151
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Gryczynski I, Malicka J, Lukomska J, Gryczynski Z, Lakowicz JR. Surface plasmon-coupled polarized emission of N-acetyl-l-tryptophanamide. Photochem Photobiol 2004. [PMID: 15623334 DOI: 10.1562/0031-8655(2004)080<0482:sppeon>2.0.co;2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
We report an observation of ultraviolet (UV) surface plasmon-coupled emission (SPCE) of N-acetyl-l-tryptophanamide (NATA). The sample was spin coated from poly(vinyl alcohol) (PVA) solution on 20 nm aluminum film deposited on a quartz substrate. The directional UV SPCE occurs within a well-defined narrow angle at 52 degrees from the normal to the coupling hemicylinder quartz prism. The NATA directional emission is highly p polarized as expected for surface plasmon-coupled radiation. The 10 nm protective SiO2 layer deposited on top of the aluminum film significantly neutralized the fluorophore quenching by the metal surface. SPCE of NATA demonstrates a remarkable intrinsic dispersive property-the maximum of the emission spectrum depends on the observation angle. The efficient spectral resolution of SPCE can be used in the construction of miniaturized spectrofluorometers. The observation of SPCE of tryptophan opens a new possibility for the study of many unlabeled proteins with the technique complementary to surface plasmon resonance analysis.
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Affiliation(s)
- Ignacy Gryczynski
- Center for Fluorescence Spectroscopy, Department of Biochemistry and Molecular Biology, University of Maryland at Baltimore, Baltimore, MD 21201, USA
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152
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Matveeva E, Gryczynski Z, Gryczynski I, Malicka J, Lakowicz JR. Myoglobin immunoassay utilizing directional surface plasmon-coupled emission. Anal Chem 2004; 76:6287-92. [PMID: 15516120 PMCID: PMC6848856 DOI: 10.1021/ac0491612] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We described an immunoassay for the cardiac marker myoglobin on a thin silver mirror surface using surface plasmon-coupled emission (SPCE). SPCE occurs for fluorophores in proximity (within approximately 200 nm) of a thin metal film (in our case, silver) and results in a highly directional radiation through a glass substrate at a well-defined angle from the normal axis. We used the effect of SPCE to develop a myoglobin immunoassay on the silver mirror surface deposited on a glass substrate. Binding of the labeled anti-myoglobin antibodies led to the enhanced fluorescence emission at a specific angle of 72 degrees . The directional and enhanced directional fluorescence emission enables detection of myoglobin over a wide range of concentrations from subnormal to the elevated level of this cardiac marker. Utilizing SPCE allowed us also to demonstrate significant background suppression (from serum or whole blood) in the myoglobin immunoassay. We expect SPCE to become a powerful technique for performing immunoassays for many biomarkers in surface-bound assays.
