• Title/Summary/Keyword: Resistance Mechanism

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A Study of Methodology Based on Role-Based Serucity Agent Medical Information System Security Architecture Design (보안 에이전트 역할 기반에 기초한 의료정보시스템 소프트웨어 보안아키텍쳐 설계방안)

  • Lee, Dae-Sung;Noh, Si-Choon
    • Convergence Security Journal
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    • v.11 no.4
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    • pp.77-83
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    • 2011
  • In addition to the rapid development of health information technology services for the development of new medical information, a lot of research is underway. Improve health care services for patients are many ways to help them. However, no information about the security, if only the technology advances in health care systems will create an element of risk and threat. Today's issues and access issues are stable over a public network. Ad hocsensor network using secure, non-integrated health information system's security vulnerabilities does not solve the security vulnerabilities. In the development and utilization of health information systems to be subject to greater restrictions. Different security policies in an environment with a medical information system security policy mechanism that can be resolved if people get here are needed. Context-aware and flexible policy of integration and confidential medical information through the resistance should be guaranteed. Other cross-domain access control policy for telecommunications should be protected. In this paper, that the caller's medical information system, diversification, diversification Security agent in the environment, architecture, design, plan, role-based security system are proposed. The proposed system architecture, design work in the field and in the utilization of one model are expected to be.

Wear Mechanism and Machinability of PCD Tool in Turning Tungsten Carbides (초경합금재의 선반절삭에 있어서 PCD공구의 마멸 기구와 절삭성)

  • Heo, Sung Jung
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.22 no.1
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    • pp.85-91
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    • 2013
  • The machinability of wear-resistible tungsten carbides and the tool wear behavior in machining of V30 and V50 tungsten carbides using PCD (Poly Crystalline Diamond) cutting tool was investigated to understand machining characteristics. This material is one of the difficult-to-cut materials in present, but their usage has been already broadened to every commercial applications such as mining tools, and impact resistant tools etc. Summary of the results are as follows. (1) Tool wear progression of PCD tools in turning of wear-resistible tungsten carbides were observed specially fast in primary cutting distance within 10m. (2) Three components of cutting resistance in this research were different in balance from the ordinary cutting such as that cutting of steel or cast iron. Those were expressed large value by order of thrust force, principal force, feed force. (3) If presume from viewpoint of high efficient cutting within this research, a proper cutting speed was 15m/min and a proper feed rate was 0.1mm/rev. In this case, it was found that the tool life of PCD tool was cutting distance until 230m approximately. (4) In cutting of wear-resistible tungsten carbides such as V30 and V50, it was recognized that the tool wear rate of V30 was very fast as compared with V50. (5) When the depth of cut was 0.1mm, there was no influence of the feed rate on the feed force. And the feed force tended to decrease as the cutting distance was long, because the tool was worn and the tool edge retreated. (6) It was observed that the tungsten carbides were adhered to the flank.

Disulfide Bond as a Structural Determinant of Prion Protein Membrane Insertion

  • Shin, Jae Yoon;Shin, Jae Il;Kim, Jun Seob;Yang, Yoo Soo;Shin, Yeon-Kyun;Kim, Kyeong Kyu;Lee, Sangho;Kweon, Dae-Hyuk
    • Molecules and Cells
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    • v.27 no.6
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    • pp.673-680
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    • 2009
  • Conversion of the normal soluble form of prion protein, PrP ($PrP^C$), to proteinase K-resistant form ($PrP^{Sc}$) is a common molecular etiology of prion diseases. Proteinase K-resistance is attributed to a drastic conformational change from ${\alpha}$-helix to ${\beta}$-sheet and subsequent fibril formation. Compelling evidence suggests that membranes play a role in the conformational conversion of PrP. However, biophysical mechanisms underlying the conformational changes of PrP and membrane binding are still elusive. Recently, we demonstrated that the putative transmembrane domain (TMD; residues 111-135) of Syrian hamster PrP penetrates into the membrane upon the reduction of the conserved disulfide bond of PrP. To understand the mechanism underlying the membrane insertion of the TMD, here we explored changes in conformation and membrane binding abilities of PrP using wild type and cysteine-free mutant. We show that the reduction of the disulfide bond of PrP removes motional restriction of the TMD, which might, in turn, expose the TMD into solvent. The released TMD then penetrates into the membrane. We suggest that the disulfide bond regulates the membrane binding mode of PrP by controlling the motional freedom of the TMD.

