혈액 투석 환자에서 중심정맥 협착에 대한 스텐트 삽입술 : Wallstent Placement

임대승,노상필,이유선,정승현,김보영,이정우,강정아,김정희,이민수,정준용,최시완,정진옥,성인환,이강욱,신영태 충남대학교 의과대학 의학연구소 2002 충남의대잡지 Vol.29 No.1

Stenosis of central vein is a common complication arising after percutaneous subclavian vein catheter insertion performed for temporary vascular access in chronic renal failure patients undergoing hemodialysis. There are several treatment methods for the condition like percutaneous angioplasty(PTA), stent insertion, and surgery, but recent trend is toward PTA and stents. Among the patients diagnosed with chronic renal failure from March 1993 to May 2002 and undergoing hemodialysis through AV fistula, the 14 Patients in whom central vein stenosis arose were selected for the study. A total of 28 percutaneous interventions(5 PTA and 23 stent placement) were performed, and restenosis rate and the time taken till the restenosis in de novo lesions and instant lesions were compared. All 28 cases were operated successfully. The 14 cases that received both anigioplasty and stent placement initially. (de novo lesion : 14 cases), Among the 10 cases with de novo lesion that followed up more than 1 year, 3 cases are currently undergoing hemodialysis without restenosis, and the remaining 7 cases have recurred stenosis with the mean time to restenosis of 10.9 months. In the 7 cases in whom stenosis recurred, 11 interventions were done(instent lesion: 11 cases). 4 of these were using only ballon angioplasty with 100% restenosis rate and the mean time of 3 months until restenosis. The remaining 7 cases were using both balloon angioplasty and stent placement, also with 100% restenosis rate but with the mean time of 12 months until restenosis, which was later than the group receiving only balloon angioplasty. In treating the patients with central vein stenosis, stent placement seems to be more advantageous over PTA in terms of restenosis rate and the mean duration of patency. In the case of instent lesion, inserting the stent for the second time after stenosis recurred lengthened the duration of patency compared to performing balloon angioplasty alone.

Monitoring of carbamate and organophosphate resistance levels based on bioassay and quantitative sequencing in Nilaparvata lugens

Deok Ho Kwon,Si Woo Lee,Ji Hyeon Park,Si Hyeock Lee 한국응용곤충학회 2011 한국응용곤충학회 학술대회논문집 Vol.2011 No.10

The resistance levels against carbamates (CB) and organophosphates (OP) were determined through bioassay and quantitative sequencing (QS) methods in 16 field populations of Nilaparvata lugens. The resistance levels to CB and OP by bioassay were 1.3~47.5-fold and 1.4~14.4-fold higher than a susceptible strain, respectively. The QS protocol was established to determine the allele frequencies of eight point mutations on acetylcholinesterase putatively associated CB and OP resistance. The allele frequencies of four mutations in local populations (G119A, F/S330Y, F331H and I332L) ranged from ca. 0.0~51.7%, 1.0~44.3%, 8.5~57.3% and 7.12~56.6%, respectively. The average prediction limits were –9.6±5.1~7.7±2.9%. The F330Y, F331H and I332L were tightly linked each other, suggesting these mutations may occur simultaneously. In the correlation analysis, G119A was not well correlated with both insecticides (r2= less 0.25), whereas F/S330Y, F331H and I332L showed better correlation with the resistance levels of carbamate (r2=0.590) than organophosphate (r2=0.235). This finding indicates that F/S330Y, F331H and I332L mutation frequencies are suitable for detecting carbamate resistance in N. lugens. QS will be applicable for the rapid monitoring of resistance levels to CB insecticides in N. lugens.

