• Title/Summary/Keyword: stress sensitivity

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Water Physiology of Panax ginseng. 1. Habitat observation. cultural experience, weather factors and characteristics of root and leaf (인삼의 수분생리 1. 자생지관찰.재배 경험.기상요인과 근 및 엽의 특성)

  • Park, Hoon
    • Journal of Ginseng Research
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    • v.4 no.2
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    • pp.197-221
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    • 1980
  • Habitat observation, cultural experience of old and present plantation, weather factors in relation to crop stand and water physiology of root and leaf were reviewed. According to habitat observation ginseng plants love water but plate wit talus well grow at drained place with high moisture content in air and soil while ginseng plants were not found in dry or wet place. According to cultivation experience ginseng plants require abundant water in nursery and main field but most old planters believe that ginseng plaints are draught-loving thus require little water. The experience that rain especially in summer i.e unfavorable might be due to mechanical damage of leaves arid leaf disease infection, or severe leaf fall which is caused by high air temperature and coinsided with rain. According to crop stand observation in relation to weather factors abunsant water increased each root weight but decreased total yield indicating tile increase of missing root rate. Rain in summer was unfavorable too. Though rain in June was favorable for high yield general experience that cloudy day and rain were unfavorable might be due to low light intensity under shade. Present leading planters also do loot consider the importance of water in main field. Water content is higher in top than in root and highest in central portion of root and in stem of top. For seedling the heavier the weight of root is tile higher the water content while it reveries from two years old. Water potential of intact root appeared to be -2.89 bar suggesting high sensitivity to water environment. Under water stress water content severly decreased only in leaf. Water content of leaf appeared to be 78% for optimum, below 72% for functional damage and 68% for perm anent wilting. Transpiration or curs Principally through stomata in lower side of leaf thus contribution of upper side transpiration decreased with the increase of intensity. Transpiration is greater in the leaves grown under high light intensity. Thus water content is lower with high light inte nsity under field condition indicating that light is probable cause of water stress in field. Transpiration reached maximum at 10K1ut The decrease of transpiration at higher temperature seems to be due to the decrease of stomata aperture caused by water stress. Severe decrease of photosynthesis under water stress seems to be principally due to functional damage which is not caused by high temperature and Partly due to poor CO2 supply. Water potential of leaf appeared to be -16.8 bar suggesting weakness in draught tolerance. Ginseng leaves absorb water under high humidity. Water free space of leaf disc is %mailer than that of soybean leaf and water uptake appears to be more than two steps.

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The Clinical Study On Posttraumatic Stress Disorder Patients due to a Serise of Traffic Accidents;SCL-90-R (교통사고 후 외상성 스트레스 장애 후유증 환자에 대한 고찰;SCL-90-R 중심으로)

  • Ko, Kyoung-Mo;Choi, Sung-Hun;Kim, Jae-Su;Park, Seo-Young;Lee, Yun-Kyu;Lee, Yoon-Kyoung;Lee, Kyung-Min;Lee, Bong-Hyo;Lim, Seong-Chul;Choi, Hong-Sik;Lee, Eun-Kyung;Jung, Tae-Young;Seo, Jung-Chul
    • Journal of Acupuncture Research
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    • v.24 no.6
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    • pp.63-68
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    • 2007
  • Objectives : The purpose of this study was designed to estimate the effects of Oriental medical treatment on posttraumatic stress disorder patient due to a series of traffic accidents by using SCL-90-R. Methods : We studied 20 patients who were admitted to Daegu Haany University Oriental Hospital from October2006 to May 2007. Results : 4 symptoms of SCL-90-R, somatization, obsessive-compulsive, depression and anxiety were significantly different when comparing after-treatment with before-treatment. But, 5 symptoms of SCL-90-R, interpersonal sensitivity, hostility, phobic anxiety, paranoid ideation and psychoticism showed no difference between after-treatment with, before-treatment measurements. The total impact or SCL-90-R was significant comparing after-treatment with before-treatment measurements. Conclusions : We concluded that there was a significant effectof Oriental medical treatment on posttraumatic stress disorder patients caused by a seriesof traffic accident. However, the findings of this study need to be confirmed in more patients with further studies.

