• Title/Summary/Keyword: on-state resistance

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Biofilm Formation and Low pH Viability of Cronobacter spp. (Enterobacter sakazakii) Isolated from Powdered Infant Formula and Infant Foods in Korea (국내 분유 및 영.유아식품에서 분리된 Cronobacter spp. (Enterobacter sakazakii)의 Biofilm 생성 특성 및 내산성 비교)

  • Kim, Sun-Ae;Lee, Yu-Mi;Oh, Se-Wook;Gwak, Hyo-Sun;Hwang, In-Gyun;Kang, Dong-Hyun;Woo, Gun-Jo;Rhee, Min-Suk
    • Food Science of Animal Resources
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    • v.29 no.6
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    • pp.702-708
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    • 2009
  • We investigated biofilm formation in various media, growth in low pH, and the hemolytic activity of 14 strains of Cronobacter spp. (Enterobacter sakazakii) isolated from a variety of foods including powdered infant formula (n=75), infant cereal (n=100), honey (n=30), and other infant foods (n=100) in Korea. The Cronobacter spp. adhered and formed biofilms on polyethylene, and a greater extent of biofilm was observed in nutrient-rich media. No clear difference in biofilm-forming ability was noted among the media constituents and the pattern of biofilm formation was strain-dependent. Seven strains out of 14 strains (50%) grew at pH 4.1, indicating that the acid resistance of these Cronobacter spp. isolated in Korea was relatively low. Hemolytic activity was not observed in any of the strains. This study provides basic information for the physiological and biochemical characteristics of Cronobacter spp. isolated from a variety of infant foods in Korea.

Structural Integrity Assessment of Helicopter Composite Rotor Blade by Analyzing Bird-strike Resistance (조류충돌 해석을 통한 헬리콥터 복합재 로터 블레이드 구조 건전성 평가)

  • Park, Jehong;Jang, Jun Hwan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.8
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    • pp.8-14
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    • 2019
  • Bird-strike is one of the most important design factors for safety in the aviation industry. Bird-strikes have been the cause of significant damage to aircraft and rotorcraft structures and the loss of life. This study used DYTRAN software to simulate the transient response of an Euler-Lagrangian composite helicopter blade that has been impacted by a bird. The Arbitrary Lagrangian Eulerian (ALE) method and a suitable equation of state were applied to model the bird. ALE was applied to the bird-strike analysis due to the large difference between the properties of the blade and bird. The debris of the bird was assumed to be a fluid and applied as Euler elements after the collision. Through the analysis of bird impacts, the leading-edge of the rotor blade (50.8 mm) was used to identify a positive margin of 1.18 based on the TSAI-FILL criteria. The results are assessed to be sufficiently reliable and may be evaluated to replace tests with various analysis conditions. The structural stability of the rotor blade could be assessed by applying various load conditions and different modeling methods in the future.

Study on Electrochemical Performances of PEO-based Composite Electrolyte by Contents of Oxide Solid Electrolyte (산화물계 고체전해질 함량에 따른 PEO 기반 복합전해질 전기화학 성능 연구)

  • Lee, Myeong Ju;Kim, Ju Young;Oh, Jimin;Kim, Ju Mi;Kim, Kwang Man;Lee, Young-Gi;Shin, Dong Ok
    • Journal of the Korean Electrochemical Society
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    • v.21 no.4
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    • pp.80-87
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    • 2018
  • Safety issues in Li-ion battery system have been prime concerns, as demands for power supply device applicable to wearable device, electrical vehicles and energy storage system have increased. To solve safety problems, promising strategy is to replace organic liquid electrolyte with non-flammable solid electrolyte, leading to the development of all-solid-state battery. However, relative low conductivity and high resistance from rigid solid-solid interface hinder a wide application of solid electrolyte. Composite electrolytes composed of organic and inorganic parts could be alternative solution, which in turn bring about the increase of conductivity and conformal contact at physically rough interfaces. In our study, composite electrolytes were prepared by combining poly(ethylene oxide)(PEO) and $Li_7La_3Zr_2O_{12}$ (LLZO). The crystallinity, morphology and electrochemical performances were investigated with the control of LLZO contents from 0 wt% to 50 wt%. From the results, it is concluded that optimum content and uniform dispersion of LLZO in polymer matrix are significant to improve overall conductivity of composite electrolyte.

