33 results on '"Jae-Sook Song"'
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2. Mechanical Performance and Microstructural Evolution of (NiCo)75Cr17Fe8Cx (x = 0~0.83) Medium Entropy Alloys at Room and Cryogenic Temperatures
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Jae Sook Song, Byung Ju Lee, Won Jin Moon, and Sun Ig Hong
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medium entropy alloy (MEA) ,deformation twin ,strength/ductility ,carbon ,strengthening ,Mining engineering. Metallurgy ,TN1-997 - Abstract
We investigated the effects of the addition of Co and carbon on the deformation behavior of new medium-entropy alloys (MEAs) designed by increasing the entropy of the conventional NiCrFe-type Alloy 600. The strength/ductility combination of carbon-free (NiCo)75Cr17Fe8 MEA was found to be 729 MPa/81% at 298 K and it increased to a remarkable 1212 MPa/106% at 77 K. The excellent strength and ductility of (NiCo)75Cr17Fe8 at cryogenic temperature is attributed to the increased strain hardening rate caused by the interaction between dislocation slip and deformation twins. Strength/ductility combinations of carbon-doped (NiCo)75Cr17Fe8C0.34 and (NiCo)75Cr17Fe8C0.83 at cryogenic temperature were observed to be 1321 MPa/96% and 1398 MPa/66%, respectively, both of which are superior to those of other high-entropy alloys (HEAs). Strength/ductility combinations of (NiCo)75Cr17Fe8C0.34 and (NiCo)75Cr17Fe8C0.83 at room temperature were found to be 831 MPa/72% and 942 MPa/55%, respectively and both are far superior to 676 MPa/41% of the commercial Alloy 600. Yield strengths of carbon-free and carbon-doped alloys comprised strengthening components from the friction stress, grain size strengthening, carbide strengthening and interstitial strengthening and excellent agreement between the predictions and the experiments was obtained. A design strategy to develop new MEAs by increasing the entropy of the conventional alloys was found to be effective in enhancing the mechanical performance.
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- 2020
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3. Biosynthesis of Zinc Oxide Nanoparticles and Structural Characterization and Antibacterial Performance
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Jae Sook Song, Joghee Suresh, and Sun Ig Hong
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chemistry.chemical_classification ,Materials science ,chemistry ,Diffusion ,Biomolecule ,Nanoparticle ,General Materials Science ,Crystallite ,Particle size ,Selected area diffraction ,Antimicrobial ,Tem analysis ,Nuclear chemistry - Abstract
We prepare ZnO nanoparticles by environmentally friendly synthesis using Cyathea nilgiriensis leaf extract. Various phytochemical constituents are identified through the assessment of ethanolic extract of plant Cyathea nilgiriensis holttum by GC-MS analysis. The formation of ZnO nanoparticles is confirmed by FT-IR, XRD, SEM-EDX, TEM, SAED and PSA analysis. TEM observation reveals that the biosynthesized ZnO nanopowder has a hexagonal structure. The calculated average crystallite size from the high intense plane of (1 0 1) is 29.11 nm. The particle size, determined by TEM analysis, is in good agreement with that obtained by XRD analysis. We confirm the formation of biomolecules in plant extract by FT-IR analysis and propose a possible formation mechanism of ZnO nanoparticles. Disc diffusion method is used for the analyses of antimicrobial activity of ZnO nanoparticles. The synthesized ZnO nanoparticles exhibit antimicrobial effect in disc diffusion experiments. The biosynthesized ZnO nanoparticles display good antibacterial performance against B. subtilis (Gram-positive bacteria) and K. pneumonia (Gram-negative bacteria). Bio-synthesized nanoparticles using green method are found to possess good antimicrobial performance.
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- 2020
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4. High-Temperature Deformability of a Fe-Cr-Mn-Ni Austenite Stainless Steel with High Nitrogen and High Carbon Contents
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Byung Ju Lee, Jae Sook Song, and Sun Ig Hong
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deformability ,dynamic recrystallization ,effective elongation ,fracture ,Fe-Cr-Mn-Ni ,stainless steel ,Mining engineering. Metallurgy ,TN1-997 - Abstract
High temperature deformability and fracture behavior of deformation-processed high nitrogen high carbon Fe-Cr-Mn-Ni stainless steel rods were studied. The effective fracture elongation increased rapidly from 1000 °C, and reached high values (>45%) at 1100–1200 °C, accompanied by strain softening and stress serrations, supporting periodic dynamic recrystallization (DRX). Dynamically recrystallized grains were observed close to the fracture surface, suggesting that active DRX worked until its fracture. Pre-deformation-annealing of Fe-Cr-Mn-Ni stainless steel rods at 1200 °C was found to deteriorate in deformability above 1000 °C, while it enhanced ductility below 950 °C. Pre-deformation annealing had a negative effect on the deformability above 1000 °C due to the reduction of driving forces for DRX, but it exhibited a beneficial effect on the ductility at lower temperatures because of the ease of slip in large-grained structures. The fracture surface at 1250 °C exhibited intergranular fractures due to partial melting at grain boundaries, supported by the thermodynamic calculation of the solidus temperature of Fe-Cr-Mn-Ni austenite stainless steel. In this study, effective fracture elongation, defined based on the assumption that the effective gage length decreases with straining, was found to be an accurate measure of hot deformability.
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- 2018
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5. Recycling Zr-Nb-Sn-Fe Scrap in Casting of Nuclear-Grade Alloy Ingots and Its Effects on Mechanical Performance and Integrity
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Jae Sook Song and Sun Ig Hong
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zr-nb-sn-fe ,lcsh:GE1-350 ,Materials science ,Alloy ,Metallurgy ,Scrap ,recycling ,engineering.material ,ductility ,nuclear energy ,Casting (metalworking) ,engineering ,scrap ,Nuclear grade ,oxygen ,lcsh:Environmental sciences ,General Environmental Science - Abstract
Recycling of Zr-Nb-Sn-Fe scraps in casting enhances the price competitiveness of nuclear-grade Zr alloys and accordingly the energy from nuclear power plants. Increasing the fraction of scrap in casting of new alloy ingots increases the price competitiveness, but it aggravates the deformability and mechanical reliability of cast alloys. In this study, the effect of scrap ratio on the mechanical reliability of Zr-Nb-Sn-Fe alloys was studied. The increase of scrap fraction in casting increases the oxygen content in the ingot and nuclear claddings fabricated from cast ingots. The increase of oxygen content is caused by the surface oxide of scraps such as small pieces of turning, chips, etc. Iron content was not found to increase appreciably with the increasing fraction of scrap because scraps were well kept in the iron-free container. The microstructure of ss-cast Zr alloy with increasing fraction of scraps displayed plate/or needle α phase and the microstructural features were observed to be affected by increase of scrap fraction. The strength increases with increasing fraction of scrap, which can be attributed to the increase of oxygen content. The ductility decreased slightly with increase of scrap fraction. The strength increased at the expense of ductility with increase of scrap fraction. In some ingots, iron oxide flakes were intentionally added to explore the effects of iron oxide which may be added from the scarp storage container. The alloys with the addition of iron oxide flakes exhibited the drastic decrease of the formability and exhibited the brittle fracture behavior during rolling. The increase of oxide fraction increased the oxidation resistance because of high oxygen content the matrix may have prevented oxygen diffusion into matrix.
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- 2020
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6. Toralactone glycoside in Cassia obtusifolia mediates hepatoprotection via an Nrf2-dependent anti-oxidative mechanism
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Yongtaek Seo, Young Pyo Jang, Jae-Sook Song, and Young-Mi Kim
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0301 basic medicine ,Programmed cell death ,Cell Survival ,NF-E2-Related Factor 2 ,Cassia ,Ethyl acetate ,Disaccharides ,Protective Agents ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Nutraceutical ,Humans ,Hepatoprotective Agent ,Toralactone ,chemistry.chemical_classification ,biology ,Traditional medicine ,Plant Extracts ,Glycoside ,Hep G2 Cells ,biology.organism_classification ,Oxidative Stress ,030104 developmental biology ,Biochemistry ,chemistry ,Hepatoprotection ,Pyrones ,030220 oncology & carcinogenesis ,Seeds ,Food Science - Abstract
Cassia obtusifolia L. (Leguminosae) seeds are a well-known medicinal food in East Asia and are used to clear liver heat, sharpen vision, lubricate the intestines, and promote bowel movement. The aims of the present study were to identify the hepatoprotective components of C. obtusifolia seeds by bioactivity-guided isolation and to elucidate their mechanisms of action. Ten phenolic glycosides were isolated from the most active ethyl acetate fraction, and their chemical structures were elucidated by spectroscopic analyses. Among the isolated compounds, toralactone 9-O-gentiobioside (5) had the highest hepatoprotective efficacy against tert-butylhydroperoxide-induced cell death in HepG2 cells. Immunoblotting and real-time polymerase chain reaction analyses revealed that the hepatoprotective effects were exerted through nuclear factor erythroid-2-related factor 2 (Nrf2)-dependent antioxidative signaling. Together, these results provide insights into the effects of this medicinal plant as well as a basis for developing hepatoprotective agents as pharmaceuticals and/or nutraceuticals.
