• Title/Summary/Keyword: light stress

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An Inquiry to the Causal Perceptions & Emotions of Rheumatoid Arthritis Patients (류마티스 관절염 환자의 원인지각에 대한 연구 - Q방법론적 접근 -)

  • Kim, Boon-Han;Jung, Yun
    • Journal of muscle and joint health
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    • v.6 no.2
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    • pp.226-241
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    • 1999
  • This study was undertaken to find out the causal perception of rheumatoid arthritis patients, and to understand the typology. The Q-population consisted of 236 statements of causal perception were collected. Thirty eight Q-samples of causal perception were selected. The P-sample for this study were made up of 28 first visiting female rheumatoid arthritis patients from a rheumatoid arthritis specialty hospital. Each respondent responded Q-set of causal perception according to 9-point scale. The result of Q-sorting were coded and analyzed using QUANL PC program. 1) Typological Observation on Causal Perception (1) Physical Fatigue Type : Type 1 perceived that the illness occurred due to excessive work requiring physical labor or strain that had occurred from not resting after excessive physical labor, therefore, thinking the origin of the illness was from physical strain. (2) Physical origin Type : Type 2 perceived that the major cause for the illness is not only excessive physical labour but also fecundity and old age. (3) Causality to Environment Type : Type 3 perceived that rheumatoid arthritis occurred from injury to the joints or bad and humid weather. (4) Conscience of Guilty Type : Type 4 consisted of people with guilty conscience for lack of religious commitment. They perceived that the illness was a punishment from God for not praying or because of bad luck. (5) Rationally Perceiving Type : People who belong in type 5 perceived the cause of illness in light of scientific facts such as genetics, unbalanced diet or lack of exercise. (6) Psychological Stress Type : People who belong in type 6 believed that excessive stress was the cause of the illness. 2) Emotions of Rheumatoid arthritis patients Rheumatoid arthritis patients' positive emotions included determination, courage, coping, acceptance, hope, and adoption ; and their negative emotions were prostration, worry, stupor, conflicts, grievance, giving-up, resignation, depression, loss, solitariness, fear, anxiety, avoidance, anger and loneliness. Rheumatoid arthritis patients experience different level of emotions from their suffering experience from the severe pains. Rheumatoid arthritis patients also experience negative emotions when they could not perform self-care and lose their self-esteem from painful suffering ; however, they regain positive emotions when they recover from pain with the use of drugs, physical therapy or exercise. Their emotional states are closely connected to level of and presence of pain.

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Photochemical Index Analysis on Different Shading Level of Garden Plants (정원 식물의 차광 조건별 광화학적 생리지표 해석)

  • Kang, Hong Gyu;Kim, Tae Seong;Park, So Hyun;Kim, Tae Wan;Yoo, Sung Yung
    • Korean Journal of Environmental Biology
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    • v.34 no.4
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    • pp.264-271
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    • 2016
  • The objective of this study was to determine the growth and light utilization efficiency of garden plants in shade area through chlorophyll fluorescence reaction analysis. Ten garden plants was grown for 75 days under 50% and 80% shading conditions. Under shading, $ET2_O/RC$, the fluorescence parameter related to electron-transport in photosystem II, was effectively enhanced. However, the electron transport flux until PSI acceptors per reaction center ($RE1_O/RC$) was reduced. These changes in photochemical parameters evoked a decrease in performance index (PI) and driving force (DF) of electron transport flux. In addition, some photochemical parameters such as $F_V$, $FV/F_O$, $RE1_O/RC$, $ET2_O/RC$, $PI_{TOTAL\;ABS}$, and $DF_{TOTAL\;ABS}$ were found to be important for shade tolerance. Three species (Pachysandra terminalis Siebold & Zucc, Physostegia virginiana L., and Carex maculata Bott) were found to be shade tolerant. Based on these results, shading factor index (SFI) deduced from photochemical parameters is useful for evaluating of shading stress of garden plants.

