• Journal of Chest Surgery
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• v.37 no.6
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• pp.467-473
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• 2004

Background: The sinus conversion rate after the maze procedure in chronic atrial fibrillation using radiofrequency energy is lower than with either conventional 'cut and saw' technique or cryothermia. The creation of incomplete transmural lesions due to poor tissue-catheter contact is thought to be the main cause. To address this problem, the current study was aimed to evaluate the effectiveness of a specially constructed compression device designed to enhance tissue catheter contact during unipolar radiofrequency catheter ablation. Material and Method: Circum-ferential right auricular epicardial lesions were created with a linear radiofrequency catheter in 10 anesthetized pigs. A device specially designed to increase contact by compression of the catheter to the atrial wall was used in 5 pigs (study group). This device was not used in the control group (5 pigs). Conduction block across the right auricular lesion was assessed by pacing, and the transmurality of the lesions were confirmed by microscopic examination. Result: Conduction block was observed in a total of 8 pigs; 5 in study group and 3 in control group. Transmural injury was confirmed microscopically by the accumulation of acute inflammatory cells and loss of elastic fibers in the endocardium. In two pigs with failed conduction block, microscopic examination of the endocardium appeared normal. Conclusion: Failed radiofrequency ablation is strongly related to non-transmural energy delivery. The specially constructed compression device in the current study was successful in creating firm tissue-catheter contact and thereby generating transmural lesions during unipolar radiofrequency ablation.

• KSBB Journal
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• v.24 no.1
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• pp.1-8
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• 2009

In the past decade, we have observed rapid advances in the development of biochips in many fields including medical and environmental monitoring. Biochip experiments involve immobilizing a ligand on a solid substrate surface, and monitoring its interaction with an analyte in a sample solution. Metal nanoparticles can display extinction bands on their surfaces. These charge density oscillations are simply known as the localized surface plasmon resonance (LSPR). The high sensitivity of LSPR has been utilized to design biochips for the label-free detection of biomolecular interactions with various ligands. LSPR-based optical biochips and biosensors are easy to fabricate, and the apparatus cost for the evaluation of optical characteristics is lower than that for the conventional surface plasmon resonance apparatus. Furthermore, the operation procedure has become more convenient as it does not require labeling procedure. In this paper, we review the recent advances in LSPR research and also describe the LSPR-based optical biosensor constructed with a core-shell dielectric nanoparticle biochip for its application to label-free biomolecular detections such as antigen-antibody interaction.

• Clinical and Experimental Reproductive Medicine
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• v.24 no.1
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• pp.83-93
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• 1997

Although IVF-ET is widely applied in the treatment of couples with male factor infertility, it may fail in many infertile couples with normal semen parameters, and certain couples cannot be accepted for standard IVF-ET due to unfertilization or extremely low fertilization rate of oocytes. Recently, several procedures of microassisted fertilization (MAF) using micromanipulation have been introduced, and pregnancies and births have been obtained after partial zona dissection (PZD), subzonal insertion (SUZI), and intracytoplasmic sperm injection (ICSI). This clinical study was performed to develop and establish ICSI as an effective procedure of MAF in infertile couples who could not undergo standard IVF-ET repetitively because of failure in fertilization or extremely low fertilization rate of oocytes with the conventional fertilization technique in the previous IVF-ET cycles. From March, 1995 to May, 1996, 27 cycles of IVF-ET with ICSI in 19 infertile patients were included in study group, and the outcomes of ICSI were analyzed according to fertilization rate, cumulative embryo score (CES), and pregnancy rate. The number of oocytes retrieved after controlled ovarian hyperstimulation (COH) was $10.50{\pm}6.13$ in 30 previous cycles, and $10.57{\pm}5.53$ in 27 ICSI cycles. In ICSI cycles, the number of oocytes optimal for ICSI procedure was $7.89{\pm}4.30$, and the fertilization rate of $67.9{\pm}20.2%$ could be obtained after ICSI. The number of embryos transferred was $1.43{\pm}2.40$ in previous cycles, and $4.36{\pm}1.77$ with the mean CES of $41.8{\pm}27.4$ in ICSI cycles. In ICSI cycles, the overall pregnancy rate was 29.6% (8/27) per cycle and 42.1% (8/19) per patient with the clinical pregnancy rate of 22.2% (6/27) per cycle and 31.6% (6/19) per patient. In conclusion, MAF of human oocytes with ICSI is a promising fertilization method for IVF-ET patients, especially with the past history of failure in fertilization or low fertilization rate of oocytes in the previous IVF-ET cycles, and ICSI using micromanipulation procedures applied to human oocytes will provide a range of novel techniques which may dramatically improve the pregnancy rate in IVF-ET program and contribute much to effective management of infertile couples.

