• Journal of the Korea Convergence Society
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• v.8 no.10
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• pp.215-223
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• 2017

This article has tried to analyse the effect of the corporate earning return tax empirically through analysis on the impact of previous internal reservation on the dividends rate of the current year. In addition to this, this article has tried to the effectiveness of government policies with leverage ratio as a moderating variable. Moreover, DRF and GBM model were used to see the effect again. As a result of the actual proof analysis, OCF, ROE, FOR have a significance level of 99% in model1, model2, model3. However, ADV and MSE has appeared not to be meaningful in all models. In the result of DRF and GBM model for convergence was higher than GBM in depth and leaves. However, when it comes to a model explaining capability, GBM high than DRF. The further study will be required to examine the effect of government policy by time series analysis in the period of enforcement of the reflux tax, from 2015 to 2017.

• Korean Journal of Bronchoesophagology
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• v.13 no.1
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• pp.29-32
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• 2007

Background and Objectives: Improvements in the fields of neonatology and surgical subspecialities make tracheotomy possible to the younger population. But complication rates for infantile tracheotomy are significantly higher than that for the other pediatric tracheotomy. This study was designed to present our 9-year experiences of infantile tracheotomy and to evaluate the effect of several factors of complications. Materials and Methods: From 1996 through 2004, 60 tracheotomies were performed. Charts were reviewed with respect to indications for tracheotomy, underlying diseases, success rate in decannulation and length of support time until decannulation, complication and mortality rate. Results: There were 41 male patients and 19 female patients. Ventilatory support for neurological impairment(38.3%) was the leading indication for tracheotomy, followed by subglottic stenosis(36.7%), laryngomalacia(13.3%). Decannulation was accomplished in 60.0% of infants with an average of 56.5momths with tracheotomy. Complications occurred in 43.3%. There was one tracheotomy-related mortality in case of tracheal atresia. Most common complication was subglottic stenosis. Conclusion: Infantile tracheotomy had significant morbidities and its outcomes are thought to be usually related to the underlying disease and age. To prevent complication, early decannulation is advisable, and for long-term tracheotomy patients, regulation of reflux and infection may be necessary.

• Journal of the Korean Chemical Society
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• v.55 no.6
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• pp.1007-1011
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• 2011

Dioctyl succinates and succinic anhydride were synthesized from succinic acid in the presence of a cation exchange resin, Amberlite IR-120. The synthesis of dioctyl succinate from succinic acid and octanol was perfomed in 18 h reflux condition with Amberlite IR-120 and the isolated yield of product was over 90%. For the synthesis of succinic anhydride, succinic acid was refluxed in isopropenyl acetate for 18 h with Amberlite IR-120 as a catalyst. The long reaction time was significantly reduced to less than 10 min under microwave irradiation. The catalyst was reusable at least 4 times with keeping product yield of higher than 80%.

• Nuclear Engineering and Technology
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• v.18 no.2
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• pp.107-116
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• 1986

The steady and unsteady state models were established for the performance analysis and design of heavy water distillation columns packed with corrugated wire mesh. After the steady state model was derived with pressure drops, separated D$_2$O concentration and temperature profiles and pressure gradients in the column were obtained by solving MESH equations with equation tearing method. For the analysis of unsteady state behavior, the equilibrium stage transient model deduced from modifying the Cohen's ideal cascade equation was used to predict the concentration change of heavy water with time. These models were in good agreement with the experimental results of heavy water distillation at total reflux. And the newly developed packing material turned out to be very efficient separation device for very small HETP, pressure drop and holdup.

• The Korea Journal of Herbology
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• v.39 no.1
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• pp.39-47
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• 2024

Objectives : This study evaluates how various traditional Korean herbal medicines assess MUC5AC expression for esophageal mucosal defense and analyzes the associated mechanisms involved in inflammation. Methods : Forty types of traditional Korean herbal medicines were assessed for in vitro antioxidant activities, and the real-time PCR method was employed to analyze MUC5AC expression under pH 4.5 conditions in human esophageal epithelial cells (HET-1A). Eight types of Korean herbal medicines were evaluated for in vitro antioxidant activities, and Reactive oxygen specise (ROS) expression was analyzed under bile salt (480 𝜇M) and pH 5.5 conditions in human esophageal epithelial cells (HET-1A). Simulation experiments involving bile salts and acidity were conducted for one hour to assess the efficacy of four drugs, and the activities of Mitogen-activated Protein Kinase (MEK), Nuclear Factor Kappa B (NF-𝜅B), and Cyclooxygenase-2 (COX-2) were detected through Western blot analysis. Results : Compared to the Normal group, the Control group exhibited higher ROS generation. Such increased ROS levels were significantly reduced by four extracts: Citrus Unshius Pericarpium (CUP), Cnidium officinale Rhizoma (CR), Ginseng Radix (GR), and Linderae Radix (LR). The protein expression of COX-2 decreased with the treatment of LR, CUP, and CR. Particularly, CUP and CR exhibited superior effects compared to other groups in inhibiting the phosphorylation of NF-𝜅B. Conclusion : Based on the results obtained, we have identified drugs that inhibit oxidative stress and inflammation caused by bile acid in esophageal epithelial cells. Our future plans involve comparing and analyzing the efficacy of these herbal medicines through animal experiments.

