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Shin HJ, Song JH, Jung JY, Kwak YK, Kay CS, Kang YN, Choi BO, Jang HS, Son SH. Advantage of 3D volumetric dosemeter in delivery quality assurance of dynamic arc therapy: comparison of pencil beam and Monte Carlo calculations. Br J Radiol 2013; 86:20130353. [DOI: 10.1259/bjr.20130353] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Yoo EJ, Kim JH, Song JH, Yoon TS, Choi YJ, Kang CJ. Resistive switching characteristics of the Cr/ZnO/Cr structure. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2013; 13:6395-6399. [PMID: 24205668 DOI: 10.1166/jnn.2013.7615] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Resistive random access memory (ReRAM) with conductor-dielectric-conductor structures has attracted extensive attention for next generation nonvolatile memory devices. The resistive switching effect has been observed in various materials, such as metal oxides and chalcogenide oxides. From our findings, we advocate the resistive switching characteristics of zinc oxide thin film, due to its simple composition and ease of manipulation. In this study, we investigated the current-voltage (I-V) characteristics of the Cr/ZnO/Cr capacitor structure. The Cr electrode and ZnO thin film were deposited by radio frequency magnetron sputtering at room temperature. The top electrode layers were patterned by 100 microm x 100 microm. The fabricated devices of the Cr/ZnO/Cr structures exhibited bipolar switching behavior. In addition, using the Cr-coated AFM tip replaced with the top electrode enabled us to map the local current image and measure the current flow at each point. This gave us more information to verify the resistive switching mechanism of ZnO thin film.
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Ponnusamy K, Kappachery S, Thekeettle M, Song JH, Kweon JH. Anti-biofouling property of vanillin on Aeromonas hydrophila initial biofilm on various membrane surfaces. World J Microbiol Biotechnol 2013; 29:1695-703. [PMID: 23539151 DOI: 10.1007/s11274-013-1332-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Accepted: 03/20/2013] [Indexed: 11/29/2022]
Abstract
Biofouling is a serious problem on filter membranes of water purification systems due to formation of bacterial biofilms, which can be detrimental to the membrane performance. Biofouling occurs on membrane surface and therefore greatly influences the physical and chemical aspects of the surface. Several membranes including microfiltration, ultrafiltration, and reverse osmosis (RO) membranes were used to learn about the anti-biofouling properties of vanillin affecting the membrane performances. Vanillin has been recognized as a potential quorum quenching compound for Aeromonas hydrophila biofilms. The initial attachment and dynamics of biofilm growth were monitored using scanning electron microscopy and confocal laser scanning microscopy. Biofilm quantities were measured using a plate count method and total protein determinations. Vanillin addition was effective in the prevention of biofilm formation on the tested membrane surfaces. Among the membranes, RO membranes made with cellulose acetate showed the most substantial reduction of biofilm formation by addition of vanillin. The biofilm reduction was confirmed by the results of surface coverage, biomass and protein accumulation. The HPLC spectrum of the spent culture with vanillin addition showed that vanillin may interfere with quorum sensing molecules and thus prevent the formation of the biofilms.
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Park JW, Jang AN, Song JH, Park CY, Lee YS. Electronic structure of Zn doped Fe3O4 thin films. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2013; 13:1895-1898. [PMID: 23755615 DOI: 10.1166/jnn.2013.6996] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We investigated the effect of Zn doping on the electronic property of magnetite by using optical spectroscopy. The (Zn(x)Fe(1-x))Fe2O4 (ZFFO) (x = 0, 0.2, 0.4, and 0.5) samples were prepared by PLD technique. The XRD measurement revealed that all the samples have an inverse spinel-type of crystalline structure. The M-H curves indicate that the saturation magnetization reduces with the increasing x. From the spectroscopic ellipsometry and infrared spectroscopy, we found that the doping of nonmagnetic Zn2+ ions leads to the dramatic change in the electronic structure of the ZFFO films. We discuss the correlation of our spectra with the electric and magnetic properties of the ZFFO films.
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Song JH, Kim DH, Kim J. Total hip replacement arthroplasty with Mallory-Head system--minimum ten-year follow-up results. INTERNATIONAL ORTHOPAEDICS 2012; 36:2055-9. [PMID: 22864458 DOI: 10.1007/s00264-012-1627-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Accepted: 07/11/2012] [Indexed: 10/28/2022]
Abstract
PURPOSE The purpose of this study was to assess the clinical and radiographic results of a total hip arthroplasty with the double tapered Mallory-Head system. METHODS The clinical and radiographic results of a consecutive series of 81 total hip replacements in 75 patients were reviewed 10-15 years (average 11.4 years) postoperatively. The patients' underlying conditions were avascular necrosis in 46 hips (57 %), osteoarthritis in 12 hips (15 %), RA in nine hips (11 %), and others. Clinical results were evaluated based on the modified Harris hip score and modified Merle d'Aubigné-Postel score. A radiographic analysis was performed. RESULTS The average modified Harris hip score improved from a preoperative score of 56 points to a postoperative 92 points. The average modified Merle d'Aubigné-Postel score was 15 points at the latest follow up, and 55 hips (68 %) were classified as the clinical grades of excellent or good results. One acetabular component was revised because of loosening, and one was revised for recurrent dislocation. CONCLUSION The clinical and radiological evaluations of the total hip replacements using the Mallory-Head system showed good results.