• Journal of the Korea Institute of Building Construction
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• v.9 no.4
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• pp.119-129
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• 2009

Building construction trends have been changed dramatically in terms of size and mass. With the need to maximize land usage, there has been an increase in the construction of high-rise buildings. This affects not only the entire construction duration and cost, but also subsequent construction activities, such as work to increase underground facilities and in reclamation land area construction. These types of site conditions require soft ground reinforcement and the proper uplift water pressure treatment. In general, two kinds of methods have been used for uplift water pressure treatment systems. However, there have been some problems arising as the result of a lack of research and analysis on underground construction techniques, and a reliance on experiments over actual survey and analysis of site conditions. This paper focused on the problems of conventional selection procedure, by analyzing drawings and proposing a kind of modeling for a reasonable procedure. The results were applied to OO project as a sample construction case to be verified in this research. The initial plan in the case project was the Rock Anchor System. However, as there were terrible miscalculations of basic site conditions that had an extraordinary influence on the underground water level, such as the site's proximity to the Han-river, it was necessary to change the plan to include apermanent drainage system. This achieved a direct construction cost reduction \ 406,702,000 and a maximum sayings of 4% of operational cost, based on the 50-year building Life Cycle Cost.

• Journal of the Korean Society of Radiology
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• v.17 no.3
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• pp.385-392
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• 2023

Caroli's disease is a fibrocystic liver disease. Autosomal recessive disorder is characterized by congenital multiple dilatation of the bile duct. Computerized tomography, magnetic resonance imaging, cholangiography and ultrasound are among the methods for diagnosing caroli disease. Computerized tomography is essential for detecting and distinguishing fibroplastic liver disease and is useful for determining intrahepatic bile duct dilatation. However, awareness of the possible side effects of using contrast mediums is necessary. A typical method of magnetic resonance cholangiography is used for magnetic resonance imaging. A non-invasive examination can reduce the pain of the patient, and the anatomical structure of the bile pancreatic duct and the presence or absence of lesions can be easily and quickly observed. Biliary contrast is an effective diagnostic method that can directly visualize various cystic dilatations throughout the enlarged bile duct. However, since this procedure is also an invasive procedure, it is recommended not for diagnosis but for treatment purposes. Ultrasonography can confirm similar findings to computerized tomography. The hepatic artery root is difficult to prove with conventional grayscale ultrasound. However, it is of clinical value in that it can not only describe dilated bile ducts with vascular roots in the tube but also easily identify color Doppler signals in the tube. With the development of video diagnostics, early diagnosis has become possible through computerized tomography, magnetic resonance imaging, cholangiography, and ultrasound. In order to further contribute to the development of video diagnostics so that long-term prognosis can be improved after treatment through early diagnosis, we examined what aspects of each test's caroli disease appear.