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Affiliation(s)
- Evgenia Matveeva
- Center for Fluorescence Spectroscopy, Department of Biochemistry and Molecular Biology, University of Maryland at Baltimore, 725 West Lombard Street, Baltimore, Maryland 21201
| | - Zygmunt Gryczynski
- Center for Fluorescence Spectroscopy, Department of Biochemistry and Molecular Biology, University of Maryland at Baltimore, 725 West Lombard Street, Baltimore, Maryland 21201
| | - Ignacy Gryczynski
- Center for Fluorescence Spectroscopy, Department of Biochemistry and Molecular Biology, University of Maryland at Baltimore, 725 West Lombard Street, Baltimore, Maryland 21201
| | - Joanna Malicka
- Center for Fluorescence Spectroscopy, Department of Biochemistry and Molecular Biology, University of Maryland at Baltimore, 725 West Lombard Street, Baltimore, Maryland 21201
| | - Joseph R. Lakowicz
- Center for Fluorescence Spectroscopy, Department of Biochemistry and Molecular Biology, University of Maryland at Baltimore, 725 West Lombard Street, Baltimore, Maryland 21201
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153
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Abstract
A new method of fluorescence detection that promises to increase sensitivity by 20- to 1000-fold is described. This method will also decrease the contribution of sample autofluorescence to the detected signal. The method depends on the coupling of excited fluorophores with the surface plasmon resonance present in thin metal films, typically silver and gold. The phenomenon of surface plasmon-coupled emission (SPCE) occurs for fluorophores 20-250 nm from the metal surface, allowing detection of fluorophores over substantial distances beyond the metal-sample interface. SPCE depends on interactions of the excited fluorophore with the metal surface. This interaction is independent of the mode of excitation; that is, it does not require evanescent wave or surface-plasmon excitation. In a sense, SPCE is the inverse process of the surface plasmon resonance absorption of thin metal films. Importantly, SPCE occurs over a narrow angular distribution, converting normally isotropic emission into easily collected directional emission. Up to 50% of the emission from unoriented samples can be collected, much larger than typical fluorescence collection efficiencies near 1% or less. SPCE is due only to fluorophores near the metal surface and may be regarded as emission from the induced surface plasmons. Autofluorescence from more distal parts of the sample is decreased due to decreased coupling. SPCE is highly polarized and autofluorescence can be further decreased by collecting only the polarized component or only the light propagating with the appropriate angle. Examples showing how simple optical configurations can be used in diagnostics, sensing, or biotechnology applications are presented. Surface plasmon-coupled emission is likely to find widespread applications throughout the biosciences.
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Affiliation(s)
- Joseph R Lakowicz
- Center for Fluorescence Spectroscopy, Department of Biochemistry and Molecular Biology, University of Maryland at Baltimore, 725 West Lombard Street, Baltimore, MD 21201, USA.
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154
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Zhang J, Gryczynski Z, Lakowicz JR. First observation of surface plasmon-coupled electrochemiluminescence. Chem Phys Lett 2004; 393:483-487. [PMID: 19763232 PMCID: PMC2744989 DOI: 10.1016/j.cplett.2004.06.050] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Electrochemiluminescence (ECL) is often used for high sensitivity detection. We describe a new approach to collecting the ECL signal, by coupling of the excited state of [Ru(bpy)(3)](2+) with the surface plasmons in a thin gold film. The energy then radiates into the substrate at a defined angle. Surface plasmon-coupled ECL promises to be useful in chemical and biological assays.
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Affiliation(s)
- Jian Zhang
- Center for Fluorescence Spectroscopy, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 725 West Lombard Street, Baltimore, MD 21201, USA
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155
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Gryczynski I, Malicka J, Gryczynski Z, Lakowicz JR. Surface Plasmon-Coupled Emission with Gold Films. J Phys Chem B 2004; 108:12568-12574. [PMID: 20729993 PMCID: PMC2924592 DOI: 10.1021/jp040221h] [Citation(s) in RCA: 134] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In a recent report we demonstrated efficient collection of emission by coupling to surface plasmons on a thin silver film, resulting in a directional signal in the glass substrate. We call the phenomenon surface plasmon coupled emission (SPCE). In the present report we examined sulforhodamine 101 (S101) in thin polymer films on 50 nm thick gold films on glass. We observed efficient SPCE through thin gold films. This result was surprising because metallic gold is typically an efficient quencher of fluorescence. The energy effectively coupled through the gold film into the glass at a sharply defined angle, but somewhat less sharp than for a comparable silver film. About 50% of the total emission appeared as SPCE, irrespective of direct excitation or excitation via the plasmon resonance evanescent wave. The emission was p-polarized with different wavelengths appearing at different angles. The lifetime of S101 was mostly unaffected by the gold film. These results indicate that SPCE occurs over long distances, larger than for quenching by energy transfer to the gold. We conclude highly efficient detection devices can be constructed by using fluorophores on gold-coated surfaces.
