16 results on '"Hwu, Y."'
Search Results
2. The Synthesis of Iron Oxide Nanoparticles via Seed-Mediated Process and its Cytotoxicity Studies
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Huang, J.-H., Parab, H. J., Liu, R. S., Lai, T.-C., Hsiao, M., Chen, C. H., Tsai, D.-P., Hwu, Y.-K., Magjarevic, R., editor, Nagel, J. H., editor, Lim, Chwee Teck, editor, and Goh, James C. H., editor
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- 2009
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3. pH dependence of synchrotron x-ray induced electroless nickel deposition.
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Borse, P. H., Yi, J. M., Je, J. H., Tsai, W. L., and Hwu, Y.
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ALKALIES ,SYNCHROTRONS ,X-rays ,NICKEL ,CHEMICAL reduction ,NANOPARTICLES ,ELECTROLYTES ,NUCLEATION - Abstract
We investigated the room temperature electroless nickel deposition on glass, induced by synchrotron x ray. By irradiating electrolytes with intense x ray the onset time for Ni reduction disappears at high electrolyte pH (>6.0) in sharp contrast with conventional electroless deposition. The time for Ni reduction in irradiated solution also decreases with increase in electrolyte pH. Consequently higher reduction rates in alkaline solutions (pH>8.0) raise the Ni nucleation density during deposition, as illustrated by homogeneous and complete coverage of the substrate by nanoparticles within a short period of 1 min. The enhancement in reduction rate is attributed to high redox efficiency of hydrated electrons produced by x ray as well as their redox potential enhancements under higher electrolyte pH conditions. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]
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- 2004
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4. Synchrotron X-Ray Synthesized Gold Nanoparticles for Tumor Therapy.
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Chien, C. C., Wang, C. H., Hua, T. E., Tseng, P. Y., Yang, T. Y., Hwu, Y., Chen, Y. J., Chung, K. H., Je, J. H., and Margaritondo, G.
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GOLD ,NANOPARTICLES ,TUMOR treatment ,IRRADIATION ,RADIOTHERAPY ,CELL lines ,CYTOPLASM - Abstract
Highly concentrated gold nanoparticles (20 ± 5 nm) were produced by an x-ray irradiation method. The particles were then examined for the interactions between gold and tumor cells under x-ray radiation conditions. The biological effects of gold nanoparticles were investigated in terms of the internalization, cytotoxicity and capability to enhance x-ray radiotherapy. The results of this investigation indicated that x-ray derived gold nanoparticles were nontoxic to CT-26 cell line and immobilized within cytoplasm. The irradiation experiments provided further evidence that gold nanoparticles were capable of enhancing the efficiency of radiotherapy. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]
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- 2007
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5. Nanoparticle Decoration of Carbon Nanotubes by X-Ray Irradiation.
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Yang, T. Y., Wang, C. H., Hwu, Y., Liu, C. J., Lin, H. M., Je, J. H., and Margaritondo, G.
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NANOTUBES ,CARBON ,NANOPARTICLES ,X-rays ,IRRADIATION ,TITANIUM dioxide - Abstract
Titanium oxide (TiO2) nanoparticles were immobilized onto the surfaces of multiwall carbon nanotubes (MWNTs) by a facile synchrotron X-ray exposure method. The influence of processing parameters such as beam dose and duration on the structures and properties of nanoparticle/nanotube hybrid were investigated by X-ray Absorption Spectroscopy (XAS), Raman spectroscopy, Transmission Electron Microscopy (TEM). The influences of synchrotron x-ray exposure on the sol-gel process and structure of produced TiO2 nanoparticles were also investigated. Furthermore, the locations of functional groups between TiO2 and MWNTs were also probed. This new approach is envisaged to be quite promising for the synthesis of novel nanocomposite materials. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]
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- 2007
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6. Synchrotron X-Ray Induced Gold Nanoparticle Formation.
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Yang, Y. C., Wang, C. H., Yang, T. Y., Hwu, Y., Chen, C. H., Je, J. H., and Margaritondo, G.