Concept Analysis of Frail Elderly based on Walker and Avant's Method (Walker와 Avant 방법에 근거한 허약 노인 개념 분석)

  • Kim, Jae-Hyeon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.5
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    • pp.394-405
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    • 2019
  • The purpose of this study is to clarify the concept of the frail elderly and to obtain theoretical evidence. The research method was conducted using the basic principles for conceptual analysis of Walker and Avant(2005). As a Result of a review of the literature about how to utilize the concept of a frail elderly, frail elderly might be in the intermediate state of health and disease. They can be defined as physically vulnerable in the sarcopenia, inflammation, insulin resistance, and preceding advanced disease, lead to hospitalization, falls, disability, and death. The attributes were physiological, psychological, and socio-environmental and economic factors, so they had multidimensional factors. They were required the assist daily living of another person. Also, their attributes had decreased the amount of recovery time and degree, and exhaustion. The attributes of frail elderly consisted of these facts: dynamic process, multidimensional factors, dependency, vulnerability. The frail elderly was a dynamic process that involves the possibility of change to health and disease, and include physical, mental, cognitive, and social environmental factors. In addition, the frail elderly was difficulty in daily life, physical vulnerability and difficulty in adaption. In conclusion, frail elderly as defined by the results of this study will contribute to the foundation of health care systems, including community visiting nursing to understand the level of frail elderly and systemic management to do not go into long term care.

A Study on Social welfare relevance Appearing in Freud's psychoanalytic theory (프로이트의 정신분석이론에 나타난 사회복지 연관성 연구)

  • Yang, Chol-Soo
    • Industry Promotion Research
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    • v.4 no.1
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    • pp.29-43
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    • 2019
  • This study is to discusses the relevance of social welfare in Freud's psychoanalytic theory. The results of the study are as follows. First, psychoanalytic theory details the client's family history and personal history to help them identify the characteristics of the problem they have today. At this time, social workers actively listen to clients and try to get various information.Second, when used in psychoanalytic techniques, the resistance of the client can be interpreted and analyzed to help the client maintain friendly relationships with the client.Third, psychoanalytic theory can properly apply the client's current state of mind by understanding the potential conflicts or emotions that exist in the client's unconscious mind. Fourth, during the process of intervention, social workers need to deal well with the client's transition response. This process allows social workers to observe the effect of reducing the stimuli that can cause nervousness in clients.In conclusion, all the techniques of interpretation used in psychoanalytic theory are, after all, techniques that help social workers improve clients' insight into their problems and help clients solve their psychological problems themselves. The psychoanalytic theory is widely applied in social welfare.

Pilot Study of Single Session Song-Based Music Therapy for Decreasing ICU Caregiver Anxiety (중환자 보호자의 불안 감소를 위한 단회기 노래중심 음악치료 적용 예비연구)

  • Jung, Yu Sun;Na, Sungwon
    • Journal of Music and Human Behavior
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    • v.16 no.1
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    • pp.25-46
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    • 2019
  • This pilot study involved a single session of song-based music therapy to relieve the anxiety of intensive care unit (ICU) caregivers. Six caregivers of ICU patients participated in the intervention session individually. During the initial stage of the intervention, the participants' current emotional states were identified. Then they listened to familiar songs and playing a tone chime, which was intended to help them relax their body and reduce their psychological resistance. During singing experiences as an essential part of the intervention, the participants discussed the lyrics of songs in an attempt to find the meaning related to them. Also, they sang the songs with a live accompaniment in which their emotional states were reflected with changes in musical elements (e.g., tempo, dynamics, rhythm, or chords). In the final stage, they identified personal application to their everyday lives. To analyze the results, the State-Trait Anxiety Inventory (STAI) and a visual analog scale on emotional states were completed by participants before and after the session, and participants' verbal responses during the session were also recorded. According to the results, STAI anxiety scores significantly declined following the session. Also, they showed significant increases in positive emotions and significant decreases in negative emotions. This suggests that short-term music therapy can be an effective intervention for relieving the psychological distress of ICU caregivers.

A case of maxilla implant overdenture using Pekkton telescopic attachment with severe alveolar bone resorption (심한 치조골 소실이 있는 상악 무치악 환자에서 Pekkton telescopic attachment를 이용한 임플란트 피개의치 증례)

  • Park, Ha Eun;Lee, Won Sup;Lee, Cheol Won;Lee, Su Young
    • The Journal of Korean Academy of Prosthodontics
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    • v.57 no.2
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    • pp.189-194
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    • 2019
  • It is necessary to set the correct occlusal plane and to distribute the occlusal force uniformly considering the state of the opposing dentition during the prosthetic of the single edentulous patient with severe alveolar bone resorption. Implant supported overdenture is superior to complete denture in terms of maintenance and stability, and limited implants are used in fully edentulous patients with high alveolar bone resorption. Telescopic attachments using a newly introduced material based on poly-aryl-ether-ketone (PAEK) have the advantages of typical telescopic copping, excellent abrasion resistance, and are lighter and more economical than conventional implant overdentures. In this case, we restored maxillary arch with a implant retained overdenture using the telescopic attachment made of Pekktonand the mandible was restored with fixed implant prosthesis. Through these procedures esthetic aspects and functional outcomes were satisfactorily achieved.

