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      • KCI등재

        Clear Cell 'Sugar' Tumor of the Lung: A Well-Enhanced Mass with an Early Washout Pattern on Dynamic Contrast-Enhanced Computed Tomography

        Kim, Woong Ji,Kim, So Ri,Choe, Yeong Hun,Lee, Ka Young,Park, Seoung Ju,Lee, Heung Bum,Chung, Myoung Ja,Jin, Gong Yong,Lee, Yong Chul The Korean Academy of Medical Sciences 2008 JOURNAL OF KOREAN MEDICAL SCIENCE Vol.23 No.6

        <P>Clear cell tumor of the lung is a rare and very unusual benign pulmonary tumor. As clear cell tumor of the lung contains abundant cytoplasmic glycogen, this tumor is called 'sugar tumor'. We report a case of sugar tumor in a 64-yr-old man presenting as a round pulmonary nodule. On dynamic computed tomography (CT) scans, the solitary pulmonary nodule showed early wash-in enhancement with an early washout pattern like a lung malignancy. The patient underwent wedge resection for the tumor. Pathologic examination, including immunohistochemical studies, revealed that the nodule was a benign clear cell tumor, so-called 'sugar tumor'. Because only a small number of cases have been reported previously, clinical aspects, radiological characteristics on dynamic contrast-enhanced CT, and differential diagnosis of the tumor are not well established. Herein we present a clear cell tumor of the lung and discuss the clinical, radiological, and pathological features of the tumor.</P>

      • KCI등재
      • KCI등재

        타타늄의 열처리 조건에 따른 동전위 양극분극특성 및 표면 미세구조 변화

        주동현,이용렬,정영화,양홍서,박상원,이도재,송호준,박영준 大韓齒科器材學會 2002 대한치과재료학회지 Vol.29 No.2

        The corrosion resistance of metallic implants is essential for successful implant osseointegration. Moreover, the implant surface should have appropriate surface roughness for the attachment of the osteoblast and collagen fibrils. When titanium is exposed to air a thermodynamically very stable oxide film is formed at once. This oxide is very thin and yet it protects the metal from corrosion instantaneously. However, the oxide would not be ideal, and it would be supposed that the state of oxide film would be various by the different conditions when it is formed. The objective of this study was to evaluate the electrochemical properties and surface microstructural changes of titanium after passivation treatment or exposure to high heat (in vacuum or in air). ASTM grade 2 commercially pure titanium (Ti) disks of 10㎜ diameter were wet ground and polished with 240 and 600 grit SiC, and then ultrasonically cleaned with distilled water and ethanol. Cleansed as-received samples (As-R group) were passivated with 30% nitric acid solution at 50℃ for 15 minutes to make the Pas group. The Std-V samples were made by treating the Ti disks in vacuum quartz tube (10^-8 Torr) at 530℃ for 40 min for stress relieving, followed by annealing at 700℃ for 90 min, and then slow cooling to room temperature. The Std-A samples undergo identical procedure as the Std-V group except that it is done in air. For 530℃-V samples, Ti disks were heated at 530℃ for 40 minutes and slow cooled to room temperature. The 1000℃-V samples were produced by heating Std-V specimens again at 1000℃ for 2 hr, followed by cooling to room temperature. 530℃-A and 1000℃-A samples were also prepared. Potentiodynamic anodic polarization measurement, SEM, AFM and XRD analysis were performed to evaluate the effects of the various treatments. The difference in the mean values of E_corr between groups showed statistically significant difference (P<0.05), but that of I_corr did not show significance (P>0.05). When Ti surface was passivated there was a shift of corrosion potential (E_corr) in the noble direction and a lower corrosion current density (I_corr) value. Std-A samples showed most noble E_corr value among the tested groups. 530℃-V samples showed more noble E-corr than other tested groups except Std-A group. 1000℃-V samples showed more noble E-corr than those of Std-V sample. In the case of Std-, 530℃- and 1000℃-groups, -A sub-groups showed better corrosion resistant characteristics than -V sub-groups in regard to E-corr and I_corr values. In the SEM observations, the surfaces of the As-R samples showed only scratch line on smooth surface. In Pas samples, thick oxide layer covered the surface under high magnification observation. 530℃-A samples were covered by oxide granules, and Std-A samples had 25~50 nm-thick acicular oxides. The 1000℃-A samples were covered by coarse oxide crystals with a granule diameter of 0.1~0.6 μm having a gross appearance of milky white color, which was identified by XRD as a rutile. On the other hand, 1000℃-V samples showed an Widmansta¨tten structrue of which the orientation of the lattice is formed along crystallographic planes of the parent crystals. On the AFM observation, 530℃-A samples showed RMS roughness of 79.38 nm which is 5 times rougher than those of the As-R samples. Std-A sample had a roughness of 330.47 nm which is about 20-times rougher than that of the As-R sample. 1000℃-A samples were covered by coarse granular oxides and the roughness were about 0.56 μm. Vacuum sub-group samples showed a more smooth surface than air sub-group samples, and the oxide film was more dense. Due to variability of the surface treatment and heat treatment conditions, the process of the oxide formation seems to be affected thereby making the corrosion properties and surface micro-morphology different. However, more various electrochemical analysis together with surface analysis, and an investigation for the effects of those on the osteoblast cell adhesion and calcium phosphate apposition are needed for the improvement of the osseointegration rates of the titanium implants.

