위장관 ; 헬리코박터 파일로리에 감염된 위 상피세포에서 DNA 이중나선절단 관찰

장영준 ( Young Jun Chang ),변상원 ( Sang Won Byun ),김형근 ( Hyung Keun Kim ),조영석 ( Young Seok Cho ),김성수 ( Sung Soo Kim ),김진일 ( Jin Il Kim ),김재광 ( Jae Kwang Kim ),정은선 ( Eun Sun Jung ) 대한소화기학회 2012 대한소화기학회지 Vol.60 No.2

Background/Aims: DNA double strand breaks (DSB) is one of the critical types of DNA damage. If unrepaired, DSB is accumulated in the nucleus of cells, the cells become apoptotic or transform to tumor by way of genomic instability. Some of malignant cancers and its premalignant lesions were proven to have DSB in their nuclei. There was no report that Helicobacter pylori (H. pylori), the gastric carcinogen, induce DNA DSB in gastric epithelium in vivo. The aim of this study was to investigate whether H. pylori induce DSB in the gastric epithelial cells of chronic gastritis. Methods: Immunohistochemical stains were performed for the DSB markers, phospho-53BP1 and γH2AX, in the gastric epithelium derived from 44 peptic ulcer disease patients before and after H. pylori eradication. DNA fragmentation assay was performed in the cell line to investigate the DNA damage by H. pylori infection. Results: The mean expression score of γH2AX was significantly higher in the H. pylori infected gastric epithelium as compared to the H. pylori eradicated gastric epithelium (8.8±5.5 vs. 6.2±5.3 respectively; p=0.008). The expression score of phospho-53BP1 between before and after eradication of H. pylori was not statistically different, but tended to be higher in H. pylori infection. DNA fragmentation was developed significantly more in the cell lines after infection with H. pylori. Conclusions: DSB of DNA damage was typical feature of H. pylori infection in the gastric epithelium. (Korean J Gastroenterol 2012;60:79-85)

위선종 및 위암 조직에서의 DNA 이중사슬 절단

김정호 ( Jeong Ho Kim ),김성수 ( Sung Soo Kim ),변상원 ( Sang Won Byun ),장영준 ( Young Jun Chang ),김진수 ( Jin Su Kim ),김재광 ( Jae Kwang Kim ),조항주 ( Hang Joo Cho ),임근우 ( Keun Woo Lim ),정은선 ( Eun Sun Jung ) 대한소화기학회 2010 대한소화기학회지 Vol.55 No.1