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Song JH, Lee JY, Chung YG, Park IJ. Distal interphalangeal joint arthrodesis with a headless compression screw: morphometric and functional analyses. Arch Orthop Trauma Surg 2012; 132:663-9. [PMID: 22012197 DOI: 10.1007/s00402-011-1413-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Indexed: 10/16/2022]
Abstract
INTRODUCTION We performed radiologic measurement of the distal and middle phalanges in volunteers to determine the size of a headless compression screw suitable for distal interphalangeal (DIP) joint arthrodesis in Korean subjects and report on clinical results using an acutrak fusion screw. MATERIALS AND METHODS Radiologic measurements on the distal and middle phalanx were performed to determine the optimal size of screw. Five hundred fingers from 50 adult Koreans without any abnormality on plain radiographs were selected and anteroposterior and lateral radiographs were obtained for measurements. For the distal phalanx, the narrowest diameter of the cortical bone was measured to determine the minimal diameter of the screw that would not penetrate the cortex. For the middle phalanx, the narrowest diameter of the medullary canal was measured to determine the appropriate size of the screw for fixation. Between May 2004 and December 2007, there were 23 fingers in 22 patients (6 male, 16 female) that had finger DIP joint or thumb IP joint arthrodesis performed with the acutrak fusion screws. At the final follow up, time to union, complications, clinical fusion angle, pinch power, visual analogue score (VAS) for pain and the Korean version of the disabilities of the arm, shoulder and hand (DASH) questionnaire were assessed. RESULTS In the distal phalanx, the narrowest diameter of the cortex was 2.64 ± 0.51 mm for the little finger. In the middle phalanx, the narrowest diameter of the medullary canal was 1.83 ± 0.50 mm for the little finger and 4.17 ± 0.68 for the thumb. The mean time to union was 10 weeks (range 8-12). The mean clinical fusion angle of the DIP joint was 11.9° (range 0-20). The VAS pain score was 0.4 (range 0-3). Pinch power was 75% of the normal side. The average Korean DASH score was 5 points (range 0-8). We experienced one intraoperative fixation failure for thumb IP joint arthrodesis caused by a wide medullary canal of the proximal phalanx. CONCLUSION The acutrak fusion screw was a feasible and adequate tool for DIP arthrodesis, particularly in Koreans. However, meticulous attention to technique was important to avoid complications in some little fingers. If preoperative radiographs suggest the thumb has a wide medullary canal, alternate methods of fixation should be considered.
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Kim J, Park S, Kang HM, Ahn CW, Kwon HC, Song JH, Lee YJ, Lee KH, Yang H, Baek SY, Yoo SH, Kim SH, Kim H. Human insulin secreted from insulinogenic xenograft restores normoglycemia in type 1 diabetic mice without immunosuppression. Cell Transplant 2012; 21:2131-47. [PMID: 22490341 DOI: 10.3727/096368912x636803] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
In the present study, we examined the therapeutic potential of human amnion-derived insulin-secreting cells for type 1 diabetes. Human amniotic mesenchymal stem cells (hAMs) were isolated from amnion and cultivated to differentiate into insulin-secreting cells in vitro. After culture in vitro, the differentiated cells (hAM-ISCs) were intensively stained with dithizone and secreted insulin and c-peptide in a high-glucose-dependent manner. They expressed mRNAs of pancreatic cell-related genes, including INS, PDX1, Nkx6-1, NEUROG3, ISL1, NEUROD1, GLUT1, GLUT2, PC1/3, PC2, GCK, PPY, SST, and GC, and were positive for human insulin and c-peptide. Transplantation of hAM-ISCs into the kidneys of mice with streptozotocin-induced diabetes restored body weight and normalized the blood glucose levels, which lasted for 210 days. Only human insulin and c-peptide were detected in the blood of normalized mice after 2 months of transplantation, but little mouse insulin and c-peptide. Removal of graft-bearing kidneys from these mice resulted in causing hyperglycemia again. Human cell-specific gene, hAlu, and human pancreatic cell-specific genes, insulin, PDX1, GLUT1, GLP1R, Nkx6-1, NEUROD1, and NEUROG3, were detected in the graft-bearing kidneys. Colocalization of human insulin and human nuclei antigen was also observed. These results demonstrate that hAMs could differentiate into functional insulin-secreting cells in vitro, and human insulin secreted from hAM-ISCs following transplantation into type 1 diabetic mice could normalize hyperglycemia, overcoming immune rejection for a long period.
