• Title/Summary/Keyword: stress regions

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Alzheimer's Disease and Apoptosis

  • Kim, Young-Hoon;Kim, Hye-Sun;Park, Cheol-Hyoung;Jeong, Sung-Jin;Kim, Young-Kyung;Kim, Sun-Hee;Lee, Sang-Kyeng;Suh, Yoo-Hun;Kim, Sung Su
    • Korean Journal of Biological Psychiatry
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    • v.5 no.1
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    • pp.66-70
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    • 1998
  • Apoptosis is a form of cell death in which the cells shrink and exhibit nuclear chromatin condensation and DNA fragmentation, and yet maintain membrane integrity. Many lines of evidence have shown that brain neurons are vulnerable to degeneration by apoptosis. Also it has been suggested that apoptosis is one of the mechanism contributing neuronal loss in Alzheimer's disease(AD), since the conditions in the disease($A{\beta}$ peptide, oxidative stress, low energy metabolism) are the inducers that activate apoptosis. Indeed some neurons in vulnerable regions of the AD brain show DNA damage, chromatin condensation, and apoptic bodies. Consistently, mutations in AD causative genes(Amyloid precursor protein, Presenilin-1 and Presenilin- 2) increase $A{\beta}$ $peptide_{1-42}(A{\beta}_{1-42})$ and sensitize neuronal cell to apoposis. However, several lines of evidence have shown that the location of neuronal loss and $A{\beta}$ peptide deposition is not correlated in AD brain and transgenic mice brain over-expressing $A{\beta}_{1-42}$. Taken together, these data may indicated that $A{\beta}$ peptide(and other causative factors of AD) can interact with other cellular insults or risk factors to exacerbate pathological mechansim of AD through apoptosis. Thus, this review discusses possible role and mechanism of apoptosis in AD.

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Molecular Changes in Remote Tissues Induced by Electro-Acupuncture Stimulation at Acupoint ST36

  • Rho, Sam-Woong;Choi, Gi-Soon;Ko, Eun-Jung;Kim, Sun-Kwang;Lee, Young-Seop;Lee, Hye-Jung;Hong, Moo-Chang;Shin, Min-Kyu;Min, Byung-Il;Kee, Hyun-Jung;Lee, Cheol-Koo;Bae, Hyun-Su
    • Molecules and Cells
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    • v.25 no.2
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    • pp.178-183
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    • 2008
  • To investigate the effects of electro-acupuncture (EA) treatment on regions remote from the application, we measured cellular, enzymatic, and transcriptional activities in various internal tissues of healthy rats. The EA was applied to the well-identified acupoint ST36 of the leg. After application, we measured the activity of natural killer cells in the spleen, gene expression in the hypothalamus, and the activities of antioxidative enzymes in the hypothalamus, liver and red blood cells. The EA treatment increased natural killer cell activity in the spleen by approximately 44%. It also induced genes related to pain, including 5-Hydroxytryptamine (serotonin) receptor 3a (Htr3a) and Endothelin receptor type B (Ednrb) in the hypothalamus, and increased the activity of superoxide dismutase in the hypothalamus, liver, and red blood cells. These findings indicate that EA mediates its effects through changes in cellular activity, gene expression, and enzymatic activity in multiple remote tissues. The sum of these alterations may explain the beneficial effects of EA.

The Development of a Non-Linear Finite Element Model for Ductile Fracture Analysis - For Mini-Computer - (연성파괴 해석을 위한 비선형 유한요소 모델의 개발 -소형 컴퓨터를 위한 -)

  • 정세희;조규종
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.10 no.1
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    • pp.25-33
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    • 1986
  • In this paper, the frontal method based elastic-plastic F.E.M. program for mini-computer was developed. Since, the executable source program size was restricted by the system core memory size on the mini-computer, the active variables were memorized by the element base and the nonactive varables were memorized to the external disc file. The active variables of the finally developed program were reduced enough to execute about 1,000 freedom finite element on the mini-computer on which available variables were restricted as 32,767 integers. A modified CT fracture test specimen was examined to test the developed program. The calculated results were compared with experimental results concerning on the crack tip plastic deformation zone. Recrystallization technique was adopted to visualize the intensive plastic deformation regions. The Von-Mises criterion based calculation results were well agreed with the experimental results in the intensive plastic region which was over than 2% offset strain. The F.E.M. results using the developed program were well agreed with the theoritical plastic boundary which was calculated by the stress intensity factor as r$_{p}$=(K$_{1}$$^{2}$/2.pi..sigma.$_{y}$$^{2}$).f(.theta.).).).