      • 알레르기 피부 반응 검사시 판독 시간에 따른 팽진의 크기 변화

        박장규,윤소영,이웅재,서기범,이증훈 충남대학교 의과대학 지역사회의학연구소 1996 충남의대잡지 Vol.23 No.2

        There have been several positive criteria for skin prick test, which has been most commonly used in the diagnosis of allergic diseases. Among them, comparing wheal size induced by allergen to that induced by histamine is logical for criteria of skin prick test positivity. We measured the wheal sizes induced by histamine and various causative allergens with five minutes interval, from 5 minutes to 40 minutes, and compared of the time which the wheal size of both reached at peak. The followings were the summary of the findings. 1. Maximal sizes of wheals induced by histamine reached at 12 minutes in average. 2. Maximal sizes of wheals induced by allergens reached at 15 minutes in average. 3. There was no statistical difference between the time of maximal size of wheal induced by histamine and causative allergen.

      • 티타늄의 산화 조건에 따른 산화막의 특성 및 인산칼슘 생성에 미치는 영향

        김인,양홍서,박연준,송호준,이용렬 전남대학교 치의학연구소 2003 구강과학 Vol.15 No.3

        The objective of this study was to evaluate the changes of micro morphology, roughness and crystalline structure of titanium surface after various oxidation treatments. Moreover, the effect of titanium surface oxide characteristics on the formation of calcium phosphate in Eagle's MEM. Commercially pure Ti disks were treated at various thermal conditions of 530℃ (Ti-530), 600℃(Ti-600), 700℃(Ti-700), 800℃(Ti-800), 900℃(Ti-900), and 1000℃(Ti-1000), respectively, and as received cp Ti (AS-R) and passivated cp Ti (PAS) were used as comparison groups. Surface characteristics were investigated using FE-SEM, profilometer and XRD. After immersing each sample in MEM for 7days, calcium phosphate (Ca-P) formation was evaluated using FE-SEM and EDS. Crystallites of 10~30nm-size were observed on the surface of Ti-530 and Ti-600 samples. Needle-like crystals were formed on Ti-700 samples, and the crystal grain size was increased dramatically as the temperature increased higher than 800℃. The roughness of Ti-530 was higher comparing to AS-R and PAS, and the roughness decreased in the treatment range of 530-700 with dense crystalline oxide formation. However, at treatment temperatures higher than 800℃, the roughness increased and its degree was depended to the size of the crystals. The anatase structures were observed in Ti-530 and Ti-600, and anatase and rutile structures were co-existed in Ti-700 specimen. Only rutile TiO_(2) were observed in Ti-800, Ti-900 and Ti-1000 specimens. The Ca-P formation on AS-R and PAS specimens was low in MEM solution. However, the Ca-P formation was well observed on heat-treatedgroups, and its degree of formation and micro-morphology was different by the specimen groups. The crystalline and chemical structure, micro-morphology, and surface roughness of titanium were various by the conditions of heat treatments, and the grain size and crystal structure of titanium oxide affected on the degree of Ca-P formation on Ti samples in MEM solution