A Unified Random Coding Bound

Lee, Si-Hyeon,Chung, Sae-Young IEEE 2018 IEEE transactions on information theory Vol.64 No.10

<P>In this paper, we prove a unified achievability bound that generalizes and improves random coding bounds for any combination of source coding, channel coding, joint source–channel coding, and coding for computing problems assuming blockwise node operation. As a general network setup, we consider an acyclic discrete memoryless network, where the network demands and constraints are specified by a joint-typicality constraint on the whole channel input and output sequences. For achievability, a basic building block for node operation consists of simultaneous nonunique decoding, simultaneous compression, and symbol-by-symbol mapping. Our bound can be useful for deriving random coding bounds without error analysis, especially for large and complex networks. In particular, our bound can be used for unifying and generalizing many known relaying strategies. For example, a generalized decode-compress-amplify-and-forward bound is obtained as a simple corollary of our main theorem, and it is shown to strictly outperform the previously known relaying schemes. Furthermore, by exploiting the symmetry in our bound, we formally define and characterize three types of network duality based on channel input–output reversal and network flow reversal combined with packing–covering duality.</P>

Capacity of a Class of Multicast Tree Networks

Si-Hyeon Lee,Sae-Young Chung IEEE 2013 IEEE transactions on information theory Vol.59 No.6

<P>In this paper, we characterize the capacity of a new class of discrete memoryless multicast networks having a tree topology. For achievability, a novel coding scheme is constructed where some relays employ a combination of decode-and-forward and compress-and-forward and the other relays perform a random binning such that codebook constructions and relay operations are independent for each node and do not depend on the network topology. For converse, a new technique of iteratively manipulating inequalities exploiting the tree topology is used. This class of multicast tree networks includes the class of diamond networks studied by Kang and Ulukus as a special case.</P>

Newborn English Bulldogs with Multiple Malformation Syndrome and Lethal Characters

Si-Jung Jang,Minkyung Kim,Hyeon-Jeong Lee,Young-Sung You,Jaehoon Lee,Sung-Lim Lee 한국동물생명공학회(구 한국동물번식학회) 2019 Journal of Animal Reproduction and Biotechnology Vol.34 No.3

A female English bulldog was gave birth two neonates by cesarean section on the sixty one days after mating, but both neonates were died soon after birth. The bodies of neonates were diagnosed using radiography, ultrasonography, computed tomography and necropsy immediately after death. Both neonates had caudal regression syndrome, butterfly vertebra, hydrocephalus, umbilical hernia, cleft palate and bow-legged hind-limb. At necropsy, neonates had mild fetal anasarca, cleft lip and the skull was remained non-union. At thoracic cavity, only three ribs and thoracic spines were existed and patent ductus arteriosus was found. At abnormal cavity, the renal ectopia was found with abnormal morphology. In the present case, those English bulldog neonates with multiple congenital malformation syndromes seriously suffered vertebral column anomalies and that may induced by neural tube defects in during embryonic period. To prevent congenital malformation occurring in English bulldog, further in depth studies are needed for the breed specific genetic diversity and for the reason of behind genetic abnormality in these breed.

Flavisolibacter tropicus sp. nov., isolated from tropical soil

Lee, Jae-Jin,Kang, Myung-Suk,Kim, Gyung Soon,Lee, Chang Soek,Lim, Sangyong,Lee, Jidam,Roh, Si Hyeon,Kang, Hyerin,Ha, Jung Min,Bae, Sojung,Jung, Hee-Young,Kim, Myung Kyum Microbiology Society 2016 International journal of systematic and evolutiona Vol.66 No.-

Covert Communication With Channel-State Information at the Transmitter

Lee, Si-Hyeon,Wang, Ligong,Khisti, Ashish,Wornell, Gregory W. IEEE 2018 IEEE transactions on information forensics and sec Vol.13 No.9

