ZnO 압전박막을 이용한 FET형 압력센서의 특성

양규석,권대혁,남기홍,손병기 경북대학교 센서기술연구소 1994 센서技術學術大會論文集 Vol.5 No.1

A new FET type pressure sensor has been investigated to overcome the problems of the conventional silicon piezoresistive and capacitive pressure sensor. The PSFET( pressure sensitive field effect transistor) is a new FET type pressure sensor which the operation theory is combined with the field effect of MOSFET and the piezoelectric effect of piezoelectric thin films. This sensor can overcome the fabrication problems of conventional silicon pressure sensors and realize productivity, standardization, miniaturization, integration because the whole fab. process is compatible to the planar technology. A ZnO thin film as a piezoelectric material, 5000Å thick, was deposited on a FET gate by RF magnetron sputtering and the optimum deposition condition was 300℃ substrate temperature, 5mtorr working pressure, Ar ambient and 140watt RF power, respectively. And the device was annealed at 400℃, O_(2) ambient for 1 hour to obtain a better C-axis poling structure. The fabricated PSFET device showed piezoelectric voltage(40mV/kgf/cd) and sensitivity (21μA/kgf/cm^(2)) according to an applied pressure(1kgf/cm^(2)~4kgf/cm^(2)).

心拍數에 의한 足球경기의 强度硏究

최대우,신양섭,현광석 忠南大學校體育科學硏究所 1994 體育科學硏究誌 Vol.12 No.1

I measured the heart rate of 5 male students of the department of phisical education, Chungnam National University, with a heart cheker and a pedometer, during footvolley ball games. The results are following: 1. The intensity which needs the improvement of Endurance Over Whole Body is 60-70% of VO₂ Max. The event suiting this was the play with 3persons without breaking time. 2. Whey they took warming-up for 5 minutes before the footvolley ball game, their mean heart rate was 122.3 beat/min. When they played footvolley ball without warming-up, their heart rate was 145.6 beat/min. The latter was higher than the former by 23.3 beat/min. 3. The mean heart rate of the footvolley ball with 3 persons was 126.4 beat/min ; The mean heart rate of footvolley ball with 4 persons was 124.1 beat/min ; The mean heart rate of footvolley ball with 5 persons was 108.1 beat/min. thus 3 person play indicated the highest intensity the shortest unit time. (P〈0.001) 4. The mean heart beat was 5.7 best/min with or without time ; the heart beat without breaking time was higher. (P〈0.001) 5. The heart beat of Forward and Backard was that Backward (3 persons) was a little higher and Forward (4 or 5 persons) was a little higher.

Cone-beam CT를 이용한 제II급 부정교합 아동의 상기도 형태에 관한 3차원적 연구

홍지숙,김대성,오경민,김윤지,이규홍,박양호 대한치과교정학회 2010 대한치과교정학회지 Vol.40 No.3

Objective: The aim of this study was to evaluate the volumes and areas of the upper airways in children with Class II malocclusion, using three dimensional cone-beam computed tomography (CBCT) and to compare the volumetric and cross-sectional measurements and cephalometric variables to investigate possible relationships between the upper airway and facial morphology. Methods: CBCT scans were obtained from 37 subjects (17 boys and 20 girls; average age, 11.02 years). The upper airway volumes and areas were measured, and compared with cephalometric variables. Results: The area of the PNS-posterior plane (SPP) was significantly smaller in the Class II malocclusion group (p < 0.05). Also, the volumetric and cross-sectional measurements were lower in Class II than in Class I malocclusion groups, although the differences were not significant between the two groups (p > 0.05). The Class II malocclusion group showed significantly smaller values of PFH, mandibular body length, pog to N perp and showed larger values of FMA, ANB, and facial convexity than the Class I malocclusion group. The volume of the upper airway in front of PNS point (WN) showed negative correlation with ANB (p < 0.05). Conclusions: The Class II malocclusion group had a narrower upper airway associated with a decreased posterior facial height and a divergent growth pattern than the Class I malocclusion group. 성장기 아동의 상기도 협착은 두개안면 성장에 영향을 미칠 수 있다. 본 연구는 3차원 cone-beam computed tomography (CBCT)를 이용하여 제II급 부정교합 아동의 상기도 부피 및 단면적 계측치와 측모두부계측치를 비교하여 상기도와 안면 형태와의 연관성을 알아보고자 하였다. 37명의 아동(남자 17명, 여자 20명, 평균 연령 11.02세)의 CBCT를 촬영하였다. 연구 결과, 상기도의 PNS-posterior plane에서의 단면적(S_(PP))은 제II급 부정교합군에서 유의하게 작았다 (p < 0.05). 상기도 부피 계측치는 제II급 부정교합군에서 제I급 부정교합군보다 작았으나, 두 군 간 통계적으로 유의한 차이는 없었다. 제II급 부정교합군은 후안모고경(PFH), mandibular body length (p < 0.05), Pog to N perp (p < 0.01)에서 제I급 부정교합군보다 유의하게 작은 값을 보였고, FMA (p < 0.05), ANB, facial convexity (p < 0.01)는 유의하게 큰 값을 보였다. 제II급 부정교합군의 PNS 전방의 상기도 부피(W_(N))는 ANB difference 각도와 음의 상관관계를 보였다 (p < 0.05). 제II급 부정교합 아동은 상대적으로 좁은 상기도 부피를 가지며 이에 따른 감소된 후안모고경(PFH)과 하악골의 divergent한 안면 성장 양상을 보였다.