      • Calcium phosphate 결정 성장 최적화를 위한 Ti 표면의 BaTiO_3 박막 형성에 관한 연구

        조진우,양홍서,박영준,황규석,송종은,이용렬 전남대학교 치과대학 2001 구강과학 Vol.13 No.2

        This study was purposed to establish an optimized manufacturing process for a negatively charged ferroelectric thin flim on titanium substrate in order to develop a new implant system having the mechanical strength and bone forming ability. Ferroelectric materials show an alignment of positive and negative charges by poling treatment. Based on this property, this study was performed with the assumption that the Ca^2+ ions would be easily attracted on negatively charged surface and the attracted cation might behave as nuclei for bone-like crystal grownth in biological solutions. In order to have an osteoinducibility by the ferroelectric thin film coating, continuous and flawless crystalline thin film should be formed with ferroelectricity, and finally should be adequately poling treated. In this study, BaTiO_3 (BTO) was selected as a ferroelectric material. Before thin film coating process, most favorable poling condition was investiged with the evaluation of the difference in calcium phosphate (Ca-P) formation in simulated body fluid (SBF). Moreover, the parameters to form an optimum thin film were studied. Dense bulk BTO disks were fabricate using cold isostatic pressing(CIP) and sintered in air at 1300℃ for 2 hours. Sintered BTO disk was polished, and he crystallinity, microstructure, and ferroelectric characteristics were evaluated using an X-ray diffraction analysis (XRD), a field emission scanning electron microscope (FE-SEM), and an Impedance analyzer. To find the optimum poling condition for the calcium phosphate crystal formation, sintered bulk BTO specimens were treated with either of following poling conditions; 1) room temperature poling treatment [ polarizing field (Ep) = 25kV/cm, at 25℃ for 2 hours], 2) under Tc medium-temperaturepoling treatment (Ep=20kV/cm, from 85˚C to 25˚C for 2 hour), and 3) above Tc high-temperature poling were immesed in simulated body fluid (SBF) for 30 days, and the formation of calcium phosphate (Ca-P) layer n the surface was evaluated. The crystallinity, microstructure, and ferroelectric characteristic of BTO thin film were evaluated withthe variation of final heat treatment. It was performed after establishing the starting substance-solvent mixing ratio, coating times, and pre-heating temperature optimal to form continuous and flawless BTO thin film adequate for having ferroelectricity. Perparation of BTO thin film was made by dipping-pyrolysis technique using metal naphthenates as starting substances. BTO thin films was spin-coated on Ti substrate by dipping-pyrolysis technique using sol obtained by mixing Ba-naphthenate and Ti-naphthenate as starting substances. Pre-firing temperature of BTO thin film was performed at 450℃ because organic-solvent ws completely volatilized without any crystal growth, and the final heat treatment was performed at 600, 700 or 800℃, respectively. The results are as follows; 1. BTO disk sintered at 1300℃ for 2 hours showed average grain size of about 1㎛ and the relative dielectric constant at 1㎑ was abut 3000∼3500. 2. After immersing the sintered bulk BTO poled at respective conditions in SBF for 30 days, Ca-P layers were present on the negatively charged surfaces. In contrary, positively charged Bto surface did not show any noticeable charge of the surface microstructure after SBF immersion. 3. In he case of poling condition 1 and 2 treated with below Tc, Ca/P ratio showed a relatively low value of 1,.2∼1.5. While, in the case of poling condition 3 treated with above Tc, Ca/P ratio was 1.5∼1.67, which is similar to that of biological apatite. This phenomenon demonstrates that poling the BTO above the temperature of Tc is preferable for the Ca-P formation. 4. For thin film BTO coastin, the starting substance was prepared by an equimolar mixing of the Ba and Ti-naphthenate. Dilution of the starting substance with toluene was most appropriate at sol : toluene ratio of 5.2:4.8 Too thin sol produced porosity in film, and too thick sol resulted cracks in the film. By repeating the coating and pre-firing procedure 15 times, homogeneous film of 0.5㎛ thickness could be fabricated, and perfomed well during the poling treatment without breakdown. 5. The heat-treatmen of the BTO thin film at 700℃ produced a homogeneous crystalline structure without heterogeneous TiO2 formation. The BTO thin film heat-treated at 600℃ showed non-crystallinity and no ferroelectricity. Treatment at 800℃ produced heterogeneous TiO2 phase in the film, which is unfavorabe for having ferroelectricity by the distortion of the perovskite structure. The relative dielectic constant at 1 ㎑ was 152 and 112 by heat-treatment at 700 and 800℃, respectively. In summary, these results demonstrated that poling the ferroelectric B_aT_iO_3 surface negatively is effective for the formation of Ca-P layer in simulated body fluids. Poling condition at a temperature cooling from above Tc down to room temperature is most effective. By optimizing the method of BTO thin film coating on metal substrate for the formation of Ca-P layer, the data of this study might be applied for the manufacture of new bioactive implant system.

