• Korean Circulation Journal
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• v.48 no.11
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• pp.1002-1011
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• 2018

Background and Objectives: The prognostic impact of left axis deviation (LAD) on clinical outcomes in acute heart failure syndrome (AHFS) with left bundle branch block (LBBB) is unknown. The aim of this study was to determine the prognostic significance of axis deviation in acute heart failure patients with LBBB. Methods: Between March 2011 and February 2014, 292 consecutive AHFS patients with LBBB were recruited from 10 tertiary university hospitals. They were divided into groups with no LAD (n=189) or with LAD (n=103) groups according to QRS axis <-30 degree. The primary outcome was all-cause mortality. Results: The median follow-up duration was 24 months. On multivariate analysis, the rate of all-cause death did not significantly differ between the normal axis and LAD groups (39.7% vs. 46.6%, adjusted hazard ratio, 1.01; 95% confidence interval, 0.66, 1.53; p=0.97). However, on the multiple linear regression analysis to evaluate the predictors of the left ventricular ejection fraction (LVEF), presence of LAD significantly predicted a worse LVEF (adjusted beta, -3.25; 95% confidence interval, -5.82, -0.67; p=0.01). Right ventricle (RV) dilatation was defined as at least 2 of 3 electrocardiographic criteria (late R in lead aVR, low voltages in limb leads, and R/S ratio <1 in lead V5) and was more frequent in the LAD group than in the normal axis group (p<0.001). Conclusions: Among the AHFS with LBBB patients, LAD did not predict mortality, but it could be used as a significant predictor of worse LVEF and RV dilatation (Trial registry at KorAHF registry, ClinicalTrial.gov, NCT01389843).

• Journal of the Korean Vacuum Society
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• v.16 no.5
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• pp.359-365
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• 2007

In this paper we present a bottom-gate type of zinc oxide (ZnO) and Gallium (Ga) doped zinc oxide (GZO) based thin film transistors (TFTs) through applying a radio frequency (RF) magnetron sputtering method at room temperature. The gate leakage current can be reduced up to several ph by applying $SiO_2$ thermally grown instead of using new gate oxide materials. The root mean square (RMS) values of the ZnO and GZO film surface were measured as 1.07 nm and 1.65 nm, respectively. Also, the transmittances of the ZnO and GZO film were more than 80% and 75%, respectively, and they were changed as their film thickness. The ZnO and GZO film had a wurtzite structure that was arranged well as a (002) orientation. The ZnO TFT had a threshold voltage of 2.5 V, a field effect mobility of $0.027\;cm^2/(V{\cdot}s)$, a on/off ratio of $10^4$, a gate voltage swing of 17 V/decade and it operated in a enhancement mode. In case of the GZO TFT, it operated in a depletion mode with a threshold voltage of -3.4 V, a field effect mobility of $0.023\;cm^2/(V{\cdot}s)$, a on/off ratio of $2{\times}10^4$ and a gate voltage swing of 3.3 V/decade. We successfully demonstrated that the TFTs with the enhancement and depletion mode type can be fabricated by using pure ZnO and 1wt% Ga-doped ZnO.

• Development and Reproduction
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• v.5 no.1
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• pp.73-79
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• 2001

Recently many studies have reported that total and bioavailable androgens reduced in male and female athletes and that physical exercise reduces the body weight and increases the reproductive abnormalities such as oligomenorrhea, anovulation, inadequate luteal phase, and delayed puberty in women by the inhibition of the hypothalamic-pituitary-gonadal (HPG) axis . In addition, high mileage endurance 겨nning, psychological stress, and military endurance training in men also reduce the secretion of reproductive hormones. To investigate the efffcts of physical endurance exercise on the secretion of reproductive hormones in men, androgenic hormones from adrenal glands and testis were measured in serum by the conventional radioimmunoassays after long-term (more than3 months), short-term (1 week), and acute (1${sim}$2 hours) physical exercises. Androgenic hormones from adrenal glands and testis such as total testosterone (TT), free testosterone (fT), dehydroepiandrosterone (DHEA), and androstenedione (A) decreased after thesestrenuous endurance trainings, whereas ACTH, cortisol, and dehydroepiandrosterone sulfetes (DHEAS) increased. Conadotropins (LH and FSH) were not idluenced by the physical exercises. Based upon the present results, we assume that the decrease in adrenal and testicular androgens by physical endurance exercises might be associated with the reproductive abnormalities in athletes by unknown factor(s) in addition to the HPG axis disturbance.

