Effect of Intraoperative Mitomycin C on the Surgical Outcomes of Ahmed Glaucoma Valve Implantation with Ciliary Sulcus Tube Placement

Na Eun Kim(Na Eun Kim),Sung Sik Kim(Sung Sik Kim),Jihei Sara Lee(Jihei Sara Lee ),Kwanghyun Lee(Kwanghyun Lee),Hyoung Won Bae(Hyoung Won Bae),Sang Yeop Lee(Sang Yeop Lee),Wungrak Choi(Wungrak Choi),Ch 대한안과학회 2023 Korean Journal of Ophthalmology Vol.37 No.3

Purpose: To evaluate the effect of intraoperative mitomycin C (MMC) on the surgical outcomes of ciliary sulcus (CS) Ahmed glaucoma valve (AGV) tube placement. Methods: A retrospective review of medical records of 54 consecutive patients who underwent AGV implantation with tube placed in CS was performed. Consecutive cases operated without the use of intraoperative MMC from 2017 to 2019 were compared with consecutive cases operated with MMC from 2019 to 2021. Surgical failure was defined as intraocular pressure (IOP) exceeding 21 mmHg in two consecutive visits after postoperative 3 months or ≤30% IOP reduction, IOP ≤5 mmHg in two consecutive visits, or loss of light perception. Kaplan-Meier survival analysis and log-rank test were performed to compare the surgical failure rates. Results: A total of 54 eyes of 54 patients were investigated. Mean follow-up period after AGV implantation was 1.4 ± 0.8 years. The MMC group showed significantly lower IOP during the 1st postoperative month (20.5 ± 8.6 mmHg vs. 15.8 ± 6.4 mmHg, p = 0.027), but the difference did not persist 6 months after the surgery (p = 0.805). The mean number of postoperative antiglaucoma medications was significantly lower in the MMC group in the 1st postoperative month (p = 0.047) but no difference was found at 6 months. No statistical difference was noted in the rates of postoperative complications. Kaplan- Meier survival analysis showed comparable survival rates between MMC group and no MMC group (p = 0.356). Conclusions: The intraoperative use of MMC significantly lowered IOP in the 1st postoperative month but did not increase 6 months success rates in patients receiving AGV tube placement in CS.

Optimization of Delay-Constrained Video Transmission for Ad Hoc Surveillance

Kwanghyun Lee,Sungjin Lee,Sanghoon Lee IEEE 2014 IEEE Transactions on Vehicular Technology VT Vol.63 No.4

<P>Recent increases in demand by militaries and disaster relief operations has greatly accelerated research on delay-constrained video surveillance with low-delay and high-quality video transmission. The following factors should be systematically analyzed due to the tradeoff between low delay and high quality: the visual importance of surveillance objects, quality degradation due to wireless channel dynamics, and variant end-to-end delay. We propose and optimize a low-delay video transmission technique for video surveillance over an ad hoc network. The proposed protocol is composed of intercommunication and intraprocessing parts. Through intercommunication optimization, we identify an optimal routing path and an associated relaying in terms of channel throughput that meet the source-rate, the flow-rate, and delay constraints. Through intraprocessing optimization, we identify an optimal packet length and an associated number of packets to adapt to the delay in the variant dynamic channel. Through simulations, we demonstrate that delay and throughput control significantly contribute to improvements in visual quality of up to 1.7-3 dB compared with conventional schemes.</P>

Single-Crystalline Silicon-Based Heterojunction Photodiode Arrays on Flexible Plastic Substrates

Sangwook Lee,Juree Hong,Ja Hoon Koo,Seulah Lee,Kwanghyun Lee,Seongil Im,Taeyoon Lee IEEE 2011 IEEE transactions on electron devices Vol.58 No.10

