• Journal of Chest Surgery
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• v.51 no.2
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• pp.100-108
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• 2018

Background: The question of which type of prosthetic aortic valve leads to the best outcomes in patients in their 60s remains controversial. We examined the hemodynamic and clinical outcomes of aortic valve replacement in sexagenarians according to the type of prosthesis. Methods: We retrospectively reviewed 270 patients in their 60s who underwent first-time aortic valve replacement from 1995 to 2011. Early and late mortality, major adverse valve-related events, anticoagulation-related events, and hemodynamic outcomes were assessed. The mean follow-up duration was $58.7{\pm}44.0$ months. Results: Of the 270 patients, 93 had a mechanical prosthesis (mechanical group), and 177 had a bioprosthesis (tissue group). The tissue group had a higher mean age and prevalence of preoperative stroke than the mechanical group. The groups had no differences in the aortic valve mean pressure gradient (AVMPG) or the left ventricular mass index (LVMI) at 5 years after surgery. In a sub-analysis limited to prostheses in the supra-annular position, the AVMPG was higher in the tissue group, but the LVMI was still not significantly different. There was no early mortality. The 10-year survival rate was 83% in the mechanical group and 90% in the tissue group. The type of aortic prosthesis did not influence overall mortality, cardiac mortality, or major adverse valve-related events. Anticoagulation-related events were more common in the mechanical group than in the tissue group (p=0.034; hazard ratio, 4.100; 95% confidence interval, 1.111-15.132). Conclusion: The type of aortic prosthesis was not associated with hemodynamic or clinical outcomes, except for anticoagulation-related events.

• Journal of Korean Neurosurgical Society
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• v.61 no.2
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• pp.267-276
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• 2018

Objective : The beneficial effect of hypothermia after hemicraniectomy in malignant middle cerebral artery (MCA) infarction has been controversial. We aim to investigate the safety and clinical efficacy of hypothermia after hemicraniectomy in malignant MCA infarction. Methods : From October 2012 to February 2016, 20 patients underwent hypothermia (Blanketrol III, Cincinnati Sub-Zero, Cincinnati, OH, USA) at $34^{\circ}C$ after hemicraniectomy in malignant MCA infarction (hypothermia group). The indication of hypothermia included acute cerebral infarction >2/3 of MCA territory and a Glasgow coma scale (GCS) score <11 with a midline shift >10 mm or transtentorial herniation sign (a fixed and dilated pupil). We retrospectively collected 27 patients, as the control group, who had undergone hemicraniectomy alone and simultaneously met the inclusion criteria of hypothermia between January 2010 and September 2012, before hypothermia was implemented as a treatment strategy in Dong-A University Hospital. We compared the mortality rate between the two groups and investigated hypothermia-related complications, such as postoperative bleeding, pneumonia, sepsis and arrhythmia. Results : The age, preoperative infarct volume, GCS score, National institutes of Health Stroke Scale score, and degree of midline shift were not significantly different between the two groups. Of the 20 patients in the hypothermia group, 11 patients were induced with hypothermia immediately after hemicraniectomy and hypothermia was initiated in 9 patients after the decision of hypothermia during postoperative care. The duration of hypothermia was $4{\pm}2days$ (range, 1 to 7 days). The side effects of hypothermia included two patients with arrhythmia, one with sepsis, one with pneumonia, and one with hypotension. Three cases of hypothermia were discontinued due to these side effects (one sepsis, one hypotension, and one bradycardia). The mortality rate of the hypothermia group was 15.0% and that of the control group was 40.7% (p=0.056). On the basis of the logistic regression analysis, hypothermia was considered to contribute to the decrease in mortality rate (odds ratio, 6.21; 95% confidence interval, 1.04 to 37.05; p=0.045). Conclusion : This study suggests that hypothermia after hemicraniectomy is a viable option when the progression of patients with malignant MCA infarction indicate poor prognosis.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.2
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• pp.170-178
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• 2015

