• Journal of Chest Surgery
• /
• 제46권5호
• /
• pp.346-352
• /
• 2013

Background: Transcatheter aortic valve implantation (TAVI) has been an alternative to conventional aortic valve replacement (AVR) in old and high risk patients. The goal of this study is to compare the early outcomes of conventional AVR vs. TAVI in high risk severe AS patients. Methods: From January 2008 to July 2012, 44 high risk severe aortic stenosis patients underwent conventional AVR, and 15 patients underwent TAVI. We compared echocardiographic data, periprocedural complication, and survival. The mean follow-up duration was $14.5{\pm}10$ months (AVR), and $6.8{\pm}3.5$ months (TAVI), respectively. Results: AVR group was younger ($78.2{\pm}2.4$ years vs. $82.2{\pm}3.0$ years, p<0.001) and had lower operative risk (Euroscore: $9.4{\pm}2.7$ vs. $11.0{\pm}2.0$, p=0.044) than TAVI group. There was no significant difference in early mortality (11.4% vs. 13.3%, p=0.839), and 1 year survival ($87.4%{\pm}5.3%$ vs. $83.1%{\pm}1.1%$, p=0.805). There was no significant difference in postoperative functional class. There was no significant difference in periprocedural complication except vascular complication (0% [AVR] vs. 13.3% [TAVI], p=0.014). TAVI group had more moderate and severe paravalvular leakage. Conclusion: In this study, both groups had similar periprocedural morbidity, and mortality. However, TAVI group had more greater than moderate paravalvular leakage, which can influence long-term outcome. Since more patients are treated with TAVI even in moderate risk, careful selection of the patients and appropriate guideline need to be established.

• Journal of Chest Surgery
• /
• 제46권4호
• /
• pp.249-255
• /
• 2013

Background: The continuous suture (CS) technique has several advantages as a method for simple, fast, and secure aortic valve replacement (AVR). We used a simple CS technique without the use of a pledget for AVR and evaluated the surgical outcomes. Materials and Methods: Between October 2007 and 2012, 123 patients with aortic valve disease underwent AVR alone (n=28) or with other concomitant cardiac procedures (n=95), such as mitral, tricuspid, or aortic surgery. The patients were divided into two groups: the interrupted suture (IS) group (n=47), in which the conventional IS technique was used, and the CS group (n=76), in which the simple CS technique was used. Results: There were two hospital deaths (1.6%), which were not related to the suture technique. There were no significant differences in cardiopulmonary bypass time or aortic cross-clamp time between the two groups for AVR alone or AVR with concomitant cardiac procedures. In the IS group, two patients had prosthetic endocarditis and one patient experienced significant perivalvular leak. These patients underwent reoperations. In the CS group, there were no complications related to the surgery. Postoperatively, the two groups had similar aortic valve gradients. Conclusion: The simple CS method is useful and secure for AVR in patients with aortic valve disease, and it may minimize surgical complications, as neither pledgets nor braided sutures are used.

• 한국정보통신학회논문지
• /
• 제25권1호
• /
• pp.96-101
• /
• 2021

아두이노는 오픈 소스 마이크로컨트롤러 프로젝트 중 하나로 AVR 마이크로컨트롤러를 사용한 아두이노 보드가 흔히 사용된다. AVR 마이크로컨트롤러에서는 일반적으로 ISP(In System Programming) 방식 업로드를 사용하지만, 아두이노에서는 부트로더를 통한 시리얼 방식 업로드를 기본으로 하며 이를 위해 전용 마이크로컨트롤러를 보드에 내장하고 있다. 아두이노에서 ISP 방식 업로드를 사용하기 위해서는 별도의 전용 업로드 장치가 필요하지만, 아두이노 보드에는 포함되어 있지 않다. 이 논문에서는 ISP 방식 업로드와 시리얼 방식 업로드를 하나의 전용 마이크로컨트 롤러를 통해 처리할 수 있는 통합 프로그래머를 제안하고, 통합 프로그래머를 사용하여 ISP 방식과 시리얼 방식 업로드가 가능함을 보인다. 이외에도 제안하는 통합 프로그래머는 USB-시리얼 변환장치로 동작하여 컴퓨터와의 시리얼 통신을 지원하며 아두이노의 부트로더를 굽는 것도 가능하다. 통합 프로그래머의 모든 동작은 실험 결과를 통해 확인할 수 있다.

