• Journal of Chest Surgery
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• 제27권3호
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• pp.177-186
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• 1994

Pentastarch is a hydroxyethyl starch similar to hetastarch, but lower average molecular weight and fewer hydroxyethyl groups which result in enhanced enzymatic hydrolysis and faster renal elimination.This report was performed to compare the clinical efficacy and safety of 10 % pentastarch[Pentaspan , group I] for plasma volume expansion after open heart surgery with that of 5% albumin[Plasmanate, group II]. There were no statistically significant differences between the group I [n=18] and group II [n:19] in the preoperative parameters [age, sex, body weight] and operative parameters[bypass time, aorta cross clamping time]. During the first 24 hours after arrival of the patient in the surgical intensive care unit, colloid solution [500--1000 ml] was infused to maintain left atrial pressure of more than 8 mmHg, or cardiac index of 2.0 L/min/M2 of more. In results, there were 3 complications of hypotension immediately after infusion of 5 % albumin solution and 2 among the 3 patients were excluded for the study. However there was no complication after infusion of 10 % pentastarch solution. Hemodynamic responses to infusion was similar for both groups, although in group I a greater increase in both left atrial pressure[mean 1.8 versus 0.7 mmHg, p< 0.05] and right atrial pressure [mean 2.2 versus 1.7 mmHg, p < 0.05] was observed during infusion of the first 500 ml. There were no significant differences in any of the measured respiratory parameters[PaO2, intrapulmonary shunt, and effective lung compliance]. Homodilution with colloid significantly reduced hemoglobin [mean 1.2 versus 0.8 gm/dl], and serum protein and albumin level[total protein;4.8$\pm$ 0.5 versus 5.2 $\pm$0.5 gm/dl, p < 0.05: albumin: 3.2 $\pm$0.4 versus 3.6 $\pm$0.6 gm/dl, p < 0.05] by 6:00 AM on 1 day postoperatively, however there were no significant differences on 7 day postoperatively. The mean serum colloid osmotic pressure and osmolarity was similar in both group.There were no abnormal findings of liver function and kidney function in all the patients. There were no significant between-group differences in bleeding time, platelets, prothrombin time, activated partial thromboplastin time and amount of chest tube output measured on 1st and 7th postoperative day. These findings demonstrated that 10% pentastarch is more effective and safe for plasma volume expension than 5 % albumin solution with no adverse effects on coagulation. Also 10 % pentastarch is less expensive than 5 % albumin and it would appeare to be a reasonable first choice for plasma volume expansion.

• 한국전기전자재료학회논문지
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• 제29권8호
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• pp.461-465
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• 2016

n-type silicon shows the better tolerance towards metal impurities with a higher minority carrier lifetime compared to p-type silicon substrate. Due to better lifetime stability as compared to p-type during illumination made the photovoltaic community to switch toward n-type wafers for high efficiency silicon solar cells. We fabricated the front electrode of the n-type solar cell with AgAl paste. The electrodes characteristics of the AgAl paste depend on the contact junction depth that is closely related to the firing temperature. Metal contact depth with p+ emitter, with optimized depth is important as it influence the resistance. In this study, we optimize the firing condition for the effective formation of the metal depth by varying the firing condition. The firing was carried out at temperatures below $670^{\circ}C$ with low contact depth and high contact resistance. It was noted that the contact resistance was reduced with the increase of firing temperature. The contact resistance of $5.99m{\Omega}cm^2$ was shown for the optimum firing temperature of $865^{\circ}C$. Over $900^{\circ}C$, contact junction is bonded to the Si through the emitter, resulting the contact resistance to shunt. we obtained photovoltaic parameter such as fill factor of 76.68%, short-circuit current of $40.2mA/cm^2$, open-circuit voltage of 620 mV and convert efficiency of 19.11%.