• Development and Reproduction
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• v.4 no.1
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• pp.115-123
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• 2000

A few enzymeimmunoassay (EfA) for testosterone (T) have been reported but was not suitable for all biological samples. The present study was designed to develop a rapid, ultrasensitive EIA and to apply this technique for study the physiological changes of T in biological samples. Saliva samples were collected at 06:00～09:00 hour during one menstrual cycle from 18 normally menstruating women and on 09:00～10:00 hour from 20 normal men. The present study shows an established EIA for testosterone, using horseradish peroxidase (HRP), which was covalently bonded to testosterone-3-carboxymethyloxime (T-3-CMO). One batch of T-antisera was also covalently linked to microcrystalline cellulose particles by a mixed anhydride method in order to facilitate separation of bound and free steroids. The established EIA was validated in terms of sensitivity, accuracy, specificity, precisions etc., comparing with conventional radioimmunoassay. The sensitivity of the established EIA was less than 25 pg/tube. The correlation coefficients between the expected T-values and observed T-values measured by EIA or RIA were r=0.985 and r=0.941 respectively. The cross reactivity of antiserum in EIA was a little higher than that of RIA, especially by 5 ${\alpha}$-DHT. The intra- and inter-assay precisions of the present EIA were similar to those of RIA. The present study also demonstrates that the normal T-values in saliva of Korean male ＆ female samples are 265.65${\pm}$15.80 pmol／l and 109.74${\pm}$ 12.01 pmol／l, respectively. The present EIA seems to be established and suitable for use in the endocrinological studies. The advantages of this EIA system also might make the present T-EIA an ideal procedure for use in a routine assay of ordinary laboratory with a conventional spectrophotometer.

• Journal of Food Hygiene and Safety
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• v.26 no.1
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• pp.70-75
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• 2011

A new and improved analytical method involving alkaline pyridine extraction was proposed to quantity chlorophyll contents in syrup and candy type chlorella products. The performance of analytical method was compared with the conventional Korea food standard method which involves acetone extraction. The application of sonication chlorophyll extraction form alkaline pyridine sample was also explored. The analytical procedure was validated by evaluating accuracy, precision and reproducibility. For liquid samples, the pyridine extraction method showed higher accuracy and precision compared to acetone extraction method. The CV values of pyridine extract method and the acetone extraction method were 18.82 and 40.0, and the accuracy to theoretical values were 106.3% and 78.1%, respectively. When sonication extraction method was applied to the pyridine extraction, the precision was improved as indicated by reduced CV values from 18.82 to 11.36. The improved performance of pyridine-sonication extraction was also validated by recovery test of chlorophyll that was previously spiked into the sample matrix. For solid matrix, the pyridine extraction method showed better performance in analysis of chlorophyll in solid food matrix (CV = 7.05) compared to conventional acetone extraction method (CV = 30.0). However, the accuracy to theoretical values of pyridine and acetone extraction methods only showed only 62.7% an 40%, respectively. The relatively low accuracy of pyridine extraction method (62.7%) was improved to 99.4% by applying additional sonication extraction method. The improved performance of applying additional sonication extraction was validated by standard deviation, CV values and accuracy to theoretical values.

• Journal of Chest Surgery
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• v.39 no.8 s.265
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• pp.604-610
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• 2006

Background: Recent improvements in interventional procedure and medical therapy for congestive heart failure result in an increase of number of patients with ischemic cardiomyopathy considered for coronary artery bypass grafting. We retrospectively review the results of CABG in these patients with decreased LV function to know the early and mid-term follow-up results. Material and Method: Between January 2001 and June 2005, 1,143 patients underwent coronary artery bypass grafting and 144 of these patients had preoperative left ventricular function of equal to or less than 35% ${(LVEF{\leq}\;35%)}$. There were off-pump coronary artery bypass grafting (OPCAB) in 66 cases (45.8%), on-pump beating heart coronary artery bypass grafting in 34 cases (23.6%) and conventional coronary artery bypass grafting in 44 cases (30.6%). The combined operations including mitral annuloplasty were 48 cases in thirty five patients (24.3%). Result: The mean number of dstal anastomosis were $3.5{\pm}1.3$. The median postoperative duration of stay in intensive care unit and hospital was 2 days and 8 days, respectively. There were 6 early death (4.2%) and causes of deaths were ventricular tachycardia in 5 patients, small bowel infarction in one patient. Mean follow-up time was $21{\pm}14$ months $(4{\sim}54\;months)$. The 1-year was $95{\pm}2%$ and 3-year survival rate was $83{\pm}7%$, the 1-year and 3-year cardiac event-free survival were ${88{\pm}3%\;and\;69{\pm}7%}$, respectively. Conclusion: Based on satisfactory early and mid-term results in our study, CABG should be carried out as actively as possible in patients with ischemic cardiomyopathy. Postoperative aggressive management for ventricular arrhythmia would be helpful for better results.

