1
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Ning Y, Yang S, Yang DB, Cai YY, Xu J, Li R, Zhang Y, Kagan CR, Saven JG, Murray CB. Dynamic Nanocrystal Superlattices with Thermally Triggerable Lubricating Ligands. J Am Chem Soc 2024; 146:3785-3795. [PMID: 38295018 DOI: 10.1021/jacs.3c10706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2024]
Abstract
The size-dependent and collective physical properties of nanocrystals (NCs) and their self-assembled superlattices (SLs) enable the study of mesoscale phenomena and the design of metamaterials for a broad range of applications. However, the limited mobility of NC building blocks in dried NCSLs often hampers the potential for employing postdeposition methods to produce high-quality NCSLs. In this study, we present tailored promesogenic ligands that exhibit a lubricating property akin to thermotropic liquid crystals. The lubricating ability of ligands is thermally triggerable, allowing the dry solid NC aggregates deposited on the substrates with poor ordering to be transformed into NCSLs with high crystallinity and preferred orientations. The interplay between the dynamic behavior of NCSLs and the molecular structure of the ligands is elucidated through a comprehensive analysis of their lubricating efficacy using both experimental and simulation approaches. Coarse-grained molecular dynamic modeling suggests that a shielding layer from mesogens prevents the interdigitation of ligand tails, facilitating the sliding between outer shells and consequently enhancing the mobility of NC building blocks. The dynamic organization of NCSLs can also be triggered with high spatial resolution by laser illumination. The principles, kinetics, and utility of lubricating ligands could be generalized to unlock stimuli-responsive metamaterials from NCSLs and contribute to the fabrication of NCSLs.
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2
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Cai YY, Choi YC, Kagan CR. Chemical and Physical Properties of Photonic Noble-Metal Nanomaterials. Adv Mater 2023; 35:e2108104. [PMID: 34897837 DOI: 10.1002/adma.202108104] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Revised: 11/15/2021] [Indexed: 06/14/2023]
Abstract
Colloidal noble metal nanoparticles (NPs) are composed of metal cores and organic or inorganic ligand shells. These NPs support size- and shape-dependent plasmonic resonances. They can be assembled from dispersions into artificial metamolecules which have collective plasmonic resonances originating from coupled bright and dark optical electric and magnetic modes that form depending on the size and shape of the constituent NPs and their number, arrangement, and interparticle distance. NPs can also be assembled into extended 2D and 3D metamaterials that are glassy thin films or ordered thin films or crystals, also known as superlattices and supercrystals. The metamaterials have tunable optical properties that depend on the size, shape, and composition of the NPs, and on the number of NP layers and their interparticle distance. Interestingly, strong light-matter interactions in superlattices form plasmon polaritons. Tunable interparticle distances allow designer materials with dielectric functions tailorable from that characteristic of an insulator to that of a metal, and serve as strong optical absorbers or scatterers, respectively. In combination with lithography techniques, these extended assemblies can be patterned to create subwavelength NP superstructures and form large-area 2D and 3D metamaterials that manipulate the amplitude, phase, and polarization of transmitted or reflected light.
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Affiliation(s)
- Yi-Yu Cai
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Yun Chang Choi
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Cherie R Kagan
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
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3
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Cai YY, Fallah A, Yang S, Choi YC, Xu J, Stein A, Kikkawa JM, Murray CB, Engheta N, Kagan CR. Open and Close-Packed, Shape-Engineered Polygonal Nanoparticle Metamolecules with Tailorable Fano Resonances. Adv Mater 2023; 35:e2301323. [PMID: 37165983 DOI: 10.1002/adma.202301323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 04/18/2023] [Indexed: 05/12/2023]
Abstract
A top-down lithographic patterning and deposition process is reported for producing nanoparticles (NPs) with well-defined sizes, shapes, and compositions that are often not accessible by wet-chemical synthetic methods. These NPs are ligated and harvested from the substrate surface to prepare colloidal NP dispersions. Using a template-assisted assembly technique, fabricated NPs are driven by capillary forces to assemble into size- and shape-engineered templates and organize into open or close-packed multi-NP structures or NP metamolecules. The sizes and shapes of the NPs and of the templates control the NP number, coordination, interparticle gap size, disorder, and location of defects such as voids in the NP metamolecules. The plasmonic resonances of polygonal-shaped Au NPs are exploited to correlate the structure and optical properties of assembled NP metamolecules. Comparing open and close-packed architectures highlights that introduction of a center NP to form close-packed assemblies supports collective interactions, altering magnetic optical modes and multipolar interactions in Fano resonances. Decreasing the distance between NPs strengthens the plasmonic coupling, and the structural symmetries of the NP metamolecules determine the orientation-dependent scattering response.
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Affiliation(s)
- Yi-Yu Cai
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Asma Fallah
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Shengsong Yang
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Yun Chang Choi
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Jun Xu
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Aaron Stein
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - James M Kikkawa
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Christopher B Murray
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Nader Engheta
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Cherie R Kagan
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
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4
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McNeill JM, Choi YC, Cai YY, Guo J, Nadal F, Kagan CR, Mallouk TE. Three-Dimensionally Complex Phase Behavior and Collective Phenomena in Mixtures of Acoustically Powered Chiral Microspinners. ACS Nano 2023; 17:7911-7919. [PMID: 37022928 DOI: 10.1021/acsnano.3c01966] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
The process of dynamic self-organization of small building blocks is fundamental to the emergent function of living systems and is characteristic of their out-of-equilibrium homeostasis. The ability to control the interactions of synthetic particles in large groups could lead to the realization of analogous macroscopic robotic systems with microscopic complexity. Rotationally induced self-organization has been observed in biological systems and modeled theoretically, but studies of fast, autonomously moving synthetic rotors remain rare. Here, we report switchable, out-of-equilibrium hydrodynamic assembly and phase separation in suspensions of acoustically powered chiral microspinners. Semiquantitative modeling suggests that three-dimensionally (3D) complex spinners interact through viscous and weakly inertial (streaming) flows. The interactions between spinners were studied over a range of densities to construct a phase diagram, which included gaseous dimer pairing at low density, collective rotation and multiphase separation at intermediate densities, and ultimately jamming at high density. The 3D chirality of the spinners leads to self-organization in parallel planes, forming a three-dimensionally hierarchical system that goes beyond the 2D systems that have so far been modeled computationally. Dense mixtures of spinners and passive tracer particles also show active-passive phase separation. These observations are consistent with recent theoretical predictions of the hydrodynamic coupling between rotlets generated by autonomous spinners and provide an exciting experimental window to the study of colloidal active matter and microrobotic systems.
