Design of a shape memory composite(SMC) using 4D printing technology

Kang, Minkyu,Pyo, Youngjun,Jang, Joon young,Park, Yunchan,Son, Yeon-Ho,Choi, MyungChan,Ha, Joo wan,Chang, Young-Wook,Lee, Caroline Sunyong Elsevier 2018 Sensors and actuators. A Physical Vol.283 No.-

<P><B>Abstract</B></P> <P>A fused deposition modeling (FDM) tool was used to fabricate a shape memory composite (SMC) that combined a shape memory alloy (SMA) with a shape memory polymer (SMP). The SMA caused a shape memory effect due to a phase change between martensite and austenite phases, in turn due to a temperature change. Also, the SMP had a shape memory effect caused by changes in the proportions of hard and soft segments near the glass transition temperature (T<SUB>g</SUB>). Usually, common SMAs and SMPs are not reversible, so these materials do not go back to their original shapes once they are deformed. In this study, we fabricated 4D printing actuator via reversible SMC actuations using 3D printing technology. Nylon 12 was used as the 3D printing material in filament form. Moreover, the volume fraction of SMA to SMP was varied to find the optimum ratio for good operation cycles. A volume fraction of SMA:SMP of 1:5 showed the largest length change, of 8 mm, and the most rapid response time, of 4 s in overall dimension of 140mm×10mm×1mm (length×width×thickness).Thus, the SMC showed promising results for the application of stents and valve controllers that could be manufactured by 3D printing technology.</P> <P><B>Highlights</B></P> <P> <UL> <LI> An 4D printed SMC actuator was fabricated using SMA and SMP with a FDM 3D printer. </LI> <LI> A volume fraction of SMA:SMP of 1:5 showed the largest length change of 8 mm, and the most rapid response time of 4 s. </LI> <LI> The reversible actuator mechanism explains the SMC actuation via each shape memory effect. </LI> <LI> SMC showed potential application for stents and valve controllers via 3D printing technology to achieve customized designs. </LI> </UL> </P>

Purge & Trap-GC를 이용한 의약품 필름코팅 정제 중 잔류용제에 관한 연구

장준식,이명자,소유섭,문춘선,이주헌,박희라,김진숙,강경모,이선옥,방성연,유미자,유문균,금오성,이병욱 식품의약품안전청 2000 식품의약품안전청 연보 Vol.4 No.-

의약품은 약물을 생체에 적풋하기 위하여 유효성분의 효과가 언제나 일정하게 확보되고 사응에 편리하도록 만들어지는 것이므로 유효썽분 이외에 약효에 영향을 주지 않는 성분이 첨가되는 경운가 많다. 이 때 사용되는 용매들은 제피의 광택 및 건쪼시간의 단축 등을 위하여 휘발점이 낮을 용매들이 주로 사용되어진다. 본 연구는 의약품 필름코팅정제 중 잔류용매 4종(chlorofonr benzen, trichloro ethylen, 1,4-dioxane)에 대한 변형된 pirge & trap-GC 장치를 이용한 동시분석방법을 개발하였으며, 각 표준품의 RSD 값은 chloroform 3.03%, benzen 3.17%, trichloroethylen 3.69% and 1,4-dioxane 3.41%였다. 또한 시중 유통중인 의약품 50종에 대하여 잔류웅매 양을 측정하였으며, 검출되는 잔류용매는 한 건도 없었다. This study nras carried out to develope the analytical method for the mixture of chlorefonn, benzen, trichloroethylen and 1,4-dioxane simultaneously and determine the remainingorgauic solvents in coating tablets by Purge & Trap-GC. The results were as follouFs ; 1. Chloroform, benzen, trio:tloroethylen and 1,4-dioxane separated by tenax #5 trap by HP-624GC column by terrlperature programming. The peaks were separated completely at retentiontime of 6.88min for chloroform, 8.21min for benzen, 10.38miu for trichloroethylen and 11.95minfor 1,4-dioxane. 2. Standard RSD were individually chloroform 3.03%, benzen 3.17%, trichloroethylen 3.69%and 1,4-diorane 3.41%. 3. 60 samples were not detrcted chloroform, benzen, trichloroethylen and 1,4-dioxane.