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Affiliation(s)
- Ignacy Gryczynski
- Center for Fluorescence Spectroscopy, University of Maryland at Baltimore, Department of Biochemistry and Molecular Biology, 725 West Lombard Street, Baltimore, Maryland 21201
| | - Joanna Malicka
- Center for Fluorescence Spectroscopy, University of Maryland at Baltimore, Department of Biochemistry and Molecular Biology, 725 West Lombard Street, Baltimore, Maryland 21201
| | - Zygmunt Gryczynski
- Center for Fluorescence Spectroscopy, University of Maryland at Baltimore, Department of Biochemistry and Molecular Biology, 725 West Lombard Street, Baltimore, Maryland 21201
| | - Joseph R. Lakowicz
- Center for Fluorescence Spectroscopy, University of Maryland at Baltimore, Department of Biochemistry and Molecular Biology, 725 West Lombard Street, Baltimore, Maryland 21201
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156
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Gryczynski I, Malicka J, Nowaczyk K, Gryczynski Z, Lakowicz JR. Effects of Sample Thickness on the Optical Properties of Surface Plasmon-Coupled Emission. J Phys Chem B 2004; 108:12073-12083. [PMID: 27340372 DOI: 10.1021/jp0312619] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In recent reports, we demonstrated coupling of excited fluorophores with thin silver or gold films resulting in directional surface plasmon-coupled emission (SPCE) through the silver film and into the glass substrate. In the present report, we describe the spectral and spatial properties of SPCE from sulforhomamine 101 in polyvinyl alcohol (PVA) films of various thicknesses on 50-nm silver films. The PVA thickness varied from about 30 to 750 nm. In thin PVA films with a thickness less than 160 nm, SPCE occurred at a single angle in the glass substrate and displayed only p polarization. As the PVA thickness increased to 300 nm, we observed SPCE at two angles, with different s or p polarization for each angle. For PVA films from 500 to 750 nm thick, we observed SPCE at three or four angles, with alternating s and p polarizations. The multiple rings of SPCE and the unusual s-polarized emission are consistent with the expected waveguide modes in the silver-PVA composite film. However, in contrast to our expectations, the average lifetimes of SPCE were not substantially changed from the PVA films. The observation of SPCE at multiple angles and with different polarization opens new opportunities for the use of SPCE to study anisotropic systems or to develop unique sensing devices.
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Affiliation(s)
- Ignacy Gryczynski
- Center for Fluorescence Spectroscopy, University of Maryland at Baltimore, Department of Biochemistry and Molecular Biology, 725 West Lombard Street, Baltimore, Maryland 21201
| | - Joanna Malicka
- Center for Fluorescence Spectroscopy, University of Maryland at Baltimore, Department of Biochemistry and Molecular Biology, 725 West Lombard Street, Baltimore, Maryland 21201
| | - Kazimierz Nowaczyk
- Center for Fluorescence Spectroscopy, University of Maryland at Baltimore, Department of Biochemistry and Molecular Biology, 725 West Lombard Street, Baltimore, Maryland 21201
| | - Zygmunt Gryczynski
- Center for Fluorescence Spectroscopy, University of Maryland at Baltimore, Department of Biochemistry and Molecular Biology, 725 West Lombard Street, Baltimore, Maryland 21201
| | - Joseph R Lakowicz
- Center for Fluorescence Spectroscopy, University of Maryland at Baltimore, Department of Biochemistry and Molecular Biology, 725 West Lombard Street, Baltimore, Maryland 21201
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157
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Gryczynski I, Malicka J, Gryczynski Z, Nowaczyk K, Lakowicz JR. Surface plasmon-coupled directional fluorescence emission. PROCEEDINGS OF SPIE--THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING 2004; 5327:37-44. [PMID: 19738927 PMCID: PMC2737471 DOI: 10.1117/12.530048] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Directional fluorescence emission of a sulforhodamine 101 in polyvinyl alcohol film has been observed from samples deposited on semi-transparent silver mirror. The fully p-polarized fluorescence emerges through the glass prism in form of hollow cone. The angle of this cone of emission depends on the thickness of the sample, and does not depend on the mode of excitation. The angular dependence of surface plasmon-coupled emission (SPCE) on the sample thickness has been discussed as well as its relevance to the surface plasmon resonance (SPR) analysis.