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NANOPARTICLES ,SYNCHROTRON radiation ,X-rays ,IRRADIATION ,SCANNING electron microscopes ,TRANSMISSION electron microscopes - Abstract
We reported a simple approach to generate gold nanoparticles from HAuCl4 containing aqueous solution by synchrotron x-ray irradiation at room temperature. The gold colloidal were investigated by a variety of characterization methods including Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM), Fourier transformation infrared (FTIR), Ultraviolet and Visible (UV-VIS) spectrometer and the effects of variables including pH value, radiation time were examined. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]
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- 2007
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7. Synchrotron microangiography studies of angiogenesis in mice with microemulsions and gold nanoparticles.
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Chia-Chi Chien, Wang, C. H., Wang, C. L., Li, E. R., Lee, K. H., Hwu, Y., Lin, Chien-Yi, Shing-Jyh Chang, Yang, C. S., Petibois, Cyril, and Margaritondo, G.
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RADIOLOGY ,ANGIOGRAPHY ,NEOVASCULARIZATION ,GOLD ,NANOPARTICLES - Abstract
We present an effective solution for the problem of contrast enhancement in phase-contrast microangiography, with the specific objective of visualising small (<8 µm) vessels in tumor-related microangiogenesis. Different hydrophilic and hydrophobic contrast agents were explored in this context. We found that an emulsified version of the hydrophobic contrast agents Lipiodol® provides the best contrast and minimal distortion of the circulation and vessel structure. Such emulsions are reasonably biocompatible and, with sizes of 0 ± 0.8 µm, sufficient to diffuse to the smallest vessel and still provide reasonable contrast. We also explored the use of Au nanoparticle colloids that could be used not only to enhance contrast but also for interesting applications in nanomedicine. Both the Lipiodol microemulsions and Au nanoparticle colloids can be conjugated with medicines or cell specific labeling agents and their small size can allow the study of the diffusion of contrast agents through the vessel leakage. This enables direct imaging of drug delivery which is important for cancer treatment. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]
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- 2010
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8. Intense X-ray induced formation of silver nanoparticles stabilized by biocompatible polymers.
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Chang-Hai Wang, Chi-Jen Liu, Cheng-Liang Wang, Chia-Chi Chien, Hwu, Y., Ru-Shi Liu, Chung-Shi Yang, Jung-Ho Je, Hong-Ming Lin, and Margaritondo, G.
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POLYMERS ,NANOPARTICLES ,HYDRODYNAMICS ,OPTICS ,NANOMEDICINE - Abstract
Colloidal Ag nanoparticles were formed by X-ray irradiation in the presence of a polymer. This new synthesis method is simple, rapid and leads to a high production yield. Compared to the citrate-reduced Ag colloidal, polymer-protected Ag nanoparticles are smaller in size and more stable—and therefore suitable for biomedical application—as verified by TEM observation, XAFS measurement and optical characterization. Ag nanoparticles so produced were also visualized in solution and in real time by a visible light microscope based on dark field light scattering. The color-derived size and distribution of Ag nanoparticles correlates well with the hydrodynamic size data. [ABSTRACT FROM AUTHOR]
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- 2009
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9. Structural properties of `naked' gold nanoparticles formed by synchrotron X-ray irradiation.
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Chang-Hai Wang, Chia-Chi Chien, Yen-Lu Yu, Chi-Jen Liu, Cheng-Feng Lee, Chih-Hsiung Chen, Hwu, Y., Chung-Shi Yang, Jung-Ho Je, and Margaritondo, G.
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NANOPARTICLES ,SYNCHROTRON radiation ,X-rays ,BIOSENSORS ,MORPHOLOGY ,PHOTONS ,IMAGING systems - Abstract
The formation of colloidal unmodified (`naked') gold nanoparticles is investigated by irradiation of a precursor solution with X-rays from a synchrotron source. An interesting morphological evolution as a function of exposure time, from cross-linked network-like structure to individual particles, has been discovered. The particle size decreased with the exposure time and was influenced by the ionic strength of the precursor solution. Contrary to γ-ray exposure, an OH radical scavenger was not required for cluster formation. [ABSTRACT FROM AUTHOR]
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- 2007
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10. Size correlated long and short range order of ternary Co2FeGa Heusler nanoparticles.