정신분열병 환자의 주관적 증상과 객관적 정신병리와의 관련성

주연호,김용식,정성훈,신민섭,이창인 大韓神經精神醫學會 2001 신경정신의학 Vol.40 No.4

연구목적 : 주관적 증상평가도구인 K-FBF(Kyung Hee-Frankfurter Beschwerde-Fragebogen)가 정신분열병 환자의 어떤 증상 영역을 반영하는지, 특히 정신분열병의 병태생리와 밀접한 관련을 가지며 객관적 평가도구로는 파악이 어려운 음성 증상 또는 인지 장애의 측면들을 반영하는지 조사하고자, 정신분열병 환자의 K-FBF 결과를 객관적 정신병리 평가도구인 PANSS(Positive and Negative Syndrome Scale for Schizophrenia), 대표적인 자기보고식 다차원 증상목록(multidimensional self-report symptom inventory)인 간이정신진단검사(SCL-90-R)의 평가 결과와 비교 분석하였다. 방 법 : 고졸이상의 학력으로 DSM-IV진단기준에 의한 정신분열병 환자 중 급성기가 경과한 66명을 대사으로 연구를 수행하였다. K-FBF, SCL-90-R을 시행한 날, 두 명의 정신과 의사가 PANSS를 수행하였다. K-FBF의 질문항목에 대한 반응양상을 조사하고, 10개 소척도에 대하여 요인분석을 시행하였다. K-FBF와 연령, 성별, 병식과의 상관관계를 조사하였다. 또한, K-FBF, PANSS, SCL-90-R제반 척도간에 상관관계 분석을 시행하였다. 결 과 : K-FBF는 높은 연령일수록 호소하는 항목의 수나 그 정도가 감소하였으며, 유병기간을 조절변수로 삼았을 때도 동일한 결과를 보였다. K-FBF의 소척도를 요인분석하여 두개의 합산척도를 추출, 각각 자각된 고통(RD, Recognized Distress)과 지각왜곡(PA, Perceptual Alteration)으로 명명하였다. 위의 합산척도와 PANSS의 상관관계에서, K-FBF 표준화 총점을 조절변수로 하여 편상관을 조사한 결과 PA척도와 PANSS 음성척도가 상관관계를 보였다. 이는 Huber의 기본증상이란 정신분열병의 음성증상을 주관적 측면에서 접근한 것이라는 평가와 관련된다. 한편, K-FBF표준화 총점과 SCL-90-R총점은 강한 상관관계를 나타낸 반면, SCL-90-R총점과 PANSS총점은 비록 통계적으로는 유의하지만 매우 미미한 상관관계만을 보였다. 따라서 평가척도의 상관성은 그 내용보다는 평가하는 주체에 더 큰 영향을 받는다고 판단되었다. 결 론 : 본 연구결과 K-FBF로 측정된 Huber의 기본증상은 정신분열병의 음성증상을 보다 더 반영하는 것으로 평가되었으며, 또 객관적 평가도구인 PANSS보다는 자기보고형 도구인 SCL-90-R과 더 높은 상관관계를 보인 것으로 나타났다. 그러나, 본 연구결과의 일반화를 위해서는 다른 질병단계, 다른 인구학적 변인을 가진 환자들을 대상으로 한 연구가 계속되어야 할 것이다. Objectives : Kyung Hee-Frankfurter Beschwerde-Fragebogen(K-FBF) is a representative subjective symptom measuring tool of schizophrenic patients. We performed psychopathology measurements using K-FBF, Positive and Negative Syndrome Scale(PANSS) and Symptom Checklist-90-Revised(SCL-90-R) in patients with schizophrenia and then compared the results of these three examinations one another, in order to examine which psychopathologic aspects K-FBF might reflect and to measure the possibility whether this instrument reflect the negative symptoms or cognitive impairments, which are difficult to measure by conventional objective instruments measuring psychopathology. Methods : All 66 patients satisfying DSM-IV criteria for schizophrenia, were approached. Their education level was more than high school and they were not in the acute stage of schizophrenia. They performed K-FBF and SCL-90-R, and at the same day, they were interviewed by one of both psychiatrists using PANSS. We examined the patterns of K-FBF response and performed facor analysis about 10 subscales. We examined the correlation between K-FBF and age, sex and insight. Also, we performed correlation analysis among the K-FBF, PANSS and SCL-90-R. Results : As for K-FBF, with increasing age, the number of positive response items and the symptom severity were decreased. Even when controlling prevalence period as control variable, the correlation remained unchanged. Performing factor analysis to the K-FBF subscales, we created 2 factors, ie summation subscales. We named those recognized distress(RD) and perceptual alteration(PA) each. Using K-FBF standardized total scores as controlling variable, we performed partial correlation between PA and PANSS negative symptom scale. The result was PA and PANSS have statistically significant correlation. This correspons with the view that Huber's basic symptoms are reflecting subjective approach of negative symptoms of schizophrenia. While K-FBF standardized total scores and PANSS total scores had statistically strong correlations, SCL-90-R total scores and PANSS total scores had statistically significant, but very mild correlations. So, we had the judgement that the correlations among the psychopathology measurement tools are more influenced by the rater than the contents of tools. Conclusion : We concluded that Huber's basic symptoms, measured by K-FBF, reflect more negative symptoms of schizophrenia than other symptoms. And K-FBF has more correlation with the PANSS, objective psychopathology. Measuring tool, than the SCL-90-R, self-report quetionnaire. But, more studies using patients with another disease stages and another demographic variables are needed in order to generalize the results of this study.