목적: DNA 이중사슬 절단은 DNA 손상의 한 형태로서 p53 돌연변이 등이 있는 세포에서 치유되지 않은 DSB가 핵 내에 축적될 경우 염색체 불안정을 유도하거나 혹은 암 발생 관련 유전자의 돌연변이 과정을 통해 암세포로 변환될 수 있다. 이에 이번 연구는 암 주위 정상, 선종 및 위암 조직에서 DNA 이중사슬 절단의 표지자인 53BP1과 γ-H2AX단백의 발현 양상을 관찰하였다. 대상 및 방법: 위절제술을 받았던 121예의 위암 환자와 내시경하 점막하 박리술을 받았던 51예의 위선종 환자를 대상으로 각각 tissue microarray를 만든 후 53BP1과 γ-H2AX 단백 각각에 대한 항체로 면역조직화학염색을 하여 발현 지수를 측정하였다. 결과: 53BP1과 γ-H2AX는 암 주위 정상 조직에 비해 위암 조직에서 발현율이 높았으나(p<0.01), 암 주위 정상 조직과 위선종 조직 간에 53BP1과 γ-H2AX 단백의 발현은 차이가 없었다. 위선종 조직에서 53BP1는 이형성 등급 I에 비해 II 및 III의 발현지수가 유의하게 높았다. 위암 환자에서 임상-병리학적 인자는 53BP1 및 γ-H2AX 단백의 발현과 상관관계가 없었다. 결론: 이상의 결과로 보아 DNA 이중사슬절단은 위암 발생과정에 관여하는 것으로 보이나 위선종 세포에서는 별다른 역할을 하지 않는 것으로 보인다. Background/Aims: DNA double strand break (DSB) is one of the critical types of DNA damage. When un-repaired DSB is accumulated in the nucleus of the cells having mutations in such genes as p53, it will lead to chromosomal instability and further more to mutation of tumor-activating genes resulting in tumorogenesis. Some of malignant cancers and its premalignant lesions were proven to have DSB in their nuclei. The aim of this study was to define the differences in expression of 53BP1 and γ-H2AX, the markers of DSB, among normal, gastric adenoma, and gastric adenocarcinoma tissues. Methods: Tissue microarray was made with the tissues taken from 121 patients who underwent gastrectomy for gastric adenocarcinoma, and 51 patients who underwent endoscopic mucosal resection for gastric adenoma. Immunochemical stain was performed for the marker of DSB, 53BP1 and γ-H2AX in the tissue microarray. The normal tissues were collected from histologically confirmed tissues with no cellular atypia obtained from the patients with gastric adenocarcinoma. Results: In gastric carcinoma cells, 53BP1 and γ-H2AX were highly expressed as compared to normal epithelial cells and gastric adenoma (p<0.01). There were no differences in the expression of 53BP1 and γ-H2AX between normal epithelium and gastric adenoma. The expression of 53BP1 in the adenoma with grade II and III atypism was more elevated than in those with grade I atypism. The expression of 53BP1 and γ-H2AX were not significantly different according to the clinicopathologic parameters in the patients with gastric adenocarcinoma. Conclusions: The DSB in DNA seems to be associated with the development of gastric adenocarcinoma, but does not affect the premalignant adenoma cells. (Korean J Gastroenterol 2010;55:19-25)

이중 H자 메타 전자파구조를 이용한 저위상잡음 발진기

이종민(Chongmin Lee),서철헌(Chulhun Seo) 대한전자공학회 2010 電子工學會論文誌-TC (Telecommunications) Vol.47 No.2

본 논문은 높은 Q 특성을 갖는 이중 H자 형태의 메타 전자파구조의 공진기를 적용한 발진기를 제안하였다. 제안된 발진기는 고성능의 주파수합성부에 적용하기 위한 것으로 저위상잡음 및 높은 출력 전력을 요구한다. 특히 이중 H자 형태의 메타 전자파구조(DHM)는 전기장의 커플링을 강하게 하여 발진 주파수에서 높은 Q 값을 갖도록 설계되었다. 이러한 특성을 통해 우수한 위상잡음 특성을 얻을 수 있다. 이중 H자 형태의 메타 전자파구조를 이용한 발진기는 레이더 시스템의 주파수 합성부에 적용하기 위한 X 대역 내 발진을 형성하였으며 출력 전력은 4.33 ㏈m, 위상잡음은 100 ㎑ 옵셋에서 -108 ㏈c를 얻을 수 있었다. In this article, a oscillator at X-band with a double H-shape metamaterial resonator (DHMR) based on high-Q is proposed with metamaterial structure to improve the phase noise and output power. The proposed oscillator is required low phase noise and high output power for the high performance frequency synthesizer. DHMR is designed to be high-Q at resonance frequency through strong coupling of E-field. This character makes phase noise excellent. The oscillator using DHMR is oscillated in X-band so as to apply frequency synthesizer of radar systems. The output power is 4.33 ㏈m and the phase noise is -108 ㏈c/㎐ at 100 ㎑ offset of carrier frequency.