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Kim H, Dwyer L, Song JH, Martin-Cano FE, Bahney J, Peri L, Britton FC, Sanders KM, Koh SD. Identification of histamine receptors and effects of histamine on murine and simian colonic excitability. Neurogastroenterol Motil 2011; 23:949-e409. [PMID: 21806740 PMCID: PMC3173574 DOI: 10.1111/j.1365-2982.2011.01760.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Inflammatory responses can include recruitment of cells of hematopoietic origin to the tunica muscularis. These cells can secrete a variety of factors which can reset the gain of smooth muscle cells (SMC) and influence motor patterns. Histamine (H), a major mediator in inflammation, is released by mast cells and exerts diverse effects in SMC by binding to H receptors. The profiles of H receptor expression in animal models used to study inflammatory diseases are unknown. METHODS Histamine receptor expression and electro-mechanical responses to H were tested in simian and murine colonic smooth muscle using qualitative and quantitative PCR, isometric force measurements, microelectrode recordings and patch clamp techniques. KEY RESULTS H1, H2, and H4 receptor transcripts were expressed at similar levels in simian colonic tissue whereas only the H2 receptor transcript was detected in murine colonic tissue. Stimulation of simian colonic muscles with H caused depolarization and contraction in the presence of tetrodotoxin. Histamine activated non-selective cation channels in simian SMC. In contrast, H caused hyperpolarization and inhibited contractions of murine colon. The hyperpolarization was inhibited by the K(ATP) channel blocker, glibenclamide. Histamine-activated K(+) currents were inhibited by glibenclamide in murine colonic SMC. CONCLUSIONS & INFERENCES Histamine receptor expression in simian SMC was similar to that reported in humans. However, H receptor profile and responses to H were considerably different in mice. Thus, monkey colon may be a more suitable model to study how inflammatory mediators affect the gain of smooth muscle excitability.
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Zhang LX, Song JH, Tan GJ, Li SS. First Report of Leaf Blight Caused by Nigrospora sphaerica on Curcuma in China. PLANT DISEASE 2011; 95:1190. [PMID: 30732046 DOI: 10.1094/pdis-04-11-0284] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Curcuma (family Zingiberaceae) is commonly cultivated for the use of rhizomes within traditional Chinese medicines. In October 2009 and 2010, severe leaf blight was observed on Curcuma wenyujin Y.H. Chen & C. Ling (4) in fields located in Ruian, China. The area of cultivation in Ruian encompasses 90% of the production in Zhejiang Province. Disease incidence was approximately 90% of plants observed in affected fields. Early symptoms were yellow-to-brown, irregular-shaped lesions on the leaf margin or tip. After several days, lesions expanded along the mid-vein until the entire leaf was destroyed. Blighted leaves turned grayish to dark brown and withered, and severely affected plants died. Eight fungal isolates were recovered from symptomatic C. wenyujin leaves, collected from eight different fields, on potato dextrose agar (PDA). These fungal colonies were initially white, becoming light to dark gray and produced black, spherical to subspherical, single-celled conidia (14 to 17 × 12 to 15 μm), which were borne on a hyaline vesicle at the tip of the conidiophores. On the basis of these morphological features, the isolates appeared to be similar to Nigrospora sphaerica (2). Strain ZJW-1 was selected as a representative for molecular identification. Genomic DNA was extracted from the isolate, and the internal transcribed spacer (ITS) region of the ribosomal DNA (ITS1-5.8S-ITS2) was amplified using ITS1 (5'-TCCGTAGGTGAACCTGCGG-3') and ITS4 (5'-TCCTCCGCTTATTGATATGC-3') primers (3). The ITS region was further cloned and sequenced (GenBank Accession No. JF738028) and was 99% identical to N. sphaerica (GenBank Accession No. FJ478134.1). On the basis of morphological data and the ITS rDNA sequence, the isolate was determined to be N. sphaerica. Pathogenicity tests were conducted on four leaves of four C. wenyujin plants by placing agar pieces (5 mm in diameter) from 8-day-old cultures on pushpin-wounded leaves. An equal number of control plants were wounded and inoculated with noncolonized PDA agar pieces. Plants were placed in moist chambers at 25°C with a 12-h photoperiod. Brown-to-black lesions were observed on wounded leaves after 3 days and expanded to an average of 56 × 40 mm 15 days after inoculation. No symptoms developed on the control leaves. The pathogen was reisolated from the margins of necrotic tissues but not from the controls. The pathogen has been reported as a leaf pathogen on several hosts worldwide (1). To our knowledge, this is the first report of N. sphaerica as a leaf pathogen of C. wenyujin in China. Future research will focus primarily on management of this disease. References: (1) D. F. Farr and A. Y. Rossman. Fungal Databases, Systematic Mycology and Microbiology Laboratory, USDA-ARS, Retrieved from http://nt.ars-grin.gov/fungaldatabases/ , March 31, 2011. (2) E. W. Mason. Trans. Brit. Mycol. Soc. 12:152, 1927. (3) T. J. White et al. PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, 1990. (4) J. Zhao et al. Molecules 15:7547, 2010.
