중추성 요붕증이 동반된 랑게르한스 세포 조직구증 1예

김진호,문준성,문선중,이지은,최재원,은미정,천경아,조인호,윤지성,원규장,이경희 신덕섭,이형우 영남대학교 의과대학 2005 Yeungnam University Journal of Medicine Vol.22 No.2

Central diabetes insipidus (DI) is a syndrome characterized by thirst, polydipsia and polyuria. Langerhans cell histiocytosis is one of the etiologies of DI. Recently we experienced a central DI associated with Langerhans cell histiocytosis. The 44 years old female patient complained right hip pain polydipsia and polyuria. We carried out water deprivation test. After vasopressin injection, urine osmotic pressure was increased form 109mOsmol/Kg to 327mOsmol/Kg (300%). Brain MRI showed a thickened pituitary stalk and at hot bone CT.CT guided biopsy revealed abnormal histiocytes proliferation and abundant lymphocytes, The final diagnosis was central DI associated with systemic Langerhans cell histiocytosis invading hip bone, L-spine and pituitary stalk. Desmopressin and etoposide chemotherapy were performed to the patient.

노인에서 한국판 행동통제척도의 표준화 및 타당도 연구

김효진,이준영,정희연,나덕렬,조성진,조맹제,장성만 大韓神經精神醫學會 2007 신경정신의학 Vol.46 No.4

The aims of this study are to demonstrate the reliability and the validity of the Korean version of Behavioral Dyscontrol Scale (BDS-K.) and to present the normative values of BDS-K among the Korean elderly. The BDS-K was administered in a standardized manner to 1,389 healthy volunteers aged over 65 years recruited from the cornmunity. The elderly with serious neurological, medical or psychiatric disorders were excluded using screening tests. BDS-K showed good intemal consistency (Cronbach's alpha=0.812), test-retest reliability (r=0.88) and inter-rater reliability (r=0.99). Age and educational level were found to affect BDS-K score. Based on this result, normative values of BDS-K. were calculated by age and educational level. The validity of the BDS-K were demonstrated in comparison with MMSE-KC (r=0.72). BDS-K is reliable and valid instrument for measuring executive function of the elderly. The normative values suggested by this study can be widely used as reference values to objectively interpret BDS-K scores of the Korean elderly.

Degradation analysis of mixed ionic-electronic conductor-supported iron-oxide oxygen carriers for chemical-looping conversion of methane

Cho, Won Chul,Lee, Jun Kyu,Nam, Gyeong Duk,Kim, Chang Hee,Cho, Hyun-Seok,Joo, Jong Hoon Elsevier 2019 APPLIED ENERGY Vol.239 No.-

<P><B>Abstract</B></P> <P>An iron-based oxygen carrier can convert natural gas into chemicals (syngas or hydrogen) with controlled CO<SUB>2</SUB> emission in a redox process. Mixed ionic-electronic conductor (MIEC)-supported iron oxides have shown high catalytic activity by facilitating inward O anion diffusion. However, their durability has been tested under limited conditions, and key factors affecting the degradation of MIEC-supported iron oxides have rarely been identified. In this work, we find that the inherent redox stability and electronic conductivity of the support material are decisive properties that determine the redox stability and activity of iron oxide/MIEC composites, such as perovskite-type La<SUB>0.8</SUB>Sr<SUB>0.2</SUB>FeO<SUB>3−δ</SUB> and fluorite-type Ce<SUB>0.9</SUB>Gd<SUB>0.1</SUB>O<SUB>2−δ</SUB>, over 100 redox cycles with the redox pair Fe – Fe<SUB>2</SUB>O<SUB>3</SUB> at 900 °C. The low redox stability of the Fe<SUB>2</SUB>O<SUB>3</SUB>/La<SUB>0.8</SUB>Sr<SUB>0.2</SUB>FeO<SUB>3−δ</SUB> composite oxygen carrier is closely related to that of La<SUB>0.8</SUB>Sr<SUB>0.2</SUB>FeO<SUB>3−δ</SUB> and the extreme redox environment. The increased electronic conductivity of Ce<SUB>0.9</SUB>Gd<SUB>0.1</SUB>O<SUB>2−δ</SUB> under reducing conditions enhances the reaction rate. However, the low electronic conductivity of Ce<SUB>0.9</SUB>Gd<SUB>0.1</SUB>O<SUB>2−δ</SUB> under oxidizing conditions (5 × 10<SUP>−4</SUP> S/cm at 750 °C) progressively promotes the formation of iron oxide product layer, resulting in low syngas selectivity (H<SUB>2</SUB>/CO > 2). This work helps design and select a compatible and commercially viable MIEC-supported iron oxide.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Degradation of mixed ionic-electronic conductor (MIEC)-iron oxide is analyzed. </LI> <LI> The used oxygen carrier shows higher rate, but low syngas selectivity. </LI> <LI> The fragmentation is related to inherent redox instability of the MIECs. </LI> <LI> Low electronic conductivity of the MIEC leads to the formation of iron oxide layer. </LI> <LI> The iron oxide product layer begets the decrease in syngas selectivity. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

