Sr·페라이트의 자기특성에 관한 연구

임재근,서강수,문현욱,신용진 明知大學校 産業技術硏究所 1992 産業技術硏究所論文集 Vol.11 No.-

This thesis is the study on the magnetic properties of strontium (Sr) ferrite. Specimens of SrO·nFe₂O₃,basic composition, with n=5.9 which is nonstoichiomatric composition region were prepared by sintering at 1275°C for 1hr, whthin air surroundings. In order to increase coercivity, additives of 0.4wt%SiO₂ and 0.7wt%CaCO₃ were added into basic composition, and 0.5wt%∼2.0wt%Cr₂O₃ was added as second additives. In case of second additives 1.5wt%Cr₂O₃, it was obtained uniformed grain size and magnetic properties was increased. The sintering temperature was 1150°C, 1180°C, 1210°C, 1240°C and 1270°C respectivily and cooling was performed in furnance. From the research and experiments on the magnetic properties of strontium (Sr) ferrite based on the complex additive technique, it was obtained good magnetic properties of (BH)mas=0.72MGOe, at the sintering temperature of 1210°C, in the case of (basic composition)+(basic additive)+(1.5wt%Cr₂O₃)

RAW 264.7 세포에 대한 중국산 천연 광물성 섬유 TAFMAG의 독성효과

임영,한진구,김지홍,김현욱,김은경,김경아,장황신 大韓産業醫學會 1999 대한직업환경의학회지 Vol.11 No.3

Objectives : This study was designed to evaluate cytotoxicity of TAFMAG, which is a trade name of natural mineral fiber mined and produced in China. Methods : The cytotoxicity of TAFMAG was evaluated by measuring iron content, lipid peroxidation, erythrocyte hemolysis, and cytotoxicity in vitro. These results were compared with the data of chrystotile and wollastonite as a positive and negative control, respectively. Results : There was significant increase of Fenton activity in TAFMAG and chrysotile with dose-response pattern. The iron chelating agent, desferrioxamine, significantly decreased Fenton activity of the particulates except wollastonite. TAFMAG and chrysotile fibers significantly increased malondialdehyde concentration from lipid peroxidation of the red blood cell membrane. In erythrocyte hemolysis test, TAFMAG & chrysotile had stronger effect on erythrocyte hemolysis than wollastonite with the concentration of 1,000g/ml. Furthermore, TAFMAG was more hemolytic than chrysotile with the concentration of 5,000g/ml. There was a significant cytotoxic effect in TAFMAG and chrysotile on RAW cell compared with wollastonite. Conclusions : In vitro study suggested that TAFMAG may have a similar health hazard as usual asbestos.

급성 심근허혈에 의해 윤발된 승모판 폐쇄부전의 기전에 관한 실험적 연구

강덕현,송현,송재관,김현숙,이재환,임희영,이재원,박성욱,박승정,송명근 대한순환기학회 1999 Korean Circulation Journal Vol.29 No.8

당뇨병 환자에서 혈장 Thrombin-Antithrombin Ⅲ 및 Plasmin-α_2-Plasmin Inhibitor 복합체의 임상적 의의

김경욱,김은숙,정상수,윤수지,박우일,이준희,남수연,안철우,문병수,김경래,차봉수,송영득,임승길,이현철,허갑범 대한당뇨병학회 2002 Diabetes and Metabolism Journal Vol.25 No.5