• Molecules and Cells
• /
• 제39권5호
• /
• pp.426-438
• /
• 2016

Plant disease resistance occurs as a hypersensitive response (HR) at the site of attempted pathogen invasion. This specific event is initiated in response to recognition of pathogen-associated molecular pattern (PAMP) and subsequent PAMP-triggered immunity (PTI) and effector-triggered immunity (ETI). Both PTI and ETI mechanisms are tightly connected with reactive oxygen species (ROS) production and disease resistance that involves distinct biphasic ROS production as one of its pivotal plant immune responses. This unique oxidative burst is strongly dependent on the resistant cultivars because a monophasic ROS burst is a hallmark of the susceptible cultivars. However, the cause of the differential ROS burst remains unknown. In the study here, we revealed the plausible underlying mechanism of the differential ROS burst through functional understanding of the Magnaporthe oryzae (M. oryzae) AVR effector, AVR-Pii. We performed yeast two-hybrid (Y2H) screening using AVR-Pii as bait and isolated rice NADP-malic enzyme2 (Os-NADP-ME2) as the rice target protein. To our surprise, deletion of the rice Os-NADP-ME2 gene in a resistant rice cultivar disrupted innate immunity against the rice blast fungus. Malic enzyme activity and inhibition studies demonstrated that AVR-Pii proteins specifically inhibit in vitro NADP-ME activity. Overall, we demonstrate that rice blast fungus, M. oryzae attenuates the host ROS burst via AVR-Pii-mediated inhibition of Os-NADP-ME2, which is indispensable in ROS metabolism for the innate immunity of rice. This characterization of the regulation of the host oxidative burst will help to elucidate how the products of AVR genes function associated with virulence of the pathogen.

• 한국통신학회:학술대회논문집
• /
• 한국통신학회 2006년도 하계종합학술발표회 논문 초록집
• /
• pp.352-352
• /
• 2006

• Journal of Chest Surgery
• /
• 제50권4호
• /
• pp.255-262
• /
• 2017

Background: Transcatheter aortic valve replacement (TAVR) has been suggested as a less invasive treatment for high-risk patients with aortic valve disease. I n this study, we compared the outcomes of conventional surgical aortic valve replacement (AVR) and TAVR in elderly patients aged over 80. Methods: A total of 108 patients aged 80 years or older who underwent isolated AVR (n=35) or TAVR (n=73) from 2010 through 2015 at Asan Medical Center were identified. Early and late clinical outcomes, including echocardiographic findings, were evaluated in both groups. The mean follow-up duration was $766.4{\pm}528.7days$ in the AVR group and $755.2{\pm}546.6days$ in the TAVR group, and the average timing of the last follow-up echocardiography was at $492.6{\pm}512.5days$ in the AVR group and $515.7{\pm}526.8days$ in the TAVR group. Results: The overall early mortality was 2.8% (0 of 35, 0% in the AVR group vs. 3 of 73, 4.1% in the TAVR group). Permanent pacemaker insertion was significantly more common in the TAVR group (p=0.010). Renal failure requiring dialysis and new-onset atrial fibrillation was more frequent and the length of hospital stay was longer in the AVR group; however, this difference did not reach statistical significance. In the TAVR group, 14 patients (19.2%) were rehospitalized due to cardiac problems, and 13 patients (17.8%) had developed significant paravalvular leakage by the time of the last follow-up echocardiography. Conclusion: TAVR could be a good alternative to conventional surgical AVR in elderly patients. However, TAVR has several shortcomings, such as frequent significant paravalvular leakage or readmission, which should be considered in decision-making.