절단된 원형 패치 안테나의 대역폭 개선에 관한 연구

조영빈,나종덕,전계석 慶熙大學校 레이저 工學硏究所 2002 레이저공학 Vol.13 No.-

In this paper, the truncated circular patch antenna is designed with the short pin. The designed antenna has the center frequency of 4.6815GHz and fractional bandwidth of 4.04%. It has been shown that the measured results are increased by 0.87% in the fractional bandwidth, but decreased by 57.5MHz in the center frequency compared to simulations. It seems to be an error in fabrication. Also, the gain in the measurement is 5.39dB. The change of the radiation pattern by the variation of the short pin and the truncation of the patch haven't seriously affect on the performance of antenna. Therefore, the truncated circular patch antenna has the characteristics of extended bandwidth and is easier to match impedance than conventional one.

SrNb₂O₆ nanotubes with enhanced photocatalytic activity

Cho, In-Sun,Lee, Sangwook,Noh, Jun Hong,Kim, Dong Wook,Lee, Duk Kyu,Jung, Hyun Suk,Kim, Dong-Wan,Hong, Kug Sun Royal Society of Chemistry 2010 Journal of materials chemistry Vol.20 No.19

<P>SrNb<SUB>2</SUB>O<SUB>6</SUB> having a rhombic nanotubular structure with a diameter of 300 nm, average length of 3 μm and wall thickness of 50 nm was synthesized <I>via</I> a facile hydrothermal route. The prepared powders were characterized using X-ray diffraction, field-emission electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM) and Raman spectroscopy. Compared to the same material prepared by the solid-state reaction method, the rhombic nanotubes of SrNb<SUB>2</SUB>O<SUB>6</SUB> exhibited enhanced photocatalytic activity for the production of H<SUB>2</SUB> from pure water, which was mainly attributed to their higher surface area. Moreover, the increased optical absorption properties resulting from the variation of the crystal structure also contributed to their higher photocatalytic activity.</P> <P>Graphic Abstract</P><P>SrNb<SUB>2</SUB>O<SUB>6</SUB> powder with a nanotubular structure was synthesized <I>via</I> a facile hydrothermal route. This nanotube exhibited enhanced photocatalytic activity for the production of H<SUB>2</SUB> from water splitting compared with the bulk powder. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=b926694a'> </P>

Characterization of PVdF Nanofibers by Electrospinning

Duk-Rae Chang,Yong-Jun Cho,Gie-Seok Heo 한국고분자학회 2006 한국고분자학회 학술대회 연구논문 초록집 Vol.2006 No.10

A Hybrid AMOLED Driver IC for Real-Time TFT Nonuniformity Compensation

Jun-Suk Bang,Hyun-Sik Kim,Ki-Duk Kim,Oh-Jo Kwon,Choong-Sun Shin,Joohyung Lee,Gyu-Hyeong Cho IEEE 2016 IEEE journal of solid-state circuits Vol.51 No.4