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Wang, C. H., Guo, Y. Z., Casper, F., Balke, B., Fecher, G. H., Felser, C., and Hwu, Y.
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NANOPARTICLES ,SPECTRUM analysis ,CRYSTALS ,X-ray diffraction ,ABSORPTION spectra - Abstract
The long and short range order of chemically prepared Co
2 FeGa Heusler nanoparticles with various sizes are determined by x-ray diffraction (XRD) and extended x-ray absorption fine structure (EXAFS) spectroscopy. Specifically, EXAFS fittings reveal the size dependent crystal structure and short range order of the Heusler type Co2 FeGa nanoparticles. With decreasing particle size, the degree of L21 order in the nanoparticles decreases and the probability of B2 disorder increases simultaneously. The consequences of antisite disorder on the size correlated structure of Co2 FeGa nanoparticles are also discussed. [ABSTRACT FROM AUTHOR]- Published
- 2010
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11. X-ray microscopy and tomography detect the accumulation of bare and PEG-coated gold nanoparticles in normal and tumor mouse tissues
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Chien, C.-C., Cheng, C.-C., Chen, H. H., Hwu, Y., Chu, Y. S., Petibois, C., Chen, A., Ching, Y.-T., and Margaritondo, G.
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High resolution X-ray microscopy ,3D tissue imaging ,Nanoparticles - Abstract
We demonstrate that, with appropriate staining, high-resolution X-ray microscopy can image complicated tissue structures-cerebellum and liver-and resolve large or small amounts of Au nanoparticles in these tissues. Specifically, images of tumor tissue reveal high concentrations of accumulated Au nanoparticles. PEG (poly(ethylene glycol)) coating is quite effective in enhancing this accumulation and significantly modifies the mechanism of uptake by reticuloendothelial system (RES) organs.
12. X-ray synthesized PEGylated (polyethylene glycol coated) gold nanoparticles in mice strongly accumulate in tumors
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Wang, Chang-Hai, Liu, Chi-Jen, Chien, Chia-Chi, Chen, Hsin-Tai, Hua, Tzu-En, Leng, Wei-Hua, Chen, Hsiang-Hsin, Kempson, Ivan M., Hwu, Y., Hsiao, Michael, Lai, Tsung-Ching, Wang, J.L., Yang, Chung-Shi, Lin, Hong-Ming, Chen, Yu-Jen, and Margaritondo, G.
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INORGANIC synthesis , *POLYETHYLENE glycol , *SURFACE coatings , *COLLOIDAL gold , *LABORATORY mice , *NANOPARTICLES , *X-ray microscopy , *BIOMEDICAL materials , *TUMORS in animals - Abstract
Abstract: The spatial distribution of X-ray synthesized, PEG coated Au nanoparticles in cancer-bearing mice and their time dependent accumulation were investigated with inductive coupled plasma – optical emission spectroscopy (ICP-OES), transmission electron microscopy (TEM) and histological imaging. The results conclusively demonstrate that the particles strongly accumulate in tumor regions; up to ∼25 times more than in normal muscle tissue. This accumulation increases with the time after injection for up to ∼12h in tumor, spleen and liver tissues, whereas for most non-tumor regions it saturates or decreases (blood, lung, brain, heart, and kidney). The impact of this result is discussed with special emphasis on passive targeted drug delivery and could also be used for the delineation and early-stage imaging of small tumors. [ABSTRACT FROM AUTHOR]
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- 2011
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13. Enhanced photocatalysis, colloidal stability and cytotoxicity of synchrotron X-ray synthesized Au/TiO2 nanoparticles
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Liu, Chi-Jen, Yang, Tsung-Yeh, Wang, Chang-Hai, Chien, Chia-Chi, Chen, Shin-Tai, Wang, Cheng-Liang, Leng, Wei-Hua, Hwu, Y., Lin, Hong-Ming, Lee, Yao-Chang, Cheng, Chia-Liang, Je, J.H., and Margaritondo, G.