일차적 비확공성 골수강 고정술로 치료한 제3형 개방성 경골 골절

오창욱,경희수,김도헌,박일형,김풍택,인주철,우연기,이정엽 대한골절학회 2004 대한골절학회지 Vol.17 No.2

중학교 가정과 '인간발달과 가족관계' 영역의 교육자료 (CD-Rom) 개발 및 현장 적용 연구 : 실천적 추론 수업을 중심으로

유태명,장혜경,유지연,김주연,김항아,김효순 한국 가정과 교육 학회 2000 한국가정과교육학회지 Vol.12 No.3

The purpose of this study is to develop lesson plans. teaching guide, and teaching materials applying practical reasoning teaching model in the area of 'human development and family relationship' in middle school home economics. The practical reasoning teaching model consists of five factors: Desired results, Awareness of context. Alternative approaches, Consequences of action, and Action. This study based on practical reasoning has following process: Curriculum development, Developing lesson plan. teaching material, and teaching guide. Experimental teaching and evaluation, Feedback, Production of CD-Rom. Teaching guide includes lesson Plan. workbook, multimedia materials and teaching resources, Especially teaching guide in CD-Rom can be used effectively in the actual teaching. In the classroom, this teaching model accomplished active and interesting Participation of teachers and students. It is proposed that practical reasoning teaching model should be applied to other areas of home economics. In addition, various teaching materials based on Practical reasoning need to be developed.

