• 제목/요약/키워드: Persistent current

검색결과 161건 처리시간 0.028초

Topological implications of DNA tumor viral episomes

  • Eui Tae, Kim;Kyoung-Dong, Kim
    • BMB Reports
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    • 제55권12호
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    • pp.587-594
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    • 2022
  • A persistent DNA tumor virus infection transforms normal cells into cancer cells by either integrating its genome into host chromosomes or retaining it as an extrachromosomal entity called episome. Viruses have evolved mechanisms for attaching episomes to infected host cell chromatin to efficiently segregate the viral genome during mitosis. It has been reported that viral episome can affect the gene expression of the host chromosomes through interactions between viral episomes and epigenetic regulatory host factors. This mini review summarizes our current knowledge of the tethering sites of viral episomes, such as EBV, KSHV, and HBV, on host chromosomes analyzed by three-dimensional genomic tools.

Digital Forensics Investigation Approaches in Mitigating Cybercrimes: A Review

  • Abdullahi Aminu, Kazaure;Aman Jantan;Mohd Najwadi Yusoff
    • Journal of Information Science Theory and Practice
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    • 제11권4호
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    • pp.14-39
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    • 2023
  • Cybercrime is a significant threat to Internet users, involving crimes committed using computers or computer networks. The landscape of cyberspace presents a complex terrain, making the task of tracing the origins of sensitive data a formidable and often elusive endeavor. However, tracing the source of sensitive data in online cyberspace is critically challenging, and detecting cyber-criminals on the other hand remains a time-consuming process, especially in social networks. Cyber-criminals target individuals for financial gain or to cause harm to their assets, resulting in the loss or theft of millions of user data over the past few decades. Forensic professionals play a vital role in conducting successful investigations and acquiring legally acceptable evidence admissible in court proceedings using modern techniques. This study aims to provide an overview of forensic investigation methods for extracting digital evidence from computer systems and mobile devices to combat persistent cybercrime. It also discusses current cybercrime issues and mitigation procedures.

YBCO 2G 선재간 접합 특성 연구 (Charateristics analysis of the joining of YBCO 2G HTS wire)

  • 장기성;박동근;양성은;안민철;조대호;김현규;;고태국
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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    • pp.741-742
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    • 2006
  • This paper deals with an efficient superconducting joint method between 2G high superconducting(HTS) wire, YBCO coated conductor(CC). Recently CC is one of the most promising superconducting wire due to high n-value and critical current independency from external magnetic field. It is expected to be used many superconducting application such as fault current limiter, persistent current system and cable etc. In most HTS applications, superconducting magnet is used, and it is necessary to joint between superconducting wire to fabricate superconducting magnet system. A CC tape used in this research consists of copper stabilizer, silver layer, YBCO layer, buffer and substrate. Direct joint using soldering method was inefficient due to resistance of copper, then copper lamination is removed by chemical etching method to reduce resistance between CC tapes. Jointed tapes were fabricated and tested. Transport current through jointed area and induced voltage were measured to characterize the I-V curve. Resistance between CC wire using chemical etching was compared with resistance of direct jointed tapes using soldering method in this paper.

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자장감쇠법을 이용한 $(Bi,Pb)_2Sr_2Ca_2Cu_3O_x$/Ag 초전도선재의 접합저항 측정 (Measurement of Joint Resistance of $(Bi,Pb)_2Sr_2Ca_2Cu_3O_x$/Ag Superconducting Tape by Field decay Technique)

  • 김정호;이승묵;주진호
    • Progress in Superconductivity
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    • 제14권1호
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    • pp.1-10
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    • 2012
  • We fabricated a closed coils by using resistive-joint method and the joint resistance of the coils were estimated by field decay technique in liquid nitrogen. We used the Runge-kutta method for the numerical analysis to calculate the decay properties. The closed coil was wound by $(Bi,Pb)_2Sr_2Ca_2Cu_3O_x$/Ag tape. Both ends the tape were overlapped and soldered to each other. The current was induced in a closed coils by external magnetic flux density. Its decay characteristic was observed by means of measuring the magnetic flux density generated by induced current at the center of the closed coil with hall sensor. The joint resistance was calculated as the ratio of the inductance of the loop to the time constants. The joint resistances were evaluated as a function of critical current of loop, contact length, sweep time, and external magnetic flux density in a contact length of 7 cm. It was observed that joint resistance was dependent on contact length of a closed coil, but independent of critical current, sweep time, and external magnetic flux density. The joint resistance was measured to be higher for a standard four-probe method, compared with that for the field decay technique. This implies that noise of measurement in a standard four-probe method is larger than that of field decay technique. It was estimated that joint resistance was $8.0{\times}10^{-9}{\Omega}$ to $11.4{\times}10^{-9}{\Omega}$ for coils of contact length for 7 cm. It was found that 40Pb/60Sn solder are unsuitable for persistent mode.