<P>A silicon-based photodiode array was fabricated on a flexible polyethylene terephthalate substrate using a transfer printing technique. A heterojunction structure composed of a 15-nm-thick highly doped hydrogenated amorphous-silicon (n<SUP>+</SUP> a-Si:H) layer and a 3-μm-thick p-type single-crystal silicon (p c-Si) membrane layer was adopted as the active layer of the flexible photodiode. The highly ordered photodiode array formed on the flexible substrate exhibited superior stability in electrical properties under bent conditions with no mechanical deformation. The variation of the spectral quantum efficiency (QE) under short-wavelength light illumination (λ ≤ 580 nm) was in excellent agreement with that of a heterojunction photodiode composed of a-Si:H and a bulk c-Si substrate. Relatively low QE values were observed under longer wavelength (λ ≥ 600 nm) illumination due to the finite thickness of the active layer. The <I>C</I>-<I>V</I> measurement results of the fabricated photodiode array were in accordance with the abrupt junction model. A closer inspection of the junction area of the device using high-resolution cross-sectional transmission micrograph exhibited an interface depth of 2 ± 0.5 nm, which is unavoidable in plasma-enhanced a-Si:H deposition processes.</P>

3D Visual Activity Assessment Based on Natural Scene Statistics

Kwanghyun Lee,Moorthy, Anush Krishna,Sanghoon Lee,Bovik, Alan Conrad IEEE 2014 IEEE TRANSACTIONS ON IMAGE PROCESSING - Vol.23 No.1

<P>One of the most challenging ongoing issues in the field of 3D visual research is how to perceptually quantify object and surface visualizations that are displayed within a virtual 3D space between a human eye and 3D display. To seek an effective method of quantification, it is necessary to measure various elements related to the perception of 3D objects at different depths. We propose a new framework for quantifying 3D visual information that we call 3D visual activity (3DVA), which utilizes natural scene statistics measured over 3D visual coordinates. We account for important aspects of 3D perception by carrying out a 3D coordinate transform reflecting the nonuniform sampling resolution of the eye and the process of stereoscopic fusion. The 3DVA utilizes the empirical distortions of wavelet coefficients to a parametric generalized Gaussian probability distribution model and a set of 3D perceptual weights. We conducted a series of simulations that demonstrate the effectiveness of the 3DVA for quantifying the statistical dynamics of visual 3D space with respect to disparity, motion, texture, and color. A successful example application is also provided, whereby 3DVA is applied to the problem of predicting visual fatigue experienced when viewing 3D displays.</P>

Molecular mechanism of Jmjd3‐mediated interleukin‐6 gene regulation in endothelial cells underlying spinal cord injury

Lee, Kwanghyun,Na, Wonho,Lee, Jee Youn,Na, Jungtae,Cho, Heejung,Wu, Hongjin,Yune, Tae Young,Kim, Won‐,Sun,Ju, Bong‐,Gun Blackwell Publishing Ltd 2012 Journal of Neurochemistry Vol.122 No.2

<P><I>J. Neurochem.</I> (2012) <B>122</B>, 272–282.</P><P><B>Abstract</B></P><P>The inflammatory response contributes substantially to secondary injury cascades after spinal cord injury, with both neurotoxic and protective effects. However, epigenetic regulations of inflammatory genes following spinal cord injury have yet to be characterized thoroughly. In this study, we found that histone H3K27me3 demethylase Jmjd3 expression is acutely up‐regulated in blood vessels of the injured spinal cord. We also observed up‐regulation of <I>Jmjd3</I> gene expression in bEnd.3 endothelial cells that were subjected to oxygen‐glucose deprivation/reperfusion injury. When <I>Jmjd3</I> was depleted by siRNA, oxygen‐glucose deprivation/reperfusion injury‐induced up‐regulation of IL‐6 was significantly inhibited. In addition, Jmjd3 associated with NF‐κB (p65/p50) and CCAAT‐enhancer‐binding protein β at the <I>IL‐6</I> gene promoter. The recruitment of Jmjd3 coincided with decreased levels of tri‐methylated H3K27 as well as increased levels of mono‐methylated H3K27 at the <I>IL‐6</I> gene promoter. Furthermore, <I>Jmjd3</I> depletion did not result in significant changes of methylation level of H3K27 at the <I>IL‐6</I> gene promoter. Collectively, our findings imply that Jmjd3‐mediated H3K27me3 demethylation is crucial for <I>IL‐6</I> gene activation in endothelial cells, and this molecular event may regulate acute inflammatory response and integrity of the blood‐spinal cord barrier following spinal cord injury.</P>

Regulation of DU145 prostate cancer cell growth by Scm-like with four mbt domains 2.