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The Clinical Efficacy of Lung to Heart Ratio in 1 Hour Delayed Tc-99m Tetrofosmin Gated Myocardial SPECT after Adenosine Stress: Comparison with Coronary Angiography (아데노신 부하 1시간 지연 Tc-99m tetrofosmin 게이트 심근 SPECT에서 관찰되는 심장 대 폐 섭취비의 임상적 유용성: 관상동맥조영술과의 비교)

  • Won, Kyoung-Sook
    • Nuclear Medicine and Molecular Imaging
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    • v.42 no.5
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    • pp.362-368
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    • 2008
  • Purpose: It is well known that lung to heart ratio (LHR) is one of the high risk findings in TI- 201 myocardial perfusion SPECT. We evaluated the clinical efficacy of LHR to identify severe coronary artery disease in adenosine stress Tc-99m tetrofosmin gated myocardial perfusion SPECT (gSPECT). Materials and Methods: The study population was 157 patients who underwent both adenosine stress Tc-99m gSPECT and coronary angiography (CAG) within one month. According to the results of CAG and gSPECT LHR and the incidence of increased LHR were compared. Results: Among 53 patients with normal coronary arteries increased LHR was found in 2 patients (3.8%) and 0 in 44 patients (0%) with one vessel disease, 2 in 27 with two vessel disease (7.4%) and 8 in 33 with triple vessel disease (24.2%). Significant differences were found in LHR between subgroups of summed stress score, summed rest score and LV ejection fraction (LVEF). There were weak negative correlation between LHR and LVEF and weak positive correlation between LHR and SSS and SRS. Conclusion: Increased LHR had higher incidence in patients with triple vessel disease, severe LV dysfunction and/or extensive perfusion defect than those of normal group. Although its sensitivity might be low to identify severe coronary artery disease, LHR could be helpful in abnormal myocardial perfusion SPECT to stratify risk and prognosis.

Analysis of Temperature Characteristics on Accelerometer using SOI Structure (SOI 구조 가속도센서의 온도 특성 해석)

  • Son, Mi-Jung;Seo, Hee-Don
    • Journal of Sensor Science and Technology
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    • v.9 no.1
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    • pp.1-8
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    • 2000
  • One of today's very critical and sensitive accurate accelerometer which can be used higher temperature than $200^{\circ}C$ and corrosive environment, is particularly demanded for automotive engine. Because silicon is a material of large temperature dependent coefficient, and the piezoresistors are isolated with p-n junctions, and its leakage current increase with temperature, the performance of the silicon accelerometer degrades especially after $150^{\circ}C$. In this paper, The temperature characteristic of a accelerometer using silicon on insulator (SOI) structure is studied theoretically, and compared with experimental results. The temperature coefficients of sensitivity and offset voltage (TCS and TCO) are related to some factors such as thermal residual stress, and are expressed numerically. Thermal stress analysis of the accelerometer has also been carried out with the finite-element method(FEM) simulation program ANSYS. TCS of this accelerometer can be reduced to control the impurity concentration of piezoresistors, and TCO is related to factors such as process variation and thermal residual stress on the piezoresistors. In real packaging, The avarage thermal residual stress in the center support structure was estimated at around $3.7{\times}10^4Nm^{-2}^{\circ}C^{-1}$ at sensing resistor. The simulated ${\gamma}_{pT}$ of the center support structure was smaller than one-tenth as compared with that of the surrounding support structure.

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Identification of Heat Stress-related Proteins and Low Molecular Weight HSP Expressed in Stem Tissues of Rice Plants by Proteomic Analysis (프로테옴 분석법에 의한 벼 줄기에서 발현하는 고온 스트레스 관련 단백질 및 저분자량 Heat Shock Protein의 분리 동정)

  • Lee, Dong-Gi;Kim, Kyung-Hee;Kim, Yong-Gu;Lee, Ki-Won;Lee, Sang-Hoon;Lee, Byung-Hyun
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.31 no.2
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    • pp.99-106
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    • 2011
  • In order to investigate rice stem proteome in response to heat stress, rice plants were subjected to heat treatment at 42$^{\circ}C$ and total soluble proteins were extracted from stem tissues, and were fractionated with 15% PEG (poly ethylene glycol) and separated by two-dimensional polyacrylamide gel electrophoresis (2-DE). After staining of 2-DE gels, 46 of differentially expressed proteins were extracted, digested by trypsin, and subjected to matrix assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) analysis. Proteins were identified through database search by using peptide mass fingerprints. Among them, 10 proteins were successfully identified. Seven proteins were up- and 3 proteins were down-regulated, respectively. These proteins are involved in energy and metabolism, redox homeostasis, and mitochondrial small heat shock proteins. The identification of some novel proteins in the heat stress response provides new insights that can lead to a better understanding of the molecular basis of heat-sensitivity in plants, and also useful to molecular breeding of thermotolerant forage crops.