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Affiliation(s)
- Jeffrey M McNeill
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Yun Chang Choi
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Yi-Yu Cai
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Jiacen Guo
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - François Nadal
- Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough LE11 3TU, United Kingdom
| | - Cherie R Kagan
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Thomas E Mallouk
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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5
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Yang S, LaCour RA, Cai YY, Xu J, Rosen DJ, Zhang Y, Kagan CR, Glotzer SC, Murray CB. Self-Assembly of Atomically Aligned Nanoparticle Superlattices from Pt-Fe 3O 4 Heterodimer Nanoparticles. J Am Chem Soc 2023; 145:6280-6288. [PMID: 36912558 DOI: 10.1021/jacs.2c12993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2023]
Abstract
Multicomponent nanoparticle superlattices (SLs) promise the integration of nanoparticles (NPs) with remarkable electronic, magnetic, and optical properties into a single structure. Here, we demonstrate that heterodimers consisting of two conjoined NPs can self-assemble into novel multicomponent SLs with a high degree of alignment between the atomic lattices of individual NPs, which has been theorized to lead to a wide variety of remarkable properties. Specifically, by using simulations and experiments, we show that heterodimers composed of larger Fe3O4 domains decorated with a Pt domain at one vertex can self-assemble into an SL with long-range atomic alignment between the Fe3O4 domains of different NPs across the SL. The SLs show an unanticipated decreased coercivity relative to nonassembled NPs. In situ scattering of the self-assembly reveals a two-stage mechanism of self-assembly: translational ordering between NPs develops before atomic alignment. Our experiments and simulation indicate that atomic alignment requires selective epitaxial growth of the smaller domain during heterodimer synthesis and specific size ratios of the heterodimer domains as opposed to specific chemical composition. This composition independence makes the self-assembly principles elucidated here applicable to the future preparation of multicomponent materials with fine structural control.
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Affiliation(s)
- Shengsong Yang
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - R Allen LaCour
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
- Biointerfaces Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Yi-Yu Cai
- Department of Electrical and System Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Jun Xu
- Department of Electrical and System Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Daniel J Rosen
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Yugang Zhang
- Center for Functional Nanomaterials, Brookhaven National Laboratories, Upton, New York 11973, United States
| | - Cherie R Kagan
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Electrical and System Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Sharon C Glotzer
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
- Biointerfaces Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Christopher B Murray
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Electrical and System Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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6
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Nguyen HA, Sharp D, Fröch JE, Cai YY, Wu S, Monahan M, Munley C, Manna A, Majumdar A, Kagan CR, Cossairt BM. Deterministic Quantum Light Arrays from Giant Silica-Shelled Quantum Dots. ACS Appl Mater Interfaces 2023; 15:4294-4302. [PMID: 36507852 DOI: 10.1021/acsami.2c18475] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Colloidal quantum dots (QDs) are promising candidates for single-photon sources with applications in photonic quantum information technologies. Developing practical photonic quantum devices with colloidal materials, however, requires scalable deterministic placement of stable single QD emitters. In this work, we describe a method to exploit QD size to facilitate deterministic positioning of single QDs into large arrays while maintaining their photostability and single-photon emission properties. CdSe/CdS core/shell QDs were encapsulated in silica to both increase their physical size without perturbing their quantum-confined emission and enhance their photostability. These giant QDs were then precisely positioned into ordered arrays using template-assisted self-assembly with a 75% yield for single QDs. We show that the QDs before and after assembly exhibit antibunching behavior at room temperature and their optical properties are retained after an extended period of time. Together, this bottom-up synthetic approach via silica shelling and the robust template-assisted self-assembly offer a unique strategy to produce scalable quantum photonics platforms using colloidal QDs as single-photon emitters.
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Affiliation(s)
- Hao A Nguyen
- Department of Chemistry, University of Washington, Seattle, Washington 98189, United States
| | - David Sharp
- Department of Physics, University of Washington, Seattle, Washington 98185, United States
| | - Johannes E Fröch
- Department of Physics, University of Washington, Seattle, Washington 98185, United States
- Department of Electrical and Computer Engineering, University of Washington, Seattle, Washington 98195, United States
| | - Yi-Yu Cai
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Shenwei Wu
- Department of Chemistry, University of Washington, Seattle, Washington 98189, United States
| | - Madison Monahan
- Department of Chemistry, University of Washington, Seattle, Washington 98189, United States
| | - Christopher Munley
- Department of Physics, University of Washington, Seattle, Washington 98185, United States
| | - Arnab Manna
- Department of Physics, University of Washington, Seattle, Washington 98185, United States
| | - Arka Majumdar
- Department of Physics, University of Washington, Seattle, Washington 98185, United States
- Department of Electrical and Computer Engineering, University of Washington, Seattle, Washington 98195, United States
| | - Cherie R Kagan
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Brandi M Cossairt
- Department of Chemistry, University of Washington, Seattle, Washington 98189, United States
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7
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Forcherio GT, Ostovar B, Boltersdorf J, Cai YY, Leff AC, Grew KN, Lundgren CA, Link S, Baker DR. Single-Particle Insights into Plasmonic Hot Carrier Separation Augmenting Photoelectrochemical Ethanol Oxidation with Photocatalytically Synthesized Pd-Au Bimetallic Nanorods. ACS Nano 2022; 16:12377-12389. [PMID: 35894585 DOI: 10.1021/acsnano.2c03549] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Understanding the nature of hot carrier pathways following surface plasmon excitation of heterometallic nanostructures and their mechanistic prevalence during photoelectrochemical oxidation of complex hydrocarbons, such as ethanol, remains challenging. This work studies the fate of carriers from Au nanorods before and after the presence of reductively photodeposited Pd at the single-particle level using scattering and emission spectroscopy, along with ensemble photoelectrochemical methods. A sub-2 nm epitaxial Pd0 shell was reductively grown onto colloidal Au nanorods via hot carriers generated from surface plasmon resonance excitation in the presence of [PdCl4]2-. These bimetallic Pd-Au nanorod architectures exhibited 14% quenched emission quantum yields and 9% augmented plasmon damping determined from their scattering spectra compared to the bare Au nanorods, consistent with injection/separation of intraband hot carriers into the Pd. Absorbed photon-to-current efficiency in photoelectrochemical ethanol oxidation was enhanced 50× from 0.00034% to 0.017% due to the photodeposited Pd. Photocurrent during ethanol oxidation improved 13× under solar-simulated AM1.5G and 40× for surface plasmon resonance-targeted irradiation conditions after photodepositing Pd, consistent with enhanced participation of intraband-excited sp-band holes and desorption of ethanol oxidation reaction intermediates owing to photothermal effects.
