• Journal of Chest Surgery
• /
• v.56 no.5
• /
• pp.359-361
• /
• 2023

Coronary ostium obstruction due to dislodgement of the prosthetic valve is a rare and life-threatening complication, and particular caution is required for sutureless aortic valve replacement (AVR) with concomitant valvular surgery. In general, coronary artery bypass surgery is performed when coronary ostium obstruction occurs after AVR, but other options may need to be considered in some cases. Herein, we present a case of coronary artery occlusion in an 82-year-old female patient who had undergone AVR and mitral valve replacement for aortic valve stenosis and mitral valve stenosis at the age of 77 years. A hybrid procedure involving redo AVR and percutaneous coronary intervention after left main coronary ostium endarterectomy was performed. To summarize, we present a case of hybrid AVR in a patient with coronary artery obstruction after AVR that was successfully managed using this method.

• 한국균학회소식:학술대회논문집
• /
• 2015.05a
• /
• pp.61-61
• /
• 2015

Rice blast, caused by the fungal pathogen Magnaporthe oryzae, is one of the most destructive diseases of rice worldwide. The rice - M. oryzae pathosystem has become a model in the study of plant - fungal interactions due to its economic importance and accumulating knowledge. During the evolutionary arms race with M. oryzae, rice plants evolved a repertoire of Resistance (R) genes to protect themselves from diseases in a gene-for-gene fashion. M. oryzae secretes a battery of small effector proteins to manipulate host functions for its successful infection, and some of them are recognized by host R proteins as avirulence effectors (AVR), which turns on strong immunity. Therefore, the analysis of interactions between AVRs and their cognate R proteins provide crucial insights into the molecular basis of plant - fungal interactions. Rice blast resistance genes Pik, Pia, Pii comprise pairs of protein-coding ORFs, Pik-1 and Pik-2, RGA4 and RGA5, Pii-1 and Pii-2, respectively. In all three cases, the paired genes are tightly linked and oriented to the opposite directions. In the AVR-Pik/Pik interaction, it has been unraveled that AVR-Pik binds to the N-terminal coiled-coil domain of Pik-1. RGA4 and RGA5 are necessary and sufficient to mediate Pia resistance and recognize the M. oryzae effectors AVR-Pia and AVR1-CO39. A domain at the C-terminus of RGA5 characterized by a heavy metal associated domain was identified as the AVR-binding domain of RGA5. Similarly, physical interactions among Pii-1, Pii-2 and AVR-Pii are being analyzed.

• Journal of Microbiology and Biotechnology
• /
• v.18 no.9
• /
• pp.1500-1509
• /
• 2008

The hybridization patterns with the avrBs3 gene that is known to determine the recognition of host specificity were used to study the diversity of Xanthomonas axonopodis pv. glycines causing bacterial leaf pustule in soybean. A total of 155 strains were isolated from diverse tissues of soybean cultivars collected in Korea and were classified into six different type strains of OcsF, SL1017, SL1018, SL1045, SL1157, and SL2098 according to the patterns of avrBs3-homologous bands. When these type strains were inoculated on various cultivars, most of the Korean strains mildly induced disease symptoms on the resistant CNS1 cultivars. Unlike other type strains, strain SL2098, which appeared not to contain any avrBs3 homolog, induced only a few pustules on even highly susceptible cultivars. When a plasmid carrying the 3.7-kb avrBs3-homologous gene from strain SL1045 was introduced into SL2098, the transformant could not recover the pathogenicity in susceptible host plants. However, when avrBs3-homologous genes of strain SL1018 were mutated by transposon mutagenesis, one of the mutants in which a 5.2-kb chromosomal band homologous to avrBs3 was disrupted could not induce the hypersensitive response on resistant cultivars such as William82 or CNS2. Our results suggest that the avrBs3 homologs may play important roles in the pathogenicity of Xanthomonas axonopodis pv. glycines and the recognition of soybean cultivars.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2015.10a
• /
• pp.246-247
• /
• 2015

Type of Automatic Voltage Regulator (AVR) can be divided into Analog and Digital Type. Automatic Voltage Regulator (AVR) of the synchronous generators of the brushless type are to be reduced to the voltage fluctuation on the basis of the total load. The PID control method is a general control technique is commonly widely used. In this study, the control target parameter iPID does not reset the parameters of the controller for the variable (Intelligent PID) using the controller synchronous generator Digital automatic voltage to you like all applied to the adjusting device (AVR) the voltage change is small, improved responsiveness was studied in this controller.