Lee, Kwanghyun,Na, Wonho,Maeng, Je-Heon,Wu, Hongjin,Ju, Bong-Gun Indian Academy of Sciences 2013 Journal of biosciences Vol.38 No.1

<P>Mammalian SFMBTs have been considered to be polycomb group repressors. However, molecular mechanisms underlying mammalian SFMBTs-mediated gene regulation and their biological function have not been characterized. In the present study, we identified YY1 and methylated histones as interacting proteins of human SFMBT2. We also found that human SFMBT2 binds preferentially to methylated histone H3 and H4 that are associated with transcriptional repression. Using DU145 prostate cancer cells as a model, we showed that SFMBT2 has a transcriptional repression activity on HOXB13 gene expression. In addition, occupancy of SFMBT2 coincided with enrichment of diand tri-methylated H3K9 and H4K20 as well as tri-methylated H3K27 at the HOXB13 gene promoter. When SFMBT2 was depleted by siRNA in DU145 prostate cancer cells, significant up-regulation of HOXB13 gene expression and decreased cell growth were observed. Collectively, our findings indicate that human SFMBT2 may regulate cell growth via epigenetic regulation of HOXB13 gene expression in DU145 prostate cancer cells.</P>

Does Accountability Policy Diminish Teachers' Intrinsic Motivation to Teach? Evidence From the 2000 SASS Database

Kwanghyun Lee 한국교육행정학회 2005 敎育行政學硏究 Vol.23 No.2

이 논문은 관료적 책무성 정책이 교사에게 미치는 심리적 영향에 대하여 검토하는 것을 목적으로 하고 있다. 심리학의 자기 결정 이론(self-determination theory)에 따르면 수행과 연결된 보상이나 제재의 위협과 같은 통제 기제들은 행위자의 활동이유의 인식근거를 내부에서 외부로 변환시킴으로 인해서 행위자의 내적 동기를 삭감시킨다. 자기 결정 이론은 따라서 강한 책무성 정책이 교사들의 교수에 대한 내적 동기를 삭감시킬 것을 예측한다. 이러한 연구가정에 근거하여 미국 연방교육통계센터에서 시행한 2000년도 학교와 교원 조사 데이터를 순위 로짓과 순위 프로빗 모델을 통해 분석한 결과, 책무성 정책 하에서 일하는 교사들의 경우 다시 대학에서부터 인생을 시작한다면 교사라는 직업을 선택하지 않을 것이라고 대답할 확률이 높은 것으로 드러났다. 한편 최선을 다해서 학생들을 가르치는 것이 시간낭비라는 응답을 할 확률이 역시 높은 것으로 나타났다. 이러한 내적 동기의 대리변수를 종속변수로 연구한 결과, 자발적이 아닌 하향식으로 재정적 보상과 연관되어 있는 관료적 책무성 제도가 교사의 교수에 대한 내적 동기를 삭감시킴으로 인해 교육현장에 오히려 부정적인 영향을 미칠 수도 있음을 보여주고 있다. 따라서 관료적 책무성제도보다는 교사의 내적 동기를 향상시키기 위한 여타 교원정책이 필요함을 보여주고 있다. This article examines the psychological effect of accountability policy on teachers. Self-determination theory (SDT) in psychology states that controlling mechanism such as performance-contingent rewards and threat of sanction will turn agents' perceived locus of causality from inwardly to externally directed, thus undermining agents' intrinsic motivation. SDT implies that teachers under the pressure of bureaucratic accountability policy will be more likely to lose their intrinsic motivation for teaching. Analysis of the 2000 NCES Schools and Staffing Survey database using ordered probit and logit models confirms that teachers under strong accountability policy are more likely to mention that they would not become a teacher again if they were to start over, controlling for other variables. They also respond that it is a waste of time to try to do one's best as a teacher, which shows that teachers working under strong accountability policy are likely to lose intrinsic motivation.