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Song JH, Choi HJ. Silymarin efficacy against influenza A virus replication. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2011; 18:832-5. [PMID: 21377857 DOI: 10.1016/j.phymed.2011.01.026] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Revised: 11/26/2010] [Accepted: 01/23/2011] [Indexed: 05/16/2023]
Abstract
The anti-influenza A/PR/8/34 virus activity of silymarin was evaluated in MDCK cells and investigated the effect of silymarin on synthesis of viral mRNAs. Silymarin was investigated for its antiviral activity against influenza A/PR virus using a cytopathic effect (CPE) reduction method. Silymarin exhibited anti-influenza A/PR/8/34 virus activity of 98% with no cytotoxicity at the concentration of 100 μg/ml reducing the formation of a visible CPE. Oseltamivir also did show moderate antiviral activity of about 52% against influenza A/PR/8/34 virus at the concentration of 100 μg/ml. Furthermore, the mechanism of anti-influenza virus action in the inhibition of viral mRNA synthesis was analyzed by Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR), and the data indicated an inhibitory effect in late viral RNA synthesis compared with oseltamivir in the presence of 100 μg/ml of silymarin. Therefore, the potential of silymarin for use in treating influenza virus infection merits greater attention.
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Kourkoutis LF, Song JH, Hwang HY, Muller DA. Microscopic origins for stabilizing room-temperature ferromagnetism in ultrathin manganite layers. Proc Natl Acad Sci U S A 2010; 107:11682-5. [PMID: 20547875 PMCID: PMC2900658 DOI: 10.1073/pnas.1005693107] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
La(0.7)Sr(0.3)MnO(3) is a conducting ferromagnet at room temperature. Combined with thin SrTiO(3) layers, the resulting heterostructures could be used as highly spin-polarized magnetic-tunnel-junction memories. However, when shrunk to dimensions below an apparent critical thickness, the structures become insulating and ferromagnetic ordering is suppressed. Interface spin and charge modulations are thought to create an interfacial dead layer, thus fundamentally limiting the use of this material in atomic-scale devices. The thickness of this dead layer, and whether it is intrinsic, is still controversial. Here we use atomic-resolution electron spectroscopy to demonstrate that the degradation of the magnetic and transport properties of La(0.7)Sr(0.3)MnO(3)/SrTiO(3) multilayers correlates with atomic intermixing at the interfaces, and the presence of extended two-dimensional cation defects in the La(0.7)Sr(0.3)MnO(3) layers (in contrast to three-dimensional precipitates in thick films). When these extrinsic defects are eliminated, metallic ferromagnetism at room temperature can be stabilized in five-unit-cell-thick manganite layers in superlattices, placing the upper limit for any intrinsic dead layer at two unit cells per interface.
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Choi HJ, Bae EY, Song JH, Baek SH, Kwon DH. Inhibitory effects of orobol 7-O-D-glucoside from banaba (Lagerstroemia speciosa L.) on human rhinoviruses replication. Lett Appl Microbiol 2010; 51:1-5. [PMID: 20497313 DOI: 10.1111/j.1472-765x.2010.02845.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIMS The anti-human rhinovirus (HRV) activity of orobol 7-O-d-glucoside (O7G) from Lagerstroemia speciosa L. (Lythraceae) was evaluated in Hela cells. METHODS AND RESULTS We tested anti-HRV activity of O7G using a cytopathic effect (CPE) reduction method, which exhibited broad-spectrum anti-HRVs activity with a 50% inhibitory concentration (IC(50)) ranging from 0.58 to 8.80 microg ml(-1). The 50% cytotoxicity concentration (CC(50)) of O7G is more than 100 microg ml(-1), and the derived therapeutic indices are more than 12. Ribavirin didn't possess antiviral activity against HRV15, HRV3 and HRV5, but exhibited weak antiviral activity against HRV2 and HRV3, and showed strong anti-HRV6 and -14 activities. CONCLUSIONS These results suggest that O7G is a novel drug class with broad spectrum antiviral activity against HRV species A (HRV1B, HRV2, HRV15 and HRV40) and species B (HRV3, HRV6 and HRV14), as well as pleconaril-resistant virus (HRV5). SIGNIFICANCE AND IMPACT OF THE STUDY Therefore, these findings provide important information for the utilization of Q7G promising broad spectrum for human rhinovirus treatment.