성인에서 Haemophilus influenzae 감염증의 임상양상과 미생물학적 특성

이종섭,황병연,정희진,김우주,박승철,이도현,이창규,신종희,황규잠,이영희 대한화학요법학회 2000 대한화학요법학회지 Vol.18 No.2

목적 : H. influenzae는 성인에서 흔히 호흡기 감염을 일으키는 균주로, 최근 ampicillin 내성 β-lactamase 생성 균주들이 지속적인 증가를 보이고 있어, 이에 국내 성인에서 H. influenzae에 의한 감염의 임상양상과 분리된 균주들의 미생물학적 특성을 조사하고자 하였다. 방법 : 1998년 3월부터 1999년 9월까지 고려대 구로병원에 내원한 환자중에서 H. influenzae가 분리된 68명을 대상으로 임상양상을 조사하고 항균제 감수성 검사를 시행하였다. 분리된 33주에 대해서 혈청형, 생물형, 세포외막 단백분석을 시행하였고, β-lactamase 생성여부에 따른 감염 환자군간 임상상 및 예후의 차이를 비교하였다. 결과 : 환자의 평균연령은 68세였고, 지역사회 획득감염이 전체의 85%를 차지하였다. 폐렴과 기관지염과 같은 하기도 감염이 전체환자의 75%를 차지하였고 분리 검체 역시 객담이 84%로 가장 많았다. 환자의 71%가 기저질환을 가지고 있었으며, 그 중에 만성 폐쇄성 폐질환, 심혈관 질환, 악성종양, 당뇨병이 대부분이었다. 혈청형으로는 nontypeable 형이 68%로 가장 많았고 b형은 한 예도 없었다. β-lactamase 생성율은 63.2%였고, β-lactamase 양성균주의 항균제 내성율이 음성균주에 비하여 높았으나 β-lactamase 생성 여부에 관계없이 cefotaxime, azithromycin, ciprofloxacin에 대하여 100%의 감수성을 나타내었고 cefaclor, cefuroxime에 대해서는 10% 이하의 낮은 내성율을 보여 이들 항균제들이 치료에 효과적일 것으로 사료된다. 세포외막 단백분석에서는 C형과 D형이 전체의 64%로 가장 많았으며, 혈청형과의 유의한 연관성은 보이지 않았다. 결론 : 성인에서 H. influenzae는 주로 만성 기저질환자에서 급성 호흡기감염 또는 만성 폐쇄성 폐질환의 급성 악화를 유발한다. 기존의 보고에 비해 β-lactamase 양성율이 증가하였고, 이에 따른 항균제 내성율도 증가하여 항균제의 선택에 유의하여야 할 것으로 생각된다. 세포외막 단백분석상 특정한 유형의 균주에 의해 감염이 집중적으로 발생하고 있어 향후 역학 조사의 도구로 이용할 수 있겠다. Purpose : H. influenzae is one of the common causative microorganisms of respiratory tract infections in adults. Recently. β-lactamase producing, ampicillin-resistant H. infiuenzae has become worldwide problem as well as in Korea. We studied to investigate the clinical features and microbiologic characteristics of H. infiuenzae infections in adults. Materials & Methods : From March 1998 to September 1999, 68 patients were enrolled in this study. Clinical features of H. infiuenzae infections were investigated, 68 isolates were subjected to the β-lactamase test, and 33 isolates were used for serotyping. biotyping, antibiotic susceptibility and outer membrane protein (OMP) analysis. Results : Mean age of study patients was 68 years-old and the acquisition rate in community was 85%. Pneumonia and bronchitis were the most common type of infection such as 80%, sputum was the most common clinical specimen for H. mQuenzae isolation. 70% of patients had chronic underlying diseases. Non-typeable strains were 68% and β-lactamase producing rate was 63%. There was no difference in the clinical features and prognosis of H. influenzae infection between the β-lactamase positivie and -negative groups. The susceptibility of cefotaxime, azithromycin, and ciprofloxacin was 100% and that of cefaclor, cefuroxime was under 10% in spite of β-lactamase positivity. In OMP analysis, C and D types were dominant (64%). Conclusion : H. influenzae caused acute respiratory infections in adults with chronic underlying disorders. This study shows higher β-lactamase producing rate and antibiotic-resistance rate than that were reported previously. OMP analysis shows that two major types of strains cause clinical infections intensively.

항산화제 섭취가 탈진적 운동 시 장딴지근의 GPx 및 GR의 활성에 미치는 영향

정성태,김연수,이왕록,박익렬,강현주 서울대학교 체육연구소 2001 서울大學校 體育硏究所論集 Vol.22 No.1

The purpose of this present study was to investigate the effect of maximal exercise and a long-term antioxidants supplementation on antioxidant enzyme(GPx and GR) activity of gastrocnemius muscle in rats. Twenty four male Sprague-Dawley rats(4 weeks old) were used as subjects. The subjects were divided into 4 groups such as, CON(n=6 in control group), NAE(n=6 in non antioxidants exercise group), AC(n=6 in antioxidants control group) or AE(n=6 in antioxidants exercise group). Non-antioxidants group(CON & NAE) fed general food(Samyang, Inc., Korea) for 16 weeks. Antioxidants group(AC & AE) fed the general food and the mixed antioxidants which were consist of vitamin E(200 lu/kg/day), vitamin C(50 mg/rat/day), vitamin B6(250 ug/kg/day), β carotene(300 mg/kg/day) and selenomethionine(0.1 mg/mg/day), The weight of each subject group was weighed 2-3 times per week. After the diet experiment for 16 weeks, exercise groups(NAE & AE) completed acute treadmill running(speed increased gradually to 25 m/min, 15% uphill grade, ∼50±10 min) until exhaustion. Immediately after exhaustive treadmill exercise, all the subjects were sacrificed for the isolation of gastrocnemius. Then, GPx(Glutathione Peroxidase) and GR(Glutathione Reductase) of the gastrocnemlus muscle were assayed. The protein concentration in the muscle and heart was determined by the Lowry method. After finishing the analysis of antioxidant activity, statistical analysis was carried out by two-way ANOVA and independant t-test. The results of this study can be summarized as follows: Maximal exercise increased the GPx and GR activity of gastrocnemius muscle, Further, a long-term antioxidants supplementation more significantly increased the GPx and GR activity of gastrocnemius muscle than those of non-antioxidants group. In conclusion, the present results clearly show that the exhaustive maximal exercise gave rise to increase oxidative stress which led to oxidative damage so that the antioxidant enzyme activity of gastrocnemius muscle were increased. Further, it has been found that the long-term antioxidants supplementation could decrease oxidative stress in the tissues so that the antioxidant enzyme activity of skeletal muscles was more increased.