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Affiliation(s)
- Gregory T Forcherio
- U.S. Army Combat Capabilities Development Command - Army Research Laboratory, Adelphi, Maryland 20783 United States
- Electro-Optic Technology Division, Naval Surface Warfare Center, Crane, Indiana 47522 United States
| | | | - Jonathan Boltersdorf
- U.S. Army Combat Capabilities Development Command - Army Research Laboratory, Adelphi, Maryland 20783 United States
| | | | - Asher C Leff
- U.S. Army Combat Capabilities Development Command - Army Research Laboratory, Adelphi, Maryland 20783 United States
- General Technical Services, Adelphi, Maryland 20783, United States
| | - Kyle N Grew
- U.S. Army Combat Capabilities Development Command - Army Research Laboratory, Adelphi, Maryland 20783 United States
| | - Cynthia A Lundgren
- U.S. Army Combat Capabilities Development Command - Army Research Laboratory, Adelphi, Maryland 20783 United States
| | | | - David R Baker
- U.S. Army Combat Capabilities Development Command - Army Research Laboratory, Adelphi, Maryland 20783 United States
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8
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Abstract
The mechanism of light emission from metallic nanoparticles has been a subject of debate in recent years. Photoluminescence and electronic Raman scattering mechanisms have both been proposed to explain the observed emission from plasmonic nanostructures. Recent results from Stokes and anti-Stokes emission spectroscopy of single gold nanorods using continuous wave laser excitation carried out in our laboratory are summarized here. We show that varying excitation wavelength and power change the energy distribution of hot carriers and impact the emission spectral lineshape. We then examine the role of interband and intraband transitions in the emission lineshape by varying the particle size. We establish a relationship between the single particle emission quantum yield and its corresponding plasmonic resonance quality factor, which we also tune through nanorod crystallinity. Finally, based on anti-Stokes emission, we extract electron temperatures that further suggest a hot carrier based mechanism. The central role of hot carriers in our systematic study on gold nanorods as a model system supports a Purcell effect enhanced hot carrier photoluminescence mechanism. We end with a discussion on the impact of understanding the light emission mechanism on fields utilizing hot carrier distributions, such as photocatalysis and nanothermometry.
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Affiliation(s)
- Yi-Yu Cai
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, USA
| | - Lawrence J Tauzin
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, USA
| | - Behnaz Ostovar
- Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, Texas 77005, USA
| | - Stephen Lee
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, USA
| | - Stephan Link
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, USA
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9
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Collins SSE, Searles EK, Tauzin LJ, Lou M, Bursi L, Liu Y, Song J, Flatebo C, Baiyasi R, Cai YY, Foerster B, Lian T, Nordlander P, Link S, Landes CF. Plasmon Energy Transfer in Hybrid Nanoantennas. ACS Nano 2021; 15:9522-9530. [PMID: 33350807 DOI: 10.1021/acsnano.0c08982] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Plasmonic metal nanoparticles exhibit large dipole moments upon photoexcitation and have the potential to induce electronic transitions in nearby materials, but fast internal relaxation has to date limited the spatial range and efficiency of plasmonic mediated processes. In this work, we use photo-electrochemistry to synthesize hybrid nanoantennas comprised of plasmonic nanoparticles with photoconductive polymer coatings. We demonstrate that the formation of the conductive polymer is selective to the nanoparticles and that polymerization is enhanced by photoexcitation. In situ spectroscopy and simulations support a mechanism in which up to 50% efficiency of nonradiative energy transfer is achieved. These hybrid nanoantennas combine the unmatched light-harvesting properties of a plasmonic antenna with the similarly unmatched device processability of a polymer shell.