• Journal of the East Asian Society of Dietary Life
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• v.21 no.6
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• pp.853-862
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• 2011

We reproduced and investigated the quality characteristics of Samhaeju (one type of Korean traditional rice wine), which has been described in ancient documents. During fermentation, the room temperature was $9.1{\sim}25.0{\circ}C$, and each treatment's material temperature was $11.7{\sim}23^{\circ}C$. As the fermentation proceeded, the pH rapidly decreased (initial pH was 6.6~6.9) and rose gradually from the 18th day. Titratable acidity and amino acidity slowly increased in general. Regarding soluble solid contents, there were various change patterns depending on the production method, and they were affected by initial room temperature. In the treatments using 1 (Sang-ga-yo-rok), 3 (Eum-sik-di-mi-bang), 7 (Jo-sun-mu-ssang-sin-sik-yo-ri-je-beop), 8 (Sang-ga-yo-rok $15^{\circ}C$), reducing sugar contents decreased rapidly after 1st mashing day and then increased slightly after 2nd mashing. The alcohol content increased as the fermentation proceeded, and most of the treatments produced 1/2 the amount of total alcohol content before the 2nd mashing day, followed by a slight increase until the end of fermentation (about 100 days from the 2nd mashing day). In the sensory evaluation, Samhaeju using methods 2, 4, 5, and 6 got high scores and had much reducing sugar contents than other treatments. Among the seven manufacturing processes, method 2 was relatively simple and got the highest score in the sensory evaluation. Therefore, method 2 would be suitable for industrialization and popularization of Korean traditional alcoholic beverage.

• Journal of Chest Surgery
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• v.23 no.2
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• pp.213-221
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• 1990

We have experienced 62 cases of modified Fontan operations in Seoul Nat’l University Hospital from Apr. 1986 to Jul. 1989, They were 38 males and 24 females, and their age was ranged from 16 months to 15.5 years of age. [mean age : 5.73$\pm$2.99 years] There were 16 operative deaths and 2 late deaths, therefore 29% of overall mortality. Their diagnoses were as follows; 28 single ventricle, 11 tricuspid atresia, 6 DORV with LV hypoplasia, 3 pulmonary atresia with hypoplastic RV, 3 TGA with hypoplastic RV, 3 cor\ulcornerGA with hypoplastic LV and PA, 6 AV canal defects with PA, and 2 others. Low cardiac output and pleural effusion were developed frequently, so we divide 40 patients into some groups to analyze the physiologic and anatomic causes of them. By the degree of the LCO, group A was no LCO[mean amount of inotropics used: 0-5 \ulcornerg/kg/min] with 17 cases, B mild LCO [5-10] with 11, C moderate to severe LCO but alive[>10] with 8, D severe LCO to death with 4 cases. For the pleural effusion, group 1 was to be removed the chest tube within 1 week with 8 cases, group II within 3 weeks with 21 cases, group III beyond 3 weeks with 12 cases. We considered their age, diagnosis, pulmonary artery size[PA index], pulmonary artery abnormality, palliative shunt, systemic ventricular type, pulmonary artery wedge pressure, as preoperative factors, and operative methods, and as postoperative factors, CVP, LAP, arrhythmia, thrombosis, atrioventricular valvular insufficiency, etc. In the view of LCO, pulmonary artery size and PCWP were statistically significant [P<0.05], and arrhythmia, A-V valve insufficiency were inclined to the group C and D Pleural effusion was influenced by the pulmonary artery size, pulmonary artery resistance, PCWP, and CVP significantly. [P<0.05] And arrhythmia, residual shunt, and A-V valvular insufficiency were inclined to group II and III, too. As a results, the followings are to be reminded as the important factors at the care of post-Fontan LCO, and persistent pleural effusion [1] pulmonary artery size, [2] pulmonary artery resistance, [3] PCWP, [4] CVP, [5] arrhythmia, [6] residual shunt, [7]A-V valvular insufficiency.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.351-352
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• 2012

UV LED에서 p-GaN층의 높은 일함수와 자체 면저항이 크기 때문에 current spreading layer인 ITO (indium tin oxide) 투명전극이 사용되고 있다. 따라서 높은 UV 파장대 투과율과 낮은 면 저항이 매우 중요하다. 본 연구에서, RF magnetron sputter를 사용하여 ITO 투명전극을 glass(boro33)에 120 nm 두께로 증착하였다. 그 후 RTA (rapid thermal annealing)을 이용해 120초 동안 $600^{\circ}C$에서 Air, $N_2$ (15 sccm), vacuum 환경에서 열처리를 하여 UV-Vis-NIR spectrophotometer를 사용해 ITO 박막의 투과율을 측정하고, Hall measurement system을 이용하여 전기적 특성을 측정하였다. Fig. 1과 같이 열처리 환경에 따라 ITO 박막의 투과율이 변하고 또한 Table 1과 같이 전기적 특성도 변함을 알 수 있었다. Air 환경에서의 열처리는 reference 샘플과 비교 했을 때 400 nm 이하의 파장에서 투과율이 증가하였지만 400 nm 이상의 파장에서는 투과율이 낮아짐을 볼 수 있고, 면 저항 (Ohm/sq)은 오히려 reference (as deposited) 샘플과 비교하여 24 Ohm/sq 증가하는 것을 알 수 있었다. 반면에 $N_2$, vacuum 환경에서 열처리는 reference (as deposited) 샘플 보다 380 nm 파장대에서 16% 정도 높은 투과율을 보였고, 면저항 역시 2배 이상 낮아졌다. 둘 다 비슷한 투과율과 면저항을 나타내었지만 vacuum 환경이 좀 더 우수한 광학적 특성을 나타내었고 반면에 $N_2$ 환경은 좀 더 낮은 면저항을 나타내었다. ITO 박막을 증착한 후 vacuum 환경에서 열처리를 통하여 제작된 UV-LED (중심 파장 380 nm)가 Fig. 2와 같이 입력 전류 450 mA에서 광출력이 46% 정도 향상 되었고 안정된 I-V 특성 보였다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.5
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• pp.324-329
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• 2018