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158
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Matveeva E, Gryczynski Z, Gryczynski I, Lakowicz JR. Immunoassays based on directional surface plasmon-coupled emission. J Immunol Methods 2004; 286:133-40. [PMID: 15087228 PMCID: PMC2737394 DOI: 10.1016/j.jim.2003.12.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2003] [Accepted: 12/16/2003] [Indexed: 11/18/2022]
Abstract
We described a new approach to immunoassays using surface plasmon-coupled emission (SPCE). Fluorescence is visually isotropic in space, so that the sensitivity is limited in part by the light collection efficiency. By the use of SPCE, we can efficiently collect the emission and convert it to a cone-like directional beam in a glass substrate. SPCE is the coupling of excited fluorophores with a thin metal film, resulting in radiation of surface plasmons into the higher refractive index media. We used SPCE to develop a model affinity assay using labeled goat anti-rabbit immunoglobulin G (IgG) antibodies against rabbit IgG bound to a 50-nm-thick silver film. Binding of labeled IgG to the surface resulted in increased intensity observed at an angle of 75 degrees from the normal in the glass substrate. The SPCE intensity depends on proximity of the fluorophore to the silver film and does not require a change in quantum yield upon binding. The use of SPCE is shown to provide background suppression because excited fluorophores distant from the silver film do not result in SPCE. Sensitivity and selectivity can be further increased by excitation under conditions of surface plasmon resonance (SPR) because the evanescent field is enhanced by the resonance interaction and excitation is limited to the region near the metal. We believe SPCE will provide a new technology for high sensitivity and selectivity in surface-bound assays and microfluidic systems.
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Affiliation(s)
- Evgenia Matveeva
- Department of Biochemistry and Molecular Biology, Center for Fluorescence Spectroscopy, University of Maryland at Baltimore, 725 West Lombard Street, Baltimore, MD 21201, USA.
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159
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Matveeva E, Malicka J, Gryczynski I, Gryczynski Z, Lakowicz JR. Multi-wavelength immunoassays using surface plasmon-coupled emission. Biochem Biophys Res Commun 2004; 313:721-6. [PMID: 14697250 PMCID: PMC2737410 DOI: 10.1016/j.bbrc.2003.12.010] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
We describe a new method for multi-wavelength immunoassays using surface plasmon-coupled emission (SPCE). This phenomenon is coupling of excited fluorophores with a nearby thin metal film, in our case silver, resulting in strongly directional emission into the underlying glass substrate. The angle at which the radiation propagate through the prism depends on the surface plasmon angle for the relevant wavelength. These angles depend on emission wavelength, allowing measurement of multiple analytes using multiple emission wavelengths. We demonstrated this possibility using antibodies labeled with either Rhodamine Red-X or AlexaFluor 647. These antibodies were directed against an antigen protein bound to the silver surface. The emission from each labeled antibody occurred at a different angle on the glass prism, allowing independent measurement of surface binding of each antibody. This method of SPCE immunoassays can be readily extended to 4 or more wavelengths.