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Lee MJ, Kim YS, Yoo CK, Song JH, Hwang SJ. Sewage sludge reduction and system optimization in a catalytic ozonation process. ENVIRONMENTAL TECHNOLOGY 2010; 31:7-14. [PMID: 20232674 DOI: 10.1080/09593330903283799] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The main objective of this study was to suggest a feasible, effective process for the reduction of sewage sludge using ozone oxidation catalysed by metal ion. A series of lab-scale experiments was conducted to select a suitable catalyst and its proper dose to achieve optimum sludge reduction. Using a central composite design under response surface methodology (RSM), system optimization with respect to sludge reduction and cost-effectiveness was performed by varying the independent parameters: dosages of ozone and ions. Five metal ions, Mn2+, Fe2+, Zn2+, CU2+, and Al3+1, were tested, and the manganese ion showed the highest sludge reduction, as measured by a decrease in total suspended solids. The ozone/Mn combination achieved approximately twice as much sludge reduction as the ozonation alone. Furthermore, the Mn dose of 10 mg/g-TS (total solids) resulted in the highest sludge reduction efficiency among the different doses, which ranged from 0 to 20 mg-Mn/g-TS. The predicted efficiency of sewage sludge reduction using the RSM was found to agree well with the experimental results, and the statistical analyses predicted optimum ranges for the doses of ozone and Mn ions, taking into account the overall cost for sewage sludge treatment.
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Lin SS, Hong JI, Song JH, Zhu Y, He HP, Xu Z, Wei YG, Ding Y, Snyder RL, Wang ZL. Phosphorus doped Zn(1-x)Mg(x)O nanowire arrays. NANO LETTERS 2009; 9:3877-3882. [PMID: 19757858 DOI: 10.1021/nl902067a] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We demonstrate the growth of phosphorus doped Zn(1-x)Mg(x)O nanowire (NW) using pulsed laser deposition. For the first time, p-type Zn(0.92)Mg(0.08)O:P NWs are likely obtained in reference to atomic force microscopy based piezoelectric output measurements, X-ray photoelectron spectroscopy, and the transport property between the NWs and a n-type ZnO film. A shallow acceptor level of approximately 140 meV is identified by temperature-dependent photoluminescence. A piezoelectric output of 60 mV on average has been received using the doped NWs. Besides a control on NW aspect ratio and density, band gap engineering has also been achieved by alloying with Mg to a content of x = 0.23. The alloyed NWs with controllable conductivity type have potential application in high-efficiency all-ZnO NWs based LED, high-output ZnO nanogenerator, and other optical or electrical devices.
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Lin SS, Song JH, Lu YF, Wang ZL. Identifying individual n- and p-type ZnO nanowires by the output voltage sign of piezoelectric nanogenerator. NANOTECHNOLOGY 2009; 20:365703. [PMID: 19687547 DOI: 10.1088/0957-4484/20/36/365703] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Based on a comparative study between the piezoelectric outputs of n-type nanowires (NWs) and n-core/p-shell NWs along with the previous study (Lu et al 2009 Nano. Lett. 9 1223), we demonstrate a one-step technique for identifying the conductivity type of individual ZnO nanowires (NWs) based on the output of a piezoelectric nanogenerator without destroying the sample. A negative piezoelectric output voltage indicates an NW is n-type and it appears after the tip scans across the center of the NW, while a positive output voltage reveals p-type conductivity and it appears before the tip scans across the central line of the NW. This atomic force microscopy based technique is reliable for statistically mapping the majority carrier type in ZnO NWs arrays. The technique may also be applied to other wurtzite semiconductors, such as GaN, CdS and ZnS.
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Song JH, Murphy RJ, Narayan R, Davies GBH. Biodegradable and compostable alternatives to conventional plastics. Philos Trans R Soc Lond B Biol Sci 2009; 364:2127-39. [PMID: 19528060 DOI: 10.1098/rstb.2008.0289] [Citation(s) in RCA: 268] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Packaging waste forms a significant part of municipal solid waste and has caused increasing environmental concerns, resulting in a strengthening of various regulations aimed at reducing the amounts generated. Among other materials, a wide range of oil-based polymers is currently used in packaging applications. These are virtually all non-biodegradable, and some are difficult to recycle or reuse due to being complex composites having varying levels of contamination. Recently, significant progress has been made in the development of biodegradable plastics, largely from renewable natural resources, to produce biodegradable materials with similar functionality to that of oil-based polymers. The expansion in these bio-based materials has several potential benefits for greenhouse gas balances and other environmental impacts over whole life cycles and in the use of renewable, rather than finite resources. It is intended that use of biodegradable materials will contribute to sustainability and reduction in the environmental impact associated with disposal of oil-based polymers. The diversity of biodegradable materials and their varying properties makes it difficult to make simple, generic assessments such as biodegradable products are all 'good' or petrochemical-based products are all 'bad'. This paper discusses the potential impacts of biodegradable packaging materials and their waste management, particularly via composting. It presents the key issues that inform judgements of the benefits these materials have in relation to conventional, petrochemical-based counterparts. Specific examples are given from new research on biodegradability in simulated 'home' composting systems. It is the view of the authors that biodegradable packaging materials are most suitable for single-use disposable applications where the post-consumer waste can be locally composted.