연구배경:당뇨병 환자에서 혈액응고 및 섬유소용해 체계의 이상경향이 있어 그 결과로 여러 혈관합병증의 발생위험이 높다는 사실은 널리 알려져 있다. 그 기전은 아직 확실히 밝혀지지 않았으나, 고혈당으로 인한 혈장 단백질들의 비효소성 당화작용이나 산화성 스트레스로 인한 유리 라티칼 작용으로 응고항진이나 섬유소용해 활성의 저하를 유발하는 것으로 생각되고 있다. 최근 응고 및 용해인자와 그 억제자의 복합체들의 증가가 이 상태를 비교적 예민하게 반영한다고 알려져 있다. 방법:본 연구에서는 당뇨병 환자 101명과 정상 대조군 20명에서 혈장내 thrombin­antithrombin complex(TAT)와 plasmin­α₂­plasmin inhibitor complex(PIC)를 측정하여 비교하고, 당뇨병 환자에서 미세혈관 합병증과 대혈관합병증의 유무에 따른 차이와, 이미 혈관 질환의 위험인자로 알려져 있는 인자들간의 상관성을 알아보고자 하였다. 결과:1. 환자의 분포를 살펴보면 혈관합병증이 있는 군은 85명, 혈관합병증이 없는 군은 16명이었고, 평균연령은 각각 57.9±14.1세, 49.9±16.6세로 혈관 합병증이 있는 군에서 더 나이가 많았고, 체질량지수는 23.2±3.4㎏/㎡, 24.1±3.4㎏/㎡로 두 군간 유의한 차이는 없었다. 또 두 군간의 혈압 및 HbA1c, 공복혈당 및 인슐린과 C­peptide, 총 콜레스테롤, 중성지방, HDL­콜레스테롤, Lp⒜는 유의한 차이가 없었고, 미세혈관합병증이 있는 군에서 당뇨병의 유병기간이 길었다. 2. TAT 및 PIC의 농도는 정상 대조군에서는 2.8±1.2 ng/mL, 240.4±69.7 ng/mL이었고, 당뇨병 환자군에서는 9.5±22.6 ng/mL, 472.2±258.7 ng/mL이었다. TAT와 PIC 모두 당뇨병 환자군에서 정상 대조군에 비해 유의하게 증가되어 있었고(p<0.001), TAT/PIC ratio는 두 군간 차이가 없었다. 3. 당뇨병 환자의 혈관합병증에 따른 TAT 및 PIC, fibrinogen 농도는 합병증이 없는 군은 각각 4.1±2.4ng/mL, 362.2±272.0ng/mL, 322.7±102.4mg/mL으로 PIC와 fibrinogen의 증가를 보였으나, 연령을 보정한 후에는 통계학적 유의성은 없었다. 또 대혈관 합병증군에서는 각각 6.0±4.9 ng/mL, 507.4±321.6 ng/mL, 427.1±194.7 mg/dL이었으며 미세·대혈관 합병증군에서는 10.4±6.4 ng/mL, 484.8±269.7 ng/mL, 388.4±132.4 mg/dL으로 TAT의 증가를 보였으나 역시 연령을 보정한 후에는 통계학적 유의성은 없었다. 4. 미세혈관합병증군에서 HbA1c(>8%)가 높은 군의 PIC 농도가 유의하게 높았고(p=0.049), 대혈관합병증군에서 HbA1c(>8%)가 높은 군의 총 콜레스테롤 농도가 유의하게 높았다(p=0.042). 5. 총 당뇨병 환자군에서 PIC는 fibrinogen과 HbA1c와 양의 상관관계를, BMI와 음의 상관관계를 보였으며(r=0.47, 0.31,-0.25), 혈관 합병증이 없는 당뇨병 환자군에서만 TAT는 HbA1c와 양의 상관관계를 보였다(r=0.67). 결론:이상의 결과에서 혈장 TAT 및 PIC 농도는 당뇨병 환자에서 정상 대조군에 비해 의미있게 증가되어 있었고, 당뇨병 환자군에서는 연령의 증가와 유병기간이 혈액응고항진 및 용해의 장애에 큰 역할을 함을 알 수 있었으며, 총 당뇨병 환자군에 PIC와 HbA1c와 양의 상관관계를, BMI와 음의 상관관계를 보였으며 혈관 합병증이 없는 당뇨병 환자군에서만 TAT는 HbA1c와 양의 상관관계를 보였다. 따라서 당뇨병 환자에서 혈액응고 및 용해의 장애가 동반되어 있다고 볼 수 있으며, 혈장 TAT 및 PIC는 혈관합병증으로의 진행을 예측하는 지표로서 유용하리라 생각된다. 또 혈당조절정도와 상관성이 있으므로 혈당조절후에 추적검사를 시행하여 합병증의 예방이 가능한지 추후 연구가 필요하리라 생각된다. Background : Abnormality of coagulation and fibrinolystic system is known as a predisposing factor of vascular complication in diabetes. Although the pathogenesis is not well known, non-enzymatic glycation reaction and the increase in production of free radicals due to an increased oxidative stress may be linked to the hypercoagulibility and hypofibrinolytic activity. As indices of abnormality in coagulation and firinolysis in peripheral blood, plasma thrombin-antithrombin Ⅲ complex (TAT) and plasmin-α_2-plasmin inhibitor complex (PIC) were measured. The purpose of this study was to clarify whether hypercoagulability exists in diabetic patients with or without vascular complication. Methods : In our study, we measured plasma thrombin-antithrombin Ⅲ compelx (TAT) and plasmin-α_2-plasmin inhibit or complex (PIC) in 101 diabetic subjects and 20 controls. Comparing TAT and PIC levels in diabetic microvascular complication group, diabetic