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Affiliation(s)
- Evgenia Matveeva
- Department of Biochemistry and Molecular Biology, Center for Fluorescence Spectroscopy, University of Maryland at Baltimore, 725 West Lombard Street, Baltimore, MD 21201, USA
| | - Joanna Malicka
- Department of Biochemistry and Molecular Biology, Center for Fluorescence Spectroscopy, University of Maryland at Baltimore, 725 West Lombard Street, Baltimore, MD 21201, USA
| | - Ignacy Gryczynski
- Department of Biochemistry and Molecular Biology, Center for Fluorescence Spectroscopy, University of Maryland at Baltimore, 725 West Lombard Street, Baltimore, MD 21201, USA
| | - Zygmunt Gryczynski
- Department of Biochemistry and Molecular Biology, Center for Fluorescence Spectroscopy, University of Maryland at Baltimore, 725 West Lombard Street, Baltimore, MD 21201, USA
| | - Joseph R. Lakowicz
- Department of Biochemistry and Molecular Biology, Center for Fluorescence Spectroscopy, University of Maryland at Baltimore, 725 West Lombard Street, Baltimore, MD 21201, USA
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160
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Geddes CD, Gryczynski I, Malicka J, Gryczynski Z, Lakowicz JR. Directional surface plasmon coupled emission. J Fluoresc 2004; 14:119-23. [PMID: 15622871 PMCID: PMC6986359 DOI: 10.1023/b:jofl.0000014809.64610.a8] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Chris D. Geddes
- Institute of Fluorescence and Center for Fluorescence Spectroscopy, Medical Biotechnology Center, University of Maryland Biotechnology Institute, 725 West Lombard St., Baltimore, MD, 21201
| | - Ignacy Gryczynski
- Center for Fluorescence Spectroscopy, University of Maryland School of Medicine, 725 West Lombard St., Baltimore, MD, 21201
| | - Joanna Malicka
- Center for Fluorescence Spectroscopy, University of Maryland School of Medicine, 725 West Lombard St., Baltimore, MD, 21201
| | - Zygmunt Gryczynski
- Center for Fluorescence Spectroscopy, University of Maryland School of Medicine, 725 West Lombard St., Baltimore, MD, 21201
| | - Joseph R. Lakowicz
- Center for Fluorescence Spectroscopy, University of Maryland School of Medicine, 725 West Lombard St., Baltimore, MD, 21201
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161
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Gryczynski I, Malicka J, Lukomska J, Gryczynski Z, Lakowicz JR. Surface Plasmon–coupled Polarized Emission of N-Acetyl-l-Tryptophanamide¶. Photochem Photobiol 2004; 80:482-5. [PMID: 15623334 PMCID: PMC6848917 DOI: 10.1562/0031-8655(2004)080<0482:sppeon>2.0.co;2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We report an observation of ultraviolet (UV) surface plasmon-coupled emission (SPCE) of N-acetyl-l-tryptophanamide (NATA). The sample was spin coated from poly(vinyl alcohol) (PVA) solution on 20 nm aluminum film deposited on a quartz substrate. The directional UV SPCE occurs within a well-defined narrow angle at 52 degrees from the normal to the coupling hemicylinder quartz prism. The NATA directional emission is highly p polarized as expected for surface plasmon-coupled radiation. The 10 nm protective SiO2 layer deposited on top of the aluminum film significantly neutralized the fluorophore quenching by the metal surface. SPCE of NATA demonstrates a remarkable intrinsic dispersive property-the maximum of the emission spectrum depends on the observation angle. The efficient spectral resolution of SPCE can be used in the construction of miniaturized spectrofluorometers. The observation of SPCE of tryptophan opens a new possibility for the study of many unlabeled proteins with the technique complementary to surface plasmon resonance analysis.
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Affiliation(s)
| | - Joanna Malicka
- To whom correspondence should be addressed: Center for Fluorescence Spectroscopy, Department of Biochemistry and Molecular Biology, University of Maryland at Baltimore, 725 West Lombard Street, Baltimore, MD 21201, USA. Fax: 410-706-8408;
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162
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Gryczynski Z, Gryczynski I, Matveeva E, Malicka J, Nowaczyk K, Lakowicz JR. Surface-Plasmon–Coupled Emission: New Technology for Studying Molecular Processes. Methods Cell Biol 2004; 75:73-104. [PMID: 15603423 DOI: 10.1016/s0091-679x(04)75004-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Zygmunt Gryczynski
- Center for Fluorescence Spectroscopy, University of Maryland at Baltimore, Department of Biochemistry and Molecular Biology, Baltimore, Maryland 21201, USA
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