Reactive oxygen species increase neuronal excitability via activation of nonspecific cation channel in rat medullary dorsal horn neurons

  • Lee, Hae In;Park, Byung Rim;Chun, Sang Woo
    • The Korean Journal of Physiology and Pharmacology
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    • 제21권4호
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    • pp.371-376
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    • 2017
  • The caudal subnucleus of the spinal trigeminal nucleus (medullary dorsal horn; MDH) receives direct inputs from small diameter primary afferent fibers that predominantly transmit nociceptive information in the orofacial region. Recent studies indicate that reactive oxygen species (ROS) is involved in persistent pain, primarily through spinal mechanisms. In this study, we aimed to investigate the role of xanthine/xanthine oxidase (X/XO) system, a known generator of superoxide anion ($O_2{^-}$), on membrane excitability in the rat MDH neurons. For this, we used patch clamp recording and confocal imaging. An application of X/XO ($300{\mu}M/30mU$) induced membrane depolarization and inward currents. When slices were pretreated with ROS scavengers, such as phenyl N-tert-butylnitrone (PBN), superoxide dismutase (SOD), and catalase, X/XO-induced responses decreased. Fluorescence intensity in the DCF-DA and DHE-loaded MDH cells increased on the application of X/XO. An anion channel blocker, 4,4-diisothiocyanatostilbene-2,2-disulfonic acid (DIDS), significantly decreased X/XO-induced depolarization. X/XO elicited an inward current associated with a linear current-voltage relationship that reversed near -40 mV. X/XO-induced depolarization reduced in the presence of $La^{3+}$, a nonselective cation channel (NSCC) blocker, and by lowering the external sodium concentration, indicating that membrane depolarization and inward current are induced by influx of $Na^+$ ions. In conclusion, X/XO-induced ROS modulate the membrane excitability of MDH neurons, which was related to the activation of NSCC.

사회적 지속가능성을 위한 고령친화 환경 분야 최근 경향연구 -노인환경전문학술대회 발표물을 중심으로- (Analysis of Major Trends appeared in recent Aging Friendly Environment for Social Sustainability -with Reference to Presentations of the Conference on Environments for Elderly-)

  • 안소미;이연숙
    • KIEAE Journal
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    • 제10권3호
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    • pp.117-125
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    • 2010
  • Entering into the 21th century, the whole world is facing the various problems such as environmental disruption, resource exhaustion, and social isolation due to the consequences of population growth and economic development. Especially, as the world population is aging, the solutions for these problems are being suggested with a new paradigm of environmental design for sustainable society providing more affluent and safer life for them. Aging societies are experiencing the difficulty in pursuing persistent vitality of life when aged population is socially excluded, and communities are stagnant due to the decrease of economic activities. In other words, those factors are causing the problems of social sustainability associated with the vital duration of local society and communities. In order to develop successful environment for aging society, it is necessary for us to precisely review how advanced countries are changing their directions. Therefore, the purpose of this study is to examine current trends of the aging friendly environment and find out the measures to promote social sustainability under the crisis of aging society. For this purpose, using qualitative methods, this study analyzed the contents presented at a professional conference , that showed current trends clearly, into three dimensions of social sustainability; the social integration of senior living communities with local society, the vitality of the communities, and the invigoration of individual senior lives. As a result, this study found that the measures that attempt to enhance the social sustainability of aging population can be also used to invigorate the communities.

HPV and Cervical Cancer Epidemiology - Current Status of HPV Vaccination in India

  • Chatterjee, Sharmila;Chattopadhyay, Amit;Samanta, Luna;Panigrahi, Pinaki
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권8호
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    • pp.3663-3673
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    • 2016
  • Cervical cancer (CaCx) is the second most fatal cancer contributing to 14% of cancers in Indian females, which account for 25.4% and 26.5% of the global burden of CaCx prevalence and mortality, respectively. Persistent infection with high-risk human papilloma virus (HPV- strains 16 and 18) is the most important risk factor for precursors of invasive CaCx. Comprehensive prevention strategies for CaCx should include screening and HPV vaccination. Three screening modalities for CaCx are cytology, visual inspection with acetic acid, and HPV testing. There is no Indian national policy on CaCx prevention, and screening of asymptomatic females against CaCx is practically non-existent. HPV vaccines can make a major breakthrough in the control of CaCx in India which has high disease load and no organized screening program. Despite the Indian Government's effort to introduce HPV vaccination in the National Immunization Program and bring down vaccine cost, challenges to implementing vaccination in India are strong such as: inadequate epidemiological evidence for disease prioritization, duration of vaccine use, parental attitudes, and vaccine acceptance. This paper reviews the current epidemiology of CaCx and HPV in India, and the current status of HPV vaccination in the country. This article stresses the need for more research in the Indian context, to evaluate interventions for CaCx and assess their applicability, success, scalability and sustainability within the constraints of the Indian health care system.