E/H-평면의 방사 패턴 대칭성이 개선된 이중슬롯 비발디 안테나의 설계

김우중,소영민,박성진,윤영중 한국전자파학회 2020 한국전자파학회논문지 Vol.31 No.5

종래의 이중슬롯 비발디 안테나는 이중슬롯 구조를 통하여 E-평면으로 전기장이 집중되어 E-평면의 빔 폭이 감소한다. 따라서 E-평면과 H-평면의 방사 패턴 비대칭성이 발생한다. 본 논문에서는 이중슬롯 비발디 안테나의 E/H-평면에대한 방사 패턴 대칭성을 향상하기 위해 확장된 유전체 구조를 가지는 이중슬롯 비발디 안테나를 제안한다. 제안된 안테나는 확장된 유전체와 공기 사이의 경계면에서 전기장이 굴절되는 현상을 이용하여, H-평면상의 전기장을 안테나의 축방향으로 집중시켜 빔 폭을 줄였다. 이를 통해서 E/H-평면에 대한 방사 패턴 대칭성을 개선하였다. 확장된 유전체의 유무에 따른 H-평면의 빔 폭 감소 효과를 비교한 결과, 확장된 유전체 구조는 주파수에 따라 최대 25도의 빔 폭 감소 효과를가진다.

H-coextension of the double four spiral semigroup Dsp4

K.Indhira,V.M.Chandrasekaran 장전수학회 2014 Advanced Studies in Contemporary Mathematics Vol.24 No.3

In 1978, Byleen, Meakin and Pastijn[2,3] introduced the four - spiral semigroup Sp4 and the double four-spiral semigroup DSp4 and studied their semigroup Sp4 and studied their properties in detail. These regular semigroups play an important role in the theory of idempotent generated bismple but not completely simple semigroups. The semigroup A(1, 2) was introduced as a tool to analyse the structure of DSp4 [3]. In 2003, Chandrasekaran and Loganathan[7] observed that A(1, 2) has an inverse transveral which is a bicyclic monoid and applied this fact to represent DSp4 as a regular Rees matrix semigroup over A(1,2). This result is analogous to the representation due to Byleen [1] of the fundamental four spiral semigroup analogous to Reilly`s description of the bisimple-w-semigroups[21]. So it is natural to ask the following question. Determine the H-coextension of the R-unipotent semigroup A(1, 2) and then we describe the H-coextension of the double four spiral semigroup DSp4.

A novel DNA double-strand breaks biosensor based on fluorescence resonance energy transfer

서정수,김태진 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Revealing the spatiotemporal behavior of DNA double-strand breaks (DSBs) is crucial for understanding the processes of DNA damage and repair. Traditionally, γH2AX and DNA damage response (DDR) factors have been used to detect DSBs using classical biochemical assays, such as antibody-based immunostaining. However, a reliable method to visualize and assess DSB activity real-time in living cells is yet to be established. Herein, we developed a novel DNA double-strand breaks biosensor (DSBS) based on fluorescence resonance energy transfer (FRET) by employing the H2AX and BRCT1 domains. By applying FRET imaging with DSBS, we show that DSBS specifically reacts to drug- or ionizing radiation (IR)-induced γH2AX activity, allowing for the quantification of DSB events at high spatiotemporal resolutions. Taken together, we provide a new experimental tool to evaluate the spatiotemporal dynamics of DNA double-strand breaks. Ultimately, our biosensor can be useful for elucidating the molecular mechanisms underlying DNA damage and repair processes.

Direct Fabrication of Vertically Stacked Double Barrier Tunnel Junctions Based on Graphene and h-BN

Ali Alzahrani,Milinda Kalutara Koralalage,Jacek Jasinski,Gamini Sumanasekera 대한금속·재료학회 2022 ELECTRONIC MATERIALS LETTERS Vol.18 No.3

Direct manufacturing of two-dimensional material-based double barrier (DB) tunnel junctions, based on a lithographyfreeapproach was developed. Graphene/h-BN/Graphene/h-BN/Graphene devices were deposited on Si/SiO2 substrates byemploying a plasma enhanced chemical vapor deposition technique in a sequential manner. DB tunneling junctions withvarying barrier widths (by varying the thickness of the second graphene layer) were studied. Samples were characterizedusing Raman, Atomic Force Microscopy and X-ray photoemission spectroscopy. The I–V characteristics of tunneling currentshowed resonant tunneling behavior at room temperature with a negative differential conductance. The behavior could beexplained with quantum mechanical double barrier tunneling model in which analytic solutions to Schrödinger’s equationwere obtained in each region of the system. Resonances in transmission probability coefficient for varying barrier widthswere evaluated and compared with the experimental results.

