Name: bio-inspired polydopamine surface modification of nanodiamonds and its reduction of silver nanoparticles
Uploaded: 2018-11-14T13:00:00
Description: Watch this Scientific Journal Video about Bio-inspired Polydopamine Surface Modification of Nanodiamonds and Its Reduction of Silver Nanoparticles at JoVE.com

This research was supported by National Science Foundation (CCF 1814797) and University of Missouri Research Board, Material Research Center, and the College of Arts and Science at Missouri University of Science and Technology

1 . Preparation of Reagents
CAUTION: Please read and understand all relevant material safety data sheets (MSDS) before use. Some of the chemicals are toxic and volatile. Please follow special handling procedures and storage requirements. During the experimental procedure, use personal protective equipment, such as gloves, safety glasses, and a lab coat to avoid potential hazards.
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	<li>Preparation of Tris-HCl buffer
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		<li>Dissolve 30.29 g of Tris powder in 100 mL of deionized H<sub...

<ol>
	<li>Mochalin, V. N., Shenderova, O., Ho, D., Gogotsi, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+properties+and+applications+of+nanodiamonds.">The properties and applications of nanodiamonds.</a> Nature Nanotechnology. 7 (1), 11-23 (2011).</li><li>Kucsko, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanometre-scale+thermometry+in+a+living+cell.">Nanometre-scale thermometry in a living cell.</a> Nature. 500 (7460), 54-58 (2013).</li><li>Liu, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Origin+of+the+Robust+Catalytic+Performance+of+Nanodiamond-Graphene-Supported+Pt+Nanoparticles+Used+in+the+Propane+Dehydrogenation+Reaction.">Origin of the Robust Catalytic Performance of Nanodiamond-Graphene-Supported Pt Nanoparticles Used in the Propane Dehydrogenation Reaction.</a> ACS Catalysis. 7 (5), 3349-3355 (2017).</li><li>Chang, B. -. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Highly+Fluorescent+Nanodiamonds+Protein-Functionalized+for+Cell+Labeling+and+Targeting.">Highly Fluorescent Nanodiamonds Protein-Functionalized for Cell Labeling and Targeting.</a> Advanced Functional Materials. 23 (46), 5737-5745 (2013).</li><li>Ho, D., Wang, C. H., Chow, E. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanodiamonds:+The+intersection+of+nanotechnology,+drug+development,+and+personalized+medicine.">Nanodiamonds: The intersection of nanotechnology, drug development, and personalized medicine.</a> Science Advances. 1 (7), 1500439 (2015).</li><li>Hsu, M. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Directly+thiolated+modification+onto+the+surface+of+detonation+nanodiamonds.">Directly thiolated modification onto the surface of detonation nanodiamonds.</a> ACS Applied Materials and Interfaces. 6 (10), 7198-7203 (2014).</li><li>Krueger, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diamond+Nanoparticles:+Jewels+for+Chemistry+and+Physics.">Diamond Nanoparticles: Jewels for Chemistry and Physics.</a> Advanced Materials. 20 (12), 2445-2449 (2008).</li><li>Turcheniuk, K., Trecazzi, C., Deeleepojananan, C., Mochalin, V. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Salt-assisted+ultrasonic+deaggregation+of+nanodiamond.">Salt-assisted ultrasonic deaggregation of nanodiamond.</a> ACS Applied Materials and Interfaces. 8 (38), 25461-25468 (2016).</li><li>Akiel, R. D., Zhang, X., Abeywardana, C., Stepanov, V., Qin, P. Z., Takahashi, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Investigating+Functional+DNA+Grafted+on+Nanodiamond+Surface+Using+Site-Directed+Spin+Labeling+and+Electron+Paramagnetic+Resonance+Spectroscopy.">Investigating Functional DNA Grafted on Nanodiamond Surface Using Site-Directed Spin Labeling and Electron Paramagnetic Resonance Spectroscopy.