• Childhood Kidney Diseases
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• v.3 no.2
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• pp.180-186
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• 1999

Purpose : It has been well known that urinary tract infection(UTI) in infants and children is frequently associated with vesicoureteral reflux(VUR). However, the publishied papers dealing with congenital anomalies associated with UTI emphasized the importance of VUR only. The aim of our study was to evaluate the type, incidence and spectrum of urologic anomalies associated with UTI. Methods : Medical records of clinical, bacteriologic and radiologic study were assessed retrospectively in 65 infants or children with documented UTI who were admitted to the Department of Pediatrics, Samsung Seoul Hospital from March 1996 to February 1998. Results : Spectrum of anomalies were associated with UTI as follows: VUR(n=23), both ectopic kidney(n=1), ureterovesical junction(UVJ) obstruction(n=1), multicystic dysplastic kidney(n=1), ureteropelvic junction(UPJ) obstruction with hydronephrosis(n=1), hutch diverticulum(n=1), UPJ stenosis(n=1), posterior urethral valve(n=1), urachal remnant(n=1) and bladder diverticula(n=1). Congenital urinary anomalies other than VUR were detected in 9 children among 65 patients with UTI(13.8%). 4 children among 9 congenital urinary anomalies other than VUR were combined with VUR. Sex distribution with congenital urinary anomalies other than VUR was more prevalent in male than female (7 males : 2 females). Age distribution at the time of UTI was less than 5 years in most patient (under 1 year in 1 patient, 1-2 year in 5 patients, 3-5 year in 1 patient, and above 5 year in 2 patients). And age distribution at the time of UTl associated with VUR was less than 5 years in most patient (under 1 year in 6 patients, 1-2 year in 8 patients, 3-5 year in 5 patients, and above 5 year in 4 patients), too Conclusion : Because congenital urinary anomalies other than VUR are seen in as high as 13.8% of patients, more careful evaluation of all possible congenital urinary anomalies as well as VUR is mandatory in pediatric patient with UTI.

• Childhood Kidney Diseases
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• v.9 no.1
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• pp.64-68
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• 2005

Purpose : Renal abscess is very rare in children and its diagnosis is difficult because symptoms are often nonspecific. In previous studies, on]y 15% to 25% of patients were reported to be diagnosed at the time of admission. Early diagnosis and treatment are important be cause mortality rate correlates positively with the time of diagnosis. The purpose of this study is to clarify the clinical features of children with renal abscess and to investigate the possible indicators of this disease for early diagnosis and Proper treatment. Methods : Twelve children diagnosed with renal abscess from Jan. 1996 to Jul. 2004 were included. The age of patients ranged from S months to 15 years. We retrospectively analyzed the demographics of patients, their symptoms, predisposing factors, diagnostic methods and causative organisms and the treatment modalities. Results : Fever was the most common manifestation, Five children(42%) had vesicoureteral reflux. Renal ultrasonography and computerized tornography were the most frequently used imaging tools to detect renal abscess. Gram negative bacteria were isolated in 7 patients and Staphylococcus aureus grew in 2 patients. All patients received intravenous antibiotics and 4 patients underwent aspiration or drainage of renal abscess. The average admission duration was 30 days. Conclusion : Renal abscess should be included in the differential diagnosis of prolonged fever in children, especially when flank pain is combined. For early diagnosis and a better prognosis, patients should be promptly investigated with ultrasonography or computerized tomography.