A Historical Study on the Treatments of 鼻鼽(bí qiú) ('비구(鼻鼽)'에 대한 의사학적 연구)

  • Oh, Byung-Gun;Maeng, Woong-Jae;Kim, Hoon
    • The Journal of Korean Medical History
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    • v.24 no.1
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    • pp.97-110
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    • 2011
  • Rhinitis, inflammation of the nasal cavity caused by the disease in our country that a recent trend is the rapidly increasing number of patients. It causes multiple complications and interfere with daily life and social life in case of being viewed as a mild cold. The rhinitis treatment for symptomatic therapy in modern medicine is staying because the situation is exposing the limitations. so traditional medicine is trying to find a solution but that is not easy. In modern medicine, rhinitis is defined as a set of histological lesions and clinical symptoms, but traditional medicine has developed in dealing with each symptoms in disease. The treatment that doesn't distinguish any treatment in growing numbers of patients does not seem to validate, because doctors treat without considering the difference of recognition. Looking at the symptoms for each, I found that each symptoms and causes are varied according to doctors and era. In spite of considering all of that in treatment, it was ignored or underestimated in modern medicine. Furthermore, in traditional medicine, they just conjugated certain period theory and only had limited treatment by a lack of integrated awareness about definition and mechanism. In addition, in case of mentioning about the causes of prescription in each medical books, there were not enough explain about pathological states. Therefore, these causes should be made to further the research about the validity, pathogenesis and treatment. We can see that theory could be established and modified by the accumulation of clinical experience, observations through classification by each of the causes, prescription and treatment. In traditional medicine simply does not pay attention only to nasal inflammation, such as the impact of Meridian and organs considered to have focused on the fundamental treatment. This increased immune resistance to the modern rhinitis patients may offer new therapeutic approaches. I hope this paper would be helpful to find the treatment with uncovered theory in modern medicine.

Lifespan Extension Property of Quercetin-3-O-${\beta}$-D-glucopyranoside-7-O-${\alpha}$-L-rhamnopyranoside from Curcuma longa L. In Caenorhabditis elegans (강황지하부 부산물에서 분리한 Quercetin-3-O-${\beta}$-D-glucopyranoside-7-O-${\alpha}$-L-rhamnopyranoside가 선충의 수명연장에 미치는 영향)

  • Ahn, Dalrae;Lee, Eun Byeol;Kim, Ban Ji;Lee, So Yeon;Ahn, Min-Sil;Eun, Jae Soon;Shin, Tae-Yong;Kim, Dae Keun
    • Korean Journal of Pharmacognosy
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    • v.45 no.4
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    • pp.275-281
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    • 2014
  • After harvesting the medicinal parts of Curcuma longa, the remaining underground parts were discarded. From the remaining underground parts of Curcuma longa quercetin-3-O-${\beta}$-D-glucopyranoside-7-O-${\alpha}$-L-rhamnopyranoside (Q37) was isolated. The antioxidant activities in vitro and lifespan-extension effect of Q37 were elucidated using the Caenorhabditis elegans. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging effect of Q37 showed similar potent activities in comparison with vitamin C. Q37 also showed potent superoxide quenching activities as measured by the riboflavin- and xanthine-originated superoxide quenching activity tests. Q37 prolonged lifespan of worms under normal culture condition. In terms of protective effect of Q37 on the stress conditions such as thermal and oxidative stresses, Q37-treated worms exhibited enhanced survival rate, as compared to control worms. To know the possible mechanism of Q37-mediated increased lifespan and stress resistance of worms, we examined the activities of Q37on superoxide dismutase (SOD), and invested intracellular reactive oxygen species (ROS) levels. The results revealed that Q37 was able to elevate SOD activity of worms and reduce intracellular ROS accumulation in a dose-dependent manner.