macrovascular complication group and controls, we examined correlation between risk factors associated with diabetic vascular complication. Results : 1. The group with diabetic vascular complication was older than group without complication. There was no significant difference in BMI, blood pressure, HbA_ic, blood sugar level, insulin, C-peptide, serum creatinine, total cholesterol, triglyceride, HDL-cholesterol, Lp (a) between two groups. The group with diabetic microvascular complication had longer duration of diabetes. 2. Concentration of TAT and PIC were 2.8±1.2 ng/ mL, 240.4±69.7 ng/ mL in controls and 9.5±22.6 ng/ mL, 472.2±258.7 ng/ mL in diabetic patients, respectively. TAT and PIC were significantly higher in diabetic patients than in control (p<0.001). But TAT/PIC ratio was no significant difference between two groups. 3. In diabetic patients, concentration of TAT and PIC and fibrinogen were respectively 4.1±2.4 ng/ mL, 362.2±272.0 ng/ mL, 322.7±102.4 mg/ dL in group without vascular complication and 5.3±4.1 ng/ mL, 529.5±258.7 ng/ mL, 374.9±106.2 mg/ dL in group with microvascular complication, which group had increase in PIC and Fibrinogen but no significance after correction of age. Concentration of TAT and PIC and Fibrinogen were 60.±4.9 ng/ mL, 507.4±321.6 ng/ mL, 427.1±194.7 mg/ dL in macrovascular complication, and 10.4±6.7 mg/ mL, 484.8±269.7 ng/ mL, 388.4±132.4 mg/ dL in combined vascular complication which group showed increase of TAT but also had no significant increase after correction of age. 4. In diabetic microvascular complication patients, group of high HbA_1c (>8%) (p=0.049) had significant high PIC concentration. In diabetic macrovascular complication patients, group of high HbA_1c (>8%) (p=0.042) had significant high total cholesterol concentration. 5. In all diabetic patients, PIC was positively correlated with fibrinogen and HbA_1c and negatively correlated BMI (r=0.47, 0.31, -0.25). Only in daibetic patients without angiopathy, TAT was positively correlated with HbA_1c (r=0.67). Conclusion : In this study, plasma TAT and PIC concentration significantly increased in diabetic patients compared with controls, and PIC was increased in group with microvascular complication, TAT were increased in group with combined micro macrovascular complication. However, there was no significance relationship existed when correctinf for age. PIC was correlated with HbA_1c. TAT was correlated with HbA_1c only in the group without angiopathy. Abnormality of coagulation and fibrinolysis were combined in diabetes, plasma TAT and PIC can be used as an index of vascular complication. Also we found the correlation with the degree of the blood glucose control. Therefore we need follow up study for the possibility of prevention of vascular complication after controlling the blood glucose to age-matched patients (J Kor Diaabetes Asso 25:354~363, 2001).

