Efficacy and Safety of Low-Dose Intravesical OnabotulinumtoxinA Injections in Female Patients With Detrusor Overactivity With Detrusor Underactivity

나현석,이충렬,임재성,송기학,신주현,박종목,이지용 대한배뇨장애요실금학회 2024 International Neurourology Journal Vol.28 No.1

Purpose: We assessed the effectiveness and safety of using intravesical onabotulinumtoxinA (onabotA; BOTOX) injection with a low dose (75 units) for treating urinary storage symptoms in patients with detrusor overactivity with detrusor underactivity (DODU) compared to using the standard 100 units of onabotA in patients with overactive bladder (OAB).Methods: This ambidirectional study included 121 female patients who received intravesical onabotA injections at our hospitals. A total of 87 patients with OAB and 34 patients with DODU were reviewed using a 3-day voiding diary, uroflowmetry, and questionnaires including the International Prostate Symptom Score (IPSS), Overactive Bladder Symptom Score, and Patient Perception of Bladder Condition. Patients were evaluated at baseline, within 2 weeks of treatment, and beyond 3 months after treatment.Results: Questionnaire scores of the DODU group demonstrated significant improvement in the short term, with a subsequent decline, but an overall improvement compared to baseline in the long term. Notably, the DODU group exhibited enhanced IPSS voiding scores after the treatment. In the OAB group, most questionnaire scores, excluding the IPSS voiding score, showed significant posttreatment improvement, which was sustained to some extent in the long term. Voiding diary parameters related to storage symptoms were enhanced in both groups. The maximum and mean flow rates decreased in the OAB group but increased in the DODU group, particularly in the short term (P=0.000). The postvoid residual volume increased in both groups after posttreatment, with a mitigated change in the long term. Safety assessments revealed manageable adverse events in both groups with comparable frequencies.Conclusions: Low-dose intravesical onabotA for DODU demonstrated a relatively shorter duration of efficacy than OAB. Nonetheless, the treatment improved both storage and voiding symptoms in patients with DODU without significant adverse effects.

진화론적 최적화된 RBF 뉴럴 네트워크를 이용한 전력기기 내부 고장 진단

나현석,진용하,오성권 대한전기학회 2010 대한전기학회 학술대회 논문집 Vol.2010 No.10

RBF 뉴럴 네트워크를 이용한 3상 부분방전 패턴인식에 관한 연구

나현석,오성권,김정태 대한전기학회 2011 정보 및 제어 심포지엄 논문집 Vol.2011 No.10

Growth of AlN Thin Film on Sapphire Substrates and ZnO Templates by RF-magnetron Sputtering

나현석,Na, Hyun-Seok The Korean Vacuum Society 2010 Applied Science and Convergence Technology Vol.19 No.1

먼저 RF 마그네트론 스퍼터링법을 이용하여 사파이어 기판 위에 AlN 박막을 증착하였다. AlN 공급원으로는 분말소결된 AlN 타겟을 적용하였다. 플라즈마 파워를 50에서 110 W로 증가시켰을 때 AlN 층의 두께는 선형적으로 증가하였다. 그러나 동작압력을 3에서 10 mTorr로 증가시켰을 때는 동작기체인 아르곤 양이 증가함에 따라 AlN 타겟으로부터 스퍼터링되어 나온 AlN 입자들의 평균자유행정의 거리가 감소하기 때문에 AlN 층의 두께는 약간 감소하였다. 질소 기체를 아르곤과 섞어주었을 때는 질소의 낮은 스퍼터링 효율에 의해서 AlN의 두께는 크게 감소하였다. 다음으로는 ZnO 형판 위에 AlN를 증착하였다. 그러나 700도 이상의 열처리에 의해서 AlN와 ZnO의 계면이 약간 분리되어 계면의 열적 안정성이 낮다는 결과를 얻었다. 게다가 스퍼터링으로 증착한 AlN 박막의 나쁜 결정성으로 인하여 700도에서 MOCVD의 반응기 기체인 수소와 암모니아에 의해서 AlN 밑의 ZnO 층이 분해되는 현상도 관찰하였다. 그리고 900도 이상에서는 ZnO가 완전히 분해되어 AlN 박막이 완전히 분리되었다. AlN thin films were deposited on sapphire substrates and ZnO templates by rf-magnetron sputtering. Powder-sintered AlN target was adopted for source material. Thickness of AlN layer was linearly dependent on plasma power from 50 to 110 W, and it decreased slightly when working pressure increased from 3 to 10 mTorr due to short mean free path of source material sputtered from AlN target by Ar working gas. When $N_2$ gas was mixed with Ar, the thickness of AlN layer decreased significantly because of low sputter yield of nitrogen. AlN layer was also deposited on ZnO template. However, it showed weak thermal stability that the interface between AlN and ZnO was deteriorated by rapid thermal annealing treatment above $700^{\circ}C$. In addition, ZnO layer was largely attacked by MOCVD ambient gas of hydrogen and ammonia around $700^{\circ}C$ through inferior AlN layer deposited by sputtering. And AlN layers were fully peeled off above $900^{\circ}C$.