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Affiliation(s)
- Sean S E Collins
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- Smalley-Curl Institute, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Emily K Searles
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Lawrence J Tauzin
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Minhan Lou
- Laboratory for Nanophotonics, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Luca Bursi
- Laboratory for Nanophotonics, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- Department of Physics & Astronomy, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Yawei Liu
- Department of Chemistry, Emory University, 1515 Dickey Drive, NE, Atlanta, Georgia 30322, United States
| | - Jia Song
- Department of Chemistry, Emory University, 1515 Dickey Drive, NE, Atlanta, Georgia 30322, United States
| | - Charlotte Flatebo
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- Applied Physics Program, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Rashad Baiyasi
- Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Yi-Yu Cai
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Benjamin Foerster
- Advanced Materials & Systems Research, Polymer Colloid Technology, BASF SE, 67056 Ludwigshafen am Rhein, Germany
| | - Tianquan Lian
- Department of Chemistry, Emory University, 1515 Dickey Drive, NE, Atlanta, Georgia 30322, United States
| | - Peter Nordlander
- Smalley-Curl Institute, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- Laboratory for Nanophotonics, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- Department of Physics & Astronomy, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Stephan Link
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- Smalley-Curl Institute, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, Texas 77005, United States
| | - Christy F Landes
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- Smalley-Curl Institute, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, Texas 77005, United States
- Department of Chemical and Biomolecular Engineering, Rice University, 6100 Main Street, Houston, Texas 77005, United States
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10
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Ostovar B, Cai YY, Tauzin LJ, Lee SA, Ahmadivand A, Zhang R, Nordlander P, Link S. Increased Intraband Transitions in Smaller Gold Nanorods Enhance Light Emission. ACS Nano 2020; 14:15757-15765. [PMID: 32852941 DOI: 10.1021/acsnano.0c06771] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Photoinduced light emission from plasmonic nanoparticles has attracted considerable interest within the scientific community because of its potential applications in sensing, imaging, and nanothermometry. One of the suggested mechanisms for the light emission from plasmonic nanoparticles is the plasmon-enhanced radiative recombination of hot carriers through inter- and intraband transitions. Here, we investigate the nanoparticle size dependence on the photoluminescence through a systematic analysis of gold nanorods with similar aspect ratios. Using single-particle emission and scattering spectroscopy along with correlated scanning electron microscopy and electromagnetic simulations, we calculate the emission quantum yields and Purcell enhancement factors for individual gold nanorods. Our results show strong size-dependent quantum yields in gold nanorods, with higher quantum yields for smaller gold nanorods. Furthermore, by determining the relative contributions to the photoluminescence from inter- and intraband transitions, we deduce that the observed size dependence predominantly originates from the size dependence of intraband transitions. Specifically, within the framework of Fermi's golden rule for radiative recombination of excited charge carriers, we demonstrate that the Purcell factor enhancement alone cannot explain the emission size dependence and that changes in the transition matrix elements must also occur. Those changes are due to electric field confinement enhancing intraband transitions. These results provide vital insight into the intraband relaxation in metallic nanoconfined systems and therefore are of direct importance to the rapidly developing field of plasmonic photocatalysis.
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11
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Cai YY, Sung E, Zhang R, Tauzin LJ, Liu JG, Ostovar B, Zhang Y, Chang WS, Nordlander P, Link S. Anti-Stokes Emission from Hot Carriers in Gold Nanorods. Nano Lett 2019; 19:1067-1073. [PMID: 30657694 DOI: 10.1021/acs.nanolett.8b04359] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The origin of light emission from plasmonic nanoparticles has been strongly debated lately. It is present as the background of surface-enhanced Raman scattering and, despite the low yield, has been used for novel sensing and imaging applications because of its photostability. Although the role of surface plasmons as an enhancing antenna is widely accepted, the main controversy regarding the mechanism of the emission is its assignment to either radiative recombination of hot carriers (photoluminescence) or electronic Raman scattering (inelastic light scattering). We have previously interpreted the Stokes-shifted emission from gold nanorods as the Purcell effect enhanced radiative recombination of hot carriers. Here we specifically focused on the anti-Stokes emission from single gold nanorods of varying aspect ratios with excitation wavelengths below and above the interband transition threshold while still employing continuous wave lasers. Analysis of the intensity ratios between Stokes and anti-Stokes emission yields temperatures that can only be interpreted as originating from the excited electron distribution and not a thermally equilibrated phonon population despite not using pulsed laser excitation. Consistent with this result as well as previous emission studies using ultrafast lasers, the power-dependence of the upconverted emission is nonlinear and gives the average number of participating photons as a function of emission wavelength. Our findings thus show that hot carriers and photoluminescence play a major role in the upconverted emission.
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12
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Yi C, Su MN, Dongare PD, Chakraborty D, Cai YY, Marolf DM, Kress RN, Ostovar B, Tauzin LJ, Wen F, Chang WS, Jones MR, Sader JE, Halas NJ, Link S. Polycrystallinity of Lithographically Fabricated Plasmonic Nanostructures Dominates Their Acoustic Vibrational Damping. Nano Lett 2018; 18:3494-3501. [PMID: 29715035 DOI: 10.1021/acs.nanolett.8b00559] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The study of acoustic vibrations in nanoparticles provides unique and unparalleled insight into their mechanical properties. Electron-beam lithography of nanostructures allows precise manipulation of their acoustic vibration frequencies through control of nanoscale morphology. However, the dissipation of acoustic vibrations in this important class of nanostructures has not yet been examined. Here we report, using single-particle ultrafast transient extinction spectroscopy, the intrinsic damping dynamics in lithographically fabricated plasmonic nanostructures. We find that in stark contrast to chemically synthesized, monocrystalline nanoparticles, acoustic energy dissipation in lithographically fabricated nanostructures is solely dominated by intrinsic damping. A quality factor of Q = 11.3 ± 2.5 is observed for all 147 nanostructures, regardless of size, geometry, frequency, surface adhesion, and mode. This result indicates that the complex Young's modulus of this material is independent of frequency with its imaginary component being approximately 11 times smaller than its real part. Substrate-mediated acoustic vibration damping is strongly suppressed, despite strong binding between the glass substrate and Au nanostructures. We anticipate that these results, characterizing the optomechanical properties of lithographically fabricated metal nanostructures, will help inform their design for applications such as photoacoustic imaging agents, high-frequency resonators, and ultrafast optical switches.