An Effect of Surface Dashpot for KC-1 Basic Insulation System Under Sloshing Loads (슬로싱 하중을 받는 KC-1 단열시스템의 표면 완충 효과)

  • Jin, Kyo Kook;Yoon, Ihn Soo;Yang, Young Chul
    • Transactions of the KSME C: Technology and Education
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    • v.3 no.3
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    • pp.193-199
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    • 2015
  • Sloshing of LNG cargo can cause high impact loads on the supporting and containing structures. This is particularly critical for membrane-type tanks since these will have flat surfaces and corner regions which can lead to increased peak pressures for sloshing impacts. The membrane-type containment system is much more flexible compared to the steel hull structure. As a result, fluid-structure interaction plays an important role in the structural analysis of the containment system under sloshing load. This study is based on the direct calculation method of applying sloshing loads to the KC-1 basic insulation system using finite element analysis. The structural analysis of KC-1 basic insulation system considers the dashpot as fluid-structure interaction between liquid cargo and the LNG containment system. The maximum stress of the polyurethane form for KC-1 insulation system is 1.5 times lower than one without dashpot.

Numerical modeling of brittle failure of the overstressed rock mass around deep tunnel (심부 터널 주변 과응력 암반의 취성파괴 수치모델링)

  • Lee, Kun-Chai;Moon, Hyun-Koo
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.18 no.5
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    • pp.469-485
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    • 2016
  • The failure of rock mass around deep tunnel, different from shallow tunnel largely affected by discontinuities, is dominated by magnitudes and directions of stresses, and the failures dominated by stresses can be divided into ductile and brittle features according to the conditions of stresses and the characteristics of rock mass. It is important to know the range and the depth of the V-shaped notch type failure resulted from the brittle failure, such as spalling, slabbing and rock burst, because they are the main factors for the design of excavation and support of deep tunnels. The main features of brittle failure are that it consists of cohesion loss and friction mobilization according to the stress condition, and is progressive. In this paper, a three-dimensional numerical model has been developed in order to simulate the brittle behavior of rock mass around deep tunnel by introducing the bi-linear failure envelope cut off, elastic-elastoplastic coupling and gradual spread of elastoplastic regions. By performing a series of numerical analyses, it is shown that the depths of failure estimated by this model coincide with an empirical relation from a case study.

Spatial and Temporal Epidemiological Assessment of Breast Cancer Incidence and Mortality in Kazakhstan, 1999-2013

  • Beysebayev, Eldar;Bilyalova, Zarina;Kozhakeeva, Lyazzat;Baissalbayeva, Ainur;Abiltayeva, Aizhan
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.15
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    • pp.6795-6798
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    • 2015
  • Breast cancer incidence and mortality in Kazakhstan are considered to be increasing but exact statistics have hitherto been lacking. The present study was therefore undertaken to retrospectively assess data for the whole country, accessed from the central registration office, for the period 1999-2013. Age standardized data for incidence and mortality were generated and compared across age groups. It was determined that during the studied period 45,891 new cases of breast cancer were registered and 20,122 women died of this pathology. Average breast cancer incidence and mortality were $37.9{\pm}1.10/10^5$ and $16.7{\pm}0.20/10^5$ respectively, and the overall ratio of mortality/incidence (M/I) was 0.44. Incidence tended to increase (T = + 2.3%), and mortality to decrease (T of =-0.3%). Peaks of incidence and mortality were noted in those aged 60-74 years and 75-84, respectively. Particularly high incidences were established in large cities of Kazakhstan, Astana ($46.8{\pm}1.80/10^5$) and Almaty ($49.7{\pm}1.30/10^5$), and high mortality was observed in the Pavlodar region ($17.9{\pm}0.60/10^5$) and Almaty city ($20.1{\pm}0.40/10^5$). Considerable variation in the mortality/incidence ratio was noted, suggesting the need for more stress on access to screening and clinical care in some regions of the country.

Healthy Life-Style Promoting Behaviour in Turkish Women Aged 18-64

  • Sonmezer, Hacer;Cetinkaya, Fevziye;Nacar, Melis
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.4
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    • pp.1241-1245
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    • 2012
  • Aim: In this study we aimed to investigate the healthy life-style behaviour of Turkish women and establish influencing features. Methods: This descriptive study performed by a questionnaire method was conducted in a primary health care centre, in an urban region in Kayseri, Turkey. Every midwife region belonging to the health care centre was accepted as a cluster, and a sample of 450 women between ages 18-64, was gathered from 9 midwife regions. The Health Promotion Life-style Profile (HPLP) was applied to evaluated the healthy lifestyle behaviour of 421 women that could be reached. T test, Tukey HSD with ANOVA, and chi square tests were used for analysis. Results: The mean total HPLP was $126.8{\pm}19.2$ (interpersonal support subscale, $74.3{\pm}14.1$; nutrition subscale, $73.6{\pm}12.6$; self-actualisation subscale, $70.6{\pm}11.9$; stress management subscale, $63.4{\pm}13.0$; health responsibility subscale, $61.2{\pm}13.2$; and exercise subscale, $47.1{\pm}15.0$). There was no statistically significant variation when evaluated for age, marital state, family type, economic status, and perception of self-health, smoking, and BMI. HPLP was high in people with an education of primary school and lower in university graduates, in people who lived mostly in the city centre and in individuals with chronic diseases. In conclusion, it was established that the health promoting behaviour in Turkish women is, in general, at a medium level, and women should be enlightened in order to develop and increase the habit of health preservation and promotion.