Glycosyl flavones from Humulus japonicus suppress MMP-1 production via decreasing oxidative stress in UVB irradiated human dermal fibroblasts

  • Nam, Eui Jeong;Yoo, Gyhye;Lee, Joo Young;Kim, Myungsuk;Jhin, Changho;Son, Yang-Ju;Kim, Sun Young;Jung, Sang Hoon;Nho, Chu Won
    • BMB Reports
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    • v.53 no.7
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    • pp.379-384
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    • 2020
  • Exposure to Ultraviolet (UV) light induces photoaging of skin, leading to wrinkles and sunburn. The perennial herb Humulus japonicus, widely distributed in Asia, is known to have anti-inflammatory, antimicrobial, and antioxidant effects. However, the physiological activities of isolated compounds from H. japonicus have rarely been investigated. This study focused on the isolation of active compounds from H. japonicus and the evaluation of their effects on photoaging in UVB-irradiated human fibroblast (Hs68) cells. When the extract and four fractions of H. japonicus were treated respectively in UVB-irradiated Hs68 cells to investigate anti-photoaging effects, the ethyl acetate (EtOAc) fraction showed the strongest inhibitory effect on MMP1 secretion. From EtOAc fraction, we isolated luteolin-8-C-glucoside (1), apigenin-8-C-glucoside (2), and luteolin-7-O-glucoside (3). These compounds suppressed UVB-induced MMP-1 production by inhibiting the phosphorylation of the mitogen-activated protein kinases (MAPKs) and activator protein-1 (AP-1). When the antioxidant activity of the compounds were estimated by conducting western blot, calculating the bond dissociation energies of the O-H bond (BDE) at different grade, and measuring radical scavenging activity, we found luteolin-8-C-glucoside (1) showed the strongest activity on the suppression of UVB-induced photoaging. These results demonstrate the inhibitory effect of three flavone glycosides derived from H. japonicus on MMP-1 production, MAPK and AP-1 signaling, and oxidative stress; this could prove useful in suppressing UVB induced photoaging.

Functional Mechanism of Calmodulin for Cellular Responses in Plants (식물의 세포반응에 대한 칼모듈린의 functional 작용기작 연구)

  • Cho, Eun-Kyung;Choi, Young-Ju
    • Journal of Life Science
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    • v.19 no.1
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    • pp.129-137
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    • 2009
  • Calcium ($Ca^{2+}$) plays pivotal roles as an intracellular second messenger in response to a variety of stimuli, including light, abiotic. and biotic stresses and hormones. $Ca^{2+}$ sensor is $Ca^{2+}$-binding protein known to function in transducing signals by activating specific targets and pathways. Among $Ca^{2+}$-binding proteins, calmodulin (CaM) has been well reported to regulate the activity of down-stream target proteins in plants and animals. Especially plants possess multiple CaM genes and many CaM target proteins, including unique protein kinases and transcription factors. Thus, plants are possible to perceive different signals from their surroundings and adapt to the changing environment. However, the function of most of CaM or CaM-related proteins have been remained uncharacterized and unknown. Hence, a better understanding of the function of these proteins will help in deciphering their roles in plant growth, development and response to environmental stimuli. This review focuses on $Ca^{2+}$-CaM messenger system, CaM-associated proteins and their role in responses to external stimuli of both abiotic and biotic stresses in plants.

Effects of the 461-nm LED Light and Combination with Acid Stress Treatment on Staphylococcus aureus and Escherichia coli (461-nm LED조사와 산의 병행처리가 Staphylococcus aureus와 Escherichia coli 생육에 미치는 영향)

  • Kim, Se-Hun;Bang, Woo-Suk
    • Korean Journal of Food Science and Technology
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    • v.45 no.4
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    • pp.526-529
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    • 2013
  • This study was conducted to evaluate the disinfection effects of Staphylococcus aureus, and Escherichia coli treated with 461-nm LED and pH 5 at $15^{\circ}C$ for 10 h. S. aureus strains were decreased by about 4 log CFU/mL after 461-nm LED irradiation treatment alone for 10 h. E. coli strains were inactivated by irradiation. However, when microorganisms were subjected to a combined treatment of 461-nm LED and pH 5, both strains were inactivated by irradiation for 7 h. The highest D-value was 5.05 h for S. aureus ATCC 27664 and the lowest D-value was 1.39 h for E.coli O157: H7 ATCC 35150 (p<0.05) with 461-nm LED irradiation. For the combined treatment (461-nm LED and pH 5), the highest D-value was 1.58 h for S. aureus ATCC 19095, whereas the lowest D-value was 0.83 h for S. aureus ATCC 27664 (p<0.05). These data showed that bactericidal effects of a combination of pH 5 with 461-nm LED irradiation were enhanced compared to 461-nm LED irradiation alone.