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- 2017
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7. Effect of roll-bonding temperature on the strength and electrical conductivity of an α-brass-clad Cu–1Cr alloy composite
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Jae Sook Song, Sun Ig Hong, and Gyeong Tae Kang
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010302 applied physics ,Materials science ,Annealing (metallurgy) ,Metallurgy ,Composite number ,02 engineering and technology ,Strain hardening exponent ,Conductivity ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Roll bonding ,Brass ,Precipitation hardening ,visual_art ,0103 physical sciences ,Materials Chemistry ,visual_art.visual_art_medium ,Composite material ,0210 nano-technology ,Softening - Abstract
Tri-layered α-brass-clad Cu–Cr-alloy composite plates were prepared by hot roll-bonding. Neither intermetallic-compound layers nor interface defects were observed at the interfaces in the as-rolled and heat-treated α-brass-clad Cu–Cr composite plates. The hardness of the as-rolled α-brass layer was greater than that of the Cu–Cr substrate, since the α-brass was strengthened by strain hardening more efficiently upon rolling. The hardness of the α-brass decreased appreciably upon annealing because of the recovery processes, whereas that of the Cu–Cr layer slightly increased after heat treatment at 450°C due to the precipitation strengthening. After the post-roll-bonding heat treatment at 450°C, the strength of the α-brass-clad Cu–Cr-alloy composite decreased with a significant increase in ductility. The electrical conductivity of the asroll-bonded α-brass clad Cu–Cr alloy composite (47–52% IACS) increased significantly (to 72–74% IACS) after the 1-h heat treatment. The strength and conductivity of the clad composite are dependent on the precipitation strengthening of Cu–Cr and recovery softening of α-brass in the course of the post-roll-bonding heat treatment.
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- 2017
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8. Data on the microstructure and deformation of Fe50Mn25Cr15Co10Nx (x=0∼1.6) supporting the modifications of partial-dislocation-induced defects (PDIDs) and strength/ductility enhancement in metastable high entropy alloys
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Sun Ig Hong, Jae Sook Song, Won Jin Moon, and Byung Ju Lee
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Nanostructure ,Materials science ,Partial-dislocation ,Nitrogen ,lcsh:Computer applications to medicine. Medical informatics ,Strain rate sensitivity ,03 medical and health sciences ,0302 clinical medicine ,Composite material ,lcsh:Science (General) ,High-entropy alloy (HEA) ,ε-martensite ,Data Article ,Strain hardening ,030304 developmental biology ,Tensile testing ,0303 health sciences ,Stacking fault ,Deformation twin ,Multidisciplinary ,High entropy alloys ,Strain rate ,Microstructure ,lcsh:R858-859.7 ,Partial dislocations ,Deformation (engineering) ,030217 neurology & neurosurgery ,lcsh:Q1-390 ,Electron backscatter diffraction - Abstract
The data presented in this article are related to a research paper on the modification of deformed nanostructure and mechanical performance of metastable high entropy alloys (HEAs) [1] . Fe50Mn25Cr15Co10 alloys with and without nitrogen were synthesized in a vacuum induction furnace using pure metals of 99.99% purity and FeCrN2 as nitrogen source. The nitrogen content was determined by Leco O/N-836 determinator for nitrogen-doped alloys. Transmission electron microscopy (TEM) were carried at 200 kV equipped with energy dispersive spectroscopy (EDS). Tensile testing was performed at room temperature. The strain rate jump tests were conducted by changing the strain rate between 10−3 and 10−2 s−1 to measure the strain rate sensitivity. The nanostructural evolutions by deformation including extended stacking faults (ESFs), e-martensite and twins were examined using EBSD and TEM for the annealed samples and those strained to different strain levels. The role of partial dislocations on the formation of various PDIDs were analysed and the energies stored as deformed nanostructure (ESDN) after the PDID band formation were used to predict the evolution of various nanostructure with strain. The data and approach would provide a useful insight into the nanostructural evolution in metastable high entropy alloys.
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- 2021
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9. Effect of Scrap Impurities on Microstructure and Mechanical Properties of Zr Alloys
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In Won Kim, Jae Sook Song, Sun Ig Hong, Gu Beom Jeong, and Pyung Woo Shin
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Materials science ,0205 materials engineering ,Impurity ,020502 materials ,Metallurgy ,Scrap ,Zr alloy ,02 engineering and technology ,021001 nanoscience & nanotechnology ,0210 nano-technology ,Ductility ,Microstructure - Published
- 2016
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10. Enviroment-Friendly Synthesis of Nanocrystalline Zinc Oxide Particles Using Fruit Peel Extract
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Pyung Woo Shin, Jae Sook Song, Sun Ig Hong, and Rathinam Yuvakkumar
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Rambutan ,Materials science ,genetic structures ,010405 organic chemistry ,Zinc ion ,chemistry.chemical_element ,02 engineering and technology ,Zinc ,021001 nanoscience & nanotechnology ,01 natural sciences ,Nanocrystalline material ,0104 chemical sciences ,Solvent ,Nanocrystal ,Chemical engineering ,chemistry ,Transmission electron microscopy ,Polyphenol ,Organic chemistry ,General Materials Science ,0210 nano-technology - Abstract
In this study, an environment-friendly synthetic strategy to process zinc oxide nanocrystals is reported. The biosynthesis method used in this study is simple and cost-effective, with reduced solvent waste via the use of fruit peel extract as a natural ligation agent. The formation of ZnO nanocrystals using a rambutan peel extract was observed in this study. Rambutan peels has the ability to ligate zinc ions as a natural ligation agent, resulting in ZnO nanochain formation due to the presence of an extended polyphenolic system over the whole incubation period. Via transmission electron microscopy, successful formation of zinc oxide nanochains was confirmed. TEM observation revealed that the bioinspired ZnO nanocrystals were spherical and/or hexagonal particles with sizes between 50 and 100 nm.
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- 2016
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11. Modifications of partial-dislocation-induced defects and strength/ductility enhancement in metastable high entropy alloys through nitrogen doping
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Jae Sook Song, Won Jin Moon, Byung Ju Lee, and Sun Ig Hong
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0303 health sciences ,Materials science ,Nanostructure ,Condensed matter physics ,Mechanical Engineering ,High entropy alloys ,Stacking ,02 engineering and technology ,Slip (materials science) ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Condensed Matter::Materials Science ,03 medical and health sciences ,Shear (geology) ,Mechanics of Materials ,Metastability ,Homogeneity (physics) ,Partial dislocations ,General Materials Science ,0210 nano-technology ,030304 developmental biology - Abstract
We identified the role of partial-dislocation-induced defects (PDIDs) on the nanostructural evolution and the resultant macroscopic deformation in high entropy alloys (HEAs) with their phase stability modified via nitrogen doping. We found that deformation proceeds by the extension and expansion of partial dislocation induced defects (PDIDs) such as extended stacking faults (ESFs), e-martensite and deformation twin bands in these alloys. Simultaneous strength/ductility enhancement was achieved through modifications of PDIDs and phase stability in Fe50Mn25Cr15Co10 by nitrogen addition. We suggest that the formation of closely spaced ESFs reduce the stacking irregularity and therefore closely spaced ESFs is the energetically stable deformation nanostructure. The formation of closely spaced ESFs has the advantage of the deformation homogeneity because of the more uniform slip strain distribution by smaller shear vector of partial dislocations and the large strain rate sensitivity, leading to the enhanced ductility. This intrinsic nature of overlapped ESFs on the effective reduction of stacking irregularities induces the development of closely spaced ESFs and their transition to e-martensite band and then to deformation twin band with increasing strain. The modifications of various PDIDs in high entropy alloys with their phase stability modified by nitrogen doping is in good agreement with the prediction of the partial dislocation induced deformation nanostrucure based on the energy criteria under quasi-static deformation proposed in this study.