</a> Journal of Physical Chemistry B. 120 (17), 4003-4008 (2016).</li><li>Gaillard, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Peptide+nucleic+acid-nanodiamonds:+covalent+and+stable+conjugates+for+DNA+targeting.">Peptide nucleic acid-nanodiamonds: covalent and stable conjugates for DNA targeting.</a> RSC Advances. 4 (7), 3566-3572 (2014).</li><li>Zhang, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=DNA-based+self-assembly+of+fluorescent+nanodiamonds.">DNA-based self-assembly of fluorescent nanodiamonds.</a> Journal of the American Chemical Society. 137 (31), 9776-9779 (2015).</li><li>Liu, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fluorescent+Nanodiamond-Gold+Hybrid+Particles+for+Multimodal+Optical+and+Electron+Microscopy+Cellular+Imaging.">Fluorescent Nanodiamond-Gold Hybrid Particles for Multimodal Optical and Electron Microscopy Cellular Imaging.</a> Nano Letters. 16 (10), 6236-6244 (2016).</li><li>Lee, H., Dellatore, S. M., Miller, W. M., Messersmith, P. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mussel-inspired+surface+chemistry+for+multifunctional+coatings.">Mussel-inspired surface chemistry for multifunctional coatings.</a> Science. 318 (5849), 426-430 (2007).</li><li>Wang, C., Zhou, J., Wang, P., He, W., Duan, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Robust+Nanoparticle-DNA+Conjugates+Based+on+Mussel-Inspired+Polydopamine+Coating+for+Cell+Imaging+and+Tailored+Self-Assembly.">Robust Nanoparticle-DNA Conjugates Based on Mussel-Inspired Polydopamine Coating for Cell Imaging and Tailored Self-Assembly.</a> Bioconjugate Chemistry. 27 (3), 815-823 (2016).</li><li>Liu, R., Guo, Y., Odusote, G., Qu, F., Priestley, R. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Core-shell+Fe3O4+polydopamine+nanoparticles+serve+multipurpose+as+drug+carrier,+catalyst+support+and+carbon+adsorbent.">Core-shell Fe3O4 polydopamine nanoparticles serve multipurpose as drug carrier, catalyst support and carbon adsorbent.</a> ACS Applied Materials and Interfaces. 5 (18), 9167-9171 (2013).</li><li>Liu, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dopamine+as+a+Carbon+Source:+The+Controlled+Synthesis+of+Hollow+Carbon+Spheres+and+Yolk-Structured+Carbon+Nanocomposites.">Dopamine as a Carbon Source: The Controlled Synthesis of Hollow Carbon Spheres and Yolk-Structured Carbon Nanocomposites.</a> Angewandte Chemie International Edition. 50 (30), 6799-6802 (2011).</li><li>Zeng, Y., Liu, W., Wang, Z., Singamaneni, S., Wang, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multifunctional+surface+modification+of+nanodiamonds+based+on+dopamine+polymerization.">Multifunctional surface modification of nanodiamonds based on dopamine polymerization.</a> Langmuir. 34 (13), 4036-4042 (2018).</li><li>Qin, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dopamine@Nanodiamond+as+novel+reinforcing+nanofillers+for+polyimide+with+enhanced+thermal,+mechanical+and+wear+resistance+performance.">Dopamine@Nanodiamond as novel reinforcing nanofillers for polyimide with enhanced thermal, mechanical and wear resistance performance.</a> RSC Advances. 8 (7), 3694-3704 (2018).</li><li>Barras, A., Lyskawa, J., Szunerits, S., Woisel, P., Boukherroub, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Direct+functionalization+of+nanodiamond+particles+using+dopamine+derivatives.">Direct functionalization of nanodiamond particles using dopamine derivatives.</a> Langmuir. 27 (20), 12451-12557 (2011).</li><li>Khanal, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Toward+Multifunctional+"Clickable"+Diamond+Nanoparticles.">Toward Multifunctional "Clickable" Diamond Nanoparticles.</a> Langmuir. 31 (13), 3926-3933 (2015).</li><li>Rad, M. H., Zamanian, A., Hadavi, S. M. M., Khanlarkhani, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Two-Stage+Kinetics+Model+for+Polydopamine+Layer+Growth.