• Childhood Kidney Diseases
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• v.9 no.1
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• pp.38-45
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• 2005

Purpose : The purpose of this study was to analyze the therapeutic effect of plasmapheresis in various pediatric diseases. Methods : Therapeutic plasmapheresis was performed by COBE Spectra centrifugation. Nine cases were included in this study. The number an[;. method of plasmapheresis, together with the progress and prognosis of each case were retrospectively reviewed. Results : The patients' ages ranged from 26 mont]Is to 16 years of age, and the mean age was 9.9 years. There were S males and 4 females. The underlying diseases requiring plasmapheresis included 2 cases of hemolytic uremic svndrome(HUS), 1 case of lupus nephritis, 2 cases of rapidly Progressive glomerulonephritis(RPGN), 1 case of focal segmental glomorulosclerosis(FSGS), 1 case of systemic vasculitis after pulmonary hemorrhage, 1 case of acute renal failure associated with pulmonary hemoIThage, and 1 case of acute rejection after renal transplantation. The average number of plasmapheresis performed was 6.2 times with a range of 3 to 13 times. The patients with HUS, lupus nephritis, ANCA positive systemic vasculitis induced by pulmonary hemorrhage and ARF-associated pulmonary hemorrhage showed a good response to therapeutic plasmapheresis, but the patients with RPGN, refractory FSGS, and acute rejection after renal transplantation were not responsive to treatment. The most common side effect was hypocalcemia which was rarely symptomatic. Vital signs were not compromised. Conclusion : Although it is presumptuous to generalize the therapeutic effects of plasma pheresis in different diseases due to the small number of study subjects, this study shows that plasmapheresis may be an effective therapeutic modality in various pediatrics diseases and should be considered as a therapeutic option.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1982.05a
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• pp.10.1-10
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• 1982

The use of phonosurgery in the recent development of laryngomicrosurgery has enabled the restoration of a normal voice in respect to functional laryngeal surgery which in Korea in the past limited to simple removal of benign laryngeal tumor such as laryngeal polyp or nodules and cordal injection of $Teflon^{{\circledR}}$ for the treatment of recurrent nerve paralysis under the vision of suspension laryngoscopy. Performance of phonosurgery for the treatment of cord paralysis, mutational dysphonia, vocal cord atrophy, hyperkinetic dysphonia and sulcus vocalis is a happy event in the view point of development of phonosurgery in Korea. In this aspect thyroplasty to change the position and physical characteristics of the cord outside the glottis instead of the direct handling of the vocal cord through direct endoscopy is popular. Among the 4 types of thyroplasty, classified by Insshiki(1974), type I thyroplasty(1ateral compression of vocal cord) and type IV thyroplasty(lengthening of vocal cord) were effective in the treatment of unilateral vocal cord paralysis. Advantages of this operation are the fine adjustment of the degree of lateral compression under local anesthesia according to the phonation of the patient during operation and avoidance of dyspnea and intralaryngeal hemorrhage due to the manipulation outside the internal perichondrium of the thyroid cartilage. We did 7 cases of thyroplasty for the treatment of unilateral vocal cord paralysis in the 7 months from September 1981 to March 1982. Before the operation aerodynamic study, psychoacoustical evaluation, stroboscopy and sound spectrographic analysis were done. Two months after the operation the above procedures were performed again. Results of preoperative and postoperative examination were compared and the following results were obtained. 1) In the aerodynamic study, maximum phonation time increased to 158% of the preoperative value and the phonation quotient and the mean flow rate decreased to 58% and 54% of preoperative values. 2) The degree of hoarseness improved in the psychoacoustical evaluation and the glottic chink during phonation was decreased in the stroboscopic examiantion. 3) In the sound spectrographic analysis, periodicity was much restored and noise distribution decreased especially in the high frequency area.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.9
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• pp.859-866
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• 2010

Nonlinear dynamics of pulsating instability-diffusional-thermal instability with Lewis numbers sufficiently higher than unity-in counterflow diffusion flames, is numerically investigated by imposing a Damkohler number perturbation. The flame evolution exhibits three types of nonlinear behaviors, namely, decaying pulsating behavior, diverging behavior (which leads to extinction), and stable limit-cycle behavior. The stable limit-cycle behavior is observed in counterflow diffusion flames, but not in diffusion flames with a stagnant mixing layer. The critical value of the perturbed Damkohler number, which indicates the region where the three different flame behaviors can be observed, is obtained. A stable simple limit cycle, in which two supercritical Hopf bifurcations exist, is found in a narrow range of Damkohler numbers. As the flame temperature is increased, the stable simple limit cycle disappears and an unstable limit cycle corresponding to subcritical Hopf bifurcation appears. The period-doubling bifurcation is found to occur in a certain range of Damkohler numbers and temperatures, which leads to extend the lower boundary of supercritical Hopf bifurcation.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.5 no.2
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• pp.147-159
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• 1995