아몰퍼스 자성박대의 자기센서 응용에 관한 연구

金大柱,林在根,金玄郁,愼鏞鎭 明知大學校 産業技術硏究所 2002 産業技術硏究所論文集 Vol.21 No.-

In this thesis, we have described about application of amorphous magnetic ribbon of FeCoSiB compound to magnetic sensing device. As the samples of our experiment, we used a near zero-magnetostrictive amorphous magnetic ribbon of (Fe0.06Co0.94)79Si2.1B18.9 composition with its thickness of 26[㎛], its length of 5[㎝] and its width of 2[㎜], which was fabricated by rapidly quenching method. In order to improve the magnetic properties of the samples, we annealed them under magnetic field where the range of the crystallization temperature Tx and the Curie temperature Tc were 300~400[℃]. Then, by measuring them with X-ray diffraction(XRD) and vibrating sample megnetometer(VSM) analysis method. we found Tx≒451[℃] and Tc≒441[℃]. From the hysteresis curve of the finally annealed sample ribbon, we found the Large Bakhausen Jump(LBJ) effect at the reversal magnetization field Hw≒0.5[Oe]. This LBJ effect was also observed at the variation of the magnetic domain in the process of magnetization. Thus, it is proved that the amorphous magnetic ribbon of FeCoSiB compound can be use as a magnetic sensing device.

한국인에서 CC-SIT와 비교한 KVSS Test의 임상적 유용성 평가 : 예비연구 Pilot study

김진국,장현종,임채형,남태욱,심대보 건국대학교 의과학연구소 2003 건국의과학학술지 Vol.13 No.-

Background and Objectives: Sniffin' Sticks test is the test of nasal chemosensory performance based on pen-like odor dispensing devices. KVSS(Korean Version of Sniffin' Sticks) Test was developed as the "Korean olfactory test" using the odorants which are familiar to Korean. Authors evaluated the clinical validity of KVSS Test compared with CC-SIT (Cross-Cultural Smell Identification Test) in Korean. Materials and Methods: The subjects of this study were 25 normosmic volunteers who were divided into five groups according to age. Each group was 5 normosmic volunteers. And they consisted of 12 men and 13 women. KVSS Test and CC-SIT were used for the evaluation of olfactory function. Results: Our study showed the negative correlation between age and olfactory function test (CC-SIT score, KVSS Test I score and KVSS Test II score). Normosmia rate of KVSS Test was more higher than that of CC-SIT. Also KVSS Test had more familiar items for Koreans compared with that of CC-SIT. CC-SIT score and KVSS Test score showed showed the positive corrclation. And each test revealed high reliability in test-retest evaluation. Conclusion: The KVSS Test can be used as an olfactory function test for Koreans.

부비동내시경수술 후 후각기능의 변화

김진국,남태욱,임채형,장현종 건국대학교 의과학연구소 2002 건국의과학학술지 Vol.12 No.-

Background and Objectives: Rhinosinusitis is the most common cause of olfactory impairment and endoscopic sinus surgery is considered as a surgical procedure of choice for treating chronic sinusitis. CC-SIT (Cross-Cultural Smell Identification Test) consists of 12 items well known in most non-English-speaking cultures. Authors evaluated the therapeutic effects of endoscopic sinus surgery on olfactory dysfuction using CC-SIT. Materials and Methods: The subjects of this study were seventeen sinusitis patient who had undergone ESS from November 2001 through April 2002. All patients were divided into two groups according to nasal polyp and CT findings. CC-SIT was used for the evaluation of olfactory function. Results: Forty seven percents of patients had improvement in olfactory function postoperatively. No correlation was found between changes in CC-SIT score and nasal polyp and preoperative CT findings. Conclusion: It is concluded that nasal polyp and CT findings have no effect on olfaction.

직업성 요통 환자에서 항 제 I 형 교원질 항체역가의 의의

이종민,권용욱,김수근,임현술,김지용,정준호 大韓再活醫學會 2000 Annals of Rehabilitation Medicine Vol.24 No.1