SLUMPING RESISTANCE AND VISCOELASTICITY OF RESIN COMPOSITE PASTES (치과용 복합레진의 중합 전 slumping resistance와 점탄성)

  • Suh, Hee-Yeon;Lee, In-Bog
    • Proceedings of the KACD Conference
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    • 2008.05a
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    • pp.235-245
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    • 2008
  • The aim of this study was to develop a method for measuring the slumping resistance of resin composites and to relate it to the rheological characteristics. Five commercial hybrid composites (Z100. Z250. DenFil, Tetric Ceram. ClearFil) and a nanofill composite (Z350) were used to make disc-shaped specimens of 2 mm thickness. An aluminum mold with square shaped cutting surface was pressed onto the composite discs to make standardized imprints. The imprints were light-cured either immediately (non-slumped) or after waiting for 3 minutes at $25^{\circ}C$ (slumped). White stone replicas were made and then scanned for topography using a laser 3-D profilometer. Slumping resistance index (SRI) was defined as the ratio of the groove depth of the slumped specimen to that of the non-slumped specimen. The pre-cure viscoelasticity of each composite was evaluated by an oscillatory shear test and normal stress was measured by a squeeze test using a rheometer. Flow test was also performed using a flow tester. Correlation analysis was performed to investigate the relationship between the viscoelastic properties and the SRI. SRI varied between the six materials (Z100 < DenFil < Z250 < ClearFil < Tetric Ceram < Z350). The SRI was strongly correlated with the viscous (loss) shear modulus G' but not with the loss tangent. Also. slumping resistance was more closely related to the resistance to shear flow than to the normal stress. Slumping tendency could be quantified using the imprint method and SRI. The index may be applicable to evaluate the clinical handling characteristics of composites.

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SLUMPING RESISTANCE AND VISCOELASTICITY OF RESIN COMPOSITE PASTES (치과용 복합레진의 중합 전 slumping resistance와 점탄성)

  • Suh, Hee-Yeon;Lee, In-Bog
    • Restorative Dentistry and Endodontics
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    • v.33 no.3
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    • pp.235-245
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    • 2008
  • The aim of this study was to develop a method for measuring the slumping resistance of resin composites and to relate it to the rheological characteristics. Five commercial hybrid composites (Z100, Z250, DenFil, Tetric Ceram, ClearFil) and a nanofill composite (Z350) were used to make disc-shaped specimens of 2 mm thickness. An aluminum mold with square shaped cutting surface was pressed onto the composite discs to make standardized imprints. The imprints were light-cured either immediately (non-slumped) or after waiting for 3 minutes at $25{\circ}C$ (slumped). White stone replicas were made and then scanned for topography using a laser 3-D profilometer. Slumping resistance index (SRI) was defined as the ratio of the groove depth of the slumped specimen to that of the nonslumped specimen. The pre-cure viscoelasticity of each composite was evaluated by an oscillatory shear test and normal stress was measured by a squeeze test using a rheometer. Flow test was also performed using a flow tester. Correlation analysis was performed to investigate the relationship between the viscoelastic properties and the SRI. SRI varied between the six materials (Z100 < DenFil < Z250 < ClearFil < Tetric Ceram < Z350). The SRI was strongly correlated with the viscous (loss) shear modulus G' but not with the loss tangent. Also, slumping resistance was more closely related to the resistance to shear flow than to the normal stress. Slumping tendency could be quantified using the imprint method and SRI. The index may be applicable to evaluate the clinical handling characteristics of composites.

Antioxidative Responses of Transgenic Tobacco Plants Expressing both Superoxide Dismutase and Ascorbate Peroxidase in Chloroplasts to Several Herbicides (Superoxide Dismutase와 Ascorbate Peroxidase가 엽록체내로 동시에 과대발현된 형질전환 담배의 제초제들에 대한 항산화 반응)