+A+Two-Stage+Kinetics+Model+for+Polydopamine+Layer+Growth.">A Two-Stage Kinetics Model for Polydopamine Layer Growth. A Two-Stage Kinetics Model for Polydopamine Layer Growth.</a> Macromolecular Chemistry and Physics. , 1700505 (2018).</li><li>Ball, V., Frari, D. D., Toniazzo, V., Ruch, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Kinetics+of+polydopamine+film+deposition+as+a+function+of+pH+and+dopamine+concentration:+Insights+in+the+polydopamine+deposition+mechanism.">Kinetics of polydopamine film deposition as a function of pH and dopamine concentration: Insights in the polydopamine deposition mechanism.</a> Journal of Colloid and Interface Science. 386 (1), 366-372 (2012).</li><li>Liu, Y., Ai, K., Lu, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Polydopamine+and+its+derivative+materials:+synthesis+and+promising+applications+in+energy,+environmental,+and+biomedical+fields.">Polydopamine and its derivative materials: synthesis and promising applications in energy, environmental, and biomedical fields.</a> Chemical Reviews. 114 (9), 5057-5115 (2014).</li><li>Hu, J., Wu, S., Cao, Q., Zhang, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+of+core-shell+structured+alumina/Cu+microspheres+using+activation+by+silver+nanoparticles+deposited+on+polydopamine-coated+surfaces.">Synthesis of core-shell structured alumina/Cu microspheres using activation by silver nanoparticles deposited on polydopamine-coated surfaces.</a> RSC Advances. 6 (85), 81767-81773 (2016).</li><li>Orishchin, N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rapid+Deposition+of+Uniform+Polydopamine+Coatings+on+Nanoparticle+Surfaces+with+Controllable+Thickness.">Rapid Deposition of Uniform Polydopamine Coatings on Nanoparticle Surfaces with Controllable Thickness.</a> Langmuir. 33, 6046-6053 (2017).</li><li>Gonza&#769;lez, A. L., Noguez, C., Bera&#769;nek, J., Barnard, A. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Size,+Shape,+Stability,+and+Color+of+Plasmonic+Silver+Nanoparticles.">Size, Shape, Stability, and Color of Plasmonic Silver Nanoparticles.</a> Journal of Physical Chemistry C. 118 (17), 9128-9136 (2014).</li><li>Muthuchamy, N., Gopalan, A., Lee, K. -. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+facile+strategy+for+higher+loading+of+silver+nanoparticles+onto+silica+for+efficient+catalytic+reduction+of+4-nitrophenol.">A new facile strategy for higher loading of silver nanoparticles onto silica for efficient catalytic reduction of 4-nitrophenol.</a> RSC Advances. 5 (93), 76170-76181 (2015).</li><li>Bastus, N. G., Comenge, J., Puntes, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Kinetically+Controlled+Seeded+Growth+Synthesis+of+Citrate-Stabilized+Gold+Nanoparticles+of+up+to+200+nm:+Size+Focusing+versus+Ostwald+Ripening.">Kinetically Controlled Seeded Growth Synthesis of Citrate-Stabilized Gold Nanoparticles of up to 200 nm: Size Focusing versus Ostwald Ripening.</a> Langmuir. 27 (17), 11098-11105 (2011).</li><li>Jana, J., Gauri, S. S., Ganguly, M., Dey, S., Pal, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Silver+nanoparticle+anchored+carbon+dots+for+improved+sensing,+catalytic+and+intriguing+antimicrobial+activity.">Silver nanoparticle anchored carbon dots for improved sensing, catalytic and intriguing antimicrobial activity.</a> Dalton Transactions. 44 (47), 20692-20707 (2015).</li><li>Zamudio, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+anchoring+of+silver+nanoparticles+on+N-doped+carbon+nanotubes.">Efficient anchoring of silver nanoparticles on N-doped carbon nanotubes.</a> Small. 2 (3), 346-350 (2006).</li><li>Chen, K., Li, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modification+of+membranes+with+polydopamine+and+silver+nanoparticles+formed+in+situ+to+mitigate+biofouling.">Modification of membranes with polydopamine and silver nanoparticles formed in situ to mitigate biofouling.</a> U.S. Patent Application. , (2016).</li></ol>