Myanmar in 2016: Starting of New Era, But Uncertain Future (미얀마 2016: 새로운 시대의 시작, 불안한 미래)

  • JANG, Jun Young
    • The Southeast Asian review
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    • v.27 no.2
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    • pp.185-212
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    • 2017
  • The National League for Democracy (NLD) has restored a civilian government since the military had taken political power in 1962 as a result of general elections on 7, November 2015. But Daw Aung San Suu Kyi could not take part in the presidential election due to some restraints in constitution, so new government created the state counsellor position and the ministry of sate counsellor's office against military's resistance. It never publicized whether the military has to back to barracks including abolish of military's occupying the parliament seats. The ruling party is still taking laissez-faire to the military's political and economic role. The National level Ceasefire Agreement called the 21st Panglong conference launched in the end of August for a week, but stakeholders only insisted their demands. Rohingya issue is not involved in the 21st Panglong conference which aims to achieve national unity. The U.S. fully lifted a comprehensive sanction toward Myanmar since 1993, Japan promised huge grant assistance succeeding the former quasi civilian government. China strived to restore alienated relations of two countries. Although Korea kept Official Development Assistance, the summit which was planed two times in 2016 did not hold. The civilian government announced twelve points of developmental agenda in July 2016, instead of destroying the national development policy of the Thein Sein government. This agenda only showed the direction of policy not road map which was the same trend of the former government. The main direction of economic development stressed agriculture but manufacture like light industry was ignored.

Flexural Behavior of Concrete Beams Reinforced with Fe based Shape Memory Alloy Bar (철계-형상기억합금 바로 제작된 콘크리트 보의 휨 거동)

  • Hong, Ki-Nam;Yeon, Yeong-Mo;Ji, Sang-Won
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.24 no.6
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    • pp.67-76
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    • 2020
  • This paper reports an experimental study to evaluate the flexural behavior of concrete beams reinforced using Fe based shape memory alloy (Fe-SMA) bars. For the experiment, a concrete beam of 200mm×300mm×2,200mm was produced, and a 4% pre-strained Fe-SMA bar was used as a tensile reinforcement. As experimental variables, type of tensile reinforcement (SD400, Fe-SMA), reinforcement ratio (0.2, 0.39, 0.59, 0.78), activation of Fe-SMA (activation, non-activation), and joint method of Fe-SMA bar (Continuous, welding, coupler) were considered. The electric resistance heating method was used to activate the Fe-SMA bar, and a current of 5A/㎟ was supplied until the specimen reached 160℃. After the upward displacement of the specimen due to the camber effect was stabilized, a three-point flexural loading experiment was performed using an actuator of 2,000 kN capacity. As a result of the experiment, it was found that the upward displacement occurred due to the camber effect as the Fe-SMA bar was activated. The specimen that activated the Fe-SMA bar had an initial crack at a higher load than the specimen that did not activate it. However, as with general prestressed concrete, the effect of the prestress by Fe-SMA activation on the ultimate state of the beam was insignificant.

Cancer Stem Cells and the Tumor Microenvironment (암줄기세포와 종양 미세환경에 대한 고찰)

  • Soo-Yeon Woo;Hee-Seon Choi;Kanghee Yoo;Junseo Kim;Yeolhee Yoon;Seungyeon Lee;Jaehyuk Choi;Kyeongho Kim;Kangjun Lee;Seunghyeon Hwang;Dongjun Lee
    • Journal of Life Science
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    • v.34 no.6
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    • pp.418-425
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    • 2024
  • Solid tumors are heterogeneous populations of multiple cell types. While the majority of the cells that comprise cancer are unable to divide, cancer stem cells have self-renewal and differentiation properties. Normal stem cell pathways that control self-renewal are overactivated in cancer stem cells, making cancer stem cells important for cancer cell expansion and progression. Dick first proposed the definition of cancer stem cells in acute myeloid leukemia, according to which cancer stem cells can be classified based on the expression of cell surface markers. Cancer stem cells maintain their potential in the tumor microenvironment. Multiple cell types in the tumor microenvironment maintain quiescent cancer stem cells and serve as regulators of cancer growth. Since current cancer treatments target proliferative cells, quiescent state cancer stem cells that are resistant to treatment increase the risk of recurrence or metastasis. Various signals of the tumor microenvironment induce changes to become a tumor-supportive environment by remodeling the vasculature and extracellular matrix. To effectively treat cancer, cancer stem cells and the tumor microenvironment must be targeted. Therefore, it is important to understand how the tumor microenvironment induces reprogramming of the immune response to promote cancer growth, immune resistance, and metastasis. In this review, we discuss the cellular and molecular mechanisms that can enhance immunosuppression in the tumor microenvironment.