• Journal of Soil and Groundwater Environment
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• v.17 no.3
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• pp.1-9
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• 2012

According to the agreement on WTO/TBT, we are under the situation to adopt international standard (ISO standard) as a national standard if it exists. However, in case of environmental area, it is a domestic legal obligation to use Korean environmental standard method(KESM) for analyzing various contaminants. Therefore it is necessary to assess the comparability between KEM and ISO standard prior to apply ISO standard to soil conservation law in Korea. The main purpose of this study is to assess the comparability of both methods for analyzing heavy metals in soil. We looked over various aspects like pre-treatment, calibration curve range, detection wavelength, soil organic matter content and so on. Apparently, the procedure of both methods is almost same. However in details, both methods are different in stationary time before aqua-regia extraction using reflux system, calibration curve range for Cu, Pb, Ni and measuring wavelength for Pb. According to the results of comparison test, the results were significantly different when the different calibration range was used. In case that all the extracts independent of methods were reanalyzed with the same calibration range of each method, both methods showed statistically same results. Other conditions like different stationary time, measuring wavelength of AAS and soil organic matter content did not have any influence on the analytical result. Therefore, we suggest to extend the calibration curve range to 0~8 mg/L which is used in KS I ISO standard(Korean standard related with environment which is translation version of ISO standard without any technical change). In case of $Cr^{6+}$, the results showed no significant differences between two methods even though the pretreatment, instrumentation and other analysis conditions were different. In addition to UV/Visble spectrometry of KESM for soil contamination, we suggest to adopt ion chromatography of ISO 15192(US EPA method 7199) for analyzing $Cr^{6+}$ with the consideration of laboratory work efficiency.

• Journal of the Korean Society of Radiology
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• v.82 no.6
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• pp.1619-1627
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• 2021

Central venous stenosis is a relatively common complication in hemodialysis patients; however, jugular venous reflux (JVR) and increased intracranial pressure are rare, and associated progressive visual disturbance was reported in only a few cases. Here, we report a case of JVR with visual disturbance and increased intracranial pressure. Notably, the MRI was accompanied by a dilatation of the superior ophthalmic vein, which was mistaken for a cavernous sinus dural arteriovenous fistula (CSdAVF). The patient had JVR on time-of-flight MR angiography (TOF-MRA) and severe stenosis of the left brachiocephalic vein on conventional angiography. After balloon angioplasty for central venous stenosis, he was discharged after improvement of his visual disturbance. Although JVR due to central venous stenosis and CSdAVF might show similar symptoms, treatment plans are different. Therefore, it is important to distinguish radiologically based on a thorough review of MRI and TOF-MRA and confirm the central venous stenosis on cerebral angiography for the accurate diagnosis.

• Childhood Kidney Diseases
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• v.9 no.2
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• pp.193-200
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• 2005

Purpose : An atrophic renal scar(RS) is one of the underlying causes for childhood hyper tension and chronic renal failure. The risk factors for atrophic renal scar were evaluated. Methods : 41 children, who presented with first febrile urinary tract Infection at the Ewha Womans University Hospital between 1995 and 2003 and had generalized atrophic RS on $^{99m}Tc-DMSA$ renal scan, were retrospectively studied. Atrophic RS was divided into severe atrophic RS(n=14) if relative uptake on renal scan was below 10$\%$, or mild atrophic RS(n=27) if relative uptake on renal scan was between 10-35$\%$. RS was defined as congenital if the scar was detected on the first renal scan, and as acquired if the scar developed on the follow-up renal scan from acute pyelonephritis of the first renal scan. The control group was consisted of randomly selected 41 children with segmental RS. The risk factors for atrophic RS such as the generation time, VUR, gender and ACE gene polymorphism were evaluated. Results : The age distribution of atrophic RS and segmental RS did not differ significantly (P>0.05). The rate of congenital RS in atrophic RS was 61.0$\%$(25/41), which was significantly higher than 9.8$\%$(4/41) of segmental RS(P<0.01). Atrophic RS developed mote frequently in male children(M:F 68.3$\%$ 31.7$\%$) than segmental RS(M:F 41.4$\%$ .58.5$\%$)(P<0.05). Vesicoureteral reflux(VUR) was found in 92.7$\%$(38/41) of 4he atrophic RS, which was significantly higher than 53.7$\%$(22/41) of segmental RS(P<0.05). In children without VUR, the male to female ratio did not differ between atrophic RS and segmental RS(P>0.05) But in children with VUR, there was a higher proportion of males with severe atrophic RS than segmental RS($85.7\%:45.5\%$) ACE gene polymorphism did not differ between the atrophic and segmental RS groups, irrespective of the presence of VUR(P>0.05). Conclusion : Most atrophic RSs were congenital which could not be preventable postnatally and the major risk factors were VUR and the male gender. ACE gene polymorphism was not the significant risk factor for an atrophic RS. (J Korean Soc Pedialr Nephrol 2005;9:193-200)