만성폐쇄성폐질환을 동반한 이직광부에서 혈장 총 Peroxide 및 산화스트레스 지수 수준에 미치는 영향요인 (Influencing Factors of Plasma Levels of Total Peroxide and Oxidative Stress Index in Retired Miners with Chronic Obstructive Pulmonary Disease)

  • 이종성;신재훈;백진이;정지영;최병순
    • 한국산업보건학회지
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    • 제30권2호
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    • pp.196-204
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    • 2020
  • Objective: Chronic obstructive pulmonary disease(COPD) is characterized by persistent airflow limitations associated with chronic inflammatory response due to noxious particles or gases in the lung. Increasing oxidative stress associated with COPD. The aim of this study was to evaluate the influencing factors of biomarkers for oxidative stress in retired miners with COPD. Methods: The levels of total peroxide(TPx), total antioxidant capacity(TAC), and oxidative stress index(TPx/TAC ratio, OSI) in plasma as biomarkers for oxidative stress, serum C-reactive protein(CRP) as a biomarker for inflammation, and general characteristics were measured in 93 male subjects with COPD. COPD was defined as post bronchodilator FEV1/FVC<0.7 by spirometry. Results: Mean levels of TPx(p=0.013), TAC(p=0.010), OSI(p=0.040), and CRP(p=0.024) were higher in current smokers. Levels of TPx(β=0.445, p<0.001), TAC(β=0.490, p<0.001), and OSI(β=0.351, p<0.001) were related to CRP levels, and CRP levels were related to %FEV1 predicted(β=-0.295, p=0.003) and current smoking(β=0.214, p=0.032). Conclusions: These results suggest that oxidative stress was related to inflammation, and inflammation were related to decreasing %FEV1 predicted and current smoking in retired miners with COPD.

Effect of Various Divalent Ions on the Calcium Current of Adrenal Medullary Chromaffin Cells in the Rat

  • Kim, Jun;Leem, Chae-Hun;Kim, Sang-Jeong
    • The Korean Journal of Physiology
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    • 제26권2호
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    • pp.113-122
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    • 1992
  • It is well known that chromaffin cells of adrenal medulla secrete catecholamine in response to sympathetic nerve activation and the influx of $Ca^{2+}$ through the voltage dependent $Ca^{2+}$ channels (VDCC) in the cell membrane do a major role in this secretory process. In this study, we explored the effect of divalent cations on VDCC of rat chromaffin cells. Rat (Sprague-Dawley rat, 150-250 gm) chromaffin cells were isolated and cultured. Standard giga seal, whole cell recording techniques were employed to study $Ca^{2+}$ current with external and internal solutions that could effectively isolate VDCC currents $(NMG\;in\;external\;and\;TEA\;and\;Cs^{2+}\;in\;internal\;solution)$. The voltage dependence and the inactivation time course of VDCC in our cells were identical to those of bovine chromaffin cells. A persistent inward current was first activated by depolarizing step pulse from the holding potential (H.P.) of -80 mV to -40 mV, increased to maximum amplitude at around +10 mV, and became smaller with progressively higher depolarizing pulses to reverse at around +60 mV. The inactivation time constant $(\tau)$, fitted from the long duration test potential (2 sec) was $1295.2{\pm}126.8$ msec $(n=20,\;1\;day\;of\;culture,\;mean\;{\pm}S.E.M.)$ and the kinetic parameters were not altered along the culture duration. Nicardipine $(10\;{\mu}M)$ blocked the current almost completely. Among treated divalent cations such as $Cd^{2+},\;Co^{2+},\;Ni^{2+},\;Zn^{2+}\;and\;,Mn^{2+},\;Cd^{2+}$ was the most potent blocker on VDCC. When the depolarizing step pulse from -80 mV to 10 mV was applied, the equilibrium dissociation constant $(K_d)$ of $Cd^{2+}\;was\;39\;{\mu}M,\;K_d\;of\;Co^{2+}\;was\;100\;{\mu}M\;and\;K_d\;of\;Ni^{2+}];was];780{\mu}M.$ The principal findings of this study are as follows. First, the majority of $Ca^{2+}$ channels in rat chromaffin cells are well classified to L-type $Ca^{2+}$ channel in the view of kinetics and pharmacology. Second, all divalent cations tested could block the $Ca^{2+}$ current and the most potent blocker among the tested was $Cd^{2+}$.

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통합보안관리시스템 보안 분석 및 개선 (Security Analysis and Improvement of Integrated Security Management System)

  • 김경신
    • 한국인터넷방송통신학회논문지
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    • 제15권1호
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    • pp.15-23
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    • 2015
  • 본 논문은 지난 2012년 이후 떠오른 개념인 '빅 데이터'의 등장으로 정보보안 환경이 어떻게 변화되고 있는지, 빅 데이터와 관련된 분석 기술을 바탕으로 보안위협으로부터 어떤 통합보안시스템을 구축해야 하는지 제안하고자 한다. 빅 데이터 분야에 대해서는 최근 활용 분야에 대한 연구가 활발히 진행 중이며 APT(Advanced Persistent Threats)와 같은 보안 위협으로부터 보호하기 위해 빅 데이터 기반 통합보안관리시스템에서는 어떤 요구사항이 필요한 지 살펴보고자 한다. 또한, 기존 통합보안관리시스템과 현재 빅 데이터 기반 통합보안관리시스템을 비교 분석하며 한계점은 무엇이며 보완되어야 할 점을 제안하여 개선된 통합보안관리시스템을 제안하고자 한다.