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Song JH, Maeng EJ, Cao Z, Kim SY, Nam SW, Lee JY, Park WS. The Glu346Lys polymorphism and frameshift mutations of the Methyl-CpG Binding Domain 4 gene in gastrointestinal cancer. Neoplasma 2009; 56:343-7. [PMID: 19469655 DOI: 10.4149/neo_2009_04_343] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
MBD4 (Methyl-CpG Binding Domain 4) is a human DNA repair protein that may be involved in DNA mismatch repair. The polymorphisms and frameshift mutations in MBD4 may influence cancer susceptibility and the development of cancer. The specific aim of this study was to investigate whether frameshift mutations of the MBD4 gene and the codon 346 polymorphism were associated with microsatellite instability (MSI) and the risk for gastrointestinal cancer. We examined the MSI, frameshift mutations and polymorphisms of the MBD4 gene in 84 patients with gastric cancers, 82 colorectal cancers and 299 healthy controls. MSI was found in 19 (22.6%) and 26 (31.7%) of the gastric and colorectal cancer samples, respectively. The mutation analysis revealed no frameshift mutations in the MBD4 gene among the gastrointestinal cancers. The frequencies of genotypes: Glu/Glu, Glu/Lys and Lys/Lys were 41.7% (35/84), 41.7% (35/84) and 16.6% (14/84), respectively, in the gastric cancer cases, and 42.7% (35/82), 36.6% (30/82) and 20.7% (17/82), respectively, in the colorectal cancers. MSI was not associated with the MBD4 codon 346 polymorphism and there was no significant difference in the frequency of the genotypes between healthy controls and gastric cancer patients (P=0.2748). However, the MBD4 codon 346 polymorphism was significantly associated with the risk of colorectal cancer (P=0.0315). Our findings suggest that microsatellite instability may not be associated with frameshift mutations in the MBD4 gene, and that the MBD4 codon 346 polymorphism may play arole in colorectal cancer susceptibility in the Korean population.
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Bae HJ, Song JH, Noh JH, Kim JK, Jung KH, Eun JW, Xie HJ, Ryu JC, Ahn YM, Kim SY, Lee SH, Yoo NJ, Lee JY, Park WS, Nam SW. Low frequency mutation of the Ephrin receptor A3 gene in hepatocellular carcinoma. Neoplasma 2009; 56:331-4. [PMID: 19469653 DOI: 10.4149/neo_2009_04_331] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
EphA3 is a component of the Eph/ephrin tyrosine kinase system, which participates in vasculature development. This receptor/ligand system is associated with various signaling pathways related to cell growth and viability, cytoskeletal organization, cell migration, and anti-apoptosis. Accumulated evidence suggests that aberrant regulation of EphA3 and its genetic alterations are implicated in the development and progression of various cancers. However, despite a high incidence of EphA3 over-expression, no such investigation has been performed in hepatocellular carcinoma. Thus, we investigated genetic alterations of the EphA3 gene in 73 cases of hepatocellular carcinoma by single-strand conformational polymorphism and sequencing. One novel D219V missense mutation was found in the extracellular domain of EphA3, and two genetic alterations in the intracellular sterile-alpha-motif (SAM) domain of EphA3 appeared to be polymorphisms. Although the functional assessments of this mutant are incomplete, it is believed that this novel EphA3 mutation may contribute to the development of hepatocellular carcinoma.
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Cao Z, Song JH, Park YK, Maeng EJ, Nam SW, Lee JY, Park WS. The p53 codon 72 polymorphism and susceptibility to colorectal cancer in Korean patients. Neoplasma 2009; 56:114-8. [PMID: 19239324 DOI: 10.4149/neo_2009_02_114] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
UNLABELLED TP53 is a major gene involved in the determination of proliferation or growth arrest at the cellular level. The polymorphism of p53 at codon 72 has been widely studied; this variation has been associated with cancer susceptibility and disease outcome. The specific aim of this study was to investigate whether the p53 codon 72 polymorphism is associated with individual susceptibility to colorectal cancer in Korean patients. The frequency of the polymorphism was examined in 156 patients with colorectal cancer and in 293 healthy controls. The polymorphism analysis was performed by amplifying exon 4 of p53 and digesting the products with restriction enzyme. The frequencies of genotypes: Arg/Arg, Arg/Pro and Pro/Pro were 34.6% (54/156), 43.0% (67/156) and 22.4% (35/156), respectively, in the cases with colorectal cancer, and 28.9% (114/293), 47.8% (140/293) and 13.3% (39/293), respectively, in the healthy controls. Statistically, there was a significant difference in the frequency of the genotypes when the healthy controls were compared to the patients with colorectal cancer (<em>p</em>=0.0459). The specific allele frequencies showed borderline significance (<em>p</em>=0.0502). Our findings suggest that the p53 Pro72 variant is associated with an increased risk for colorectal cancer in the Korean population. KEYWORDS p53, colorectal cancer, polymorphism, susceptibility, metastasis.