The Summer Benthic Environmental Conditions Assessed by the Functional Groups of Macrobenthic Fauna in Gwangyang Bay, Southern Coast of Korea (저서동물에 의한 여름철 광양만의 저서환경 상태파악)

  • Choi, Jin-Woo;Hyun, Sang-Min;Chang, Man
    • Korean Journal of Environmental Biology
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    • v.21 no.2
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    • pp.101-113
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    • 2003
  • The spatial distributional pattern of macrobenthic fauna was investigated to assess the summer benthic environmental conditions in Gwangyang Bay, the southern coast of Korea. The macrobenthic faunal community from 38 sites in Gwangyang Bay comprised 154 species and showed an overall mean density of 1,280 individuals $m^{-2}$. Polychaetes were the most important component of the macrofaunal community in species richness, abundance and biomass. The dominant species in abundance were polychaetes like Tharyx sp. (44.8%), Lumbrineris longifolia (14.0%), Heteromastus filiformis (3.6%), a mussel Mytilus edulis, and an amphipod crustacean Corophium sinense. The abundance and biomass in the western part of the bay were lower than those in the channel regions and mouth of the bay. The community indices showed the same trend in the spatial distribution with the abundance and species richness. All macrobenthic faunas were assigned into a specific functional group according to their ecological responses to the environmental stress. The benthic community health based on the Benthic Pollution Index (BPI) or Biotic Coefficient (BC) seemed to be in the normal to unbalanced er transitional condition, indicated by the dominance of small polychaete worms like Tharyx sp. in the mouth part of the bay.

Exposure assessment of musculoskeletal disorder risk factors in non routinized work: An application of PATH-KOSHA observational tool to hospital workers (비정형작업 근골격계질환 위험요인의 노출평가: 일부 병원근로자에 대한 PATH-KOSHA 관찰도구 적용사례)

  • Park, Jung-Keun;Han, Young-Sun
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.19 no.4
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    • pp.412-422
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    • 2009
  • This study was conducted to assess exposure to musculoskeletal disorder(MSD) risk factors in hospital personnel who performed non-routinized work tasks. A tool ("PATH-KOSHA" version) was newly revised from PATH(Posture, Activity, Tools and Handling) method and uploaded into a personal digital assistant(PDA). The version was used, on a basis of direct-observation, to collect PATH data at the 2 hospital settings in different regions. Job analysis was performed to get various information (e.g., work and rest time, task type) as well. The data collected were visually checked for data cleaning and stored for future data analysis. A total of 1,992 PATH observations were made for 37 hospital workers. Exposure levels varied across 18 items of the MSD risk factors. The highest percent time spent on non-neutral postures was 53% for wrist deviation, followed by 47%(pinch grip), 35%(trunk posture), 23%(neck posture), and 20%(shoulder/arm posture). The highest percent time spent among hand activity level(HAL) variables was 55% for HAL-cat2 (HAL: 3.3 - <6.7). The percent time of items with respect to both loads with more than 5kg and contact stress was less than 4%. Vibration was not exposed in the study workers. Different aspects were discussed for findings. The study results showed that wrist deviation was highest in percent time spent on awkward posture while HAL-cat2 was highest in hand repetition. The study suggests that distal upper extremity posture and HAL should be primarily addressed and controlled in non-routinized work including the hospital settings.

Development of Acoustic Emission Training Technique and Localization Method using Q-switched Laser and Multiple Sensors/Single Channel Acquisition (Q-switched 레이저와 다중센서/단일채널 신호수집을 이용한 복합재 구조 음향방출 트레이닝 및 위치탐지 기법 개발)

  • Choi, Yunshil;Lee, Jung-Ryul
    • Composites Research
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    • v.31 no.4
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    • pp.145-150
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    • 2018
  • Various structural health monitoring (SHM) systems have been suggested for aerospace industry in order to increase its life-cycle and economic efficiency. In the case of aircraft structure madden with metal, a major concern was hot spots, such as notches, bolts holes, and where corrosion or stress concentration occurs due to moisture or salinity. However, with the increasing use of composites in the aerospace industry, further advanced SHM systems have been being required to be applied to composite structures, which have much complex damage mechanism. In this paper, a method of acoustic emission localization for composite structures using Q-switched laser and multiple Amplifier-integrated PZTs have been proposed. The presented technique aims at localization of the AE with an error in distance of less than 10 mm. Acoustic emission simulation and the localization attempt were conducted in the composite structure to validate the suggested method. Localization results, which are coordinates of detected regions, grid plots and color intensity map have been presented together to show reliability of the method.