분광 반사법을 이용한 GaN 박막의 실시간 관찰

나현석,Na, Hyun-Seok 한국진공학회 2011 Applied Science and Convergence Technology Vol.20 No.5

본 연구에서는 분광 반사 측정용으로 개조된 metalorganic chemical vapor deposition를 이용하여 GaN의 성장을 반응기 내부에서 실시간으로 관찰하였다. 분광 반사법에서는 190~861 nm의 p-편광된 빛을 시편에 $75^{\circ}$로 입사시킨 후 뒤 GaN 박막으로부터 반사되어 나오는 빛을 분석한다. 관찰된 반사 스펙트럼은 다중반사로 인하여 간섭현상도 함께 보여주고 있는데, 이때 위아래로 진동하는 폭은 박막의 결정성이 나쁘면 줄어들었고, 이는 박막 내부에 존재하는 많은 결함에 의해 입사된 빛이 산란되거나 흡수되어 전체적으로 반사강도가 크게 감소하였기 때문으로 판단된다. 또한 가장 강한 보강간섭을 나타내는 파장을 선택하여 $NH_3$의 공급여부에 따른 강도변화를 실시간을 관찰하였는데, 10초 차단한 경우에는 큰 변화는 없었지만, 30초 이상인 경우에는 뚜렷한 강도 증가가 관찰되었고, 계속 차단하였을 때도 높아진 강도로 계속 유지되었다. 이러한 현상은 $NH_3$를 공급했을 때 표면은 N로 덮여 있었지만, $NH_3$ 공급을 차단하면 GaN의 높은 질소평형증기압으로 인하여 표면의 질소가 탈착되어 표면은 금속성의 Ga으로 덮인 상태로 바뀌었기 때문에 반사강도가 약간 상승한 것으로 보인다. An in-situ, real-time monitoring of GaN epilayers grown by low pressure metalorganic chemical vapor deposition system modified for spectral reflectance was performed. Reflectance spectrums from 190~861 nm were observed using p-polarized light with incident angle of $75^{\circ}$. All reflectance spectrums showed interference oscillation caused by multiple reflection within GaN epilayers, and the spectrum from GaN with low crystalline quality showed weak reflectance intensity and much low amplitude of the oscillation because many defects in GaN resulted in light scattering and absorption. Signal variation of reflected light which was selected around strong constructive wavelength range was also observed during $NH_3$ supplying and $NH_3$ cut-off. There was no significant change in signal intensity when $NH_3$ cut-off for 10 sec, but it showed higher intensity when $NH_3$ was cut off for over 30 sec and its intensity kept unchanged. This result indicates that GaN surface was N-terminated during $NH_3$ supplying but Ga-terminated during $NH_3$ cut-off because of high nitrogen equilibrium vapor pressure of GaN, and metallic Ga-terminated surface caused slightly higher reflectance intensity.

Comparative Study of Epitaxial Lateral Overgrowth on Semipolar (11-22) GaN by Using Stripe and Hexagon SiO2 Mask Patterns

나현석,송기룡,이재환,한상현,이성남 한국물리학회 2018 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.72 No.2

We investigated defect reduction of epitaxial lateral overgrown (ELO) semipolar (11-22) GaN grown on m-plane sapphire substrate by using stripe and hexagon SiO2 patterns. We obtained the fully-coalescent semipolar ELO-GaN templates successfully regardless of pattern shape and size. However, ELO-GaN film grown on hexagonal patterns were more easily coalesced than ELO-GaN grown on stripe patterns during ELO process due to the lateral growths from six directions. Xray rocking curves from ELO-GaN films indicate that ELO-GaN had much better crystal quality than GaN template. However, the effect of the lateral overgrowth on hexagon patterns on crystal quality was limited because the large frictions from the six-directional growth on hexagon pattern resulted in crystallographic tilts. The photoluminescence emissions of donor-bound exciton (D0X) recombination were observed from both samples, but the D0X emission of stripe ELO-GaN film was considerably stronger than that of hexagon ELO-GaN. In addition, the defect-related emissions of stripe ELO-GaN were also weaker, indicating that stripe ELO-GaN has efficiently eliminated the non-radiative centers and suppressed the defects.

Effect of precipitation on physico-chemical and catalytic properties of Cu-Zn-Al catalyst for water-gas shift reaction

나현석,안선용,심재오,전경원,김학민,이열림,장원준,전병훈,노현석 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.8

−To investigate the effect of precipitation on physico-chemical and catalytic properties of Cu-Zn-Al catalyst, the pH value and injection rate in the precipitation process were systematically changed, and the water-gas shift reaction was carried out. The Cu-Zn-Al catalyst showed the highest CO conversion when the optimized synthesis parameters (i.e., pH=10-10.5 and injection rate=30ml/min) were employed. This is mainly due to the enhanced physicochemical properties such as a high Brunauer-Emmett-Teller surface area, small crystallite size, high Cu dispersion, and easier reducibility.

Growth of nitride semiconductors on oxide templates by rf-magnetron sputtering

나현석,정상용,성태연 한국진공학회 2008 한국진공학회 학술발표회초록집 Vol.2008 No.8

폐기물 가스화 합성가스로부터 수소 생산을 위한 수성가스전이 반응용 Cu 기반 촉매 연구

나현석,정대운,장원준,이열림,노현석 한국수소및신에너지학회 2014 한국수소 및 신에너지학회논문집 Vol.25 No.3

Simulated waste-derived synthesis gas has been tested for hydrogen production through water-gas shift(WGS) reaction over supported Cu catalysts prepared by co-precipitation method. CeO2, ZrO2, MgO, and Al2O3were employed as supports for WGS reaction in this study. Cu-CeO2 catalyst exhibited excellent catalytic activityas well as 100% CO2 selectivity for WGS in severe conditions (GHSV = 40,206h-1 and CO concentration = 38.0%). In addition, Cu-CeO2 catalyst showed stable CO conversion for 20h without detectable catalyst deactivation. Thehigh activity and stability of Cu-CeO2 catalyst are correlated to its easier reducibility, high oxygen mobility/storagecapacity of CeO2.

최적화된 RBF 뉴럴 네트워크에 의한 정적 상황 인지 시스템에 관한 연구

나현석,오성권,김현기 대한전기학회 2011 정보 및 제어 심포지엄 논문집 Vol.2011 No.4