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Park JK, Song JH, He TC, Nam SW, Lee JY, Park WS. Overexpression of Wnt-2 in colorectal cancers. Neoplasma 2009; 56:119-23. [PMID: 19239325 DOI: 10.4149/neo_2009_02_119] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
UNLABELLED The binding of the Wnt ligand to its receptor Frizzled, activates the Wnt canonical signaling pathway in carcinogenesis as well as many cellular processes, including cellular proliferation and differentiation. Wnt-2, one of 19 members of the <em>Wnt</em> gene family, is frequently overexpressed in malignant tissues. Here, in order to investigate the role of Wnt-2 in colorectal carcinogenesis, we examined the expression of the Wnt-2 protein in 120 colorectal cancers by immunohistochemistry. Wnt-2 protein was expressed in the cell membrane and cytoplasm and up-regulated in 74 (61.7%) of 120 colorectal cancers. Statistically, overexpression of Wnt-2 protein was not associated with the clinical and pathological parameters studied, including tumor location, tumor size, clinical stage, lymph node metastasis, and 5-year survival (<em>P > </em>0.05). These results indicate that up-regulation of the Wnt-2 protein might play a role in the development of colorectal cancers, as an early event of carcinogenesis. KEYWORDS Wnt-2 protein, expression, immunohistochemistry, tissue microarray, colon cancer.
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Choi HJ, Lim CH, Song JH, Baek SH, Kwon DH. Antiviral activity of raoulic acid from Raoulia australis against Picornaviruses. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2009; 16:35-39. [PMID: 19097770 DOI: 10.1016/j.phymed.2008.10.012] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2008] [Revised: 09/02/2008] [Accepted: 10/24/2008] [Indexed: 05/27/2023]
Abstract
RNA viruses are a major source of respiratory diseases worldwide. The lack of effective therapeutical treatment underlines the importance of research for new antiviral compounds. Raoulic acid is a principal ingredient of the plant Raoulia australis Hook. F. Antiviral assay using cytopathic effect (CPE) reduction method showed that raoulic acid possessed strong antiviral activity against human rhinovirus 2 (HRV2) with a 50% inhibition concentration (IC(50)) value of less than 0.1mug/ml, human rhinovirus 3 (HRV3) with a IC(50) value of 0.19 microg/ml, coxsackie B3 (CB3) virus with IC(50) values of 0.33 microg/ml, coxsackie B4 (CB4) virus with IC(50) values of 0.40 microg/ml, and enterovirus 71 (EV71) virus with IC(50) values of less than 0.1 microg/ml. However, the compound did not possess antiviral activity against influenza A (Flu A/PR, Flu A/WS, H1N1) and B viruses at four concentrations ranging from 0.1 to 100 microg/ml.
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Lee MJ, Song JH, Hwang SJ. Enhanced bio-energy recovery in a two-stage hydrogen/methane fermentation process. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2009; 59:2137-2143. [PMID: 19494452 DOI: 10.2166/wst.2009.236] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A two-stage hydrogen/methane fermentation process has emerged as a feasible engineering system to recover bio-energy from wastewater. Hydrogen-producing bacteria (HPB) generate hydrogen from readily available carbohydrates, and organic acids produced during the hydrogen fermentation step can be degraded to generate methane in the following step. Three strong acids, HCl, H(2)SO(4), and HNO(3), were tested to determine the appropriate pre-treatment method for enhanced hydrogen production. The hydrogen production rates of 230, 290, and 20 L/kg(-glucose)/day was observed for the sludge treated with HCl, H(2)SO(4), and HNO(3), respectively, indicating that the acid pre-treatment using either HCl or H(2)SO(4) resulted in a significant increase in hydrogen production. The fluorescent in situ hybridization method indicated that the acid pre-treatment selectively enriched HPB including Clostridium sp. of cluster I from inoculum sludge. After hydrogen fermentation was terminated, the sludge was introduced to a methane fermentation reactor. This experiment showed methane production rates of 100, 30, and 13 L/kg(-glucose)/day for the sludge pre-treated with HCl, H(2)SO(4), and HNO(3), respectively, implying that both sulfate and nitrate inhibited the activity of methane-producing bacteria. Consequently, the acid pre-treatment might be a feasible option to enhance biogas recovery in the two-stage fermentation process, and HCl was selected as the optimal strong acid for the enrichment of HPB and the continuous production of methane.