• Korean Journal of Agricultural Science
• /
• v.48 no.1
• /
• pp.151-161
• /
• 2021

Fusarium wilt disease of tomato plants caused by Fusarium oxysporum f.sp. lycopersici (FOL race2) is one of the most important diseases of tomatoes worldwide. In the competition between tomato and FOL, the FOL can win by overcoming the immune system of tomato plants. Resistant interaction between the FOL race2 and tomato plants is controlled by avirulence genes (AVR2) in FOL and the corresponding resistance genes (I2) in tomato plants. In this study, 7 FOL isolates (KACC) were used to test their pathogenicity, and FOL race2 was selected because it is a broad problem in Korea. The Fol40044 isolates showed the most severe pathogenicity, and the avr2 gene was also isolated and identified. Moreover, to select resistance, 20 tomato varieties were inoculated with the Fol40044, and the degree of pathogenicity was evaluated by analyzing the expression of the avr2 gene. As a result, three resistant tomato varieties (PCNUF73, PCNUF101, PCNUF113) were selected, and the expression of the avr2 gene was much lower than that of the control Heinz cultivar. This result shows that the screening assay is very efficient when the avr2 gene is used as a marker to evaluate the expression level when selecting varieties resistant to tomato wilt disease. Based on these results, it is possible to isolate the I2 gene, which exhibits resistance and molecular biological interactions with the AVR2 gene from the three tomato-resistant varieties. The I2 gene provides breeders more opportunities for Fusarium disease resistance and may contribute to our understanding of their interactions with the FOL and host plant.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.10
• /
• pp.330-338
• /
• 2018

The proportional-integral-derivative(PID) controller has been widely used in the industry because of its robust performance and simple structure in a wide range of operating conditions. However, the AVR(Automatic Voltage Regulator) as a control system is not robust to variations of the power system parameters. Therefore, it is necessary to use PID controller to increase the stability and performance of the AVR system. In this paper, a novel design method for determining the optimal PID controller parameters of an AVR system using the particle swarm optimization(PSO) algorithm is presented. The proposed approach has superior features, including easy implementation, stable convergence characteristic and good computational efficiency. In order to assist estimating the performance of the proposed PSO-PID controller, a new performance criterion function is also defined. This evaluation function is intended to reflect when the maximum percentage overshoot, the settling time are given as design specifications. The ITAE evaluation function should impose a penalty if the design specifications are violated, so that the PSO algorithm satisfies the specifications when searching for the PID controller parameter. Finally, through the computer simulations, the proposed PSO-PID controller not only satisfies the given design specifications for the terminal voltage step response, but also shows better control performance than other similar recent studies.

