial stability in bone. The ITI $TE^{(R)}$ implant, designed originally for immediate placement has a tapered/ cylindrical form which fits the anatomical shape of the natural alvelous or tooth root. The increased diameter at the collar region coupled with more threads lead to more bone contact and enhanced stability. The aim of this retrospective study is to evaluate the clinical use and the efficacy of recently introduced ITI TE implant with a new macro-design. The following results are compiled from 139 patients who received ITl TE implant surgery at the periodontal department. of Yonsei University Hospital between July 2002 and September 2005. 1. 139 patients received 173 ITl $TE^{(R)}$ implants in their maxilla and mandible (Mx 82, Mn 91). Posterior area accounted for 84% of the whole implant surgery, 2. In the distribution of bone quality, type III(41,0%) was the most, followed by type IV(41,0%) and type II (27.7%). As for the bone quantity, type B(43.9%) was the most, followed by type C(42.2%), type D(12.2%) and type A(1.7%). 3. 125 implants(83.9%) were treated by single crown, which accounted for the majority. 4, The total implant survival rate was 100% after a mean follow-up period of 21.2 months. This preliminary data with ITl $TE^{(R)}$ implant showed excellent survival rate although the majority of implants evaluated in this study were placed in the posterior region of the jaw and compromised sites.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제33권5호
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• pp.511-517
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• 2007

Purpose: The aim of this study is to determine whether a difference in the amount of bone graft material is needed between edentulous patients and dentulous patients and to calculate the amount of augmentation for a sinus lift procedure. Methods: 19 patients(20 sinuses) were included to measure maxillary sinus volume. Facial CT scanning was performed using MX 8000 IDT CT devices(Philips, USA). And it was used for IDLvm(The IDL Virtual Machine) 6.0, CT Volume Analyzer Ver 2.3 program to measure maxillary sinus volumes Results: At edentulous patients, volumes(mean${\pm}SD$) of the inferior portion of the sinuses were $0.56{\pm}0.13cm^3$(5mm height), $2.35{\pm}0.57cm^3$(10mm height), $4.85{\pm}1.10cm^3$(15mm height). At dentulous patients, volumes(mean${\pm}SD$) of the inferior portion of the sinuses were $0.41{\pm}0.18cm^3$(5mm height), $1.76{\pm}0.42cm^3$(10mm height), $3.80{\pm}0.84cm^3$ (15mm height). A significant correlation was found between augmentation height(5mm, 10mm, 15mm) and the calculated sinus volume.(p=0.027, p=0.018, p=0.044) Conclusions: A significant correlation was found between augmentation height(5mm, 10mm, 15mm) and the calculated sinus volume. Detailed preoperative knowledge of sinus lift augmentation volume is helpful in determining the appropriate amount of the bone graft material.