Red phosphor in glasses (PiGs) for automotive light-emitting diode (LED) applications were fabricated with 620-nm $CaAlSiN_3:Eu^{2+}$ phosphor and Pb-free silicate glass. PiGs were synthesized and mounted on high-power blue LED to make a monochromatic red LED. PiGs were simple mixtures of red phosphor and transparent glass powder. After being fabricated with uniaxial press and CIP at 300 MPa for 20 min, the green bodies were thermally treated at $550^{\circ}C$ for 30 min to produce high dense PiGs. As the phosphor content increased, the density of the sintered body decreased and PiGs containing 30% phosphor had a full sintered density. Changes in photoluminescence spectra and color coordination were studied by varying the thickness of plates that were mounted after optical polishing. As a result of the optical spectrum and color coordinates, PiG plate with $210{\mu}m$ thickness showed a color purity of 99.7%. In order to evaluate the thermal stability, the thermal quenching characteristics were measured at temperatures of $30{\sim}150^{\circ}C$. The results showed that the red PIG plates were 30% more thermally stable compared to the AlGaInP red chip.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.6
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• pp.1009-1017
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• 2001

The acousto-optical spectrometer is designed by using 1 GHz bandwidth acousto-optic deflector for radio signal analysis. This system is a high resolution wide band spectrometer which uses I GHz bandwidth and a total of 2,048 channel charge coupled device. When we measured the spectrums of signals deflected by acousto-optical spectrometer, we confirmed the stability of the total system by repetitive observations of the same frequency, and each part of the system worked well. We installed this system onto 60 cm radio telescope, and observed 12CO(J= 1 ∼0) emission lines around CRL 2688, IRC 10216 and NGC 5005 Galaxy center. We could observe effectively very narrow band width radio spectrum as well as wide band radio spectrum. We also confirmed high sensitivity and resolution in observation of 12CO(J-10) omission line of NGC 5005 Galaxy center which is a weak signal.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.7 s.110
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• pp.659-664
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• 2006

This paper reports a high power 60 GHz push-push oscillator fabricated using $0.12{\mu}m$ metamorphic high electron-mobility transistors(mHEMTs). The devices with a $0.12{\mu}m$ gate-length exhibited good DC and RF characteristics such as a maximum drain current of 700 mA/mm, a peak gm of 660 mS/mm, an $f_T$ of 170 GHz, and an $f_{MAX}$ of more than 300 GHz. By combining two sub-oscillators having $6{\times}50{\mu}m$ periphery mHEMT, the push-push oscillator achieved a 6.3 dBm of output power at 59.5 GHz with more than - 35 dBc fundamental suppression. The phase noise of - 81.5 dBc/Hz at 1 MHz offset was measured. This is one of the highest output power obtained using mHEMT technology without buffer amplifier, and demonstrates the potential of mHEMT technology for cost effective millimeter-wave commercial applications.

• Korean Journal of Plant Tissue Culture
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• v.25 no.1
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• pp.37-43
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• 1998

The highest transformation frequency was observed when cotyledonary and hypocotyl explants of flowering cabbage (Brassica oleracea var. acephala DC) 'Eunbae' were cultured on shoot induction medium without kanamycin for 1 day, then cocultured with Agrobacterium tumefaciens LBA4404;;pGA1036 harboring tomato inhibitor II promoter and $\beta$-glucuronidae (GUS) fusion gene for 3 days. These explants were transferred to MS medium containing 20 mg/L kanamycin, 500 mg/L carbenicillin, and 1 mg/L BA. The explants were subsequently subcultured every 2 weeks. Incorporation of the GUS gene into flowering cabbage was confirmed by PCR analysis of DNA. Southern blot analysis showed that ECL-labeled GUS gene was hybridized to the expected amplified genomic DNA fragment of about 366 bp from transgenic flowering cabbage. Histochemical analysis based on the enzymatic activity of the GUS protein indicated that PI-II promoter activity was sysmatically associated with vascular tissue in wonded as well as in non-wounded leaves, petioles and stems, but not in roots. Partial wounding with razor blade showed not systemic induction but partial induction.