• Clinical and Experimental Reproductive Medicine
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• v.25 no.3
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• pp.323-329
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• 1998

The safety of ICSI as a novel procedure of assisted fertilization may be assessed by the health of the baby born. In order to evaluate the safety of ICSI, perinatal outcome and congenital anomaly of the babies born after ICSI were compared with those of babies born after IVF (control group). We analysed the clinical data from the obstetric and pediatric records, including the information obtained through telephone. The results are as follows; Mean gestational age $({\pm}SEM)$ and birth weight in singleton pregnancy were $38.8{\pm}1.9$ weeks and $3209.7{\pm}501.9gm$ in IVF group, $39.0{\pm}2.2$ weeks and $3289.9{\pm}479.5gm$ in ICSI group, respectively. Mean gestational age and birth weight in twins were $36.8{\pm}2.1$ weeks and $2512.8{\pm}468.0gm$ in IVF group, $36.5{\pm}2.8$ weeks and $2492.7{\pm}537.1gm$ in ICSI group. In IVF group, perinatal mortality rates were 8.5 in singletons and 56.6 in twins; for the ICSI singletons and ICSI twins, the perinatal mortality rates were 11.6 and 49.0, respectively. The incidence of congenital malformations was 3.6% (8/224) in IVF group and 2.1% (4/188) in ICSI group, there was no statistical difference (p>0.05, Fisher's exact test). The incidence of major congenital anomalies was 0.9% (2/224; pulmonary artery hypoplasia, renal cystic dysplasia) in IVF group and 1.1% (2/188; holoprosencephaly, Cri du chat syndrome) in ICSI groups (p>0.05, Fisher's exact test). Similarly, there was no significant difference in incidence of minor congenital anormalies 2.7% (6/224) in IVF group and 1.1% (2/188) in ICSI group respectively (p>0.05, Fisher's exact test). In conclusion, there was no difference in the perinatal outcome and the incidence of congenital anomalies between the babies born after ICSI and those after conventional IVF.

• Journal of Chest Surgery
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• v.39 no.1 s.258
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• pp.35-41
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• 2006

Background: The radial arteries are being used more often for coronary artery bypass grafting, We tried to the endoscopic radial artery harvest to reduce the cosmetic problems and neurologic complications of the conventional open harvesting and report the techniques and early results. Material and Method: The 86 patients underwent coronary artery bypass grafting between May 2003 and April 2005 had their nondominant radial artery endoscopically removed through a 2 cm incision at the wrist. The radial pedicle was dissected and was divided at antecubial area through a 5 mm counterincision. Result: The 23 patients complained of neuralgias on territory of superficial raidal none but no one complained of neuralgias on territory of lateral antebrachial cutaneous none. There was no functional impairment of the hand. There was no wound complication except a localized hematoma. All patients were contacted by telephone after postoperative 7.9$\pm$3.6 months. The 4 patients still complained of neuralgia. All the patients were satisfied with the aesthetics of the wounds. The multidetectional tomography was done on the 66 patients for the estimation of early patency of radial artery. There were 2 cases of stenosis and a case of occlusion. Conclusion: Endoscopic radial artery harvest had no functional impairment of the hand, lesser rate of neurologic complications and outstanding aesthetics. The results of early patency of the radial artery was similar to conventional methods. Therefore, we think that endoscopic radial artery harvest is the optimal procedure.