• Journal of Chest Surgery
• /
• v.22 no.2
• /
• pp.220-224
• /
• 1989

In candidates for aortic valve replacement [AVR]it is our primary intention to implant the largest possible vale prosthesis of at least 23 mm in diameter in patients with severe valvular aortic stenosis. However, in many patients there is an additional subvalvular asymmetric septal hypertrophy which in some cases may cause an postextrasystolic increase of the LV-aortic gradient. Another component of the aortic stenosis syndrome is a narrow valvular ring, or a combination of both. After complete removal of the diseased valve and decalcification the narrow aortic ring [< 23 mm] can be widened firstly by transaortic subvalvular septal myectomy- [TSM] thus unfolding the left ventricular outflow tract[LVOT]and secondly by extending the oblique aortic incision into the aortic valve ring or further down into the anterior leaflet of the mitral valve. The sub-and supra-valvular defect will be closed by patch enlargement of the aortic root [PEAR] using autologous pericardium. These techniques allow a considerable enlargement of the valvular ring of about 4 to 10 mm in circumference. In a retrospective study using a computerized program, 847 patients with AVR [1980-1984]were reviewed to evaluate the intraoperative hemodynamic results mainly concerning relief of the transvalvular gradient. In 626 patients AVR was performed, 151 patients had double valve replacement [AVR+MVR], and 70 patients had AVR plus additional surgical procedures. Concentrating on the AVR-group [n=626] there were 103 patients with TSM, 24 patients with PEAR and 20 patients with TSM+PEAR which demonstrated that in a total, of 147 patients of this groups [23.5%] an additional procedure was necessary. The Statistical evaluation of the intraoperative pressure measurements before and after AVR in relation to the size of the implanted prostheses indicated the lowest preoperative mean gradient in patients with AVR alone, the highest in patients who afforded TSM plus PEAR. However, after AVR the mean gradients in all three groups were very low [mean 5 to 10 mmHg]. These data indicate that in patients with a narrow aortic ring and additional considerable ASH, TSM and PEAR are suitable techniques to enlarge the aortic root to enable the implantation of an adequate aortic valve prosthesis. Long-term controls have shown that autologous pericardium is a qualified graft material for the ascending aorta.

• Journal of Life Science
• /
• v.17 no.2 s.82
• /
• pp.235-240
• /
• 2007

AvrRpt2 protein triggers hypersensitive response (HR) and strong disease resistance when it is translocated from a bacterial pathogen Pseudomonas sp. to host plant cells containing a cognate RPS2 resistance protein through Type III Secretion System (TTSS). However, AvrRpt2 protein can function as the effector that suppresses a basal defense and enhances the disease symptom when functional RPS2 resistance protein is absent in the infected plant cells. Using Affymetrix Arabidopsis DNA chip, we found that many genes were specifically regulated by AvrRpt2 protein in the rps2 Arabidopsis mutant. Here, we showed that expression of AtERF11 that is known as a member of B1a subcluster of AP2/ERF transcription factor family was down regulated specifically by AvrRpt2. To determine its function in plant resistance, we also generated the Arabidopsis thaliana transgenic plants constitutively overexpressing AtERF11 under CaMV 355 promoter, which conferred an enhanced resistance against a bacterial pathogen, Pseudomonas syringae pv. tomato DC3000. Thus, these results collectively suggest that AtERF11 plays a role as a positive regulator for disease resistance against biotrophic bacterial pathogen in plant.

• Journal of Chest Surgery
• /
• v.16 no.4
• /
• pp.476-484
• /
• 1983

Ventricular septal defect[VSD] associated with aortic regurgitation[AR] represents 2 to 7.5% of all VSD which is most common congenital heart disease. The aortic valve may by normal in infants with VSD, but the aortic regurgitation may be developed in these patients later. The aortic valve became fibrotic, thickened, deformed and prolapsed, so these late deformities require to be corrected with plication, valvuloplasty or aortic valve replacement [AVR]. There are some controversy between the early repair of VSD alone and the late repair of VSD and aortic valve till now. From December 1971 to August 1983, we had experienced 24 patients of VSD associated with AR which constitute 6.5% of our total patients with VSD. The VSD was subpulmoary [type I] in 14[58.3%], subcristal [type II] in 8[33.3%], atrioventricular canal type[type III] in 1, and combine of type I and II in 1. Patch repair of VSD was made in 15 patients and direct suture of small VSD in 9.14 patients had aortic plication of valvuloplasty and 9 had AVR accompanying VSD repair, and 1 patient had VSD closure alone. The postoperative courses of these patients were uneventful except in some cases. A patient who was undertaken AVR with Starr-Edwards ball valve and VSD closure, died due to left ventricular failure and low cardiac output syndrome. Follow up shows, in 14 patients with aortic plication or valvuloplasty, AR was developed in 9. In 9 AVR, there were two later complications which were paravalvular leakage in one and re-AVR due to subacute bacterial endocarditis in another.

• Proceedings of the Korean Society of Plant Biotechnology Conference
• /
• 2003.04a
• /
• pp.140-140
• /
• 2003