• Title/Summary/Keyword: Light stress mechanism

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Water Physiology of Panax ginseng Charcteristics of reproductit.e organs and precipitation rate and humidity of shade system. (인삼의 수분생리 II. 생식기관의 특성과 일복의 누수량 및 습도)

  • Park, Hoon
    • Journal of Ginseng Research
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    • v.6 no.1
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    • pp.84-99
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    • 1982
  • Water content and its seasonal change in reprodltctive organs were reviewed in relation to cultivation practice s. Precipitati on and humidity under shade roof were reviewed in relation to shading ,jystem and environmental factors. High water content of reproductive organs suggests vulnerability to water stress during reproductive growth stage. Watering during dehisconce treat menu seems to keep optimum temperature but cnoventional practice seems to be too often In watering. Information effe on water physiology of seeds is too rare to develop seed storing method and ctive seed use. Dehiscent mechanism was considered in terms of water absorption of embryo. Precipitation rate of conventional shade roof reaclled to 38% and at line level 50% and varied with shade patterns. Precipitation rate under shade has been investigated for itself but should be investigated in relation to light intensity and soil moisture content Relative humidity under shade depends mainly on air humidity and soil moisture, considerably on shade materials and lithe on pole height, bed width or plant density. Since relative humidity was lower in afternoon it was often less than 50% even in summer with high temperature suggesting possible disorder of phi biological function especially in photosynthesis. More information was needed on optimum humidity for productive physiological function of leaf.

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Autophagy in Cervical Cancer: An Emerging Therapeutic Target

  • Pandey, Saumya;Chandravati, Chandravati
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.10
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    • pp.4867-4871
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    • 2012
  • Cervical cancer is a leading cause of morbidity and mortality in women worldwide. Although the human papillomavirus (HPV) is considered the major causative agent of cervical cancer, yet the viral infection alone is not sufficient for cancer progression. The etiopathogenesis of cervical cancer is indeed complex; a precise understanding of the complex cellular/molecular mechanisms underlying the initiation, progression and/or prevention of the uterine cervix is therefore essential. Autophagy is emerging as an important biological mechanism in targeting human cancers, including cervical cancer. Furthermore, autophagy, a process of cytoplasm and cellular organelle degradation in lysosomes, has been implicated in homeostasis. Autophagic flux may vary depending on the cell/tissue type, thereby altering cell fate under stress conditions leading to cell survival and/or cell death. Autophagy may in turn govern tumor metastasis and subsequent carcinogenesis. Inflammation is a known hallmark of cancer. Vascular insufficiency in tumors, including cervical tissue, leads to depletion of glucose and/or oxygen perturbing the osmotic mileu causing extracellular acidosis in the tumor microenvironment that may eventually result in autophagy. Thus, targeted manipulation of complex autophagic signaling may prove to be an innovative strategy in identification of clinically relevant biomarkers in cervical cancer in the near future.

Isolation and In Vitro Culture of Vascular Endothelial Cells from Mice

  • Choi, Shinkyu;Kim, Ji Aee;Kim, Kwan Chang;Suh, Suk Hyo
    • The Korean Journal of Physiology and Pharmacology
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    • v.19 no.1
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    • pp.35-42
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    • 2015
  • In cardiovascular disorders, understanding of endothelial cell (EC) function is essential to elucidate the disease mechanism. Although the mouse model has many advantages for in vivo and in vitro research, efficient procedures for the isolation and propagation of primary mouse EC have been problematic. We describe a high yield process for isolation and in vitro culture of primary EC from mouse arteries (aorta, braches of superior mesenteric artery, and cerebral arteries from the circle of Willis). Mouse arteries were carefully dissected without damage under a light microscope, and small pieces of the vessels were transferred on/in a Matrigel matrix enriched with endothelial growth supplement. Primary cells that proliferated in Matrigel were propagated in advanced DMEM with fetal calf serum or platelet-derived serum, EC growth supplement, and heparin. To improve the purity of the cell culture, we applied shearing stress and anti-fibroblast antibody. EC were characterized by a monolayer cobble stone appearance, positive staining with acetylated low density lipoprotein labeled with 1,1'-dioctadecyl-3,3,3',3'-tetramethyl-indocarbocyanine perchlorate, RT-PCR using primers for von-Willebrand factor, and determination of the protein level endothelial nitric oxide synthase. Our simple, efficient method would facilitate in vitro functional investigations of EC from mouse vessels.