Growth, Photosynthesis and Rubisco Activity of Resistant Hybrid Poplar(Populus trichocarpa×P. deltoides) to Ozone Exposure: A Link with Compensatory Strategy (오존에 노출(露出)시켰을 때 저항성(抵抗性)을 갖는 잡종(雜種)포플러의 생장(生長), 광합성(光合成) 그리고 Rubisco 활성(活性)에 관(關)한 연구(硏究): 수목(樹木)의 보상전략(補償戰略)과의 관계(關係))

  • Woo, Su-Young
    • Journal of Korean Society of Forest Science
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    • v.86 no.1
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    • pp.80-86
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    • 1997
  • The objective of this study was to investigate how resistant poplar hybrid makes compensation to ozone stress. Growth, net assimilation rate and initial Rubisco activity were investigated. This study elucidates the physiological mechanisms associated with ozone sensitivity and resistance in 3 selected $F_2$ hybrids, a family originating from a cross between Populus trichocarpa${\times}$P. deltoides. Open-top chambers were used. Ozone concentrations varied from 90 to 115 ppb for 126 days, 6 to 9 hours in a day. This study tested the hypothesis that resistant poplar hybrid maintains the biomass production to ozone exposure via increased net assimilation rate and Rubisco activity. Growth, biomass, net assimilation rate and initial Rubisco activity were generally reduced by ozone treatment. In the tree parts, root under ozone stress was the most sensitive part. Reduced allocation of photosynthates to root growth might be due to increased respiratory demands for maintenance and repair of aboveground tissue damaged by ozone stress. Maintenance or increases remaining leaves in photosynthetic rates and Rubisco activity in resistant clone in response to ozone treatment were the results of biological compensation to ozone stress.

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A Study for the Adaptation of Simulation of Uniaxial Compressive Strength Test for Concrete in 3-Dimensional Particle Bonded Model (3차원 입자 결합 모델에서 콘크리트의 일축압축실험 모사 적용성 연구)

  • Lee, Hee-Kwang;Jeon, Seok-Won
    • Journal of the Korea Concrete Institute
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    • v.20 no.2
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    • pp.147-156
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    • 2008
  • In an uniaxial compressive test of a concrete standard specimen (150$\times$300 mm) the crack initiation and extension with the stress increase are the major reason of the failure, which is similar to the breakage of the particle bonding in the simulation by using particle bonded model, especially particle flow code in 3 dimensions (PFC3D) developed by Itasca Consulting Group Inc. That is the main motive to study the possibility of an uniaxial compressive strength test simulation. It is important to investigate the relationship between the micro-parameters and the macro-properties because the 3-dimensional particle bonded model uses the spherical particles to analyze the physical phenomena. Contact bonded model used herein has eight micro-parameters and there are five macro-properties; Young's modulus, Poisson's ratio, uniaxial compressive strength and the crack initiation stress and the ratio concerning the crack propagation with the stress. To simulate the compressive test we made quantitative relationships between the micro-parameters and the macro-properties by using the fractional factorial design and various sensitivity analyses including regression analysis, which result in the good agreement with the previous studies. Also, the stress-stain curve and the crack distribution over the specimen given by PFC3D showed the mechanical behavior of the concrete standard specimen under the uniaxial compression. It is concluded that the particle bonded model can be a good tool for the analyzing the mechanical behavior of concrete under the uniaxial compressive load.

Comparison between $180^{\circ}$ and $360^{\circ}$ Data Collection in $^{99m}Tc-MIBI$ Myocardial SPECT ($^{99m}Tc-MIBI$ 심근 SPECT에서 180도와 360도 데이터 집적의 비교)