In this study, it was developed eco-friendly alkali-activated slag fiber reinforced concrete using ground granulated blast furnace slag, alkali activator (water glass, sodium hydroxides), and steel fiber. Eight reinforced concrete beam using alkali-activated slag concrete were constructed and tested under monotonic loading. The major variables were mixture ratio of alkali activator, mixed/without of steel fiber. Experimental programs were carried out to improve and evaluate the flexural performance of such test specimens, such as the load-displacement, the failure mode, the maximum load carrying capacity, and ductility capacity. All the specimens were modeled in scale-down size. The reinforced concrete beams using the eco-friendly alkali-activated slag fiber reinforced concrete was failed by the flexure or flexure-shear in general. In addition, the maximum strength increased with the adding the mol of sodium hydroxide, and the specimen reinforced the steel fiber showed the value of maximum strength which is increased by 15.8% through 25.9%. It is thought that eco-friendly alkali-activated slag fiber reinforced concrete can be used with construction material and product to replace normal concrete. If there is applied to structures such as precast concrete member and production of 2nd concrete product, it could be improved the productivity and reduction of construction duration etc.

• Journal of Gastric Cancer
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• v.2 no.3
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• pp.145-150
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• 2002

Purpose: The aim of this study was to evaluate the shortterm outcome of a pylorus-preserving proximal gastrectomy by comparing it with a jejunal interposition after a total gastrectomy in proximal gastric adenocarcinoma. Materials and Methods: For 22 patients (12 men and 10 women) who underwent a pylorus-preserving proximal gastrectomy, several clinical parameters were obtained from the medical records retrospectively. In this study, the data were collected between September 1993 and December 1999 at Chungnam National University Hospital, and the results were compared with those of 25 patients (17 men and 8 women) who underwent an isoperistaltic simple jejunal interposition. Results: The average operative time in the pylorus-preserving proximal gastrectomy group (220 minutes) was shorter than that in the jejunal interposition group (243 minutes) (P<0.05). The hemoglobin and hematocrit levels were significantly higher in the pylorus-preserving proximal gastrectomy group at 2 years after the operation. The body weight ratio (postoperative body weight/preoparative body weight) in patients who had a pylorus-preserving proximal gastrectomy was significantly higher than that in patients with a jejunal interposition at 2 years after the operation. The jejunal interposition procedure had better outcomes in anastomotic site stricture, duration of hospital stay, and number of removed lymph nodes (P<0.05). Conclusions: We think that from the viewpoint of quality of life, a pylorus-preserving proximal gastrectomy, as well as a jejunal interposition, is a useful reconstruction method for early adenocarcinomas of the proximal stomach. However, stricture of the esophagogastrostomy site in the pyloruspreserving proximal gastrectomy is a common problem to be solved in the future.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.4 no.1
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• pp.71-82
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• 1998

The purpose of this study is to analyze the phases of back pain occurring on pregnant women, and to raise the necessity of the pain management on the basis of the former analysis. The objective group is 284 pregnant women who visited department of OBGY of hospital located both in Seoul and Andong. The results are as follows; 1. 204(71.8%) pregnant women were suffering from back pain. The ratio of pain occurrance in terms of the duration of pregnancy shows that 78.3% within 3 pregnant months, 68.4% between four and six months and 72.1% over seven month. Most common ares of pain was low back area rating 60.5%. 2. The most painful postural for the suffering women was lying on the back rating 35.9% and the next painful posture was standing rating 34.4%. And the most painful movement was to maintaining continues movement(57.8%). Twisting back rates the second(17.2%). These two variables were relevant each other(p<0.05). 3. 46.7% of pregnant women were experiencing nocturnal pain. Among women experienced the pain before pregnancy, 39.9% were suffering during the pregnancy. The occurrence of nocturnal pain was related to the pain before and after the pregnancy(p<0.05). 4. 58.8% of pregnant women who experience back pain take the pain for granted as a normal proceeding of pregnancy while 3.9% recognize the symptom as an abnormal. Pain recognition in accordance with the phases does not show much difference(p<0.05). 5. It is shown that the more one delivers the number of babies, the faster back pain occurs(p<0.01). 6. 32.3% of the pain-suffering women have family member(s) having back pain. Family member(s) of the women who does not experience the pain don't have the pain either. This case reports 46.1%. Statistically, these two variables are relevant(p<0.01). 7. 43.0% of back pain experiencing women does not have any particular management plan against the pain. 20.7% is exercising as for prevention. Women who recognize the necessity of some means of therapy for their pain marked 42.9%. The majority(65.8%) of women responded exercise gymnastic work-out are most appropriate pain management. The above results show that a great number of pregnant women is experiencing back pain, however, they properly managed. This span suggests that appropriate advocacy and education for pregnant women is necessary. It is recommended that positive contribution can be made to better health of pregnant women when pain management by physical therapist is given.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.8
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• pp.701-713
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• 2009