<P>We consider the problem of covert communication over a state-dependent channel, where the transmitter has causal or noncausal knowledge of the channel states. Here, covert means that a warden on the channel should observe similar statistics when the transmitter is sending a message and when it is not. When a sufficiently long secret key is shared between the transmitter and the receiver, we derive closed-form formulas for the maximum achievable covert communication rate (covert capacity) for discrete memoryless channels and, when the transmitter’s channel-state information (CSI) is noncausal, for additive white Gaussian noise (AWGN) channels. For certain channel models, including the AWGN channel, we show that the covert capacity is positive with CSI at the transmitter, but is zero without CSI. We also derive lower bounds on the rate of the secret key that is needed for the transmitter and the receiver to achieve the covert capacity.</P>

Successive Interference Cancellation With Feedback for Random Access Networks

Lee, Si-Hyeon,Jung, Bang Chul,Jeon, Sang-Woon IEEE 2017 IEEE communications letters Vol.21 No.4

<P>We consider a random access network in which K nodes wish to send independent packets to an access point (AP). In this letter, a novel method of feedback construction and an adaptive retransmission protocol of collided packets are proposed, which enable efficient successive interference cancellation at the AP. We show that the optimal throughput efficiency of one is achievable by only exploiting log K bits of feedback from the AP to K nodes, while the maximum throughput efficiency of slotted ALOHA is known to be e(-1) approximate to 0.37 for large K. Note that the proposed technique achieves the optimal throughput efficiency for any finite K, while the conventional techniques asymptotically achieve the optimal throughput efficiency only when K tends to infinity.</P>

The Wiretapped Diamond-Relay Channel

Lee, Si-Hyeon,Khisti, Ashish IEEE 2018 IEEE transactions on information theory Vol.64 No.11

<P>In this paper, we study a diamond-relay channel where the source is connected to <TEX>$M$</TEX> relays through orthogonal links and the relays transmit to the destination over a wireless multiple-access channel in the presence of an eavesdropper. The eavesdropper not only observes the relay transmissions through another multiple-access channel but also observes a certain number of source-relay links. The legitimate terminals know neither the eavesdropper’s channel state information nor the location of source-relay links revealed to the eavesdropper except the total number of such links. For this wiretapped diamond-relay channel, we establish the optimal secure d.o.f. In the achievability part, our proposed scheme uses the source-relay links to transmit a judiciously constructed combination of message symbols, artificial noise symbols, and fictitious message symbols associated with secure network coding. The relays use a combination of beamforming and interference alignment in their transmission scheme. For the converse part, we take a genie-aided approach assuming that the location of wiretapped links is known.</P>

Surgically induced degenerative changes in the femorotibial joints by total medial meniscectomy in minipigs closely resemble late-stage osteoarthritis

Lee, Won-Jae,Park, Byung-Joon,Lee, Hyeon-Jeong,Jang, Si-Jung,Lee, Sung-Lim,Lee, Jae-Hoon,Rho, Gyu-Jin,Kim, Seung-Joon The Korean Society of Veterinary Science 2019 大韓獸醫學會誌 Vol.59 No.1

Animal models of osteoarthritis (OA) have played a key role in understanding the etiology of OA and in the development of new therapeutic strategies. Although pigs have an advantage as an animal disease model due to their similarity to humans, there are few studies on the induction of OA in minipigs. Therefore, this study aimed to characterize disease progression of OA in total medial meniscectomy (TMM)-operated skeletally mature minipigs, up to day 180 postoperatively. There were no significant alterations in vital signs or hematological indices throughout the observation period. However, clinical manifestations of OA in the medial femoral condyles of TMM-operated minipigs were progressive, depending on postoperative duration, with respect to osteophytes formation and roughened surfaces on radiological observation, cartilage erosion under macroscopic examination, and severe cartilage defects including fibrillation, vertical fissures, and cartilage denuding on histopathological observation, with the highest score indicating late-stage OA on day 180 and without indicating apparent variation between subjects. In particular, the lateral femoral condyles were also degenerated, possibly due to localization of weight-bearing from both menisci to the lateral meniscus. Therefore, TMM in minipigs is suitable for reproducible induction of degenerative changes in the femorotibial joints that closely resemble late-stage OA, and is suitable for use in further research.