Ferritin Overload Suppresses Male Fertility Via altered Acrosome Reaction

  • Kwon, Woo-Sung;Rahman, Md Saidur;Kim, Ye-Ji;Ryu, Do-Yeol;Kahtun, Amena;Pang, Myung-Geol
    • Reproductive and Developmental Biology
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    • v.39 no.4
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    • pp.117-125
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    • 2015
  • Iron is required for cell viability but is toxic in excess. While the iron-mediated malfunction of testicular cells is well appreciated, the underlying mechanism(s) of this effect and its relationship with fertility are poorly understood. Ferritin is a ubiquitous intracellular protein that controls iron storage, ferroxidase activity, immune response, and stress response in cells. Ferritin light chain protein (FTL) is the light subunit of the Ferritin. Previously, we had identified the FTL in bovine spermatozoa following capacitation. In present study, to investigate the role of Ferritin in sperm function, mice spermatozoa were incubated with multiple doses (1, 10 and $100{\mu}M$) of sodium nitroprusside (SNP), an iron donor. SNP was increased Ferritin levels in a dose-dependent manner. The Ferritin was detected on the acrosome in spermatozoa by immunocytochemistry. Short-term exposure of spermatozoa to SNP increased tyrosine phosphorylation and the acrosome reaction (AR). Finally, SNP affected a significant decrease in the rate of fertilization as well as blastocyst formation during early embryonic development. On the basis of these results, we propose that the effects of Ferritin on the AR may reduce overall sperm function leads to poor fertility in males and compromised embryonic development.

Creep characteristic of Mg alloy at high temperature (고온에서 마그네슘 합금의 크리이프 특성)

  • An, Jung-O;Park, Kyong-Do;Kwak, Jae-Seob;Kang, Dae-Min
    • 한국금형공학회:학술대회논문집
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    • 2008.06a
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    • pp.39-44
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    • 2008
  • Magnesium alloys have given high attention to the industry of light-weigh as automobile and electronics with aluminium, titanium and composite alloys due to their high strength, low specific density and good damping characteristics. But the magnesium contained structures under high temperature have the problems related to creep deformation and rupture life, which is a reason of developing the new material against creep deformation to use them safely. The purpose of this study is to predict the creep deformation mechanism and rupture time of AZ31 magnesium alloy. For this, creep tests of AZ31 magnesium alloy were done under constant creep load and temperature with the equipment including automatic temperature controller with acquisition computer. The apparent activation energy Qc and the applied stress exponent n, rupture life have been determined during creep of AZ31 Mg alloy over the temperature range of $150^{\circ}C$ to $300^{\circ}C$. In order to investigate the creep behavior. Constant load creep tests were carried out in the equipment including automatic temperature controller, whose data are sent to computer. At around the temperature of $150^{\circ}C{\sim}300^{\circ}C$ the creep behavior obeyed a simple power-law relating steady state creep rate to applied stress and the activation energy for the creep deformation was nearly equal and a little low, respectively, to that of the self diffusion of Mg alloy.