Identification of Genes Associated with Early and Late Response of Methylmercury in Human Neuroblastoma Cell Line

  • Kim, Youn-Jung;Kim, Mi-Soon;Jeon, Hee-Kyung;Ryu, Jae-Chun
    • Molecular & Cellular Toxicology
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    • v.4 no.2
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    • pp.164-169
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    • 2008
  • Methylmercury (MeHg) is known to have devastating effects on the mammalian nervous system. In order to characterize the mechanism of MeHg-induced neurotoxicity, we investigated the analysis of transcriptional profiles on human 8k cDNA microarray by treatment of $1.4{\mu}M$ MeHg at 3, 12, 24 and 48h in human neuroblastoma SH-SY5Y cell line. Some of the identified genes by MeHg treatment were significant at early time points (3h), while that of others was at late time points (48h). The early response genes that may represent those involved directly in the MeHg response included pantothenate kinase 3, a kinase (PRKA) anchor protein (yotiao) 9, neurotrophic tyrosine kinase, receptor, type 2 gene, associated with NMDA receptor activity regulation or perturbations of central nervous system homeostasis. Also, when SH-SY5Y cells were subjected to a longer exposure (48h), a relative increase was noted in a gene, glutamine-fructose-6-phosphate transaminase 1, reported that overexpression of this gene may lead to the increased resistance to MeHg. To confirm the alteration of these genes in cultured neurons, we then applied real time-RT PCR with SYBR green. Thus, this result suggests that a neurotoxic effect of the MeHg might be ascribed that MeHg alters neuronal receptor regulation or homeostasis of neuronal cells in the early phase. However, in the late phase, it protects cells from neurotoxic effects of MeHg.

Case Studies on the Field Application of Miniature CPT's in South Korea (소형콘관입시험(Miniature CPT)의 국내현장적용 사례분석)

  • Yoon, Sung-Soo;Hwang, Dae-Jin;Kim, Jun-Ou;Ji, Wan-Goo
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09a
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    • pp.269-281
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    • 2010
  • The cone penetration test(CPT) has been increasingly used for in situ site characterization. However, the use of CPT is often limited due to specific site conditions depending on the cone size, geometry, and capacity of the CPT system used. In South Korea, it has generally been considered that the CPT could be satisfactorily performed only in soft soils. Louisiana State University/ Louisiana Transportation Research Center has implemented a field-rugged continuous intrusion miniature cone penetration test (CIMCPT) system since the 1990s. The miniature cone penetrometer of the CIMCPT system has a cross-sectional cone area of $2cm^2$ allowing finer soil profiles compared to the standard $10cm^2$. The reduced cross-sectional area also enables a system capacity reduction leading to cost saving and ease in maintenance. In addition, the continuous intrusion mechanism allows fast and economic site investigations. Samsung C&T Corporation has recently implemented a similar CIMCPT system. In this study, case studies on the field application of Samsung CIMCPT system for the last 2 years are presented to illustrate its performance investigation and its usefulness and limitation. Results of the case studies show that the CIMCPT system can be applied to soils with cone tip resistance($q_c$) values up to about 30MPa and allows a reliable and useful way to characterize soft soils. The results also show that the rod buckling limits the investigation depth by the system and the large contact pressure of the CIMCPT truck prevents the use of the system at sites with soft surface soils. According to the results of the case studies, the Samsung CIMCPT system has been being upgraded with a miniature cone with a longer rod, a crawler-type transportation system, a pre-boring system, and so on.