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- 2021
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12. Mechanical Performance and Microstructural Evolution of (NiCo)75Cr17Fe8Cx (x = 0~0.83) Medium Entropy Alloys at Room and Cryogenic Temperatures
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Sun Ig Hong, Jae Sook Song, Won Jin Moon, and Byung Ju Lee
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lcsh:TN1-997 ,Yield (engineering) ,Materials science ,Alloy ,02 engineering and technology ,engineering.material ,01 natural sciences ,Carbide ,0103 physical sciences ,General Materials Science ,Composite material ,Ductility ,lcsh:Mining engineering. Metallurgy ,medium entropy alloy (MEA) ,deformation twin ,strength/ductility ,carbon ,strengthening ,010302 applied physics ,Metals and Alloys ,Strain hardening exponent ,021001 nanoscience & nanotechnology ,Grain size ,engineering ,Deformation (engineering) ,Dislocation ,0210 nano-technology - Abstract
We investigated the effects of the addition of Co and carbon on the deformation behavior of new medium-entropy alloys (MEAs) designed by increasing the entropy of the conventional NiCrFe-type Alloy 600. The strength/ductility combination of carbon-free (NiCo)75Cr17Fe8 MEA was found to be 729 MPa/81% at 298 K and it increased to a remarkable 1212 MPa/106% at 77 K. The excellent strength and ductility of (NiCo)75Cr17Fe8 at cryogenic temperature is attributed to the increased strain hardening rate caused by the interaction between dislocation slip and deformation twins. Strength/ductility combinations of carbon-doped (NiCo)75Cr17Fe8C0.34 and (NiCo)75Cr17Fe8C0.83 at cryogenic temperature were observed to be 1321 MPa/96% and 1398 MPa/66%, respectively, both of which are superior to those of other high-entropy alloys (HEAs). Strength/ductility combinations of (NiCo)75Cr17Fe8C0.34 and (NiCo)75Cr17Fe8C0.83 at room temperature were found to be 831 MPa/72% and 942 MPa/55%, respectively and both are far superior to 676 MPa/41% of the commercial Alloy 600. Yield strengths of carbon-free and carbon-doped alloys comprised strengthening components from the friction stress, grain size strengthening, carbide strengthening and interstitial strengthening and excellent agreement between the predictions and the experiments was obtained. A design strategy to develop new MEAs by increasing the entropy of the conventional alloys was found to be effective in enhancing the mechanical performance.
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- 2020
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13. Microstructure and Deformability of Cast Zr-Nb-Fe-O Alloy with High Iron and Oxygen Content
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Gu Beom Jeong, Jae Sook Song, and Sun Ig Hong
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Materials science ,Fracture (mineralogy) ,Alloy ,Metallurgy ,General Engineering ,Oxide ,Iron oxide ,chemistry.chemical_element ,engineering.material ,Microstructure ,Oxygen ,chemistry.chemical_compound ,Brittleness ,chemistry ,Phase (matter) ,engineering - Abstract
In order to investigate the possible effect of the scrap inclusions in recycling, microstructure and deformability of Zr-Nb based alloys cast with the addition of iron and iron oxide were studied. No visible iron oxide inclusions were observed in the arc-melted cake, suggesting that Zr and Fe2O3reacted completely to dissociate Fe2O3into Fe and O in the Zr. No oxide peaks were observed by XRD analyses. In Zr-Nb alloy melted with iron oxide, the oxygen content reached up to 3150 ppm. Zr-1.2 Nb alloys with high oxygen contents exhibited needle-shaped α phase. and the the thickness of needles decreased. In Zr-1.2Nb alloys with over 2000 ppm they are brittle and cracked during rolling process. In some region of the fracture surface brittle fracture feature such as vein-like pattern was observed. In the fractograph, no brittle second phase particles were observed. EDS spectra. It is apparent that Zr-Nb alloys with the addition of iron oxide during the handling of scrap materials exhibit the extremely brittle behavior.
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- 2014
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14. Mechanical Properties of Cu-Ni-Zn/Cu-Cr/Cu-Ni-Zn Composite Plate Processed by Explosive Bonding and Cold Rolling
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Jae Sook Song, Gyeong Tae Kang, and Sun Ig Hong
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Materials science ,Interfacial bonding ,Explosive material ,Annealing (metallurgy) ,Composite plate ,Metallurgy ,Composite number ,General Engineering ,Intermetallic ,Flow stress ,Composite material ,Mechanical reliability - Abstract
Mechanical properties of 3-ply Cu-Ni-Zn/Cu-Cr/Cu-Ni-Zn clad composite plates prepared by explosive bonding and cold-rolling. No intermetallic compounds were observed at the Cu-Ni-Zn/Cu-Cr interface after explosive bonding and cold-rolling and heat-treatment at 723K. The strength of as-rolled clad plate reached up to 575MPa with the ductility of 30% after heat treatment at 723K for 1 hour. The strength dropped to 510MPa and the ductility increased to 48% after heat treatment at 723K for 1.5 hour. There are no stepwise drops of the flow stress before final fracture, meaning three plates were bonded together until the last moment of the stress-strain curve. The observation of the fractured specimens revealed no interface separation even after fracture. The excellent mechanical reliability and the good interfacial bonding strength can be attributed to the absence of detrimental interfacial reaction compounds between Cu-Ni-Zn and Cu-Cr after annealing.
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- 2014
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15. Mechanical Behavior of 3-ply Cu-Ni-Zn/Cu-Cr/Cu-Ni-Zn Composite Plate Processed by Roll Bonding
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Sun Ig Hong, Hob Yung Kim, and Jae Sook Song
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Materials science ,Composite plate ,Annealing (metallurgy) ,Metallurgy ,Composite number ,Alloy ,General Engineering ,engineering ,Intermetallic ,engineering.material ,Composite material ,Conductivity ,Roll bonding - Abstract
3-ply Cu-Ni-Zn/Cu-Cr/Cu-Ni-Zn clad composite plates were prepared by roll bonding at 823K and their properties were characterized. No intermetallic compounds were observed at Cu-Ni-Zn/Cu-Cr interfaces in the as-rolled and heat-treated Cu/Ni-Zn/Cu-Cr/Cu-Ni-Zn clad plates. The strength of as-rolled clad plate reached up to 420MPa with the ductility of 13%. After heat treatment at 723K for 1.5 hours, the strength of Cu-Ni-Zn/Cu-Cr/Cu-Ni-Zn clad composite plate dropped to 340 MPa and the ductility increased to 20%. With annealing at 723K, there is no drastic drop of the stress before final fracture, meaning three plates were bonded together until the last part of the stress-strain curve. The peak of the conductivity (>70% of IACS) was attained after aging for 1.5 hrs, compatible with the typical peak aging condition of Cu-Cr alloy.
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- 2013
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16. Hepatocyte-protective effect of nectandrin B, a nutmeg lignan, against oxidative stress: Role of Nrf2 activation through ERK phosphorylation and AMPK-dependent inhibition of GSK-3β
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Jae-Sook Song, Young-Mi Kim, Eun-Kyung Kim, Yong-Won Choi, and Won Keun Oh
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0301 basic medicine ,MAPK/ERK pathway ,Cell Survival ,MAP Kinase Signaling System ,NF-E2-Related Factor 2 ,MAP Kinase Kinase 1 ,Apoptosis ,Biology ,AMP-Activated Protein Kinases ,Toxicology ,medicine.disease_cause ,Protective Agents ,Lignans ,Myristica ,03 medical and health sciences ,chemistry.chemical_compound ,tert-Butylhydroperoxide ,medicine ,Animals ,Humans ,Viability assay ,Phosphorylation ,Luciferases ,Cells, Cultured ,Pharmacology ,Glycogen Synthase Kinase 3 beta ,Glutathione ,Hep G2 Cells ,Cytoprotection ,Cell biology ,Mice, Inbred C57BL ,Oxidative Stress ,030104 developmental biology ,medicine.anatomical_structure ,Glutathione S-transferase ,chemistry ,Biochemistry ,Hepatocyte ,biology.protein ,Hepatocytes ,Reactive Oxygen Species ,Oxidative stress - Abstract
Oxidative stress can contribute to the development and progression of liver diseases, such as drug-induced or alcoholic liver injury, nonalcoholic fatty liver disease, and nonalcoholic steatohepatitis. Nectandrin B is a bioactive lignan isolated from nutmeg extract. To date, little information is available about its pharmacological activities in the liver. This study investigated the hepatocyte-protective effect of nectandrin B against tert-butylhydroperoxide-induced oxidative injury and the underlying molecular mechanism. The cell viability assay revealed that nectandrin B prevents apoptosis stimulated by tert-butylhydroperoxide in both HepG2 cells and primary mouse hepatocytes. Nectandrin B also attenuated ROS production and restored the depleted glutathione level. Real-time PCR and immunoblot analyses showed that the expression of glutamate-cysteine ligase, an enzyme responsible for the glutathione biosynthesis, was induced by nectandrin B, indicating its indirect antioxidative effect. The NF-E2-related factor-2 (Nrf2) regulates gene expression of an array of antioxidant enzymes in hepatocytes. Nectandrin B stimulated Nrf2 activation as evidenced by its enhanced nuclear accumulation and increased antioxidant response element (ARE)-luciferase activity. Intriguingly, the hepatocyte-protective effect of nectandrin B against oxidative damage was completely abrogated by Nrf2 knockdown using Nrf2 specific siRNA. Nectandrin B promoted ERK activation, but inactivated GSK-3β through the AMPK-mediated inhibitory phosphorylation. The enforced overexpression of dominant-negative mutant of MEK1 or AMPKα, or wild-type GSK-3β inhibited the increase in the NQO1-ARE-luciferase activity stimulated by nectandrin B, suggesting that both ERK and AMPK-GSK-3β signalings are involved in the activation of Nrf2/ARE pathway by nectandrin B. Consistent with this, cytoprotection and restoration of glutathione level by nectandrin B was also blocked by the overexpression of dominant-negative MEK1 or wild-type GSK-3β. Finally, our data demonstrate that nectandrin B has the ability to protect hepatocytes against oxidative injury through the activation of Nrf2/ARE pathway mediated by ERK phosphorylation and AMPK-dependent inactivation of GSK-3β.