This article provides a detailed protocol for the surface functionalization of NDs with self-polymerized DA coating, and the reduction of Ag[(NH3)2]+ to AgNPs on PDA layers (Figure 3). The strategy is capable of producing various thicknesses of PDA layers by simply changing the concentration of DA. The size of the AgNPs can also be controlled by altering the original concentration of metal ion solution. The TEM image in Figure 1<...

Nanodiamonds (NDs), a novel carbon-based material, have attracted considerable attention in recent years for use in various applications1,2. For instance, the high surface areas of NDs provide excellent catalyst support for metal nanoparticles (NPs) because of their super-chemical stability and thermal conductivity3. Furthermore, NDs play significant roles in bio-imaging, bio-sensing, and drug delivery due to their outstanding biocompatibility and nontoxicity4,5.
To efficiently extend their capabilities, it is valuable to conjugate functional species on the surfaces of NDs, such as proteins, nucleic acids, and nanoparticles6. Although a variety of functional groups (e.g., hydroxyl, carboxyl, lactone, etc.) are created on the surfaces of NDs during their purification, the conjugation yields of the functional groups are still very low because of the low density of each active chemical group7. This results in unstable NDs, which tend to aggregate, limiting further application8.
Currently, the most common methods used to functionalize NDs, are covalent conjugation by using copper-free click chemistry9, covalent linkage of peptide nucleic acids (PNA)10, and self-assembled DNA11. The non-covalent wrapping of NDs has also been proposed, including carbohydrate-modified BSA4, and HSA12coating. However, because these methods are time consuming and inefficient, it is desirable that a simple and generally applicable method can be developed to modify the surfaces of NDs.
Dopamine (DA)13, known as a natural neurotransmitter in the brain, was widely used for adhering and functionalizing nanoparticles, such as gold nanoparticles (AuNPs)14, Fe2O315, and SiO216. Self-polymerized PDA layers enrich amino and phenolic groups, which can be further utilized to directly reduce metal nanoparticles or to easily immobilize thiol/amine-containing biomolecules on an aqueous solution. This simple approach was recently applied to functionalize NDs by Qin et al. and our laboratory17,18, although DA derivatives were employed to modify NDs via Click Chemistry in earlier studies19,20.
Here, we describe a simple PDA-based surface modification method that efficiently functionalizes NDs. By varying the concentration of DA, we can control the thickness of a PDA layer from a few nanometers to tens of nanometers. In addition, the metal nanoparticles are directly reduced and stabilized on the PDA surface without the need for additional toxic reduction agents. The sizes of the silver nanoparticles depend on the initial concentrations of Ag[(NH3)2]+. This method allows the well-controlled deposition of PDA on the surfaces of NDs and the synthesis of ND conjugated AgNPs, which dramatically extends the functionality of NDs as excellent nano-platforms of catalyst supports, bio-imaging, and bio-sensors.

<table border="0" cellpadding="0" cellspacing="0" style="width:839px;" width="838">
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		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Nanodiamond</td>
			<td style="width:121px;">FND Biotech, Inc.</td>
			<td style="width:136px;">brFND-100</td>
			<td style="width:365px;">dispersed in water, and used without further purification</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Dopamine hydrochloride</td>
			<td style="width:121px;">Sigma</td>
			<td style="width:136px;">H8502-25G</td>
			<td>prepare freshly</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Silver Nitrate</td>
			<td style="width:121px;">Fisher</td>
			<td style="width:136px;">S181-25</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Ammonium Hydroxide</td>
			<td style="width:121px;">Fisher</td>
			<td style="width:136px;">A669S-500</td>
			<td>highly toxic</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Tris Hydrochloride</td>
			<td style="width:121px;">Fisher</td>
			<td style="width:136px;">BP153-500</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">TEM grid carbon film</td>
			<td style="width:121px;">Ted Pella</td>
			<td style="width:136px;">01843-F</td>
			<td>300 mesh copper</td>
		</tr>
	</tbody>
</table>

bio-inspired polydopamine surface modification of nanodiamonds and its reduction of silver nanoparticles

Surface functionalization of nanodiamonds (NDs) is still challenging due to the diversity of functional groups on the ND surfaces. Here, we demonstrate a simple protocol for the multifunctional surface modification of NDs by using mussel-inspired polydopamine (PDA) coating. In addition, the functional layer of PDA on NDs could serve as a reducing agent to synthesize and stabilize metal nanoparticles. Dopamine (DA) can self-polymerize and spontaneously form PDA layers on ND surfaces if the NDs and dopamine are simply mixed together. The thickness of a PDA layer is controlled by varying the concentration of DA. A typical result shows that a thickness of ~5 to ~15 nm of the PDA layer can be reached by adding 50 to 100 &#181;g/mL of DA to 100 nm ND suspensions. Furthermore, the PDA-NDs are used as a substrate to reduce metal ions, such as Ag[(NH3)2]+, to silver nanoparticles (AgNPs). The sizes of the AgNPs rely on the initial concentrations of Ag[(NH3)2]+. Along with an increase in the concentration of Ag[(NH3)2]+, the number of NPs increases, as well as the diameters of the NPs. In summary, this study not only presents a facile method for modifying the surfaces of NDs with PDA, but also demonstrates the enhanced functionality of NDs by anchoring various species of interest (such as AgNPs) for advanced applications.

The formation of PDA layers on ND surfaces were analyzed by TEM (Figure 1). Different thicknesses of PDA layers were observed as higher concentrations of DA led to thicker PDA layers. In addition, after an encapsulating reaction, the color of the NDs solution changed from colorless to dark, while the higher the initial concentration of DA was, the darker the solution became.
Fig...

Watch this Scientific Journal Video about Bio-inspired Polydopamine Surface Modification of Nanodiamonds and Its Reduction of Silver Nanoparticles at JoVE.com

Bio-inspired Polydopamine Surface Modification of Nanodiamonds and Its Reduction of Silver Nanoparticles

A facile protocol is presented to functionalize the surfaces of nanodiamonds with polydopamine.

Surface functionalization of nanodiamonds (NDs) is still challenging due to the diversity of functional groups on the ND surfaces. Here, we demonstrate a ...

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