• Journal of Korean Neurosurgical Society
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• 제49권3호
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• pp.147-152
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• 2011

Objective : The aim of this study was to evaluate the reliability and validity of the Pediatric Functional Assessment of Cancer Therapy Questionnaire Brain Tumor Survivor (version 2.0) Aged 13 years and older (Parent Form) (pedsFACT-BrS parent of adolescent). Methods : The pedsFACT-BrS parent of adolescent was translated and cross-culturally adapted into Korean, following standard Functional Assessment of Chronic Illness Therapy (FACIT) methodology. The psychometric properties of the pedsFACT-BrS parent of adolescent were evaluated in 170 brain tumor patient's mothers (mean age=43.38 years). Pretesting was performed in 30 mothers, and the results indicated good symptom coverage and overall comprehensibility. The participants also completed the Child Health Questionnaire Parent Form 50 (CHQ-PF-50), Neuroticism in Eysenck Personality Questionnaire, and Karnofsky score. Results : In validating the pedsFACT-BrS parent of adolescent, we found high internal consistency, with Cronbach's ${\alpha}$ coefficients ranging from 0.76 to 0.94. The assessment of test-retest reliability using intraclass correlation coefficient revealed satisfactory values with ICCs ranging from 0.84 to 0.93. The pedsFACT-BrS for parent of adolescent also demonstrated good convergent and divergent validities when correlated with the Child Health Questionnaire Parent Form 50 (CHQ-PF-50) and the Neuroticism in Eysenck Personality Questionnaire. The pedsFACT-BrS parent of adolescent showed good clinical validity, and effectively differentiated between clinically distinct patient groups according to the type of treatment, tumor location, shunt, and Karnofsky score of parent proxy report. Conclusion : We confirmed that this reliable and valid instrument can be used to properly evaluate the quality of life of Korean adolescent brain tumor patients by their parents' proxy report.

• Tuberculosis and Respiratory Diseases
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• 제48권6호
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• pp.973-979
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• 2000

제 I 형 당원병에서 폐고혈압은 드문 합병증으로 외국 문헌에서 6예만이 보고되었으나 국내에는 아직 보고된 바가 없다. 저자들은 최근 제 Ia형 당원병으로 진단 받았던 31세 남자 환자에서 폐고혈압이 동반되었던 예를 경험하였기에 문헌 고찰과 함께 보고하는 바이다.

• Journal of Yeungnam Medical Science
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• 제19권2호
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• pp.99-106
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• 2002

단순 심실중격결손증은 선천성 심질환중 흔한 질환이지만 어린 나이 혹은 저체중환아에서 시행하는 경우 경험에 따라 만족스럽지 못한 경우도 있어 영아기에 수술을 시행한 단순 심실중격결손증 환자들의 수술 결과를 조사하였다. 1996년부터 2000년까지 첩포봉합술을 시행한 45명을 대상으로 체중 5 kg을 기준으로 수술의 결과를 분석하였다. 수술사망은 없었으며 두 군간의 합병증 발생에 있어 유의한 차이는 없었다. 수술 수기로 사용된 단순 연속봉합법은 전례에서 적용할 수 있었으며 증상이 있는 심실 중격결손증은 체중이 5kg이하의 환아에서도 시기에 관계 없이 안전하게 시행할 수 있었다.

• 대한치과보철학회지
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• 제31권3호
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• pp.423-446
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• 1993