- Published
- 2016
17. Intracavernous Delivery of Synthetic Angiopoietin-1 Protein as a Novel Therapeutic Strategy for Erectile Dysfunction in the Type II Diabetic db/db Mouse
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Guo Nan Yin, Min Ji Choi, Jun-Kyu Suh, Ji-Kan Ryu, Jae Sook Song, Mi-Hye Kwon, Munkhbayar Tumurbaatar, Gou Young Koh, Sun Hwa Shin, Kang-Moon Song, Hai-Rong Jin, Woo Jean Kim, Buyankhuu Tuvshintur, and Shuguang Piao
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Male ,medicine.medical_specialty ,Nitric Oxide Synthase Type III ,Endothelium ,Urology ,Endocrinology, Diabetes and Metabolism ,Apoptosis ,Intracavernous injection ,Neovascularization ,Mice ,chemistry.chemical_compound ,Endocrinology ,Erectile Dysfunction ,Internal medicine ,Angiopoietin-1 ,Cyclic AMP ,medicine ,Animals ,Cyclic adenosine monophosphate ,Endothelial dysfunction ,Cyclic GMP ,Cyclic guanosine monophosphate ,business.industry ,Penile Erection ,Phosphodiesterase 5 Inhibitors ,medicine.disease ,Recombinant Proteins ,Platelet Endothelial Cell Adhesion Molecule-1 ,Psychiatry and Mental health ,Db/db Mouse ,medicine.anatomical_structure ,Erectile dysfunction ,Diabetes Mellitus, Type 2 ,Reproductive Medicine ,chemistry ,Endothelium, Vascular ,medicine.symptom ,business ,Penis - Abstract
Introduction Patients with erectile dysfunction (ED) associated with type II diabetes often have impaired endothelial function and tend to respond poorly to oral phosphodiesterase type 5 inhibitors. Therefore, neovascularization is a promising strategy for curing diabetic ED. Aim To determine the effectiveness of a soluble, stable, and potent angiopoietin-1 (Ang1) variant, cartilage oligomeric matrix protein (COMP)-Ang1, in promoting cavernous angiogenesis and erectile function in a mouse model of type II diabetic ED. Methods Sixteen-week-old male db/db mice (in which obesity and type II diabetes are caused by a mutation in the leptin receptor) and control C57BL/6J mice were used and divided into four groups (N = 14 per group): age-matched controls; db/db mice receiving two successive intracavernous injections of phosphate-buffered saline (PBS) (days −3 and 0; 20 µL); db/db mice receiving a single intracavernous injection of COMP-Ang1 protein (day 0; 5.8 µg/20 µL); and db/db mice receiving two successive intracavernous injections of COMP-Ang1 protein (days −3 and 0; 5.8 µg/20 µL). Main Outcome Measures Two weeks later, erectile function was measured by electrical stimulation of the cavernous nerve. The penis was then harvested and stained with antibodies to platelet/endothelial cell adhesion molecule-1 (PECAM-1) (endothelial cell marker), phosphohistone H3 (PH3, a nuclear protein indicative of cell proliferation), phospho-endothelial nitric oxide synthase (eNOS), and eNOS. Penis specimens from a separate group of animals were used for cyclic guanosine monophosphate (cGMP) and cyclic adenosine monophosphate (cAMP) quantification. Results Local delivery of COMP-Ang1 protein significantly increased eNOS phosphorylation and cGMP and cAMP expression compared with that in the group treated with PBS. Repeated intracavernous injections of COMP-Ang1 protein completely restored erectile function and cavernous endothelial content through enhanced cavernous neoangiogenesis as evaluated by PECAM-1 and PH3 immunohistochemistry and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling assay, whereas a single injection of COMP-Ang1 protein elicited partial improvement. Conclusion Cavernous neovascularization using recombinant Ang1 protein is a novel therapeutic strategy for the treatment of ED resulting from type II diabetes. Jin H-R, Kim WJ, Song JS, Piao S, Tumurbaatar M, Shin SH, Choi MJ, Tuvshintur B, Song K-M, Kwon M-H, Yin GN, Koh GY, Ryu J-K, and Suh J-K. Intracavernous delivery of synthetic angiopoietin-1 protein as a novel therapeutic strategy for erectile dysfunction in the type II diabetic db/db mouse.
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- 2010
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18. Mycophenolic acid inhibits oleic acid-induced mesangial cell activation through both cellular reactive oxygen species and inosine monophosphate dehydrogenase 2 pathways
- Author
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Jehyun Park, Kyu Ha Huh, Soon Il Kim, Hyung Joon Ahn, Jae Sook Song, Man Ki Ju, Yu Seun Kim, and Myoung Soo Kim
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Small interfering RNA ,Guanosine ,Mice, Transgenic ,Biology ,Mice ,chemistry.chemical_compound ,IMP Dehydrogenase ,Transforming Growth Factor beta ,IMP dehydrogenase ,Animals ,Secretion ,Enzyme Inhibitors ,RNA, Small Interfering ,Antibodies, Blocking ,Cells, Cultured ,chemistry.chemical_classification ,Reactive oxygen species ,Mesangial cell ,Transforming growth factor beta ,Mycophenolic Acid ,Molecular biology ,Acetylcysteine ,Fibronectins ,Fibronectin ,chemistry ,Nephrology ,Culture Media, Conditioned ,Mesangial Cells ,Pediatrics, Perinatology and Child Health ,biology.protein ,RNA Interference ,Reactive Oxygen Species ,Drug Antagonism ,Oleic Acid - Abstract
The synthesis of extracellular matrix (ECM) in mesangial cells (MCs) plays important roles in the development and progression of renal diseases, including chronic allograft nephropathy. Mycophenolic acid (MPA), an inhibitor of inosine monophosphate dehydrogenase 2 (IMPDH2), suppresses MC proliferation and ECM synthesis. However, the exact inhibitory mechanism of MPA on MCs has not been clearly elucidated. In this study we compared the inhibitory effects of MPA and IMPDH2 reduction [by using small interfering RNA (siRNA)] on oleic acid (OA)-induced fibronectin secretion and cellular reactive oxygen species (ROS) in mouse MCs. Growth-arrested MCs were stimulated with OA in the presence or absence of MPA, IMPDH2 siRNA, N-acetylcysteine (NAC), transforming growth factor beta (TGF-beta) antibody or exogenous guanosine. Fibronectin secretion into the medium was examined by Western blot, dichlorodihydrofluorescein (DCF)-sensitive cellular ROS by fluorescence-activated cell scanning (FACS), TGF-beta levels in the media by enzyme-linked immunosorbent assay (ELISA). OA increased fibronectin secretion, TGF-beta and cellular ROS levels. A TGF-beta neutralizing antibody effectively suppressed OA-induced fibronectin secretion. NAC and MPA completely suppressed OA-induced fibronectin secretion and decreased the levels of TGF-beta and cellular ROS. However, IMPDH2 siRNA partly inhibited OA-induced MC activation. Exogenous guanosine successfully reversed the inhibitory effects of IMPDH2 siRNA on OA-induced MC activation. Pleiotropic inhibitory effect of MPA on OA-induced mouse MC activation was mediated via its antioxidant effect on cellular ROS production and partly via inhibition of IMPDH2 itself. Our results implicate ROS as an alternative therapeutic target for the prevention of hyperlipidemia-related glomerulopathy, chronic allograft nephropathy, and subsequent graft loss.