활동성 궤양성 대장염 환자에서 발생한 뇌정맥 혈전증 1예

남승우,양석균,정훈용,주연호,홍원선,민영일,김종성,유창식,서대철 大韓消化器病學會 1998 大韓消化器病學會誌 Vol.32 No.3

유치원 아동의 Resazurin Disc검사에 의한 우식활성에 영향을 미친 요인에 관한 연구

조선아,김대업,이광희,양영숙 大韓小兒齒科學會 1996 大韓小兒齒科學會誌 Vol.23 No.1

The puopose of this study was to analyze the influence of socioeconomic backgrounds and home dental behavior on the caries activity scores by resazurin disc method, 332 preschool children (boys 179, girls 153) in Iksan area were examined for their caries experience and caries activity. The parents of the children were asked to answer the questionnaire about socioeconomic backgrounds and home dental behavior. The sample was divided into five groups according to RD test score. The relationship between each group and a questionnaire was compared and analyzed. The following results were obtained. 1. No significant differences was found for child's age and sex, baby-sitter, sibling rank and tooth brushing frequency among five groups (p<0.05). 2. A statistical significance was obtained in the relationship between RD test score & dft rate (p<0.05). 3. No significant difference was found for parent's age, number of family and mother's physique among five groups (p<0.05). Siginificant difference was found for parent's education level among five groups (p<0.05). 4. No significant difference was found mother's oral hygiene state among five groups (p>0.05). 5. Children sucking human milk had more high RD test score than those who sucking bovine milk (p<0.05).

생체분해성 고분자를 이용한 사시수술용 제형개발 및 효용성에 대한 연구

민병무,김용백,김승영,김창식,박근성,길숙종,조항진,이성복,노승무,송규상,강대영,조준식,양준묵,정경수,최선웅,이진호,김학용,인현빈 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

A new device, muscle clamping system was developed to facilitate exact quatifying technique A strabismus surgery, and reduce the risk of complications. The device is composed of a lower fixing body with three jaws and an upper supporting body. They are used to clip an extraocular muscle and fix it to the sclera with a single bite. Superior rectus recession on 16 rabbit eyes were performed with this new device. Conjunctival injection, muscle adhesion strength, and light microscopic findings were examined at 1, 2, 4 and 8 weeks postoperatively. The Conjunctival injection were minimal, adhesion power ranged from 420 to 600 gram gravity, which is sufficient in withstand the normal pull of human extraocular muscle. In microscopic exam, some Inflammatory cells and fibrosis were found. The new device was technically easy, fast, and accurate, so it may be useful in stabismus surgery.

생체분해성 망막압정을 이용한 망막고정에 대한 실험적 연구

김용백,민병무,김창식,박근성,김승영,길숙종,조항진,이성복,노승무,송규상,강대영,조준식,양준묵,정경수,최선웅,이진호,김학용,인현빈 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

Biodegradable retinal fixation devices obtain mechnical fixation of the retina with desirable chorioretinal scarring and with the potential for local, sustained release of antimetabolites and steroids to inhibit proliferative vitreoretinopathy. We manufactured a biodegradable retinal tack with barb that was designed in order to prevent intrusion from implantation of retinal tacks. This study was carried to evaluate the efficacy for retinal fixation and the capability for sustained release of drugs with a newly designed biodegradable retinal tack Biodegradable retinal tacks were made of polymers of glycolic acids and were designed with barbs in a shape to prevent the disinsertion. Biodegradale retinal tacks are divided into 3 parts, a conical portion that is inserted into the sclera, a cylinder portion that remains in the vitreous, and a neck portion between the pin and the cylinder. The tapered conical end was manufactured to allow easy insertion through the retina and choroid into the sclera. A cylinder portion was manufactured with a tapered angle that fixes firmly into the orifice of 19 gauge spinal needle. A neck portion, 0.4 mm in diameter, was designed to prevent disinsertion from following implantation of retinal tack. The applicator was a 19 gauge spinal needle and its orifice was prepared to 15°angle to accept the tapered cylinder portion of the retinal tack. The retinal tacks, secured in the needles, were passed through the formed vitreous and inserted into the retina, choroid, and sclera and were released by pushing the internal needle, usually within 2-3mm of the medullary ray of the posterior rabbit retina A retinal tack was placed in each of 8 pigmented rabbit eyes. Slit-lamp biomicroscopy, indirect ophthalmoscopy and fundus photography were performed periodically from 1 day to 8 weeks after surgery. Eight eyes were enucleated and studied by light microscopy at 8 weeks. Biomicroscopic evaluation of the animals revealed edemas adjacent to the retinal surfaces immediately after insertion of the biodegradable retinal tacks in all the animals. These edemas disappeared after 1 week. The first noticeable change in the size of retinal tacks was shown after 2weeks. The size of the retinal tacks gradually got smaller, decreasing to about one-half at 4 weeks and about one-third at 8 weeks. All retinal tacks remained in inserted places without any movement for an 8 week period. On light microscopy, epiretinal proliferations were seen to extend into the vitreous cavity. Cellular capsules that lined the inner aspect of the scleral defect caused by tack insertion were found. However the adjacent retina had a normal cytologic appearance and architecture in all specimens. We manufactured a biodegradable retinal tack that is designed to prevent intrusion from implantation of retinal tacks. All biodegradable retinal tacks reduce in size with time, but no retinal tacks extruded from the inserted place. The newly designed biodegradable retinal tack can be used for retinal fixation and may be used as a vehicle for the introduction of pharmacologic agents to prevent the cellular events that promote proliferative vitreoretinopathy.