  • Kim Jin-Seog;Lee Byung-Hoi;Kwon Suk-Yoon;Kim Yun-Hee;Kim So-Hee;Cho Kwang-Yun
    • Journal of Plant Biotechnology
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    • v.32 no.2
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    • pp.97-103
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    • 2005
  • Antioxidative responses of transgenic tobacco plants expressing both superoxide dismutase (SOD) and ascorbate peroxidase (APX) in chloroplasts was investigated with several herbicides. In greenhouse test, tolerance of SOD/APX-overexpressed tobacco (CA) to photosystem (PS) I inhibitor paraquat was increased by about 40%. However, any response differences between CA and wild type (WT) tobacco was not observed in a treatment with PS II inhibitors (bromoxynil, diuron and bromacil), chlorophyll biosynthesis inhibitor(oxyfluorfen), carotenoid biosynthesis inhibitor (fluridone) and 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase inhibitor (glyphosate). This tendency was also similar in the growth chamber test of low light intensity, using paraquat and diuron. That is, increased antioxidant activity of CA was shown only in paraquat treatment. When paraquat was foliar-treated to 6 to 9-leaf stage plant, the third to fourth placed leaf from shoot tip showed relatively higher antioxidant activity. Ascorbate supplemented to paraquat solution alleviated the phytotoxicity with a similar range in both CA and WT. In conclusion, CA specifically responded to oxidative stress induced by paraquat among tested herbicides in a whole plant assay.

Physiological Evaluation of Transgenic Rice Developed for Drought Tolerance

  • Ghimiren Sita Ram;Park Sang-Kyu;Kang Dong-Jin;Lee In-Jung;Shin Dong-Hyun;Kim Sung-Uk;Kim Kil-Ung
    • Journal of Plant Biotechnology
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    • v.33 no.2
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    • pp.133-137
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    • 2006
  • Evaluation of physiological performance of trehalose-producing transgenic rice line was conducted to investigate drought tolerance at early growth stage. Under artificially induced drought condition of 8% polyethylene glycol 6000, this transgenic rice line had leaf photosynthetic rate of 11.08 uml CO$_2$ $m^{-2}s^{-1}$, leaf transpiration rate of 8.38 mmol $H_2O$ $m^{-2}s^{-1}$ and leaf water potential of -1.12 MPa after 96 hours of treatment. Nakdongbyeo, the parent of this tyansgenic rice line, had photosynthetic rate of 15.42 $\mu$mol CO$_2$ $m^{-2}s^{-1}$, leaf transpiration rate of 8,04 mmol $H_2O$ $m^{-2}s^{-1}$ and leaf water potential of -0.88 MPa. The other variety used in this experiment for comparison, IR 72, showed higher values than both tyansgenic rice line and variety Nakdonbyeo on all three parameters; leaf photosynthetic rate of 20.61 $\mu$mol CO$_2$ $m^{-2}s^{-1}$, leaf transpiration rate of 12.88 mmol $H_2O$ $m^{-2}s^{-1}$, and leaf water potential of -0.82 MPa. So this transgenic rice line did not show superior performance in leaf transpiration rate, leaf photosynthetic rate and leaf water potential compared to variety Nakdongbyeo. This result along with visual observation on leaf rolling and drying during the experimental period indicated poor physiological performance of this transgenic rice line. Further studies on metabolic status of stress-induced trehalose, along with study on physiological response of this transgenic rice line during drought stress would shed more light on overall physiological performance of this transgenic rice line.

Feasibility of Bladder Compression Molded Prepreg as Small Wind Turbine Blade Material (소형 풍력 터빈 블레이드 재료로서 블래더 가압 방식 몰드 성형 프리프레그의 타당성)

  • Yi, Bo-Gun;Seo, Seong-Won;Song, Myung-Ho
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.33 no.2
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    • pp.95-101
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    • 2020
  • The wind turbine blades should be designed to possess a high stiffness and should be fabricated with a light and high strength material because they serve under extreme combination of lift and drag forces, converting kinetic energy of wind into shaft work. The goal of this study is to understand the basic knowledge required to curtail the process time consumed during the construction of small wind turbine blades using carbon fiber reinforced polymer (CFRP) prepeg composites. The configuration of turbine rotor was determined using the QBlade freeware program. The fluid dynamics module simulated the loads exerted by the wind of a specific speed, and the stress analysis module predicted the distributions of equivalent von Mises stress for representing the blade structures. It was suggested to modify the shape of test specimen from ASTM D638 to decrease the variance in measured tensile strengths. Then, a series of experiments were performed to confirm that the bladder compression molded CFRP prepreg can provide sufficient strength to small wind turbine blades and decrease the cure time simultaneously.