• 지능정보연구
• /
• 제15권3호
• /
• pp.17-29
• /
• 2009

C 언어는 AVR사의 ATmega128을 기반으로 하는 교육용 로봇 팔의 주 프로그래밍 언어다. C 언어는 교육용 로봇 팔을 제어하고 프로그램 학습하기 원하는 중학교 또는 고등학생들에게는 매우 어렵고 복잡하였다. 더구나, 통합개발환경, 디버딩 및 테스팅 환경도 제공하지 못하였다. 본 연구에서는 이러한 문제를 해결하기 위하여 교육용 로봇을 위한 자바 기반의 통합 개발 플랫폼을 제안하였다. 이 플랫폼은 교육용 로봇 팔을 위한 최신의 초소형 자바 가상 머신(NanoVM), 이클립스 플러그인을 사용한 통합개발환경, 실제 로봇을 연결하지 않아도 테스트 및 디버깅을 할 수 있는 3차원 시뮬레이터를 포함하고 있다. 이러한 자바 개발환경은 어린 학생들이 매우 용이한 교육용 로봇 팔 학습환경을 제공하게 되었다.

• 전자공학회논문지
• /
• 제51권2호
• /
• pp.214-219
• /
• 2014

본 논문에서는 기존의 교육용 로봇을 개선한 새로운 로봇 시스템을 설계하고 제작하였다. 구현 방법으로는 제어 모듈의 메인프로세서로 ARM Cortex-M3와 보조프로세서로 각 센서모듈에서 들어오는 데이터를 처리하기 위해 AVR ATMega2560을 이용하여 제작하였다. 개발된 센서 모듈의 프로세서는 AVR ATMega8을 사용하였다. 메인컨트롤러가 처리해야 하는 부하를 덜어주기 위해 각 프로세서들과의 통신은 IIC 통신을 사용하였다. 또한 확장성을 보장하기 위해 허브 모듈을 채택한 교육용 로봇 시스템을 개발하였다.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2005년도 전력전자학술대회 논문집
• /
• pp.317-320
• /
• 2005

본 논문은 멀티-레벨 H-bridge 인버터에서 입력전압 변동에 따른 AVR(Auto Voltage Regulation)기능을 적용 그 타당성을 제안하였다. 기존의 범용 인버터에서 (V/F)로 구동되는 전동기 시스템에 있어서 인버터에 공급되는 입력 전압은 출력 주파수에 따라 출력 전압 비율을 일정하게 하고 기동에 필요한 전압을 더하여 출력하는 방식이다. 집중 제어 방식의 멀티-레벨 H-bridge 인버터에서는 Cell의 DC-Link 전압을 Master에서 받아들여서 각각의 Cell에 기준 전압값을 지령하게 된다. 그러므로 입력 전압 변동에 따른 DC-Link 전압의 변동이 발생하게 되면 상전압 Unbalance 가 발생하게 되어 부하가 원하는 출력 전압을 낼 수가 없게 된다. 또한 각각의 Cell을 제어하는 Master 제어기가 가지고 있는 문제점을 보완하여 각각의 Cell 제어기 스스로가 AVR을 수행하는 좀더 나은 방법을 제안하였다.

• Journal of the Korean Wood Science and Technology
• /
• 제41권5호
• /
• pp.456-465
• /
• 2013

Log cross sections of yellow poplar were dried in a radio frequency vacuum (RFV) dryer under alternating vacuum and release (AVR) process. The average moisture content (MC), temperature and vapor pressure at the volumetric center were monitored as functions of time. Three different log thicknesses (33, 60 and 75mm) were tested. The results show that the AVR process caused an increase in the drying rate when the moisture content was above fiber saturation point (FSP, about 30% MC) but that it had an inverse effect on the drying rate when the MC was below FSP. The effect of the AVR process on the drying rate decreased, and the severity of heart checks increased, with the increase in the thickness of the specimens.