      • 김치가 노화촉진쥐 간의 유리기 생성 및 항산화효소 활성에 미치는 영향

        김종현,권명자,이소영,류재두,문갑순,최홍식,송영옥 부산대학교 김치연구소 2002 김치의 과학과 기술 Vol.8 No.-

        본 연구는 김치가 노화 억제에 미치는 영향을 살펴보기 위하여 AIN-76마우스 식이에 배추, 갓김치, 갓배추김치를 각 동결건조 김치를 5%씩 첨가하여 만든 후 김치식이를 노화촉진쥐인 SAMP8에게 1년간 섭취시키면서 간의 노화관련 특성인 유리기 농도와 항산화효소계의 효소활성 변화를 살펴 보았다. 노화촉진쥐 간의 총유리기, OH radical, H_2O_2 그리고 TBARS모두 가령에 따라 증가되었으며, 간에서 생성된 유리기 농도와 TBARS 농도는 대조군에 비해 김치섭취시 유의적으로 감소되었다(p<0.05). 그러나 생성된 유리기를 제거하기 위한 SOD활성은 오히려 김치섭취군에서 유의적으로 증가되었으며(p<0.05), catalase와 GSH-px, GSH/GSSG의 비율도 김치섭취군에서 유의적으로 증가하였다(p<0.05). 따라서 김치섭취는 노화에 따라 발생되는 간의 유리기 및 TBARS 생성은 억제시키면서, 이를 제거하는 항산화계 효소는 활성화시켜 노화를 억제한 것으로 생각된다. 김치종류 중에서는 배추김치보다 배추갓김치와 갓김치가 유리기 생성 억제 및 항산화 효소 활성을 더욱 증진시킨 것으로 관찰되어 이는 첨가된 갓의 항산화물질 때문인 것으로 생각된다. This study was performed to investigate the effect of kimchi intake on antiaging characteristics in the brain of senescence-accelerated mouse (SAM) in terms of free radical production and anti-oxidative enzymes. Two hundreds twenty SAM (20 mice) were divided into four groups and fed kimchi diet for 12 months. Experimental groups were kimchi free AIN-76 diet (control) group, Korean cabbage kimchi diet (KCK)group, 30% mustard leaf added Korean cabbage kimchi diet (MKCK) group, and mustard leaf kimchi diet (MLK) group. Concentrations of total free radical, OH radical and H_2O_2 of control group increased up to 123%, 262% and 174% of initial value (p<0.05) after one year. Increase in free radical production in kimchi groups due to aging was decreased by kimchi feeding. Among kimchi groups. MKCK and MLK groups showed greater inhibiting effect against free radical production than KCK. The concentration of TBARS in the bruin of control group also significantly increased up to 362% of initial value as aged (p<0.05) and production of TBARS in kimchi groups were decreased. When the activities of Cu, Zn-SOD, Mn-SOD, GSH-px and catalase of kimchi groups were compared to those of control at the same experimental period, anti-oxidative enzyme activities of kimchi groups were lower than those of control (p<0.05). But GSH/GSSG in kimchi groups were higher compared to control. In conclusion, decrease in free radical production and increase in anti-oxidative enzyme activities were observed from kimchi groups suggesting that kimchi might have important role on retarding aging. Among kimchi variety tested in this experiment, MKCK and MLK seem to have greater effect on inhibiting free radical production and increasing anti-oxidative enzyme activities than KCK. Further study is needed to find out the mechanism of kimchi on retarding aging.

      • KCI등재

        數學科 問題解決 學習의 指導에 關한 硏究

        林在圭,金俊茂,金昭延,李海榮 경북대학교 과학교육연구소 1989 科學敎育硏究誌 Vol.13 No.-

        The purpose of this article is to establish some principles in helping students study in order to enhance the ability of solving problems reasonably by using fundamental mathematical skills, and to bring forth the improvement of mathematics education by using the above mentioned principles. In this work we investigate the following subjects ; (1) Fundamental concepts and strategies of teaching students for mathematics problem solving achieved in nineteen eighties in and out of Korea. (2) Current status of problem solving ability of middle and highschool students and teachers. (3) We first made 「motivation-advice cards」 about the problem solving strategy according to the classification of problem solving thought format, and then we used them in highschool classes. We test the result. We obtained the following conclusions ; (1) The style of test problems has to be changed from multiple choice form which is widely used in various evaluation examinations to writing style. (2) Studies of teaching method to help students extend their creativity, and making good problems and invention of instructive devices are required. (3) After making the students aware of the importance of problem solving strategy and of the way how to use it, we have to lead the students to acquire the habit of using them.