센서구동 방식에 의한 태양추적 시스템

박정국,최연옥,조금배,최창주 조선대학교 에너지.자원신기술연구소 2004 에너지·자원신기술연구소 논문지 Vol.26 No.2

Nowaday, almost of practical energy comes from the fossil fuel, such as coal, oil and gas. But those methode causes the environmental pollution. Photovoltaic systems are considered as a alternative energy source to overcome the shortage of electricity in the future. Photovoltaic system is easier to operate and maintain than the other power generating system since it generally contains no moving parts, operate silently and require very little maintenance. In this paper, it is proposed 150[W] solar tracking system, the system designed as the normal line of the solar cell always runs parallel the ray of the sun. This design can minimize the cosign loss of the system.

Fluoxetine 투여와 관련된 양측 측두하악관절 손상 1예

배치운,김연주,김태석,김정진,이창욱,이수정,이철,백인호 大韓神經精神醫學會 2004 신경정신의학 Vol.43 No.4

We hereupon present a case of injured temporomandibular joint (TMJ) associated with fluoxetine monotherapy-inducedrepeated yawning. Further information is needed regarding the relationship between fluoxetine administration and clinically significant yawning. Clinicians should be more careful to listen to their patients when they describe unexpected reactions to medications.

중이 진주종상피에서 bcl-2의 발현 양상

용만강,이창수,이주연,이동욱,신시옥 충북대학교 의과대학 충북대학교 의학연구소 2003 忠北醫大學術誌 Vol.13 No.1

연구목적:중이 진주종의 조직학적 특징은 진주종 상피의 과증식과 비정상적인 과각질화 라고 요약되는데 이러한 현상은 진주종 상피를 형성하는 각질세포의 증식, 분화 및 세포 사 멸로 이루어진 세포주기의 항상성 변화로 기인한다. 본 연구는 세포 고사(apoptsis)에 억제작용(inhibition)이 있는 것으로 알려져 있는bcl-2가 중이 진주종에서 발현되는지 알아 보았다. 대상 및 방법:만성 진주종성 중이염으로 수술을 시행했던 환자 10 예에서 중이 진주종 상피를 얻어 western blot analysis를 시행하여 중이 진주종 조직에서의 bcl-2의 발현을 관찰하였다. 결과:Western blot analysis 상 정상 피부 조직과는 달리 중이 진주종 조직에서는 10 예 모두에서 bcl-2가 발현되었다. 결론:이러한 결과는 bcl-2가 중이 진주종에서 과발현 되는 것으로 볼 수 있다. Keratin debris의 축적은 각질세포 사멸현상의 증가에 의한 것으로 세포고사 억제 작용이 있는 bcl-2가 중이 진주종의 병인(pathogenesis)에 중요한 역할을 할 것으로 판단된다. Purpose:The unique pathologic feature of cholesteatoma is known to be accumulation of keratin debris within the middle ear cavity resulting from hyperproliferation and hyperk-eratosis of keratinocyte in the cholesteatoma epithelium. This phenomenon is due to disturbance of the epithelial homeostasis in the cell cycle. This study was designed to identfy the expression of bcl-2 in the cholesteatoma epithelium. Materials and methods:Ten fresh human cholesteatoma tissues and five postauricular skins were obtained from patients undergoing middle ear operations. Western blot analysis was performed for detection of bcl-2 expression on the tissues. Results:Western blot analysis revealed that bcl-2 protein was expressed in all of choesteatoma epithelium specimens, while barely expressed in postauricular skins samples. Conclusion:These findings show that bcl-2 was overexpressed in cholesteatoma epithe-lium. The author suggests that bcl-2 may play a role in pathogenesis of chronic otitis media with cholesteatoma.