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Isolation and Characterization of a Theta Glutathione S-transferase Gene from Panax ginseng Meyer

  • Kim, Yu-Jin;Lee, Ok-Ran;Lee, Sung-Young;Kim, Kyung-Tack;Yang, Deok-Chun
    • Journal of Ginseng Research
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    • v.36 no.4
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    • pp.449-460
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    • 2012
  • Plants have versatile detoxification systems to encounter the phytotoxicity of the wide range of natural and synthetic compounds present in the environment. Glutathione S-transferase (GST) is an enzyme that detoxifies natural and exogenous toxic compounds by conjugation with glutathione (GSH). Recently, several roles of GST giving stress tolerance in plants have demonstrated, but little is known about the role of ginseng GSTs. Therefore, this work aimed to provide further information on the GST gene present in Panax ginseng genome as well as its expression and function. A GST cDNA (PgGST) was isolated from P. ginseng cDNA library, and it showed the amino acid sequence similarity with theta type of GSTs. PgGST in ginseng plant was induced by exposure to metals, plant hormone, heavy metals, and high light irradiance. To improve the resistance against environmental stresses, full-length cDNA of PgGST was introduced into Nicotiana tabacum. Overexpression of PgGST led to twofold increase in GST-specific activity compared to the non-transgenic plants, and the GST overexpressed plant showed resistance against herbicide phosphinothricin. The results suggested that the PgGST isolated from ginseng might have a role in the protection mechanism against toxic materials such as heavy metals and herbicides.

Experimental Study on Bond Strength between Carbon Fiber Sheet and Concrete (탄소섬유쉬트와 콘크리트의 부착강도 실험연구)

  • 유영찬;최기선;최근도;이한승;김긍환
    • Journal of the Korea Concrete Institute
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    • v.13 no.2
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    • pp.168-174
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    • 2001
  • Carbon fiber sheet(CFS) has been widely used for strengthening of the concrete building structures due to its excellent physical properties such as high strength, light weight and high durability. Bond strength or behavior, on the other hands, between carbon fiber sheet and concrete is very important in strengthening the concrete member using CFS. Therefore the bond failure mechanism between CFS and concrete should be fully verified and understood. This study is to investigate the bond strength of CFS to the concrete by the direct pull-out test and the tensile-shear test. In the direct pull-out tests, the bond strength under the various environmental conditions such as curing temperature, surface condition on concrete and water content of concrete are evaluated. Also, the effective bond length, lu and the average bond stress, $\tau$y are examined in the tensile-shear tests. Based on the test results, it is concluded that the curing temperature is the most critical element for the bond strength between CFS and concrete. And, the proper value of lu and $\tau$y is recommended with 15 cm and 9.78∼ 11.88 kgf/$\textrm{cm}^2$ respectively.

7α,25-Dihydroxycholesterol-Induced Oxiapoptophagic Chondrocyte Death via the Modulation of p53-Akt-mTOR Axis in Osteoarthritis Pathogenesis

  • Jeong-Yeon Seo;Tae-Hyeon Kim;Kyeong-Rok Kang;HyangI Lim;Moon-Chang Choi;Do Kyung Kim;Hong Sung Chun;Heung-Joong Kim;Sun-Kyoung Yu;Jae-Sung Kim
    • Molecules and Cells
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    • v.46 no.4
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    • pp.245-255
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    • 2023
  • This study aimed to exploring the pathophysiological mechanism of 7α,25-dihydroxycholesterol (7α,25-DHC) in osteoarthritis (OA) pathogenesis. 7α,25-DHC accelerated the proteoglycan loss in ex vivo organ-cultured articular cartilage explant. It was mediated by the decreasing extracellular matrix major components, including aggrecan and type II collagen, and the increasing expression and activation of degenerative enzymes, including matrix metalloproteinase (MMP)-3 and -13, in chondrocytes cultured with 7α,25-DHC. Furthermore, 7α,25-DHC promoted caspase-dependent chondrocyte death via extrinsic and intrinsic pathways of apoptosis. Moreover, 7α,25-DHC upregulated the expression of inflammatory factors, including inducible nitric oxide synthase, cyclooxygenase-2, nitric oxide, and prostaglandin E2, via the production of reactive oxygen species via increase of oxidative stress in chondrocytes. In addition, 7α,25-DHC upregulated the expression of autophagy biomarkers, including beclin-1 and microtubule-associated protein 1A/1B-light chain 3 via the modulation of p53-Akt-mTOR axis in chondrocytes. The expression of CYP7B1, caspase-3, and beclin-1 was elevated in the degenerative articular cartilage of mouse knee joint with OA. Taken together, our findings suggest that 7α,25-DHC is a pathophysiological risk factor of OA pathogenesis that is mediated a chondrocyte death via oxiapoptophagy, which is a mixed mode of apoptosis, oxidative stress, and autophagy.