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- 2009
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19. Nectandrin B, a lignan isolated from nutmeg, inhibits liver X receptor-α-induced hepatic lipogenesis through AMP-activated protein kinase activation
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Du Gon, Choi, Eun Kyung, Kim, Jin Won, Yang, Jae Sook, Song, and Young-Mi, Kim
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Lipogenesis ,Cyclic AMP-Dependent Protein Kinases ,Gene Expression Regulation, Enzymologic ,Lignans ,Myristica ,Enzyme Activation ,Fatty Liver ,Mice, Inbred C57BL ,Mice ,Liver ,Cell Line, Tumor ,Hepatocytes ,Animals ,Humans ,Fatty Acid Synthases ,Acetyl-CoA Carboxylase ,Liver X Receptors - Abstract
Nonalcoholic fatty liver disease is recognized as the most commonly occurring chronic liver disease. Liver X receptor α (LXRα) and sterol regulatory element-binding protein (SREBP)-1c play a central role in de novo fatty acid synthesis. This study investigated pharmacological effects of nectandrin B, a lignan isolated from nutmeg extract, on hepatic lipogenesis stimulated by LXRα-SREBP-1c-mediated pathway and the possible molecular basis. The reporter gene assay revealed that nectandrin B completely represses LXRα activity enhanced by a synthetic LXRα ligand (T0901317) in HepG2 cells. The inhibitory effect was further supported by the suppression of mRNA expression of LXRα target genes, SREBP-1c and LXRα itself. Nectandrin B also inhibited the increase in SREBP-1c expression promoted by insulin plus high glucose, major contributors to hepatic lipid accumulation. LXRα-SREBP-1c-mediated induction of acetyl-CoA carboxylase 1 and fatty acid synthase, major genes for de novo lipogenesis, was suppressed by nectandrin B. Moreover, Oil Red O staining showed that nectandrin B notably attenuates LXRα-induced lipid accumulation. AMP-activated protein kinase (AMPK) inhibits the activities of LXRα and SREBP-1c. Nectandrin B strongly activated AMPK signaling in HepG2 cells. Taken together, the suppressive effects of nectandrin B on lipogenic gene expression and lipid accumulation in hepatocytes may be due to its inhibitory effect on the LXRα-SREBP-1c pathway presumably via AMPK activation. These results suggest the potential of nectandrin B as a therapeutic candidate for fatty liver disease.
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- 2016
20. Mycophenolic Acid Inhibits Oleic Acid–Induced Vascular Smooth Muscle Cell Activation by Inhibiting Cellular Reactive Oxygen Species
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Jae Sook Song, Myoung Soo Kim, Hyung-Joon Ahn, Hunjoo Ha, Man Ki Ju, Ki Ho Song, Jehyun Park, and Yu Seun Kim
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Vascular smooth muscle ,Cell ,Biology ,Muscle, Smooth, Vascular ,Rats, Sprague-Dawley ,chemistry.chemical_compound ,Dichlorofluorescein ,Mesenchymal cell proliferation ,medicine ,Animals ,Cells, Cultured ,Cell Proliferation ,chemistry.chemical_classification ,Transplantation ,Reactive oxygen species ,Cell growth ,Mycophenolic Acid ,Molecular biology ,Acetylcysteine ,Fibronectins ,Rats ,Fibronectin ,medicine.anatomical_structure ,chemistry ,Biochemistry ,Cytoprotection ,biology.protein ,Reactive Oxygen Species ,Cell activation ,Oleic Acid - Abstract
BACKGROUND Vascular smooth muscle cell (VSMC) proliferation and matrix protein accumulation play important roles in the development and progression of chronic allograft vasculopathy. Mycophenolic acid (MPA) inhibits various types of mesenchymal cell proliferation and cellular reactive oxygen species (ROS) are involved in the anti-proliferative effect of MPA. In this study, we investigated the effects of MPA on oleic acid (OA)-induced VSMC proliferation and the role of ROS in this process. METHODS Primary VSMCs from Sprague-Dawley rats were stimulated with 100 microM OA, with or without MPA (0.1- 10 microM) or 5 mM N-acetylcysteine (NAC) for one hour prior to the addition of OA. Cell proliferation was measured by methylthiazoletetrazolium (MTT) assays, proliferating cell nuclear antigen (PCNA) expression, and fibronectin secretion by Western blot analysis, and dichlorofluorescein (DCF)-sensitive cellular ROS by fluorescence-activated cell scanning (FACS). RESULTS OA (100 microM) increased cell proliferation, as measured by MTT (by 1.6-fold), PCNA expression, fibronectin secretion, and cellular ROS (by 1.6-fold). Treatment with MPA dose-dependently inhibited OA-induced VSMC proliferation, fibronectin secretion, and cellular ROS. Treatment with 5 mM NAC also inhibited OA-induced rat VSMC activation. CONCLUSIONS These results suggest that MPA inhibits OA-induced VSMC proliferation and matrix protein synthesis partially by inhibiting cellular ROS.
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- 2007
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21. Role of Reactive Oxygen Species in TGF-β1-Induced Mitogen-Activated Protein Kinase Activation and Epithelial-Mesenchymal Transition in Renal Tubular Epithelial Cells
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Hi Bahl Lee, Soo Taek Uh, Dong Young Rhyu, Yanqiang Yang, Jae Sook Song, Hunjoo Ha, and Geun Taek Lee
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MAPK/ERK pathway ,Cell signaling ,MAP Kinase Signaling System ,p38 mitogen-activated protein kinases ,Smad2 Protein ,SMAD ,Biology ,p38 Mitogen-Activated Protein Kinases ,Antioxidants ,Cell Line ,Kidney Tubules, Proximal ,Mesoderm ,Transforming Growth Factor beta1 ,Transforming Growth Factor beta ,Animals ,Epithelial–mesenchymal transition ,Phosphorylation ,Extracellular Signal-Regulated MAP Kinases ,Kinase ,NADPH Oxidases ,Epithelial Cells ,Hydrogen Peroxide ,General Medicine ,Cadherins ,Oxidants ,Fibrosis ,Actins ,Fibronectins ,Rats ,Cell biology ,DNA-Binding Proteins ,Biochemistry ,Nephrology ,Mitogen-activated protein kinase ,Trans-Activators ,biology.protein ,Nephritis, Interstitial ,Reactive Oxygen Species - Abstract
Epithelial-mesenchymal transition (EMT) plays an important role in renal tubulointerstitial fibrosis and TGF-beta1 is the key inducer of EMT. Phosphorylation of Smad proteins and/or mitogen-activated protein kinases (MAPK) is required for TGF-beta1-induced EMT. Because reactive oxygen species (ROS) are involved in TGF-beta1 signaling and are upstream signaling molecules to MAPK, this study examined the role of ROS in TGF-beta1-induced MAPK activation and EMT in rat proximal tubular epithelial cells. Growth-arrested and synchronized NRK-52E cells were stimulated with TGF-beta1 (0.2 to 20 ng/ml) or H(2)O(2) (1 to 500 microM) in the presence or absence of antioxidants (N-acetylcysteine or catalase), inhibitors of NADPH oxidase (diphenyleneiodonium and apocynin), mitochondrial electron transfer chain subunit I (rotenone), and MAPK (PD 98059, an MEK [MAP kinase/ERK kinase] inhibitor, or p38 MAPK inhibitor) for up to 96 h. TGF-beta1 increased dichlorofluorescein-sensitive cellular ROS, phosphorylated Smad 2, p38 MAPK, extracellular signal-regulated kinases (ERK)1/2, alpha-smooth muscle actin (alpha-SMA) expression, and fibronectin secretion and decreased E-cadherin expression. Antioxidants effectively inhibited TGF-beta1-induced cellular ROS, phosphorylation of Smad 2, p38 MAPK, and ERK, and EMT. H(2)O(2) reproduced all of the effects of TGF-beta1 with the exception of Smad 2 phosphorylation. Chemical inhibition of ERK but not p38 MAPK inhibited TGF-beta1-induced Smad 2 phosphorylation, and both MAPK inhibitors inhibited TGF-beta1- and H(2)O(2)-induced EMT. Diphenyleneiodonium, apocynin, and rotenone also significantly inhibited TGF-beta1-induced ROS. Thus, this data suggest that ROS play an important role in TGF-beta1-induced EMT primarily through activation of MAPK and subsequently through ERK-directed activation of Smad pathway in proximal tubular epithelial cells.
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- 2005
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22. Thermo-mechanical processing and properties of Cu–Fe–Cr microcomposites
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Yong Suk Kim, Sun Ig Hong, and Jae Sook Song
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Materials science ,Scattering ,Precipitation (chemistry) ,Metallurgy ,Metals and Alloys ,chemistry.chemical_element ,Conductivity ,Microstructure ,Copper ,Industrial and Manufacturing Engineering ,Computer Science Applications ,chemistry ,Impurity ,Modeling and Simulation ,Ultimate tensile strength ,Ceramics and Composites ,Deformation (engineering) - Abstract
Thermo-mechanical treatments have been employed in this study to optimize the strength and conductivity of Cu–Fe–Cr microcomposites. The ultimate tensile strength (UTS) and the conductivity of Cu–Fe–Cr wires drawn to the cold drawing strain η =4.8 without intermediate heat treatments (NH) were observed to be 920 MPa and 33.8% IACS, respectively, and those with heat treatments (IH-2) were 891 MPa and 41% IACS. Further drawing wires to the cold drawing strain η =6.3 after an additional heat treatment increased the conductivity from 43.1 to 53.3% IACS with a slight increase of hardness. The precipitation of impurities and alloying elements during intermediate heat treatments is thought to increase the conductivity due to the reduced impurity scattering. The activation volumes for deformation increased from 138 b 3 in the as-drawn wire to 230 b 3 in the wire annealed at 500 °C. Numerous particles were observed in Cu matrix and the spacing between these particles were found to be slightly smaller than the activation length (138 b =35 nm). The most probable rate controlling mechanism of Cu–Fe–Cr microcomposites is suggested to be the interaction between dislocations and precipitates in Cu matrix.