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Affiliation(s)
- Chongyue Yi
- Department of Chemistry , Rice University , Houston , Texas 77005 , United States
| | - Man-Nung Su
- Department of Chemistry , Rice University , Houston , Texas 77005 , United States
| | - Pratiksha D Dongare
- Applied Physics Graduate Program , Rice University , Houston , Texas 77005 , United States
- Department of Electrical and Computer Engineering , Rice University , Houston , Texas 77005 , United States
| | - Debadi Chakraborty
- ARC Centre of Excellence in Exciton Science, School of Mathematics and Statistics , The University of Melbourne , Parkville , VIC 3010 , Australia
| | - Yi-Yu Cai
- Department of Chemistry , Rice University , Houston , Texas 77005 , United States
| | - David M Marolf
- Department of Chemistry , Rice University , Houston , Texas 77005 , United States
| | - Rachael N Kress
- Department of Chemistry , Rice University , Houston , Texas 77005 , United States
| | - Behnaz Ostovar
- Department of Chemistry , Rice University , Houston , Texas 77005 , United States
| | - Lawrence J Tauzin
- Department of Chemistry , Rice University , Houston , Texas 77005 , United States
| | - Fangfang Wen
- Department of Chemistry , Rice University , Houston , Texas 77005 , United States
| | - Wei-Shun Chang
- Department of Chemistry , Rice University , Houston , Texas 77005 , United States
| | - Matthew R Jones
- Department of Chemistry , Rice University , Houston , Texas 77005 , United States
| | - John E Sader
- ARC Centre of Excellence in Exciton Science, School of Mathematics and Statistics , The University of Melbourne , Parkville , VIC 3010 , Australia
| | - Naomi J Halas
- Department of Chemistry , Rice University , Houston , Texas 77005 , United States
- Department of Electrical and Computer Engineering , Rice University , Houston , Texas 77005 , United States
- Department of Physics and Astronomy , Rice University , Houston , Texas 77005 , United States
- Laboratory for Nanophotonics , Rice University , Houston , Texas 77005 , United States
| | - Stephan Link
- Department of Chemistry , Rice University , Houston , Texas 77005 , United States
- Department of Electrical and Computer Engineering , Rice University , Houston , Texas 77005 , United States
- Laboratory for Nanophotonics , Rice University , Houston , Texas 77005 , United States
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13
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Cai YY, Liu JG, Tauzin LJ, Huang D, Sung E, Zhang H, Joplin A, Chang WS, Nordlander P, Link S. Photoluminescence of Gold Nanorods: Purcell Effect Enhanced Emission from Hot Carriers. ACS Nano 2018; 12:976-985. [PMID: 29283248 DOI: 10.1021/acsnano.7b07402] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
We demonstrate, experimentally and theoretically, that the photon emission from gold nanorods can be viewed as a Purcell effect enhanced radiative recombination of hot carriers. By correlating the single-particle photoluminescence spectra and quantum yields of gold nanorods measured for five different excitation wavelengths and varied excitation powers, we illustrate the effects of hot carrier distributions evolving through interband and intraband transitions and the photonic density of states on the nanorod photoluminescence. Our model, using only one fixed input parameter, describes quantitatively both emission from interband recombination and the main photoluminescence peak coinciding with the longitudinal surface plasmon resonance.
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Affiliation(s)
- Yi-Yu Cai
- Department of Chemistry, ‡Department of Physics and Astronomy, §Department of Electrical and Computer Engineering, ⊥Department of Materials Science and NanoEngineering, and ∥Laboratory for Nanophotonics, Rice University , 6100 Main Street, Houston, Texas 77005, United States
| | - Jun G Liu
- Department of Chemistry, ‡Department of Physics and Astronomy, §Department of Electrical and Computer Engineering, ⊥Department of Materials Science and NanoEngineering, and ∥Laboratory for Nanophotonics, Rice University , 6100 Main Street, Houston, Texas 77005, United States
| | - Lawrence J Tauzin
- Department of Chemistry, ‡Department of Physics and Astronomy, §Department of Electrical and Computer Engineering, ⊥Department of Materials Science and NanoEngineering, and ∥Laboratory for Nanophotonics, Rice University , 6100 Main Street, Houston, Texas 77005, United States
| | - Da Huang
- Department of Chemistry, ‡Department of Physics and Astronomy, §Department of Electrical and Computer Engineering, ⊥Department of Materials Science and NanoEngineering, and ∥Laboratory for Nanophotonics, Rice University , 6100 Main Street, Houston, Texas 77005, United States
| | - Eric Sung
- Department of Chemistry, ‡Department of Physics and Astronomy, §Department of Electrical and Computer Engineering, ⊥Department of Materials Science and NanoEngineering, and ∥Laboratory for Nanophotonics, Rice University , 6100 Main Street, Houston, Texas 77005, United States
| | - Hui Zhang
- Department of Chemistry, ‡Department of Physics and Astronomy, §Department of Electrical and Computer Engineering, ⊥Department of Materials Science and NanoEngineering, and ∥Laboratory for Nanophotonics, Rice University , 6100 Main Street, Houston, Texas 77005, United States
| | - Anneli Joplin
- Department of Chemistry, ‡Department of Physics and Astronomy, §Department of Electrical and Computer Engineering, ⊥Department of Materials Science and NanoEngineering, and ∥Laboratory for Nanophotonics, Rice University , 6100 Main Street, Houston, Texas 77005, United States
| | - Wei-Shun Chang
- Department of Chemistry, ‡Department of Physics and Astronomy, §Department of Electrical and Computer Engineering, ⊥Department of Materials Science and NanoEngineering, and ∥Laboratory for Nanophotonics, Rice University , 6100 Main Street, Houston, Texas 77005, United States
| | - Peter Nordlander
- Department of Chemistry, ‡Department of Physics and Astronomy, §Department of Electrical and Computer Engineering, ⊥Department of Materials Science and NanoEngineering, and ∥Laboratory for Nanophotonics, Rice University , 6100 Main Street, Houston, Texas 77005, United States
| | - Stephan Link
- Department of Chemistry, ‡Department of Physics and Astronomy, §Department of Electrical and Computer Engineering, ⊥Department of Materials Science and NanoEngineering, and ∥Laboratory for Nanophotonics, Rice University , 6100 Main Street, Houston, Texas 77005, United States
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14
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De Silva Indrasekara AS, Shuang B, Hollenhorst F, Hoener BS, Hoggard A, Chen S, Villarreal E, Cai YY, Kisley L, Derry PJ, Chang WS, Zubarev ER, Ringe E, Link S, Landes CF. Optimization of Spectral and Spatial Conditions to Improve Super-Resolution Imaging of Plasmonic Nanoparticles. J Phys Chem Lett 2017; 8:299-306. [PMID: 27982600 DOI: 10.1021/acs.jpclett.6b02569] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Interactions between fluorophores and plasmonic nanoparticles modify the fluorescence intensity, shape, and position of the observed emission pattern, thus inhibiting efforts to optically super-resolve plasmonic nanoparticles. Herein, we investigate the accuracy of localizing dye fluorescence as a function of the spectral and spatial separations between fluorophores (Alexa 647) and gold nanorods (NRs). The distance at which Alexa 647 interacts with NRs is varied by layer-by-layer polyelectrolyte deposition while the spectral separation is tuned by using NRs with varying localized surface plasmon resonance (LSPR) maxima. For resonantly coupled Alexa 647 and NRs, emission to the far field through the NR plasmon is highly prominent, resulting in underestimation of NR sizes. However, we demonstrate that it is possible to improve the accuracy of the emission localization when both the spectral and spatial separations between Alexa 647 and the LSPR are optimized.