This paper studies a method for reducing performance degradation due to losing sub-carrier orthogonality caused by power transient between physical channels in LTE uplink transmission. The pattern of inter-carrier interference(ICI) caused by power transient is different from what has been studied for doppler shift, in that its pattern occurs at front and rear sides of channels in each period of power transient. The reason of ICI's occurrence results from power difference between channels, power transient duration, multi-path channel delay spread, and numbers of sub-carrier. New criterion is proposed to find out number of taps of multi-tap equalizer enough to improve the ICI. The scheme is to determine the number of taps of multi-tap equalizer when a normalized interference or a normalized ICI is greater than a normalized noise. Simulation results show that the number of taps is flexibly adjusted according to SNR(Signal to Noise Ratio) of a received signal to improve Bit Error Rate(BER), while the complexity of the proposed scheme is reduced down to 88 percentage of the classical method.

• Journal of Hydrogen and New Energy
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• v.25 no.6
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• pp.577-585
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• 2014

Nanorod and particle shape $CeO_2$ were synthesized via hydrothermal process and precipitation method, respectively, and used as supports of Pt catalyst for water gas shift (WGS) reaction. Three different durations (12, 48, and 96h) for hydrothermal process were applied for the preparation of nanorod type $CeO_2$. 1.0 wt% of Pt was loaded on the prepared supports with incipient wetness method prior to the catalytic activity tests that were carried out at a GHSV of $95,541h^{-1}$, and a temperature range of 200 to $360^{\circ}C$. Varying duration of hydrothermal process led to the difference in physical characteristics of $CeO_2$ nanorods, such as aspect ratio, BET surface area, pore diameter, and pore volume. Consequently, the catalytic activities of Pt/$CeO_2$ nanorods were affected by the physical characteristics of the supports and appeared to be in the order of Pt/$CeO_2$(12) > Pt/$CeO_2$(48) > Pt/$CeO_2$(96). The comparison of the catalytic activities and results of the analysis (XPS, XRD, SEM, BET and TPR) for the supports revealed that the activity of the catalysts depends on chemical states of the Pt and the support materials in the temperature range that is lower than $280^{\circ}C$. However, the activity is rather dependent on the physical characteristic of the supports because the increased gas velocity limits the mass transfer of reactants in micropores of the supports.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.6
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• pp.402-408
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• 2002

Rice cultivar 'Janganbyeo' was cultivated by irrigating the saline waters of high salinity (3.0%) and medium saliniy (1.5%) for 4 days, and low salinity (0.5%) for 30 days at tillering, early meiosis and heading stage. Leaf injury due to salinity was most severe at tillering stage in 1999, but at heading stage in 2000. Heading date was delayed by 1 to 5 days by treatment of saline waters only at tillering stage. Culm length and panicle length were most severely shortened by treatment at early meiosis stage. Yield and yield components except for panicle number were decreased most by high salinity treatment regardless of growth stages. In particular, ripening ratio and grain weight among the yield components were decreased most conspicuously by the saline water treatment regardless of salinity and growth stage. Regarding grain weight grain-filling rate and duration, there is no remarked difference among the concentrations and treatment durations of saline water at tillering stage. However, their reductions were very different among the concentrations and treatment durations of saline water at early meiosis stage, being greatest when treated with high salinity for 4 days and followed by low salinity for 30 days. Also their reductions were very severe only when treated with high salinity for 4 days at heading stage.