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Kim YS, Lee JY, Yang SC, Song JH, Koh HS, Park WK. Comparative study of the influence of room-temperature and warmed fluid irrigation on body temperature in arthroscopic shoulder surgery. Arthroscopy 2009; 25:24-9. [PMID: 19111215 DOI: 10.1016/j.arthro.2008.08.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2008] [Revised: 06/29/2008] [Accepted: 08/16/2008] [Indexed: 02/02/2023]
Abstract
PURPOSE The purpose of this study was to evaluate the effect of irrigation fluid temperature on body temperature and other variables, and to determine their correlations. METHODS A prospective randomized study was performed of 50 patients undergoing arthroscopic shoulder surgery who received irrigation fluid either with room temperature or warmed to 37 degrees C to 39 degrees C. Core body temperature was checked at regular intervals, and additional variables, such as length of anesthesia and surgery, amount of irrigation fluid and intravenous fluid used, amount of bleeding, weight gain, and postoperative pain were collected during surgery and postoperatively. RESULTS The final core body temperature was 35.5 +/- 0.3 degrees C in the room-temperature fluid group and 36.2 +/- 0.3 degrees C in the warmed fluid group (P < .001). The temperature drop was 0.86 +/- 0.2 degrees C in the room-temperature fluid group and 0.28 +/- 0.2 degrees C in the warmed fluid group (P < .001). Hypothermia occurred in 91.3% of patients in the room-temperature fluid group; the incidence of hypothermia was much lower in the warmed fluid group (17.4%; P < .001). Of the variables measured, the patient's age and amount of irrigation fluid used correlated with core body temperature in the room-temperature fluid group. No variables correlated with core body temperature in the warmed fluid group. CONCLUSIONS Hypothermia occurred more often in shoulder arthroscopic surgery with room-temperature fluid irrigation than with warmed fluid irrigation. The patient's age and amount of irrigation fluid used correlate with core body temperature when using room-temperature irrigation fluid. The use of warm irrigation fluid during arthroscopic shoulder surgery decreases perioperative hypothermia, especially in elderly patients. LEVEL OF EVIDENCE Level I, therapeutic randomized controlled trial.
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Song JH, Kim MH, Shin KM, Choi HY, Song WH. Neurosurgical aspects of sedimentation levels in acute intracerebral haematoma. J Clin Neurosci 2008; 5:406-8. [PMID: 18639062 DOI: 10.1016/s0967-5868(98)90272-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/1997] [Accepted: 03/03/1997] [Indexed: 10/26/2022]
Abstract
We describe the neurosurgical aspects of sedimentation levels that are rarely found in acute intracerebral haematomas (ICH). We had four patients with acute ICH whose cerebral computed tomography revealed sedimentation levels. Two patients had received thrombolytic therapy for ischaemic heart disease and one for ischaemic stroke. Another patient, who was diagnosed later as having a coagulation disorder, did not have any medical history on admission. All patients had emergency ICH drainage under local anaesthesia. In the immediate postoperative period, we observed dramatic improvement in all the patients, without surgical complications. The sedimentation level in an ICH should be identified as a specific indicator of a coagulation defect and a thorough search for possible underlying coagulopathy is warranted. We believe that simple ICH drainage should be performed as the haematoma is in a liquid form.
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Kim CJ, Song JH, Cho YG, Cao Z, Lee YS, Nam SW, Lee JY, Park WS. Down-regulation of ATBF1 is a major inactivating mechanism in hepatocellular carcinoma. Histopathology 2008; 52:552-9. [PMID: 18312352 DOI: 10.1111/j.1365-2559.2008.02980.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS alpha-Fetoprotein (AFP) is frequently detected in hepatocellular carcinomas (HCCs) and AT motif binding factor 1 (ATBF1) down-regulates AFP gene expression in hepatic cells. The ATBF1 gene also inhibits cell growth and differentiation, and altered gene expression is associated with malignant transformation. The aim was to investigate the potential role of the ATBF1 gene in HCCs. METHODS AND RESULTS Somatic mutations, allelic loss and hypermethylation of the ATBF1 gene were analysed in 76 sporadic HCCs. The level of ATBF-1 mRNA expression was analysed using quantitative real-time reverse transcriptase-polymerase chain reaction. Genetic studies of the ATBF1 gene revealed absence of somatic mutation in the hotspot region and 15 (25%) of 60 informative cases showed allelic loss at the ATBF1 locus. Hypermethylation in the intron 1 region of the ATBF1 gene was detected in only one case. Interestingly, ATBF1 mRNA expression in HCCs was significantly reduced in 55 (72.4%) samples compared with the corresponding surrounding liver tissues. Reduced expression was not statistically associated with clinicopathological parameters including stage, histological grade, infective virus type, and serum alpha-fetoprotein level. CONCLUSIONS The ATBF1 gene may contribute to the development of HCCs via transcriptional down-regulation of mRNA expression, but not by genetic or epigenetic alterations.
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