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Affiliation(s)
| | - Bo Shuang
- Department of Chemistry, Rice University , 6100 Main Street, MS-60, Houston, Texas 77005, United States
| | - Franziska Hollenhorst
- Department of Chemistry, Rice University , 6100 Main Street, MS-60, Houston, Texas 77005, United States
| | - Benjamin S Hoener
- Department of Chemistry, Rice University , 6100 Main Street, MS-60, Houston, Texas 77005, United States
| | - Anneli Hoggard
- Department of Chemistry, Rice University , 6100 Main Street, MS-60, Houston, Texas 77005, United States
| | - Sishan Chen
- Department of Chemistry, Rice University , 6100 Main Street, MS-60, Houston, Texas 77005, United States
| | - Eduardo Villarreal
- Department of Materials Science and Nanoengineering, Rice University , 6100 Main Street, MS-325, Houston, Texas 77005, United States
| | - Yi-Yu Cai
- Department of Chemistry, Rice University , 6100 Main Street, MS-60, Houston, Texas 77005, United States
| | - Lydia Kisley
- Department of Chemistry, Rice University , 6100 Main Street, MS-60, Houston, Texas 77005, United States
| | - Paul J Derry
- Department of Chemistry, Rice University , 6100 Main Street, MS-60, Houston, Texas 77005, United States
| | - Wei-Shun Chang
- Department of Chemistry, Rice University , 6100 Main Street, MS-60, Houston, Texas 77005, United States
| | - Eugene R Zubarev
- Department of Chemistry, Rice University , 6100 Main Street, MS-60, Houston, Texas 77005, United States
- Department of Materials Science and Nanoengineering, Rice University , 6100 Main Street, MS-325, Houston, Texas 77005, United States
| | - Emilie Ringe
- Department of Chemistry, Rice University , 6100 Main Street, MS-60, Houston, Texas 77005, United States
- Department of Materials Science and Nanoengineering, Rice University , 6100 Main Street, MS-325, Houston, Texas 77005, United States
| | - Stephan Link
- Department of Chemistry, Rice University , 6100 Main Street, MS-60, Houston, Texas 77005, United States
- Department of Electrical and Computer Engineering, Rice University , 6100 Main Street, MS-366, Houston, Texas 77005, United States
| | - Christy F Landes
- Department of Chemistry, Rice University , 6100 Main Street, MS-60, Houston, Texas 77005, United States
- Department of Electrical and Computer Engineering, Rice University , 6100 Main Street, MS-366, Houston, Texas 77005, United States
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15
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Jiang YQ, Zhu YX, Chen XL, Xu X, Li F, Fu HJ, Shen CY, Lu YY, Zhuang QJ, Xu G, Cai YY, Zhang Y, Liu SS, Zhu MY, Li SH. Impact of adherence to GOLD guidelines on 6-minute walk distance, MRC dyspnea scale score, lung function decline, quality of life, and quality-adjusted life years in a Shanghai suburb. Genet Mol Res 2015; 14:8861-70. [PMID: 26345817 DOI: 10.4238/2015.august.3.9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
We performed a 1-year cluster-randomized field trial to assess the effect of standardized management of chronic obstructive pulmonary disease (COPD) on lung function and quality of life (QOL) measures in patients in China. We used the Global Initiative for Chronic Obstructive Lung Disease (GOLD) treatment guidelines and assessed indexes including pulmonary function, QOL, quality-adjusted life years (QALY), Medical Research Council (MRC) dyspnea scale, 6-min walk distance (6-MWD), number of emergency visits, and frequency of hospitalization. Of a total of 711 patients with chronic cough and asthma, 132 were diagnosed as having COPD and 102 participated in this study [intervention group (N = 47); control group (N = 55)]. We found that adherence to GOLD guidelines had a perceivable impact on 6-MWD, MRC dyspnea scale score, and QOL. The average QALY increased by 1.42/person/year in the intervention group, but declined by 0.95/person/year in the control group. We conclude that standardized management improves disease severity, QOL, and QALY in COPD patients when treatment protocols adhere to GOLD guidelines.