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PHOTOCATALYSIS , *COLLOIDS , *CELL-mediated cytotoxicity , *SYNCHROTRONS , *NANOPARTICLES , *TITANIUM compounds , *X-ray diffraction , *BIOMEDICAL materials , *ELECTRON microscopy - Abstract
Abstract: Au/TiO2 nanocomposite particles were synthesized by a method based on intense X-ray irradiation without adding any reducing agent or stabilizer. The nanocomposite exhibits promising photocatalytic and biological properties at physiologically relevant concentration ([Au]=0.028mM, [TiO2]=0.5mM). The structure and photocatalysis were examined by X-ray diffraction, electron microscopy and ultraviolet–visible spectroscopy demonstrating that gold nanoparticles of 2–5nm size were successfully deposited on TiO2 nanoparticle surfaces. The nanocomposite exhibited good colloidal stability within a typical cellular environment and was nontoxic to cancer cell according to evaluations under controlled conditions. The Au/TiO2 nanoparticles were also found to enhance the photocatalytic efficiency of UV radiation and even more that of X-ray radiation. In vitro studies indicated that the cell-killing effect under X-ray irradiation is more pronounced with the addition of Au/TiO2 nanoparticles than of bare TiO2 nanoparticles. [Copyright &y& Elsevier]
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- 2009
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14. Aqueous gold nanosols stabilized by electrostatic protection generated by X-ray irradiation assisted radical reduction
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Wang, Chang-Hai, Hua, Tzu-En, Chien, Chia-Chi, Yu, Yen-Lu, Yang, Tsung-Yeh, Liu, Chi-Jen, Leng, Wei-Hua, Hwu, Y., Yang, Yung-Chin, Kim, Chong-Cook, Je, Jung-Ho, Chen, Chih-Hsiung, Lin, Hong-Ming, and Margaritondo, G.
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GOLD , *NANOPARTICLES , *SYNCHROTRON radiation , *X-rays - Abstract
Abstract: Reductant, stabilizer-free colloidal gold solutions were fabricated by a new room-temperature synchrotron X-ray irradiation method. The influence of process parameters such as the pH value and the exposure time on the structure of gold nanoparticles was investigated. The mechanisms underlying the X-ray-triggered reduction of gold ions and the formation of gold clusters are discussed in detail. The X-ray irradiation derived highly concentrated gold nanoparticles are readily to be re-dispersed and possess suitable colloidal stability within cellular environment. The characterization included a study of the possible cytotoxicity for the EMT-6 tumor cell line: the negative results indicate that the gold clusters produced with our approach are biocompatible. [Copyright &y& Elsevier]
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- 2007
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15. Gold nanoparticles as multimodality imaging agents for brain gliomas
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Giorgio Margaritondo, Chia-Chi Chien, Hsiang Hsin Chen, Ann Chen, Sheng Feng Lai, Shun‑Ming Yang, Cyril Petibois, Dueng-Yuan Hueng, Bai‑Hung Ko, Shuk-Man Ka, Chia Ju Chang, Yeukuang Hwu, Lai, Sheng-Feng, Ko, Bai-Hung, Chien, Chia-Chi, Chang, Chia-Ju, Yang, Shun-Ming, Chen, Hsiang-Hsin, Petibois, Cyril, Hueng, Dueng-Yuan, Ka, Shuk-Man, Chen, Ann, Margaritondo, G, and Hwu, Y
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fiber optic sensors ,Fluorescence-lifetime imaging microscopy ,Pharmaceutical Science ,Medicine (miscellaneous) ,Nanoparticle ,Contrast Media ,Metal Nanoparticles ,02 engineering and technology ,Applied Microbiology and Biotechnology ,Mice ,Microscopy ,Medicine ,metal nanoparticles ,Internalization ,media_common ,0303 health sciences ,Brain Neoplasms ,Optical Imaging ,Brain ,Glioma ,021001 nanoscience & nanotechnology ,Endocytosis ,3. Good health ,Colloidal gold ,Molecular Medicine ,Science & Technology - Other Topics ,fluorescence ,0210 nano-technology ,media_common.quotation_subject ,Biomedical Engineering ,Bioengineering ,Nanotechnology ,03 medical and health sciences ,In vivo ,Animals ,Nanoscience & Nanotechnology ,030304 developmental biology ,business.industry ,Research ,gold ,medicine.disease ,imaging techniques ,Targeted drug delivery ,Biotechnology & Applied Microbiology ,cytology ,cells ,nanoparticles ,Gold ,business ,Tomography, X-Ray Computed ,Neoplasm Transplantation ,Biomedical engineering - Abstract