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- 2002
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23. Intracavernous delivery of a designed angiopoietin-1 variant rescues erectile function by enhancing endothelial regeneration in the streptozotocin-induced diabetic mouse
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Munkhbayar Tumurbaatar, Guo Nan Yin, Sun Hwa Shin, Woo Jean Kim, Hai-Rong Jin, Shuguang Piao, Min Ji Choi, Jae Sook Song, Ji-Kan Ryu, Jun-Kyu Suh, and Gou Young Koh
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Male ,medicine.medical_specialty ,Complications ,Endothelium ,Nitric Oxide Synthase Type III ,Angiogenesis ,Endocrinology, Diabetes and Metabolism ,Recombinant Fusion Proteins ,Blotting, Western ,Intracavernous injection ,Vascular permeability ,Diabetes Mellitus, Experimental ,Impotence, Vasculogenic ,chemistry.chemical_compound ,Mice ,Internal medicine ,Internal Medicine ,medicine ,Angiopoietin-1 ,Animals ,Endothelial dysfunction ,Analysis of Variance ,business.industry ,medicine.disease ,Streptozotocin ,Immunohistochemistry ,Endocrinology ,Erectile dysfunction ,medicine.anatomical_structure ,chemistry ,Apocynin ,business ,medicine.drug ,Penis - Abstract
OBJECTIVE Patients with diabetic erectile dysfunction often have severe endothelial dysfunction and respond poorly to oral phosphodiesterase-5 inhibitors. We examined the effectiveness of the potent angiopoietin-1 (Ang1) variant, cartilage oligomeric matrix protein (COMP)-Ang1, in promoting cavernous endothelial regeneration and restoring erectile function in diabetic animals. RESEARCH DESIGN AND METHODS Four groups of mice were used: controls; streptozotocin (STZ)-induced diabetic mice; STZ-induced diabetic mice treated with repeated intracavernous injections of PBS; and STZ-induced diabetic mice treated with COMP-Ang1 protein (days −3 and 0). Two and 4 weeks after treatment, we measured erectile function by electrical stimulation of the cavernous nerve. The penis was harvested for histologic examinations, Western blot analysis, and cGMP quantification. We also performed a vascular permeability test. RESULTS Local delivery of the COMP-Ang1 protein significantly increased cavernous endothelial proliferation, endothelial nitric oxide (NO) synthase (NOS) phosphorylation, and cGMP expression compared with that in the untreated or PBS-treated STZ-induced diabetic group. The changes in the group that received COMP-Ang1 restored erectile function up to 4 weeks after treatment. Endothelial protective effects, such as marked decreases in the expression of p47phox and inducible NOS, in the generation of superoxide anion and nitrotyrosine, and in the number of apoptotic cells in the corpus cavernosum tissue, were noted in COMP-Ang1–treated STZ-induced diabetic mice. An intracavernous injection of COMP-Ang1 completely restored endothelial cell-cell junction proteins and decreased cavernous endothelial permeability. COMP-Ang1–induced promotion of cavernous angiogenesis and erectile function was abolished by the NOS inhibitor, N-nitro-L-arginine methyl ester, but not by the NADPH oxidase inhibitor, apocynin. CONCLUSIONS These findings support the concept of cavernous endothelial regeneration by use of the recombinant Ang1 protein as a curative therapy for diabetic erectile dysfunction.
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- 2011
24. 881 INTRACAVERNOUS DELIVERY OF DESIGNED ANGIOPOIETIN-1 VARIANT RESCUES ERECTILE FUNCTION THROUGH ENHANCED CAVERNOUS ENDOTHELIAL REGENERATION IN THE STREPTOZOTOCIN-INDUCED DIABETIC MICE
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Guo Nan Yin, Jae Sook Song, Min Ji Choi, Hae-Do Jung, Hai-Rong Jin, Ji-Kan Ryu, Woo Jean Kim, Buyankhuu Tuvshintur, Do Hwan Seong, Jun-Kyu Suh, Shuguang Piao, Sun Hwa Shin, Gou Young Koh, and Munkhbayar Tumurbaatar
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medicine.medical_specialty ,Endocrinology ,Angiopoietin-1 ,business.industry ,Urology ,Endothelial regeneration ,Internal medicine ,medicine ,Diabetic mouse ,Erectile function ,Streptozotocin ,business ,medicine.drug - Published
- 2010
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25. 1071 SKI2162, A NOVEL TRANSFORMING GROWTH FACTOR-βTYPE I RECEPTOR KINASE (ALK5) INHIBITOR, ALLEVIATES FIBROSIS IN FIBROBLASTS DERIVED FROM HUMAN PEYRONIE′S PLAQUE
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Min Ji Choi, Ji-Kan Ryu, Munkhbayar Tumurbaatar, Sun Hwa Shin, Jae Sook Song, Hae-Do Jung, Jun-Kyu Suh, Woo Jean Kim, Do Hwan Seong, Hai-Rong Jin, Buyankhuu Tuvshintur, Shuguang Piao, and Guo Nan Yin
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medicine.medical_specialty ,Kinase ,business.industry ,Urology ,medicine.disease ,Endocrinology ,Transforming growth factor, beta 3 ,Fibrosis ,Internal medicine ,medicine ,Cancer research ,Receptor ,business ,Transforming growth factor - Published
- 2010
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26. Transforming growth factor (TGF)-β type I receptor kinase (ALK5) inhibitor alleviates profibrotic TGF-β1 responses in fibroblasts derived from Peyronie's plaque
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Jae Sook Song, Min Ji Choi, Jee Young Han, Guo Nan Yin, Sang-Jin Lee, Munkhbayar Tumurbaatar, Buyankhuu Tuvshintur, Ji-Kan Ryu, Seong-Jin Kim, Shuguang Piao, Jun-Kyu Suh, Woo Jean Kim, Mi-Hye Kwon, Hai-Rong Jin, and Sun Hwa Shin
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Adult ,Male ,medicine.medical_specialty ,Urology ,Endocrinology, Diabetes and Metabolism ,medicine.medical_treatment ,Blotting, Western ,Penile Induration ,Active Transport, Cell Nucleus ,Receptor, Transforming Growth Factor-beta Type I ,SMAD ,Smad2 Protein ,Protein Serine-Threonine Kinases ,Extracellular matrix ,Transforming Growth Factor beta1 ,Endocrinology ,Internal medicine ,medicine ,Humans ,Smad3 Protein ,Phosphorylation ,Fibroblast ,Cells, Cultured ,Aged ,biology ,Chemistry ,Transforming growth factor beta ,Fibroblasts ,Middle Aged ,Molecular biology ,Extracellular Matrix ,Fibronectin ,Psychiatry and Mental health ,Cytokine ,medicine.anatomical_structure ,Reproductive Medicine ,Cell culture ,biology.protein ,Receptors, Transforming Growth Factor beta ,Transforming growth factor ,Penis - Abstract
Introduction Transforming growth factor-β1 (TGF-β1) has been identified as an important fibrogenic cytokine associated with Peyronie's disease (PD). Aim The aim of this study was to study the differential expression of the TGF-β1 and Smad transcription factors in plaque tissue from PD patients and to determine the antifibrotic effect of SKI2162 (SK Chemicals, Seoul, South Korea), a novel small-molecule inhibitor of activin receptor-like kinase 5 (ALK5), a type I receptor of TGF-β, in primary fibroblasts derived from human PD plaque. Methods Plaque tissue was isolated from five PD patients, and tunica albuginea tissue was obtained from four control patients. Plaque tissues from a patient with PD were used for primary fibroblast culture. Fibroblasts were pretreated with SKI2162 (10 µM) and then stimulated with TGF-β1 (10 ng/mL). Main Outcome Measures The plaque or tunica albuginea tissue was stained with Masson's trichrome or antibody to TGF-β1, phospho-Smad2 (P-Smad2), and P-Smad3. Protein was extracted from treated fibroblasts for Western blotting, and the membranes were probed with antibody to P-Smad2/Smad2, P-Smad3/Smad3, plasminogen activator inhibitor-1, fibronectin, collagen I, and collagen IV. We also determined the inhibitory effect of SKI2162 on TGF-β1-induced nuclear translocation of Smad2/3 in fibroblasts. Results The plaque tissue from PD patients showed higher TGF-β1, P-Smad2, and P-Smad3 immunoreactivity than did the tunica albuginea tissue from control patients. SKI2162 not only blocked TGF-β1-induced phosphorylation and nuclear translocation of Smad2 and Smad3, but also inhibited the production of extracellular matrix markers in fibroblasts derived from human PD plaque. Conclusion In light of the pivotal role of TGF-β and Smads in the pathogenesis of PD, pharmacologic inhibition of ALK5 may represent a novel targeted approach to treating PD. Piao S, Choi MJ, Tumurbaatar M, Kim WJ, Jin H-R, Shin SH, Tuvshintur B, Yin GN, Song JS, Kwon M-H, Lee S-J, Han J-Y, Kim S-J, Ryu J-K, and Suh J-K. Transforming growth factor (TGF)-β type I receptor kinase (ALK5) inhibitor alleviates profibrotic TGF-β1 responses in fibroblasts derived from Peyronie's plaque.