일개 자동차 부품공장 근로자에서 초음파로 측정한 수근관 형태와 수근관증후군 위험도

김덕수,정해관,임현술,권용욱,이종민,조대현,최대섭 大韓産業醫學會 2002 대한직업환경의학회지 Vol.14 No.3

목적 : 일개 사업장의 생산직 근로자를 대상으로 손목 계측치 및 초음파를 이용한 수근관 계측치의 상관성 분석을 통하여 수근관증후군 발생에 관여하는 개인의 감수성 및 위험요인을 파악하여 생산직 근로자들의 수근관증후군 예방에 활용하고자 본 연구를 수행하였다. 방법 : 경주시에 위치한 자동차 방음재를 생산하는 사업장에 생산직 근로자 남자 24명, 여자 11명 등 총 35명을 대상으로 2000녀 4월과 2000년 10월 반드시 각 설문조사, 이학적검사, 전기진단검사를 실시하였으며, 2000년 10월에는 초음파를 이용한 수근관계측도 실시하였다. 결과 : 수근관증후군의 신체계측 요인에 따른 분석에서는 수근관 전치/폭 비가 0.17 미만인 군에 비하여 0.17 이상인 군에서 통계적으로 유의하게 높았다(p<0.05). 총 수근관 면적(두께×폭)은 300 ㎟이상인 군에 비하여 300㎟ 미만인 군에서 통계적으로 유의하게 높았다(p<0.05). 성별을 통제변수로 처리한 신체 계측치간 상간 분석에서는 수근관폭은 전기진단 검사와 음의 상관성을 보였으며, 수근관 두께는 전기진단 검사와 양의 상관성을 보였다. 수근관 두께/폭 비는 전기진단 검사와 양이 상관성을 보였으며, 수근관비 전치/두께 비는 전기진단 검사 결과와 음의 상관성을 보였다. 하부 수근관 면적[폭×(두께-전치)]은 전기진단 검사와 양의 상관성을 보였으며, 상부 수근관 면적(폭×전치)은 전기진단 검사와 음의 상관성을 보였다. 또한 수근관 전치의 상대적 비가 클수록 수근관증후군의 회복이 유의하게 좋았다. 결론 : 수근관증후군은 수근관 폭이 좁을수록, 수근관 두께가 두꺼울수록, 수근관 전치가 작을수록 수근관증후군 위험도가 증가한다. 저자들은 초음파를 이용한 수근관 형태의 측정은 수근관증후군의 발생의 내적 요인에 대한 중요한 정보를 제공하면 수근관증후군 발생 및 회복의 개별적 위험요인을 예측하는데 중요한 근거를 제공하는 것으로 판단하였다. Objectives: This study was conducted to evaluate individual susceptibility to carpal tunnel syndrome (CTS) by ultrasonographic measurement of the carpal tunnel configuration in workers doing repetitive work. Methods: The study subjects consisted of 24 male and 11 female workers in a soundproof material manufacturing company in Gyeongju. We conducted a self-reported questionnaire survey, a physical examination and an electrodiagnostic study (EDS) in April 2000. After the examination, jobs were rearranged for workers with CTS. A follow up physical examination. EDS, and measurement of the carpal tunnel by ultrasonography was done six monsths later. Results: Of those studied. prevalence or CTS was 63.6/100 persons among women and 29.2/100 persons among men. Mean depth and width of wrist was shorter in those with CTS compareal to the controls (p<0.05). The risk of CTS was higher in workers whose carpal tunnel ratio (displacement/width) was 0.17 or higher (OR 7.13, 95% confidence interval 1.18-43.1), and in workers whose carpal tunnel area was less than 300 ㎟ (OR 8.00, 95% confidence interval 1.18-68.5). Carpal tunnel depth and depth/width ratio had a positive correlation with motor latency of the median nerve and median-ulnar sensory latency difference (p<0.05). whereas the carpal tunnel width. displacement/depth ratio, and area (width×displacement) had a negative correlation with median nerve latencies after adjusting for gender. Workers who showed an improvement in the clinical stage of CTS after job rearrangement had a significantly lower carpal tunnel displacement/width ratio and displacement/depth ratio. They also had smaller upper carpal tunnel area (width×displacement) and larger upper carpal tunner\l area [(depth-displacement)×width] than the controls (p<0.05). Conclusions:Ultrasonographic measurement of the carpal tunnel is a good predictor of susceptibility and prognosis of CTS in workers doing repetivive work.

좌심방 석회화와 관련된 반복된 좌심방 혈전 1예

김성훈,우성용,오유경,정우백,임철현,신재원,박철수,윤호중,정욱성,홍순조 대한순환기학회 2004 Korean Circulation Journal Vol.34 No.3