Surface and Chemical Properties of Surface-modified UHMWPE Powder and Mechanical and Thermal Properties of Its Impregnated PMMA Bone Cement 8. Effect of Acids Treatment on Surface Modification of UHMWPE Powder

( Dae Hyeok Yang ),( Min Suk Lee ),( Jong Tae Ko ),( Yong Sik Kim ),( Moon Suk Kim ),( John M. Rhee ),( Gil Son Khang ),( Hai Bang Lee ) 한국조직공학과 재생의학회 2006 조직공학과 재생의학 Vol.3 No.3

Ultra high molecular weight polyethylene(UHMWPE) powders were impregnated into poly(methylmethacrylate)( PMMA) bone cement to improve the poor mechanical and thermal properties of the bone cement. But, the surface inertness of UHMWPE powder generated the poor bonding force with PMMA bone cement. The surface modification after pretreating UHMWPE powder with the three kinds of acid such as acetic, hydrochloric, and sulfuric acid has been carried out to advance the interfacial adhesion between UHMWPE powder and PMMA bone cement. The tensile strengths of reinforced PMMA bone cements with 3 wt% of surface-precoated UHMWPE powder with polyMMA after acids treatment were much higher than that(33.8 MPa) of 3 wt% of intact UHMWPE powder impregnated PMMA bone cement as well as were almost same as that(44.5 MPa) of conventional PMMA bone cement. Also, it was found that the curing temperatures of the composite PMMA bone cements were much lower than that(~103oC) of conventional PMMA bone cement. From these results, it was confirmed that acids treatment effectively modified the surface of UHMWPE powder. A possible mechanism for the surface modification of UHMWPE powder by acids treatment was proposed.

Clinical and Radiologic Outcomes after Various Treatments of Mid-Shaft Clavicle Fractures in Adolescents

Dae Suk Yang,Ha Yong Kim,Kwang-Won Lee 대한견주관절의학회 2019 대한견주관절학회 학술대회논문집 Vol.2019 No.3

폐쇄성 황달에서 담도 배액 전후의 Cytokine과 Endotoxin에 대한 연구

강대환 ( Dae Hwan Kang ),허정 ( Jeong Heo ),김광하 ( Gwang Ha Kim ),문재현 ( Jae Hyeon Moon ),권대식 ( Dae Sik Kwon ),김보석 ( Bo Suk Kim ),안진광 ( Jin Kwang An ),송근암 ( Geun Am Song ),조몽 ( Mong Cho ),양웅석 ( Ung Suk Yang 대한소화기학회 2003 대한소화기학회지 Vol.41 No.6

Background/Aims: Malignant biliary obstruction are associated with high postoperative morbidity and mortality. This study was performed to determine the effect of external and internal biliary drainage on plasma concentrations of cytokines and endotoxin. Methods: Twenly-one patients with malignant biliary obstruction were enrolled in this study. They were devided into two groups, PTBD (percutaneous transhepatic biliary drainage) and ERBD (endoscopic retrograde biliary drainage)groups. Then, plasma concentrations of TNF-α, sTNFr, interleukin 1α (IL-1α), interleukin 6 (IL-6), and endotoxin were measured before and after 1 week in PTBD and ERBD groups. Results: Total bilirubin decreased significantly from 13.3±8.2 to 6.2±4.4 mg/dL after PTBD and 7.0±11.2 to 5.3±4.0 mg/dL after ERBD (p=0.005, 0.007, respectively). Plasma sTNFr in PTBD group was 5.1±1.4 before drainage and remained unchanged 5.5±1.5 ng/mL at one week after drainage (p=0.155). Plasma sTNFr in the ERBD group was 5.9±1.5 and 5.6±1.0 ng/mL before and after biliary drainage, respectivedly (p=0.333). There was no significant difference of sTNFr changes between the PTBD and ERBD groups (p=0.113). Moreover, there was no significant difference in endotoxin changes between the PTBD and ERBD groups (p=0.477). Other cytokines changed insignificantly. Conclusions: Both PTBD and ERBD did not affect significantly plasma concentrations of sTNFr and endotoxin. Although ERBD provides a better quality of life and physiologic benefit, it dose not decrease cytokines and endotoxin associated with high morbidity and mortality in patients with malignant biliary obstruction. (Korean J Gastroenterol 2003;41:493-498)