This study was conducted to introduce fundamental data of hand-arm vibration and noise exposure levels with impact wrenches(double-hammer impact wrenches and oil-pulse impact wrenches) used in automobile assembly lines considering the process variables and tool variables. In studing, products per day, required time screwing the bolts or nuts per bolts or nut were considered as process variables, and capacity of bolts or nuts, air consumptions per minute, tool weights, RPM were considered as tool variables. Hand-arm vibration levels of 3 axis in each hand were measured using the instruments compling with ISO/DIS 5349 and noise levels were measured using a noise logging dosimeter. The results were as follows : 1. Required time to screwing the bolt or nut by oil-pulse impact wrenches is shorter than double-hammer impact wrenches but total daily exposure time of oil-pulse impact wrenches was higher than double-hammer impact wrenches because the number of bolts or nuts per cycle was many. 2. Oil-pulse impact wrenches have been used to screwing the large bolt or nut in comparing with double-hammer impact wrenches and required time to screwing the bolts or nuts were shorter than double-hammer impact wrenches because oil-pulse impact wrenches were using high RPM and large air consumption per minute. Noise level of oil-pulse impact wrenches was 8 dB(A) lower than double-hammer impact wrenches. 3. Dominant hand-arm vibration levels of double-hammer impact wrenches in each hand were $8.24m/sec^2$ of Zh axis in right hand and $9.60m/sec^2$ of Xh axis in left hand. Dominant hand-arm vibration level of oil-pulse impact wrenches in each hand was $2.59m/sec^2$ of Xh axis in right hand and $3.23m/sec^2$ of Yh axis in left hand. 4. In double-hammer impact wrenches, corresponding hand-arm vibration levels of Xh, Yh, Zh axis in left hand were higher than hand-arm vibration levels of right hand in 3 axis. In oil-pulse impact wrenches, Xh axis of right, Yh axis of left, Zh axis of left were higher than the corresponding hand-arm vibration levels of Xh, Yh, Zh axis in right and left hand. 5. Correlation coefficients among Xh, Yh. Zh axis of right and left hand hand-arm vibration levels in double-hammer impact wrenches and oil-pulse impact wrenches were commonly high in Yh axis and correlation coefficients of Yh axis in double-hammer impact wrenches and oil-pulse impact wrenches were 0.76 and 0.86,respectively. 6. As a measure repetitiveness, plotting total daily exposure time with the number of bolts or nut per cycle, direct correlation was shown between repetitiveness and hand-arn vibration exposure, and correlation coefficient between the number of bolts or nut per cycle and total daily exposure time in double-hammer impact wrenches, oil-pulse impact wrenches were 0.84 and 0.50, respectively. 7. Considering the total acceleration level and tool variables in double-hammer impact wrenches and oil-pulse impact wrenches, air consumption in right hand, and bolt or nut capacity in left hand were commonly the variable that explainability was high. Considering the noise and tool variables in double-hammer impact wrenches and oil-pulse impact wrenches, air consumption per minute was commonly the variable that explainability was high.

• Childhood Kidney Diseases
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• v.1 no.2
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• pp.170-175
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• 1997

Purpose : Hemolytic uremic syndrome(HUS), known as a most common cause of childhood renal failure in western countries, has been a relatively rare disease in Korea. Although the reported cases were not related to any specific cause in Korea, there was an outbreak of HUS with bloody diarrhea in Japan last year. We report here that we experienced the several typical HUS last year. Patients : From Jan.1996 to Dec. 1996, five patients were diagnosed as HUS at Samsung Seoul Medical Center, Dept. Pediatrics. Results : 1) The age of onset was below 3 years in 3 cases and above 9 years in 2 cases. 2) All the cases happened between summer and autumn. Three patients had domestic travel and 4 patients drank well or spring water before the symptoms. 3) The clinical manifestation was generalized edema, oliguria, anuria and hematuria. The bloody diarrhea were present in 5 cases and 1 patient had operation with the impression of appendicitis. 4) There was no bacteria which was isolated from the blood or stool samples. 5) Renal biopsies were performed in 2 cases, because of protracted clinical course. One showed microthrombotic angiopathy and the other cortical necrosis with necrotizing glomeruli. 6) Complete recovery was the outcome in 4 cases and one case progressed to chronic renal failure. Conclusion : In conclusion, typical HUS associated with bloody diarrhea, epidemic and good prognosis can be found in Korea and careful surveillance of the pre-clinical cases will be necessary.