Comparison of three different surface plank exercises on core muscle activity

Lee, Jin,Jeong, Kwanghyun,Lee, Hyuna,Shin, Jaeyeon,Choi, Jaelim,Kang, Seungbeom,Lee, Byoung-Hee korean Academy of Physical Therapy Rehabilitation 2016 Physical therapy rehabilitation science Vol.5 No.1

Objective: This study compared the muscle activities of the erector spinae (ES), the external oblique (EO), and the rectus abdominis (RA) on three different surfaces. The purpose of this study was to determine which surface induces the highest muscle activity during the plank exercises. The information from this study can be used to recommend plank exercises to athletes and patients with weak core muscles. Design: Cross-sectional study. Methods: The subjects include 20 adult males attending S University in Seoul. Participants completed each plank exercise on three different surfaces. To measure muscle activities, researchers used the values from electromyography. The measurement excluded the initial two and final two seconds and collected information on the RA, EO, and ES in each posture of each subject. Results: The left external oblique showed significant differences between the plank position on stable ground (ST) and the plank position using a suspension device (SL) (p<0.05) and between the plank position on the unstable ground (US) and SL (p<0.05). The right rectus abdominis and left rectus abdominis displayed statistically significant differences between the ST and the US (p<0.05) and between the ST and the SL (p<0.05). The right erector spinae had a statistically significant difference between ST and US (p<0.05). Conclusions: The plank exercise strengthens the core muscles effectively, and muscle activity is related to the posture of the exercise and the location of the muscle. These results suggest that plank exercises improve muscle activities. Additionally, plank exercises can be applied to general medical care.

Biochemical characterization of deblocking aminopeptidase from hyperthermophilic archaeon <i>Thermococcus onnurineus</i> NA1

Lee, Hyun Sook,Cho, Yona,Kim, Yun Jae,Nam, Kwanghyun,Lee, Jung-Hyun,Kang, Sung Gyun Elsevier 2007 Journal of bioscience and bioengineering Vol.104 No.3

<P>A genomic analysis of the hyperthermophilic archaeon <I>Thermoccoccus onnurineus</I> NA1 (TNA1) revealed the presence of a deblocking aminopeptidase (DAP) gene with high similarity to the genes of DAPs from <I>Pyrococcus furiosus</I> (86%) and <I>Pyrococcus horikoshii</I> (83% identity). The optimum aminopeptidase activity of the recombinant enzyme was observed at pH 7.5 and in the range of 90°C to 100°C. The specific aminopeptidase and deblocking activities of the enzyme toward Leu-<I>p</I>NA and Ac-Leu-<I>p</I>NA were 18- and 3-fold higher than those of a <I>P. horikoshii</I> DAP (DAP2), respectively. The enzyme activity was significantly increased by Co<SUP>2+</SUP> ions. The presence of Co<SUP>2+</SUP> ions induced the activation of the enzyme with heating and changed the large oligomer to a dimer. The enzyme activated by Co<SUP>2+</SUP> ions appeared to eventually be inactivated by autodegradation, which was confirmed by mass spectrometry.</P>

3D Perception Based Quality Pooling: Stereopsis, Binocular Rivalry, and Binocular Suppression

Kwanghyun Lee,Sanghoon Lee IEEE 2015 IEEE journal of selected topics in signal processi Vol.9 No.3

<P>One of the most challenging ongoing issues in the field of 3D visual research is how to interpret human 3D perception over virtual 3D space between the human eye and a 3D display. When a human being perceives a 3D structure, the brain classifies the scene into the binocular or monocular vision region depending on the availability of binocular depth perception in the unit of a certain region (coarse 3D perception). The details of the scene are then perceived by applying visual sensitivity to the classified 3D structure (fine 3D perception) with reference to the fixation. Furthermore, we include the coarse and fine 3D perception in the quality assessment, and propose a human 3D Perception-based Stereo image quality pooling (3DPS) model. In 3DPS we divide the stereo image into segment units, and classify each segment as either the binocular or monocular vision region. We assess the stereo image according to the classification by applying different visual weights to the pooling method to achieve more accurate quality assessment. In particular, it is demonstrated that 3DPS performs remarkably for quality assessment of stereo images distorted by coding and transmission errors.</P>