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Affiliation(s)
- Y Q Jiang
- Shanghai Municipal First People's Hospital Affiliated to Shanghai Jiaotong University, Shanghai, China
| | - Y X Zhu
- Songjiang Branch of Shanghai Municipal First People's Hospital Affiliated to Shanghai Jiaotong University, Shanghai, China
| | - X L Chen
- Songjiang Branch of Shanghai Municipal First People's Hospital Affiliated to Shanghai Jiaotong University, Shanghai, China
| | - X Xu
- Songjiang Branch of Shanghai Municipal First People's Hospital Affiliated to Shanghai Jiaotong University, Shanghai, China
| | - F Li
- Songjiang Branch of Shanghai Municipal First People's Hospital Affiliated to Shanghai Jiaotong University, Shanghai, China
| | - H J Fu
- Xiaokunshan Town Primary Care of Songjiang District, Shanghai, China
| | - C Y Shen
- Xiaokunshan Town Primary Care of Songjiang District, Shanghai, China
| | - Y Y Lu
- Xiaokunshan Town Primary Care of Songjiang District, Shanghai, China
| | - Q J Zhuang
- Xinbang Town Primary Care of Songjiang District, Shanghai, China
| | - G Xu
- School of Public Health, Shanghai Jiao Tong University, Shanghai, China
| | - Y Y Cai
- Institute of Respiratory Disease, Zhongshan Hospital Affiliated to Fudan University, Shanghai, China
| | - Y Zhang
- Shanghai Songjiang District Public Health Bureau, Shanghai, China
| | - S S Liu
- Shanghai Songjiang District Center for Diseases Control and Prevention, Shanghai, China
| | - M Y Zhu
- Shanghai Songjiang District Center for Diseases Control and Prevention, Shanghai, China
| | - S H Li
- Songjiang Branch of Shanghai Municipal First People's Hospital Affiliated to Shanghai Jiaotong University, Shanghai, China
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16
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Yorulmaz M, Nizzero S, Hoggard A, Wang LY, Cai YY, Su MN, Chang WS, Link S. Single-particle absorption spectroscopy by photothermal contrast. Nano Lett 2015; 15:3041-7. [PMID: 25849105 DOI: 10.1021/nl504992h] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Removing effects of sample heterogeneity through single-molecule and single-particle techniques has advanced many fields. While background free luminescence and scattering spectroscopy is widely used, recording the absorption spectrum only is rather difficult. Here we present an approach capable of recording pure absorption spectra of individual nanostructures. We demonstrate the implementation of single-particle absorption spectroscopy on strongly scattering plasmonic nanoparticles by combining photothermal microscopy with a supercontinuum laser and an innovative calibration procedure that accounts for chromatic aberrations and wavelength-dependent excitation powers. Comparison of the absorption spectra to the scattering spectra of the same individual gold nanoparticles reveals the blueshift of the absorption spectra, as predicted by Mie theory but previously not detectable in extinction measurements that measure the sum of absorption and scattering. By covering a wavelength range of 300 nm, we are furthermore able to record absorption spectra of single gold nanorods with different aspect ratios. We find that the spectral shift between absorption and scattering for the longitudinal plasmon resonance decreases as a function of nanorod aspect ratio, which is in agreement with simulations.
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Affiliation(s)
- Mustafa Yorulmaz
- †Department of Chemistry, ‡Applied Physics Graduate Program, §Department of Electrical and Computer Engineering, Laboratory for Nanophotonics, Rice University, Houston, Texas 77005, United States
| | - Sara Nizzero
- †Department of Chemistry, ‡Applied Physics Graduate Program, §Department of Electrical and Computer Engineering, Laboratory for Nanophotonics, Rice University, Houston, Texas 77005, United States
| | - Anneli Hoggard
- †Department of Chemistry, ‡Applied Physics Graduate Program, §Department of Electrical and Computer Engineering, Laboratory for Nanophotonics, Rice University, Houston, Texas 77005, United States
| | - Lin-Yung Wang
- †Department of Chemistry, ‡Applied Physics Graduate Program, §Department of Electrical and Computer Engineering, Laboratory for Nanophotonics, Rice University, Houston, Texas 77005, United States
| | - Yi-Yu Cai
- †Department of Chemistry, ‡Applied Physics Graduate Program, §Department of Electrical and Computer Engineering, Laboratory for Nanophotonics, Rice University, Houston, Texas 77005, United States
| | - Man-Nung Su
- †Department of Chemistry, ‡Applied Physics Graduate Program, §Department of Electrical and Computer Engineering, Laboratory for Nanophotonics, Rice University, Houston, Texas 77005, United States
| | - Wei-Shun Chang
- †Department of Chemistry, ‡Applied Physics Graduate Program, §Department of Electrical and Computer Engineering, Laboratory for Nanophotonics, Rice University, Houston, Texas 77005, United States
| | - Stephan Link
- †Department of Chemistry, ‡Applied Physics Graduate Program, §Department of Electrical and Computer Engineering, Laboratory for Nanophotonics, Rice University, Houston, Texas 77005, United States
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17
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Guo LT, Cai YY, Ge JM, Zhang YN, Gong LH, Li XH, Wang KX, Ren QZ, Su J, Chen JS. Multifunctional Au–Co@CN Nanocatalyst for Highly Efficient Hydrolysis of Ammonia Borane. ACS Catal 2014. [DOI: 10.1021/cs501692n] [Citation(s) in RCA: 121] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Lin-Tong Guo
- School of Chemistry
and Chemical
Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Yi-Yu Cai
- School of Chemistry
and Chemical
Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Jie-Min Ge
- School of Chemistry
and Chemical
Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Ya-Nan Zhang
- School of Chemistry
and Chemical
Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Ling-Hong Gong
- School of Chemistry
and Chemical
Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Xin-Hao Li
- School of Chemistry
and Chemical
Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Kai-Xue Wang
- School of Chemistry
and Chemical
Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Qi-Zhi Ren
- School of Chemistry
and Chemical
Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Juan Su
- School of Chemistry
and Chemical
Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Jie-Sheng Chen
- School of Chemistry
and Chemical
Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
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18