Shell & Coil type 열교환기를 이용한 히트펌프 운전 특성

윤차주,전대헌,감형욱,장인성 한국기계기술학회 2015 한국기계기술학회 학술대회논문집 Vol.2015 No.03

The heating & cooling performance of vapor compression heat pump using seawater heat source has been investigated experimentally for fish farm heat supply system. The principal parts of the heat pump systems are compressor, condenser, expansion devices and evaporator. The evaporator and condenser are both heat transfer devices. We used double pipe H/E(CASE-1) and shell&coil H/E(CASE-2) as evaporator, condenser of heat pumps. The experimental results were higher Uvalue 25% of double pipe heat exchanger compared to shell & coil H/E. The COPc is 4.74 and the COPH is 6.18 of the heat pump with shell & coil H/E.

High efficiency H₂O/LiBr double effect absorption cycles with multi-heat sources for tri-generation application

Yang, Mina,Lee, Seung Yeob,Chung, Jin Taek,Kang, Yong Tae Elsevier 2017 APPLIED ENERGY Vol.187 No.-

<P>The objective of this study is to develop a high-efficiency double effect absorption cycle using multi-heat sources for tri-generation (trigen) application. The trigen system produces electricity, heating and cooling loads at the same time. The double-effect absorption refrigeration system consists of two generators, condensers, solution heat exchangers, expansion valves, an absorber and an evaporator. The cycle simulation is carried out for the H2O/LiBr double effect absorption cycle with multi-heat sources for parallel, serial, reverse, revised serial and revised reverse flow patterns. The absorption refrigeration system uses the high temperature steam and hot water as the multi-heat sources. A new high-efficiency cycle is selected depending on the arrangements of additional heat exchangers. This study recommends HX 2-2 cycle with two additional heat exchangers (SDHHX and DHX) as the best candidate for trigen application. It is concluded that T-Hotwater has much more significant effect on the COP and (Q) over dot(E) than T-steam, in the HX 2-2 cycle. It is also found that the most important UA to affect the COP is UA(LG) while that to affect (Q) over dot(E) is UA(A). (C) 2016 Elsevier Ltd. All rights reserved.</P>

Electromagnetic performance analysis of connected double‑modulated axial magnetic gear embedded H‑shaped pole shoes for generators

Bin Zhang,Jungang Wang,Ruina Mo 전력전자학회 2024 JOURNAL OF POWER ELECTRONICS Vol.24 No.1

With the development of new energy technologies, there has been an increasing demand for high-powered power generators. Therefore, high torque density and high stability transmission devices are needed to ensure the stable operation of generators. This paper proposes and investigates a connected double-modulated axial magnetic gear embedded H-shaped pole shoes (CDMHAMG) structure. This structure uses a spoke low-speed rotor with embedded H-shaped pole shoes and a connected modulation ring on the other side of the spoke rotor. The CDMHAMG can effectively increase the utilization of permanent magnets and suppress the leakage phenomenon, which greatly increases the torque density and suppress the torque ripple. To study the characteristics of the CDMHAMG, the electromagnetic performance of a conventional axial magnetic gear (CAMG), a spoke axial magnetic gear (SAMG), and different double-modulated axial magnetic gears are finite element analyzed. It can be found that the rotor torque density of the CMDHAMG is 80.18 kN/m3, which is 1.12 times that of the CAMG. In addition, the torque ripple of the CMDHAMG is 11.4%, which is 47.7% of that of the CAMG. Therefore, the CMDHAMG proposed in this paper has greater torque density and higher transmission stability than the CAMG and is more suitable for power generation.