Background Nanoparticles can be used for targeted drug delivery, in particular for brain cancer therapy. However, this requires a detailed analysis of nanoparticles from the associated microvasculature to the tumor, not easy because of the required high spatial resolution. The objective of this study is to demonstrate an experimental solution of this problem, based in vivo and post-mortem whole organ imaging plus nanoscale 3-dimensional (3D) X-ray microscopy. Results The use of gold nanoparticles (AuNPs) as contrast agents paved the way to a detailed high-resolution three dimensional (3D) X-ray and fluorescence imaging analysis of the relation between xenografted glioma cells and the tumor-induced angiogenic microvasculature. The images of the angiogenic microvessels revealed nanoparticle leakage. Complementary tests showed that after endocytotic internalization fluorescent AuNPs allow the visible-light detection of cells. Conclusions AuNP-loading of cells could be extended from the case presented here to other imaging techniques. In our study, they enabled us to (1) identify primary glioma cells at inoculation sites in mice brains; (2) follow the subsequent development of gliomas. (3) Detect the full details of the tumor-related microvasculature; (4) Finding leakage of AuNPs from the tumor-related vasculature, in contrast to no leakage from normal vasculature. Electronic supplementary material The online version of this article (doi:10.1186/s12951-015-0140-2) contains supplementary material, which is available to authorized users.
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- 2015
16. One-pot synthesis of AuPt alloyed nanoparticles by intense x-ray irradiation
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Bo-Jun Hsao, Giorgio Margaritondo, Ivan M. Kempson, Xiaoqing Cai, Chia-Chi Chien, Cheng-Liang Wang, Yeukuang Hwu, Hsiang-Hsin Chen, Yi-Yun Chen, Wen-Chang Chen, Sheng-Feng Lai, Wang, Cheng-Liang, Hsao, Bo-Jun, Lai, Sheng-Feng, Chen, Wen-Chang, Chen, Hsiang-Hsin, Chen, Yi-Yun, Chien, Chia-Chi, Cai, Xiaoqing, Kempson, Ivan M, Hwu, Y, and Margaritondo, G
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feed ratios ,Nanostructure ,Materials science ,Biocompatibility ,Mechanical Engineering ,technology, industry, and agriculture ,Nanoparticle ,Bioengineering ,macromolecular substances ,General Chemistry ,Polyethylene glycol ,equipment and supplies ,Colloid ,Crystallography ,chemistry.chemical_compound ,Chemical engineering ,chemistry ,Mechanics of Materials ,Colloidal gold ,Transmission electron microscopy ,X-ray crystallography ,nanoparticles ,General Materials Science ,colloidal stability ,Electrical and Electronic Engineering - Abstract
We synthesized AuPt alloyed nanoparticles in colloidal solution by a one-pot procedure based on synchrotron x-ray irradiation in the presence of PEG (polyethylene glycol). The exclusive presence of alloyed nanoparticles with fcc structure was confirmed by several different experiments including UV–vis spectroscopy, x-ray diffraction (XRD) and transmission electron microscopy (TEM). The composition of the AuPt alloyed nanoparticles can be varied in a continuous fashion by simply varying the feed ratios of Au and Pt precursors. The nanoparticles exhibited colloidal stability and biocompatibility, important for potential applications. Refereed/Peer-reviewed
- Published
- 2011
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