Titanium and its alloys are finding increasing use in medical devices and dental implants. The strong selling point of titanium is its resistance to the highly corrosive body fluids in which an implant must survive. This corrosion resistance is due to a tenacious passive oxide or film which exists on the metal's surface and renders it passive. Potentiodynamic polarization measurement is one of the most commonly used electro-chemical methods that have been applied to measure corrosion rates. And the potentiodynamic polarization test supplies detailed information such as open circuit, rupture, and passivation potential. Furthermore, it indicates the passive range and sensitivity to pitting corrosion. This study was designed to compare the corrosion resistance of the commonly used dental implant materials such as CP Ti, Ti-6A1-4V, Co-Cr-Mo alloy, and 316L stainless steel. And the effects of galvanic couples between titanium and the dental alloys were assessed for their useful-ness-as. materials for superstructure. The working electrode is the specimen , the reference electrode is a saturated calomel electrode (SCE), and the counter electrode is made of carbon. In $N_2-saturated$ 0.9% NaCl solutions, the potential scanning was performed starting from -800mV (SCE) and the scan rate was 1 mV/sec. At least three different polarization measurements were carried out for each material on separate specimen. The galvanic corrosion measurements were conducted in the zero-shunt ammeter with an implant supraconstruction surface ratio of 1:1. The contact current density was recorded over a 24-hour period. The results were as follows : 1. In potential-time curve, all specimens became increasingly more noble after immersion in the test solution and reached between -70mV and 50mV (SCE) respectively after 12 hours. 2. The Ti and Ti alloy in the saline solution were most resistant to corrosion. They showed the typical passive behavior which was exhibited over the entire experimental range. Therefore no breakdown potentials were observed. 3. Comparing the rupture potentials, Ti and Ti alloy had the high(:st value (because their break-down potentials were not observed in this study potential range ) followed by Co-Cr-Mo alloy and stainless steel (316L). So , the corrosion resistance of titanium was cecellent, Co-Cr-Mo alloy slightly inferior and stainless steel (316L) much less. 4. The contact current density sinks faster than any other galvanic couple in the case of Ti/gold alloy. 5. Ag-Pd alloy coupled with Ti yielded high current density in the early stage. Furthermore, Ti became anodic. 6. Ti/Ni-Cr alloy showed a relatively high galvanic current and a tendency to increase.

• 한국산학기술학회논문지
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• 제15권10호
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• pp.5933-5938
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• 2014

본 연구에서는 Atos 60의 시험편에 혼합가스의 변화에 따른 FCA용접을 하였고, 용접특성 분석 위하여 용접공정상의 실시간 모니터링 시스템과 용접 후 기계적 성질을 평가 하였다. Ar 80%+$CO_2$ 20% 혼합하고 낮은 속도로 용접한 경우 가장 미려한 비드와 스패터 발생이 적게 나타났으며, 반면 $CO_2$ 100%인 경우 스패터가 많이 발생하는 것을 확인하였다. 정상단락이 발생하는 저전류 영역으로 혼합가스의 사용에 대한 스패터 발생을 확인 할수 있는 조건이며, $CO_2$ 100%인 경우 각층의 단락율은 약 2배 이상 높았고, Peak의 분포가 많은 아크의 불안정 상태로 나타났다. 인장시험결과 Ar 80%+$CO_2$ 20%, Ar 90%+$CO_2$ 10%, $CO_2$ 100%의 항복강도는 각각 511MPa, 507MPa, 469MPa 이었으며, $CO_2$ 100%의 항복강도 보다 각각 약 8.9% 8.1% 향상되었다. 인장강도는 각각 622MPa, 609MPa, 581MPa로 $CO_2$ 100%의 인장강도 보다 각각 약 7.0%, 4.8% 향상되었다.

• 한국임상수의학회지
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• 제30권2호
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• pp.87-94
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• 2013

본 회고 연구에서는 동맥관 개존증에 이환된 개에서 심장중재술을 통한 치료증례의 임상적 특징과 치료예후를 조사하였다. 환축의 구성을 보면, 말티스와 암컷이 차지하는 비중이 컸다. Bounding pulse와 좌심저부의 심잡음이 가장 대표적인 신체검사 소견이며, differential cyanosis은 매우 드물게 관찰되었다. 심전도상 특징은 좌심종대소견과 동성빈맥이였다. 흉부방사선상 좌심실 종대와 대동맥 확장을 동반한 triple bumps가 대표적인 소견이 였다. 심초음파상 특징은 좌심실 종대를 동반한 폐동맥 단축단면상 심각한 와류 소견이였으며, 다수의 환자에서 이첨판 역류 소견도 관찰되었다. 37증례 중 32증례에서 thromboemolic coils (TCE)이나 Amplatz canine ductal occluder (ACDO)를 이용한 심장 중제술적 치료가 실시되었다. 일시적인 혈색소뇨가 관찰되었고 장착된 코일이나 ACDO가 이탈되는 부작용이 확인되었다. 하지만 장기 관찰이 가능했던 29증례에서 특별한 부작용은 관찰되지 않았다.