JSAP1 Interacts with Kinesin Light Chain 1 through Conserved Binding Segments (JSAP1과 Kinesin Light Chain 1의 결합 및 결합부위 규명)

  • Kim, Sang-Jin;Lee, Chul-Hee;Park, Hye-Young;Yea, Sung-Su;Jang, Won-Hee;Lee, Sang-Kyeong;Park, Yeong-Hong;Cha, Ok-Soo;Moon, Il-Soo;Seog, Dae-Hyun
    • Journal of Life Science
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    • v.17 no.7 s.87
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    • pp.889-895
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    • 2007
  • A conventional kinesin, KIF5/kinesin-I, is composed of two kinesin heavy chains (KHCs) and two kinesin light chains (KLCs) and binds directly to microtubules. KIF5 motor mediates the transport of various membranous organelles, but the mechanism how they recognize and bind to a specific cargo has not yet been completely elucidated. Here, we used the yeast two-hybrid system to identify the neuronal protein(s) that interacts with the tetratricopeptide repeats (TRP) of KLCI and found a specific interaction with JNK/stress-activated protein kinase-associated protein 1 (JSAP1/JIPP3). The yeast two-hybrid assay demonstrated that the TRP 1,2 domain-containing region of KLCI mediated binding to the leucine zipper domain of JSAP1. JSAP1 also bound to the TRP region of lac2 but not to neuronal KIF5A, KIF5C and ubiquitous KIF5B in the yeast two-hybrid assay. In addition, these proteins showed specific interactions in the GST pull-down assay and by co-immunoprecipitation. KLCI and KIF5B interacted with GST-ISAP1 fusion proteins, but not with GST alone. An antibody to JSAPI specifically co-immunoprecipitated KIF5s associated with JSAP1 from mouse brain extracts. These results suggest that JSAP1, as KLC1 receptor, is involved in the KIF5 mediated transport.

Stability Analysis Techniques of Bracing Structure in the Hard Clay Ground According to the Variation of the Groundwater Level at the Trench Excavation (경질점성토 지반에서 Trench 굴착시 지하수위 변동에 따른 가설구조체 안정해석 기법)

  • Heo, Chang-Hwan;Seo, Sung-Tag;Kim, Hee-Duck;Jee, Hong-Kee
    • Journal of the Korean Society of Hazard Mitigation
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    • v.3 no.2 s.9
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    • pp.99-110
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    • 2003
  • In this study, lightening material weight and normalizing structure of preventing system of landslide soil-rock in trench excavation was tried with focusing in safety construction availability and workability. In other words, risk estimate, safety management method investigation, applicability of bracing material and mechanical stability of bracing structure was studied. From these result, structural stability and structural analysis of light weight bracing structure was carried out with common structural analysis program, for examining movement mechanism of bracing structure and normalization of standard. The result are summarized as following. (1) Mechanical ability of bracing members and soil pressure parameter acting to member for ensuring mechanical propriety of bracing structural and useful of new material considering soil mechanics boundary were proposed. Also theory and method of analysis of bracing structural were proposed. (2) As a result of the structure analysis of geographical profile for light pannel used FRP as hard clay mechanical characteristics(bending moment, shear force, axial force) of panel were changed according to groundwater level and it is proved that the result of mechanical analysis is within allowable stress. Thus, light pannel is available for bracing structure in trench excavation.