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Static and Fatigue Behavior of RC Beams Strengthened with Steel Plates

  • Oh, Byung-Hwan;Cho, Jae-Yeol;Cha, Soo-Won
    • KCI Concrete Journal
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    • v.14 no.1
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    • pp.51-60
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    • 2002
  • Strengthening of existing concrete structures is a major concern in recent years as the number of degraded structures increases. The purpose of this paper is to investigate the static and fatigue behavior of reinforced concrete (RC) beams strengthened with steel plates. To this end, a comprehensive test program has been set up and many series of strengthened beams have been tested. The major test variables include the plate thickness, adhesive thickness, and the shear-span to depth ratio. The test results indicate that the separation of plates is the dominant failure mechanism even for the full-span-length strengthened beams with steel plate. The theoretical ultimate load capacities for strengthened beams based on the full composite action of concrete beam and steel plate are found to be larger than the actual measured load capacities. The strengthened beams exhibit more dominant shear cracking as the shear-span to depth ratio decreases. The ultimate capacity of strengthened beams increases slightly with the increase of adhesive thickness, which may be caused by the late initiation of plate separation in the beams with thicker adhesive. A realistic concept of ductility for plate-strengthened beams is proposed in this study. It is seen that the strengthened beams show relatively low ductility compared with unstrengthened beams. The present study indicates that the strengthened beams exhibit much higher fatigue resistance than the unstrengthened beams. The increase of deflections of strengthened beams according to the number of load cycles is much smaller than that of unstrengthened beams. The present study provides very useful results for the realistic application of plate-strengthening method in reinforced concrete structures.

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Luteolin attenuates migration and invasion of lung cancer cells via suppressing focal adhesion kinase and non-receptor tyrosine kinase signaling pathway

  • Masraksa, Wuttipong;Tanasawet, Supita;Hutamekalin, Pilaiwanwadee;Wongtawatchai, Tulaporn;Sukketsiri, Wanida
    • Nutrition Research and Practice
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    • v.14 no.2
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    • pp.127-133
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    • 2020
  • BACKGROUND/OBJECTIVES: Non-small cell lung cancer is mostly recognized among other types of lung cancer with a poor prognosis by cause of chemotherapeutic resistance and increased metastasis. Luteolin has been found to decrease cell metastasis. However, its underlying mechanisms remain unresolved. The objective of this study was to examine the effect (and its mechanism) of luteolin on the migration and invasion of human non-small cell lung cancer A549 cells. MATERIALS/METHODS: Cell viability was investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Wound healing and transwell assays were evaluated to assess migration and invasion, respectively. Western blot analysis and immunofluorescence were further performed to investigate the role of luteolin and its mechanisms of action. RESULTS: Administration with up to 40 μM luteolin showed no cytotoxic activity on lung cancer A549 cells or non-cancer MRC-5 cells. Additionally, luteolin at 20-40 μM significantly suppressed A549 cells' migration, invasion, and the formation of filopodia in a concentration-dependent manner at 24 h. This is similar with western blot analysis, which revealed diminished the phosphorylated focal adhesion kinase (pFAK), phosphorylated non-receptor tyrosine kinase (pSrc), Ras-related C3 botulinum toxin substrate 1 (Rac1), cell division control protein 42 (Cdc42), and Ras homolog gene family member A (RhoA) expression levels. CONCLUSIONS: Overall, our data indicate that luteolin plays a role in controlling lung cancer cells' migration and invasion via Src/FAK and its downstream Rac1, Cdc42, and RhoA pathways. Luteolin might be considered a promising candidate for suppressing invasion and metastasis of lung cancer cells.

Analysis of Performance Characteristics of Swash-Plate-Type Hydraulic Piston Motor (사판식 유압 피스톤모터의 성능특성 분석)

  • Lee, Yong-Bum;Kim, Kwang-Min
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.36 no.11
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    • pp.1441-1446
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    • 2012
  • An axial-piston-type hydraulic motor involves friction and leakage losses at the sliding parts, contact loss at the mechanism assembly parts, volumetric loss caused by the pressure drop, housing oil churning loss and compressibility from the hydraulic oil pipe resistance, etc. the friction and volumetric loss at the hydrostatic bearing between the piston shoe and the swash plate rotating at high speed and having an oil film gap of 8-15 ${\mu}m$ strongly affects the total efficiency of the hydraulic motor. In this study, a variable swash-plate-type hydraulic piston motor operating under a maximum pressure of 35 MPa, maximum speed of 2,500 rpm, and displacement of 320 cc/rev is tested to verify the optimal ratio of the hydrostatic bearing which is closely related to the hydraulic motor performance.