• 대한의용생체공학회:의공학회지
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• 제19권2호
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• pp.163-170
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• 1998

인공심장의 주된 합병증인 혈전과 감염의 문제를 줄이고 장착 환자의 삶의 질을 높이기 위하여 체내 완전 매립형 전기 유압식 인공심장을 개발하고 있는 것과 이 모델을 이용한 동물실험에 대하여 보고하는 바이다. 이 인공심장은 혈액펌프, 유압구동기, 구동제어회로, 경피적 에너지-정보 전송시스템, 체내 받테리 등으로 구성되어 있다. 실험동물은 체중 62Kg의 송아지를 이용하였다. 흉강내 이식하는데 어려움은 없었고, 수술 후 생존하는 동안 혈역학적으로 문제는 없었으며 특이한 합병증도 발생하지 않았다. 그러나 이식 11일째 기계적인 결함으로 작동이 정지하였다. 앞으로 기계적 수명이나 생체적 합성 등의 문제 등히 해결되어야 할 것이다.

• Journal of Korean Neurosurgical Society
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• 제60권5호
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• pp.604-609
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• 2017

Objective : An adjustable Ghajar guide is presented to improve the accuracy of the original Ghajar guide technique. The accuracy of the adjustable Ghajar guide technique is also investigated. Methods : The coronal adjustment angle from the orthogonal catheter trajectory at Kocher's point is determined based on coronal head images using an electronic picture archiving and communication system. For the adjustable Ghajar guide, a protractor is mounted on a C-shaped basal plate that is placed in contact with the margin of a burrhole, keeping the central $0^{\circ}$ line of the protractor orthogonal to the calvarial surface. A catheter guide, which is moved along the protractor and fixed at the pre-determined adjustment angle, is then used to guide the ventricular catheter into the frontal horn adjacent to the foramen of Monro. The adjustable Ghajar guide technique was applied to 20 patients, while a freehand technique based on the surface anatomy of the head was applied to another 47 patients. The accuracy of the ventricular catheter placement was then evaluated using postoperative computed tomography scans. Results : For the adjustable Ghajar guide technique (AGT) patients, the bicaudate index ranged from 0.23 to 0.33 ($mean{\pm}standard$ deviation [SD] : $0.27{\pm}0.03$) and the adjustment angle ranged from $0^{\circ}$ to $10^{\circ}$ ($mean{\pm}SD:5.2^{\circ}{\pm}3.2^{\circ}$). All the AGT patients experienced successful cerebrospinal fluid diversion with only one pass of the catheter. Optimal placement of the ventricular catheter in the ipsilateral frontal horn approximating the foramen of Monro (grade 1) was achieved in 19 patients (95.0%), while a suboptimal trajectory into a lateral corner of the frontal horn passing along a lateral wall of the frontal horn (grade 3) occurred in 1 patient (5.0%). Thus, the AGT patients experienced a significantly higher incidence of optimal catheter placement than the freehand catheterized patients (95.0% vs. 68.3%, p=0.024). Moreover, none of the AGT patients experienced any tract hemorrhages along the catheter or procedure-related complications. Conclusion : The proposed adjustable Ghajar guide technique, using angular adjustment in the coronal plane from the orthogonal trajectory at Kocher's point, facilitates accurate freehand placement of a ventricular catheter for hydrocephalic patients.