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- 2010
27. Functional and morphologic characterizations of the diabetic mouse corpus cavernosum: comparison of a multiple low-dose and a single high-dose streptozotocin protocols
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Min Ji Choi, Moonsuk Nam, Woo Jean Kim, Ji-Kan Ryu, Hai-Rong Jin, Sun Hwa Shin, Jun-Kyu Suh, Jae Sook Song, Munkhbayar Tumurbaatar, Shuguang Piao, and Buyankhuu Tuvshintur
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Male ,medicine.medical_specialty ,Urology ,Endocrinology, Diabetes and Metabolism ,Drug Administration Schedule ,Streptozocin ,Diabetes Mellitus, Experimental ,chemistry.chemical_compound ,Mice ,Endocrinology ,Clinical Protocols ,Erectile Dysfunction ,Enos ,In vivo ,Diabetes mellitus ,Internal medicine ,medicine ,Animals ,biology ,Dose-Response Relationship, Drug ,business.industry ,Nitrotyrosine ,Hemodynamics ,Muscle, Smooth ,Streptozotocin ,medicine.disease ,biology.organism_classification ,Pathophysiology ,Mice, Inbred C57BL ,Psychiatry and Mental health ,Disease Models, Animal ,medicine.anatomical_structure ,Erectile dysfunction ,Diabetes Mellitus, Type 1 ,Reproductive Medicine ,chemistry ,Cavernous tissue ,Feasibility Studies ,business ,medicine.drug ,Penis - Abstract
Introduction With the advent of genetically modified mice, it seems particularly advantageous to develop a mouse model of diabetic erectile dysfunction. Aim To establish a mouse model of type I diabetes by implementation of either multiple low‐dose streptozotocin (STZ) protocol or single high‐dose STZ protocol and to evaluate morphologic alterations in the cavernous tissue and subsequent derangements in penile hemodynamics in vivo. Methods Eight‐week‐old C57BL/6J mice were divided into three groups: a control group, a group administered the multiple low‐dose STZ protocol (50 mg/kg × 5 days), and a group administered the single high‐dose STZ protocol (200 mg/kg). Main Outcome Measures After 8 weeks, erectile function was measured by electrical stimulation of the cavernous nerve. The penis was then harvested and stained with hydroethidine (in situ analysis of superoxide anion), TUNEL, or antibodies to nitrotyrosine (marker of peroxynitrite formation), PECAM‐1, smooth muscle α‐actin, and phospho‐eNOS. Penis specimens from a separate group of animals were used for phospho‐eNOS and eNOS western blot or cGMP determination. Results Erectile function was significantly less in diabetic groups than in control group. The generation of superoxide anion and nitrotyrosine and the number of apoptotic cells in both cavernous endothelial and smooth muscle cells were significantly higher in diabetic groups than in control group. Cavernous tissue phospho‐eNOS and cGMP expression and the number of endothelial and smooth muscle cells were lower in diabetic groups than in control group. Both diabetic models resulted in similar structural and functional derangements in the corpus cavernosum; however, the mortality rate was higher in mice receiving single high‐dose of STZ than in those receiving multiple low‐doses. Conclusion The mouse model of type I diabetes is useful and technically feasible for the study of the pathophysiologic mechanisms involved in diabetic erectile dysfunction. Jin H‐R, Kim WJ, Song JS, Choi MJ, Piao S, Shin SH, Tumurbaatar M, Tuvshintur B, Nam M‐S, Ryu J‐K, and Suh, J‐K. Functional and morphologic characterizations of the diabetic mouse corpus cavernosum: comparison of a multiple low‐dose and a single high‐dose streptozotocin protocols.
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- 2009
28. 301 INTRACAVERNOUS DELIVERY OF COMP-ANGIOPOIETIN-1 PROTEIN RESCUES ERECTILE FUNCTION THROUGH ENHANCED CAVERNOUS ENDOTHELIAL REGENERATION IN THE STREPTOZOTOCIN-INDUCED DIABETIC MICE
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Gou Young Koh, Jae Sook Song, Ji-Kan Ryu, Hai-Rong Jin, Min Ji Choi, D.H. Seong, Jun-Kyu Suh, Sun Hwa Shin, B. Tuvshintur, Woo Jean Kim, Munkhbayar Tumurbaatar, S.M. Yoon, and Shuguang Piao
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medicine.medical_specialty ,Endocrinology ,Angiopoietin-1 ,business.industry ,Urology ,Internal medicine ,Endothelial regeneration ,medicine ,Diabetic mouse ,Erectile function ,Streptozotocin ,business ,medicine.drug - Published
- 2010
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29. INTRACAVERNOUS DELIVERY OF COMP-ANGIOPOIETIN-1 PROTEIN AS A NOVEL THERAPEUTIC STRATEGY FOR TYPE II DIABETES-INDUCED ERECTILE DYSFUNCTION
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Jae Sook Song, Sang-Min Yoon, Hai-Rong Jin, Jee Young Han, Sun Hwa Shin, Jun-Kyu Suh, Gou Young Koh, Munkhbayar Tumurbaatar, Ji-Kan Ryu, Woo Jean Kim, Shuguang Piao, and Buyankhuu Tuvshintur
- Subjects
Oncology ,Type ii diabetes ,medicine.medical_specialty ,Erectile dysfunction ,Angiopoietin-1 ,business.industry ,Urology ,Internal medicine ,medicine ,medicine.disease ,business ,Therapeutic strategy - Published
- 2009
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30. Intracavernous Delivery of a Designed Angiopoietin-1 Variant Rescues Erectile Function by Enhancing Endothelial Regeneration in the Streptozotocin-Induced Diabetic Mouse.
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Hai-Rong Jin, Woo Jean Kim, Jae Sook Song, Shuguang Piao, Min Ji Choi, Tumurbaatar, Munkhbayar, Sun Hwa Shin, Guo Nan Yin, Gou Young Koh, Ji-Kan Ryu, and Jun-Kyu Suh
- Subjects
IMPOTENCE ,STREPTOZOTOCIN ,DIABETES ,PHOSPHODIESTERASE inhibitors ,PROTEINS ,MICE - Abstract
OBJECTIVE--Patients with diabetic erectile dysfunction often have severe endothelial dysfunction and respond poorly to oral phosphodiesterase-5 inhibitors. We examined the effectiveness of the potent angiopoietin-1 (Ang1) variant, cartilage oligomeric matrix protein (COMP)-Ang1, in promoting cavernous endothelial regeneration and restoring erectile function in diabetic animals. RESEARCH DESIGN AND METHODS--Four groups of mice were used: controls; streptozotocin (STZ)-induced diabetic mice; STZ-induced diabetic mice treated with repeated intracavernous injections of PBS; and STZ-induced diabetic mice treated with COMP-Ang1 protein (days -3 and 0). Two and 4 weeks after treatment, we measured erectile function by electrical stimulation of the cavernous nerve. The penis was harvested for histologic examinations, Western blot analysis, and cGMP quantification. We also performed a vascular permeability test. RESULTS--Local delivery of the COMP-Ang1 protein significantly increased cavernous endothelial proliferation, endothelial nitric oxide (NO) synthase (NOS) phosphorylation, and cGMP expression compared with that in the untreated or PBS-treated STZ-induced diabetic group. The changes in the group that received COMP-Ang1 restored erectile function up to 4 weeks after treatment. Endothelial protective effects, such as marked decreases in the expression of p47
phox and inducible NOS, in the generation of superoxide anion and nitrotyrosine, and in the number of apoptotic cells in the corpus cavernosum tissue, were noted in COMP-Ang1-treated STZ-induced diabetic mice. An intracavernous injection of COMP-Ang1 completely restored endothelial cell-cell junction proteins and decreased cavernous endothelial permeability. COMP-Ang1-induced promotion of cavernous angiogenesis and erectile function was abolished by the NOS inhibitor, N-nitro-L-arginine methyl ester, but not by the NADPH oxidase inhibitor, apocynin. CONCLUSIONS--These findings support the concept of cavernous endothelial regeneration by use of the recombinant Ang1 protein as a curative therapy for diabetic erectile dysfunction. [ABSTRACT FROM AUTHOR]- Published
- 2011
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31. Mycophenolic acid inhibits oleic acid-induced mesangial cell activation through both cellular reactive oxygen species and inosine monophosphate dehydrogenase 2 pathways.