<P>An active matrix organic light emitting diode (AMOLED) display driver IC, enabling real-time thin-film transistor (TFT) nonuniformity compensation, is presented with a hybrid driving method to satisfy fast driving speed, high TFT current accuracy, and a high aperture ratio. The proposed hybrid column-driver IC drives a mobile UHD (3840 x 2160) AMOLED panel, with one horizontal time of 7.7 mu s at a scan frequency of 60 Hz, simultaneously senses the TFT current for back-end TFT variation compensation. Due to external compensation, a simple 3T1C pixel circuit is employed in each pixel. Accurate current sensing and high panel noise immunity is guaranteed by a proposed current-sensing circuit. By reusing the hybrid column-driver circuitries, the driver embodies an 8 bit current-mode ADC to measure OLED V-I transfer characteristic for OLED luminance-degradation compensation. Measurement results show that the hybrid driving method reduces the maximum current error between two emulated TFTs with a 60 mV threshold voltage difference under 1 gray-level error of 0.94 gray level (37 nA) in 8 bit gray scales from 12.82 gray level (501 nA). The circuit-reused current-mode ADC achieves 0.56 LSB DNL and 0.75 LSB INL.</P>

Clinical Analysis of Hemodialysis Vascular Access: Comparision of Autogenous Arterioveonus Fistula & Arteriovenous Prosthetic Graft

Duk-Sil Kim,Sung-Wan Kim,Jun-Chul Kim,Ji-Hyung Cho,Joon-Hyuk Kong,Chang-Ryul Park 대한흉부외과학회 2011 Journal of Chest Surgery (J Chest Surg) Vol.44 No.1

Background: Mature autogenous arteriovenous fistulas have better long term patency and require fewer secondary interventions compared to arteriovenous prosthetic graft. Our Study evaluated vascular patency rates and incidence of interventions in autogenous arteriovenous fistulas and grafts. Material and Methods: A total of 166 vascular access operations were performed in 153 patients between December 2002 and November 2009. Thirty seven caeses were excluded due to primary access failure and loss of follow-up. One group of 92 autogenous arterioveous fistulas and the other group of 37 arteriovenous prosthetic grafts were evaluated retrospectively. Primary and secondary patency rates were estimated using the Kaplan-Meier method. Results: The primary patency rate (84%, 67%, 51%vs. 51%, 22%, 9% at 1, 3, 5 year; p=0.0000) and secondary patency rate (96%, 88%, 68% vs. 88%, 65%, 16%at 1. 3, 5 year; p=0.0009) were better in autogenous fistula group than prosthetic graft group. Interventions to maintain secondary patency were required in 23% of the autogenous fistula group (average 0.06 procedures/patient/year) and 65% of prosthetic graft group (average 0.21 procedures/patient/year). So the autogenous fistula group had fewer intervention rate than prosthetic graft group (p=0.01) The risk factor of primary patency was diabetus combined with ischemic heart disease and the secondary patency’s risk factor was age. Conclusion:Autogenous arteriovenous fistulas showed better performance compared to prosthetic grafts in terms of primary &secondary patency and incidence of interventions.

도시지역 청소년들의 체질량지수와 스트레스간의 연관성

조한준,최순덕,이원영,조동영,유병연 대한가정의학회 2001 Korean Journal of Family Medicine Vol.22 No.5

Cu(Ⅱ)이온과 Poly(vinyl alcohol)간에 생성되는 고분자-금속 착물의 열역학적 거동에 관한 연구

전은덕, 한정호, 조태섭 영남대학교 기초과학연구소 2000 基礎科學硏究 Vol.20 No.-

The dissociation constants for poly(vinyl alcohol) (PVA) at a constant ionic strength of μ=0.1(KCl) were measured by potentiometric titration at various temperatures. The formation constants for the Cu(II)-PVA complex at the same condition were also measured in this study. From the temperature dependence of those dissociation and formation constants, various thermodynamic parameters such as ΔG, ΔH, ΔS were determined. From the thermodynamic parameters, it was concluded that the dissociation of a proton from PVA is unfavorable with a negative entropy and positive enthalpy. In contrast, the complex formation was a spontaneous and exothermic process with favorable entropy.