  • Kang, Keon-Wook;Lee, Dong-Soo;Kwark, Cheol-Eun;Hyun, In-Young;Chung, June-Key;Lee, Myung-Chul;Koh, Chang-Soon
    • The Korean Journal of Nuclear Medicine
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    • v.29 no.4
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    • pp.478-483
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    • 1995
  • We compared the influences of reconstruction methods using $180^{\circ}$ or $360^{\circ}$ data upon contrasts and discriminating capability and diagnostic accuracy in $^{99m}Tc-MIBI$ stress/rest myocardial SPECT. We reviewed SPECT images reconstructed only with $180^{\circ}$ projection data or with $360^{\circ}$ data in 18 patients and in 11 normal subjects. To compare counts of surface structures and deep structures, we measured ape# posterior wall ratios in 11 normal subjects. To compare the contrasts of images, we measured apex/ventricle ratios. To compare contrasts between normal and diseased myocardial segments, we measured count ratios of defect and normal segments in 4 patients who had single coronary artery diseases. To compare diagnostic accuracy, we scored SPECT images made with $180^{\circ}$ and $360^{\circ}$ data segmentally. Sensitivity and specificity for the diagnosis of coronary artery disease and for the revelation of diseased arteries with both $180^{\circ}$ and $360^{\circ}$ SPECT images. If involved coronary arteries had more narrowing than 50% In coronary angiogram, we considered them as diseased arteries Apex/posterior wall ratios were not different significantly in normal subjects. Apex/ ventricle ratios in normal subjects were different significantly between $180^{\circ}$ and $360^{\circ}$ SPECT images. Defect/normal ratios were different significantly between $180^{\circ}$ and $360^{\circ}$ SPECT images in single vessel disease patients. The overall diagnostic accurracy was the same between $180^{\circ}$ and $360^{\circ}$ data collection. Sensitivity was 94% and specificity was 91% for both types of data collection in this sample population. Sensitivity and specificity of each coronary artery territory were not significantly different between the images made with $180^{\circ}$ and $360^{\circ}$ data. The images made with $180^{\circ}$ data had better contrast between ventricle and myocardium and between hypoperfused and normal myocardium, though no difference was found between the ratios of the myocardial counts of surface and deep structures. However, diagnostic sensitivities of diseased artery territories were not different significantly and so were overall diagnostic accuracy between both methods of making images with $180^{\circ}$ and $360^{\circ}$ data.

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Dual-Isotope SPECT Imaging with Thallium-201 and Technetium-99m MIBI in Detecting Coronary Artery Disease (관상동맥질환 진단에서 Thallium-201과 Technetium-99m MIBI를 이용한 Dual-Isotope SPECT 영상)

  • Lee, Gyu-Gwang;Cho, Ihn-Ho;Lee, Hyoung-Woo;Park, Jong-Sun;Won, Kyu-Chang;Sin, Dong-Gu;Kim, Young-Jo;Shim, Bong-Sup
    • Journal of Yeungnam Medical Science
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    • v.16 no.1
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    • pp.101-107
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    • 1999
  • We evaluated the results of sequential SPECT dual-isotope imaging with Tl-201 and Tc-99m MIBI in 24 patients. all of whom also had coronary angiography within the past one month. Coronary angiography showed that 12 patients had no CAD, 4 patients had one-vessel CAD, 7 patients had two-vessel CAD and 1 patient had three-vessel CAD. Serial studies of resting Tl-201 and dipyridamole stress Tc-99m MIBI were completed within 2 hours. When more than 50% of coronary artery narrowing was considered significant, the overall sensitivity and specificity of CAD detection were 91.7%. The sensitivity of CAD detection in patients with one-vessel and multi-vessel diseases was 75% and 100%. respectively. Therefore, sequential dual-isotope SPECT demonstrated high sensitivity and specificity for CAD detection. In conclusion, sequential dual-isotope imaging is feasible and can be completed in a short time and may therefore enhance laboratory throughput and patient convenience.

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Mechanical Properties of High Stressed Silicon Nitride Beam Measured by Quasi-static and Dynamic Techniques

  • Shin, Dong Hoon;Kim, Hakseong;McAllister, Kirstie;Lee, Sangik;Kang, Il-Suk;Park, Bae Ho;Campbell, Eleanor E.B.;Lee, Sang Wook
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.361.1-361.1
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    • 2016
  • Due to their high sensitivity, fast response, small energy consumption and ease of integration, nanoelectromechanical systems (NEMS) have attracted much interest in various applications such as high speed memory devices, energy harvesting devices, frequency tunable RF receivers, and ultra sensitive mass sensors. Since the device performance of NEMS is closely related with the mechanical and flexural properties of the material in NEMS, analysis of the mechanical and flexural properties such as intrinsic tensile stress and Young's modulus is a crucial factor for designing the NEMS structures. In the present work, the intrinsic mechanical properties of highly stressed silicon nitride (SiN) beams are investigated as a function of the beam length using two different techniques: (i) dynamic flexural measurement using optical interferometry and (ii) quasi-static flexural measurement using atomic force microscopy. The reliability of the results is analysed by comparing the results from the two different measurement techniques. In addition, the mass density, Young's modulus and internal stress of the SiN beams are estimated by combining the techniques, and the prospect of SiN based NEMS for application in high sensitive mass sensors is discussed.

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