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Kyu Ha Huh, Hyung Joon Ahn, Jehyun Park, Man Ki Ju, Jae Sook Song, Myoung Soo Kim, Soon Il Kim, and Yu Seu Kim
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OLEIC acid ,IMP dehydrogenase ,HOMOGRAFTS ,KIDNEY diseases ,SMALL interfering RNA ,MICE - Abstract
The synthesis of extracellular matrix (ECM) in mesangial cells (MCs) plays important roles in the development and progression of renal diseases, including chronic allograft nephropathy. Mycophenolic acid (MPA), an inhibitor of inosine monophosphate dehydrogenase 2 (IMPDH2), suppresses MC proliferation and ECM synthesis. However, the exact inhibitory mechanism of MPA on MCs has not been clearly elucidated. In this study we compared the inhibitory effects of MPA and IMPDH2 reduction [by using small interfering RNA (siRNA)] on oleic acid (OA)-induced fibronectin secretion and cellular reactive oxygen species (ROS) in mouse MCs. Growth-arrested MCs were stimulated with OA in the presence or absence of MPA, IMPDH2 siRNA, N-acetylcysteine (NAC), transforming growth factor beta (TGF-β) antibody or exogenous guanosine. Fibronectin secretion into the medium was examined by Western blot, dichlorodihydrofluorescein (DCF)-sensitive cellular ROS by fluorescence-activated cell scanning (FACS), TGF-β levels in the media by enzyme-linked immunosorbent assay (ELISA). OA increased fibronectin secretion, TGF-β and cellular ROS levels. A TGF-β neutralizing antibody effectively suppressed OA-induced fibronectin secretion. NAC and MPA completely suppressed OA-induced fibronectin secretion and decreased the levels of TGF-β and cellular ROS. However, IMPDH2 siRNA partly inhibited OA-induced MC activation. Exogenous guanosine successfully reversed the inhibitory effects of IMPDH2 siRNA on OA-induced MC activation. Pleiotropic inhibitory effect of MPA on OA-induced mouse MC activation was mediated via its antioxidant effect on cellular ROS production and partly via inhibition of IMPDH2 itself. Our results implicate ROS as an alternative therapeutic target for the prevention of hyperlipidemia-related glomerulopathy, chronic allograft nephropathy, and subsequent graft loss. [ABSTRACT FROM AUTHOR]
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- 2009
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32. Intracavernous Delivery of Synthetic Angiopoietin-1 Protein as a Novel Therapeutic Strategy for Erectile Dysfunction in the Type II Diabetic db/db Mouse Jin et al. Angiopoietin-1 in Erectile Dysfunction.
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Hai-Rong Jin, Woo Jean Kim, Jae Sook Song, Shuguang Piao, Munkhbayar Tumurbaatar, Sun Hwa Shin, Min Ji Choi, Buyankhuu Tuvshintur, Kang-Moon Song, Mi-Hye Kwon, Guo Nan Yin, Gou Young Koh, Ji-Kan Ryu, and Jun-Kyu Suh
- Subjects
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IMPOTENCE , *TYPE 2 diabetes , *PHOSPHATASES , *LEPTIN , *PHOSPHORYLATION - Abstract
Patients with erectile dysfunction (ED) associated with type II diabetes often have impaired endothelial function and tend to respond poorly to oral phosphodiesterase type 5 inhibitors. Therefore, neovascularization is a promising strategy for curing diabetic ED. To determine the effectiveness of a soluble, stable, and potent angiopoietin-1 (Ang1) variant, cartilage oligomeric matrix protein (COMP)-Ang1, in promoting cavernous angiogenesis and erectile function in a mouse model of type II diabetic ED. Sixteen-week-old male db/db mice (in which obesity and type II diabetes are caused by a mutation in the leptin receptor) and control C57BL/6J mice were used and divided into four groups (N = 14 per group): age-matched controls; db/db mice receiving two successive intracavernous injections of phosphate-buffered saline (PBS) (days −3 and 0; 20 µL); db/db mice receiving a single intracavernous injection of COMP-Ang1 protein (day 0; 5.8 µg/20 µL); and db/db mice receiving two successive intracavernous injections of COMP-Ang1 protein (days −3 and 0; 5.8 µg/20 µL). Two weeks later, erectile function was measured by electrical stimulation of the cavernous nerve. The penis was then harvested and stained with antibodies to platelet/endothelial cell adhesion molecule-1 (PECAM-1) (endothelial cell marker), phosphohistone H3 (PH3, a nuclear protein indicative of cell proliferation), phospho-endothelial nitric oxide synthase (eNOS), and eNOS. Penis specimens from a separate group of animals were used for cyclic guanosine monophosphate (cGMP) and cyclic adenosine monophosphate (cAMP) quantification. Local delivery of COMP-Ang1 protein significantly increased eNOS phosphorylation and cGMP and cAMP expression compared with that in the group treated with PBS. Repeated intracavernous injections of COMP-Ang1 protein completely restored erectile function and cavernous endothelial content through enhanced cavernous neoangiogenesis as evaluated by PECAM-1 and PH3 immunohistochemistry and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling assay, whereas a single injection of COMP-Ang1 protein elicited partial improvement. Cavernous neovascularization using recombinant Ang1 protein is a novel therapeutic strategy for the treatment of ED resulting from type II diabetes. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
33. Functional and Morphologic Characterizations of the Diabetic Mouse Corpus Cavernosum: Comparison of a Multiple Low-Dose and a Single High-Dose Streptozotocin Protocols.
- Author
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Hai-Rong Jin, Woo Jean Kim, Jae Sook Song, Min Ji Choi, Shuguang Piao, Sun Hwa Shin, Munkhbayar Tumurbaatar, Buyankhuu Tuvshintur, Moon-Suk Nam, Ji-Kan Ryu, and Jun-Kyu Suh
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IMPOTENCE , *DIABETES , *LABORATORY mice , *STREPTOZOTOCIN , *TISSUES , *HEMODYNAMICS - Abstract
Introduction. With the advent of genetically modified mice, it seems particularly advantageous to develop a mouse model of diabetic erectile dysfunction. Aim. To establish a mouse model of type I diabetes by implementation of either multiple low-dose streptozotocin (STZ) protocol or single high-dose STZ protocol and to evaluate morphologic alterations in the cavernous tissue and subsequent derangements in penile hemodynamics in vivo. Methods. Eight-week-old C57BL/6J mice were divided into three groups: a control group, a group administered the multiple low-dose STZ protocol (50 mg/kg × 5 days), and a group administered the single high-dose STZ protocol (200 mg/kg). Main Outcome Measures. After 8 weeks, erectile function was measured by electrical stimulation of the cavernous nerve. The penis was then harvested and stained with hydroethidine (in situ analysis of superoxide anion), TUNEL, or antibodies to nitrotyrosine (marker of peroxynitrite formation), PECAM-1, smooth muscle α-actin, and phospho-eNOS. Penis specimens from a separate group of animals were used for phospho-eNOS and eNOS western blot or cGMP determination. Results. Erectile function was significantly less in diabetic groups than in control group. The generation of superoxide anion and nitrotyrosine and the number of apoptotic cells in both cavernous endothelial and smooth muscle cells were significantly higher in diabetic groups than in control group. Cavernous tissue phospho-eNOS and cGMP expression and the number of endothelial and smooth muscle cells were lower in diabetic groups than in control group. Both diabetic models resulted in similar structural and functional derangements in the corpus cavernosum; however, the mortality rate was higher in mice receiving single high-dose of STZ than in those receiving multiple low-doses. Conclusion. The mouse model of type I diabetes is useful and technically feasible for the study of the pathophysiologic mechanisms involved in diabetic erectile dysfunction. Jin H-R, Kim WJ, Song JS, Choi MJ, Piao S, Shin SH, Tumurbaatar M, Tuvshintur B, Nam M-S, Ryu J-K, and Suh, J-K. Functional and morphologic characterizations of the diabetic mouse corpus cavernosum: comparison of a multiple low-dose and a single high-dose streptozotocin protocols. J Sex Med 2009;6:3289–3304. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
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