      • 컴퓨터 작업 시 의자 등받이 위치가 근육 활성도에 미치는 영향

        김민우,변승진,이경은,정소영,조주영,최원자,최찬양,김경 대구대학교 특수교육재활과학연구소 2011 再活科學硏究 Vol.29 No.1

        이 연구는 컴퓨터 작업시 의자 등받이 위치가 근육활성도에 미치는 영향을 알아보기 위해 36명의 근골격에 문제가 없는 성인 남녀가 참가하였으며 대상자들은 등받이가 뒤에 있는 의자와 등받이가 없는 의자, 등받이가 앞에 있는 우리들 의자를 무작위로 배정하고 동일한 컴퓨터 작업을 실시하게 하였다. 실험 중, 표면근전도기를 사용하여 의자에 따른 위등세모근, 머리널판근 그리고 척주세움근의 근활성도 변화를 측정하였다. 이 연구의 결과를 종합해보면 등받이가 앞에 있는 의자는 허리 근육의 부담을 줄이지만 목근육에 부담이 늘어나고 등받이가 뒤에 있는 의자와 없는 의자는 허리근육에는 다소 무리가 가지만 목근육에는 부담이 덜하다는 것을 알 수 있었다. 이러한 결과로 환자의 증상에 다라 컴퓨터 작업을 하는 동안 의자 등받이의 위치를 조절하여 치료에 도움이 될 수 있다고 생각되어진다. Objective : In this study, we checked and observed people's change of body muscle and muscle activity who do computer work on different chairs. We set three kind of chairs which one is a stool and another one is the back is fixed, and the other one is the back is fixed in front of chair. Subject : Accounting for 36 health men and women, we divided these people to 3 groups and put them on the three cases(position 1, position 2, position 3). We measured muscle activity of upper trapezius, Splenius Cervics, Erector Spinae from the groups by using surface electromyogram system. Methods : The standard of the electromyogram was 'reference voluntary contraction', and we carried out 'one way anova' to compare muscle activity of three groups. Results : In position 1, reference voluntary contraction of upper trapezius muscle activity was 123.2821%, Splenius Cervics was 141.7526%, and Erector Spinae was 254.5233%. In position 2, reference voluntary contraction of upper trapezius muscle activity was 132.9395%, Splenius Cervics was 141.7526%, and Erector Spinae was 246.6540%. In position 3, reference voluntary contraction of upper trapezius muscle activity was 190.6487%, Splenius Cervics was 270.2332%, and Erector Spinae was 182.1021%. Both upper trapezius and Splenius Cervics muscle activity of position 3 group was higher than the others groups. In position 1 group, Erector Spinae muscle activity was hight than the other groups. And either was position 2 group's(p<0.05). Conclusion : Therefore the chair which is the back is fixed in front is more comfortable for waist muscle but it's not good for neck. And the other chairs are better in waist muscle but not in neck muscle. So far, when we do a computer work, it's prefer to sit on the group 1&2's chairs to reduce neck muscle's stress and sit on group 3's chair to reduce waist muscle's stress.

      • KCI등재

        초·중·고등학교 학생, 학부모, 일반교사의 보건교육 요구

        윤순녕,김영임,최정명,조희순,김영희,박영남,오경순,이분옥,조선녀,조소영,한선희,하영미 韓國學校保健學會 2004 韓國學校保健學會誌 Vol.17 No.2

        Purpose : The purpose of this study was to identify needs of health education of the students, parents, general teachers, and health teacher of the elementary, middle, and high schools. Method : 279 schools of elementary, middle, and high school were sampled nonproportionally during the period from June 28 to July 26, 2004 . The data were collected by the questionnaire from 1,888 students, 1,876 parents, 1,695 general teachers, 279 health teachers. A frequency, % and χ2-test were used to analysis by SAS program. Result : 1. It showed that 98.1% of elementary school students, 92.3% of middle school students, 89.6% of high school students answered that they need health education. The most of students, parents, and general teachers had high interests in health education. 2. In the case of students, main causes of needs of health education was 'to prevent diseases or accidents''. But parents answered that it was 'to build up a healthier behavior'. General teachers answered that it was 'more effective systematic and continuous health education'. 3. Over 80% of students, parents, and general teachers about the question of who qualified person is to teach health education as a regular class responded that health teacher is available. Especially 93% of elementary school students answered like that. 4. The most of students, parents, and general teachers answered that health education in the classroom is favorable 1 to 2 hours per week. Conclusion : As results of the study , the majority of students, parents, general teachers agreed needs of health education. Therefore, on the basis of this study, systematic and continuous health education is necessary. Additionally the establishment of independent health subject is required certainly.

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