• Korean Journal of Head & Neck Oncology
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• v.9 no.1
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• pp.16-24
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• 1993

During 7 years, from Jan. 1986 to Dec. 1992, authors studied 208 cases of the surgically managed thyroid nodules at the Department of General Surgery, Han Kang Sacred Heart Hospital and obtained the following results. 1) Among the total 208 cases, male to female ratio was 1:11.2 in benign thyroid diseases and 1:9 in malignant thyroid diseases. The benign disease was prevalent between second and forth decade comparing with malignant disease between third and fifth decade. 2) The most common duration of illness was 3 months(26.0%). 3) Palpable neck mass was the most common chief complaint(100%). Palpitation. fatigue, and sweating were common complaints in patient with benign disease, and fatigue, palpitation, and sweating in malignant disease in decreasing order of frequency. 4) 55.8 % of lesions were in right lobe, 33.2% in left lobe, 5.8% in diffuse type, 4.8% in bilateral lobes, and 0.5% in isthmus. 5) The most common size of nodule was between 2.0cm and 3.9cm in diameter, which consisted of 55.1% of benign disease and 48.0% of malignant disease. 6) 86.5% of thyroid function test showed euthyroidism, 10.1% hyperthyroidism, and 3.4% hypothyroidism. 7) Thyroid scanning of 176 patients revealed cold nodules in 92.5% of benign diseases and in 92.9% of malignant diseases. 8) The most common benign disease was adenomatous hyperplasia(62.7%), and the most common malignant disease was papillary adenocarcinoma(80.0%). 9) Fine needle aspiration cytology was performed in 91 cases, and it showed 69.0% of sensitivity, 90.3% of specificity, and 83.5% of accuracy. 10) Frozen biopsy was performed in 109 cases. and it showed 93.9% of sensitivity, 100.0% of specificity, and 98.2% of accuracy. 11) The most commonly performed operation was unilateral lobectomy(including unilateral lobectomy with isthmectomy)(79.1%) in benign disease. and total thyroidectomy(62.0%) in malignant disease. 12) Postoperative complication showed 5 cases of wound infection (2.4%), 3 cases of transient hypoparathyroidism(1.4%), 3 cases of transient hoarseness(1.4%), 2 cases of postoperative bleeding(1.0%), 1 case of permanent hypoparathyroidism(0.5%), 1 case of permanent hoarseness(0.5%), and 1 case of postoperative pneumonia (0.5%).

• Journal of Korea Water Resources Association
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• v.42 no.4
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• pp.343-353
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• 2009

The objective of this study is to evaluate the effect of the water quality improvement by water discharge through dams and to provide a benefit estimation methodology, taking domestic situation into consideration, by the replacement cost approach analyzed with a sewage treatment plant instead of an alternative dam. To this end, facility that alternates a dam must have same functions of the discharged water from the dam and the two facilities must be able to be compared objectively. To estimate the benefit, estimation methodology of alternative facility's cost is established and criteria of cost.benefit analysis that are duration period and ratio of large scale repairing expense was presented. As a case study, the water quality improvement benefit of Song-Li-Won dam was evaluated, which is planned to be built on Nae-Sung stream in Nak-Dong River system. The results of applying this methodology to Song-Li-Won dam are 644,006 million won of the annual average discharge and 1,351,526 million won of maximum discharge. The usage of the framework in this study is expected for estimation of water quality improvement benefit in case water quality improvement project is performed.