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Zhang YN, Li XH, Cai YY, Gong LH, Wang KX, Chen JS. Bio-inspired noble metal-free reduction of nitroarenes using NiS2+x/g-C3N4. RSC Adv 2014. [DOI: 10.1039/c4ra10127h] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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19
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Li XH, Cai YY, Gong LH, Fu W, Wang KX, Bao HL, Wei X, Chen JS. Photochemically Engineering the Metal-Semiconductor Interface for Room-Temperature Transfer Hydrogenation of Nitroarenes with Formic Acid. Chemistry 2014; 20:16732-7. [DOI: 10.1002/chem.201404325] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Indexed: 11/08/2022]
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20
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Borromeo GL, Bramante G, Betar D, Bhikha C, Cai YY, Cajili C. Transitioning of special needs paediatric patients to adult special needs dental services. Aust Dent J 2014; 59:360-5. [DOI: 10.1111/adj.12197] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/21/2013] [Indexed: 11/27/2022]
Affiliation(s)
- GL Borromeo
- Melbourne Dental School; The University of Melbourne; Victoria
| | - G Bramante
- Melbourne Dental School; The University of Melbourne; Victoria
| | - D Betar
- Melbourne Dental School; The University of Melbourne; Victoria
| | - C Bhikha
- Melbourne Dental School; The University of Melbourne; Victoria
| | - YY Cai
- Melbourne Dental School; The University of Melbourne; Victoria
| | - C Cajili
- Melbourne Dental School; The University of Melbourne; Victoria
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21
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Fu W, Li XH, Bao HL, Wang KX, Wei X, Cai YY, Chen JS. Synergistic effect of Brønsted acid and platinum on purification of automobile exhaust gases. Sci Rep 2014; 3:2349. [PMID: 23907148 PMCID: PMC3731646 DOI: 10.1038/srep02349] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 07/18/2013] [Indexed: 11/23/2022] Open
Abstract
The catalytic purification of automobile exhaust gases (CO, NOx and hydrocarbons) is one of the most practiced conversion processes used to lower the emissions and to reduce the air pollution. Nevertheless, the good performance of exhaust gas purification catalysts often requires the high consumption of noble metals such as platinum. Here we report that the Brønsted acid sites on the external surface of a microporous silicoaluminophosphate (SAPO) act as a promoter for exhaust gas purification, effectively cutting the loading amount of platinum in the catalyst without sacrifice of performance. It is revealed that in the Pt-loaded SAPO-CHA catalyst, there exists a remarkable synergistic effect between the Brønsted acid sites and the Pt nanoparticles, the former helping to adsorb and activate the hydrocarbon molecules for NO reduction during the catalytic process. The thermal stability of SAPO-CHA also makes the composite catalyst stable and reusable without activity decay.
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Affiliation(s)
- Wei Fu
- School of Chemistry and Chemical Engineering, Hirano Institute for Materials Innovation, Shanghai Jiao Tong University, Shanghai 200240, China
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22
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Ye TN, Xu M, Fu W, Cai YY, Wei X, Wang KX, Zhao YN, Li XH, Chen JS. The crystallinity effect of mesocrystalline BaZrO3 hollow nanospheres on charge separation for photocatalysis. Chem Commun (Camb) 2014; 50:3021-3. [DOI: 10.1039/c4cc00101j] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Mesocrystalline BaZrO3 hollow nanospheres were used as an ideal model to study the crystallinity effect of mesocrystals on charge separation for photocatalysis.
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Affiliation(s)
- Tian-Nan Ye
- School of Chemistry and Chemical Engineering
- Shanghai Jiao Tong University
- Shanghai 200240, P. R. China
| | - Miao Xu
- School of Chemistry and Chemical Engineering
- Shanghai Jiao Tong University
- Shanghai 200240, P. R. China
| | - Wei Fu
- School of Chemistry and Chemical Engineering
- Shanghai Jiao Tong University
- Shanghai 200240, P. R. China
| | - Yi-Yu Cai
- School of Chemistry and Chemical Engineering
- Shanghai Jiao Tong University
- Shanghai 200240, P. R. China
| | - Xiao Wei
- School of Chemistry and Chemical Engineering
- Shanghai Jiao Tong University
- Shanghai 200240, P. R. China
| | - Kai-Xue Wang
- School of Chemistry and Chemical Engineering
- Shanghai Jiao Tong University
- Shanghai 200240, P. R. China
| | - Yong-Nan Zhao
- Institute of Nanostructured Materials & Tianjin Key Laboratory of Fiber Modification and Functional Fiber
- School of Materials Science and Engineering
- Tianjin Polytechnic University
- Tianjin 300387, P. R. China
| | - Xin-Hao Li
- School of Chemistry and Chemical Engineering
- Shanghai Jiao Tong University
- Shanghai 200240, P. R. China
| | - Jie-Sheng Chen
- School of Chemistry and Chemical Engineering
- Shanghai Jiao Tong University
- Shanghai 200240, P. R. China
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23
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Cai YY, Li XH, Zhang YN, Wei X, Wang KX, Chen JS. Highly Efficient Dehydrogenation of Formic Acid over a Palladium-Nanoparticle-Based Mott-Schottky Photocatalyst. Angew Chem Int Ed Engl 2013; 52:11822-5. [DOI: 10.1002/anie.201304652] [Citation(s) in RCA: 194] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Indexed: 11/11/2022]
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24
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Cai YY, Li XH, Zhang YN, Wei X, Wang KX, Chen JS. Highly Efficient Dehydrogenation of Formic Acid over a Palladium-Nanoparticle-Based Mott-Schottky Photocatalyst. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201304652] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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25
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Liew YX, Lee W, Cai YY, Teo J, Tang SSL, Ong RWQ, Lim CLL, Lingegowda PB, Kwa ALH, Chlebicki MP. Utility and safety of procalcitonin in an antimicrobial stewardship program (ASP) in patients with malignancies. Eur J Clin Microbiol Infect Dis 2012; 31:3041-6. [PMID: 22678350 DOI: 10.1007/s10096-012-1662-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Accepted: 05/19/2012] [Indexed: 11/24/2022]
Abstract
As data on procalcitonin utility in antibiotics discontinuation [under an antimicrobial stewardship program (ASP)] in patients with malignancies are lacking, we aimed to evaluate the utility of procalcitonin in an ASP in patients with malignancies. We conducted a retrospective review of the ASP database of all patients with malignancies in whom at least one procalcitonin level was taken and our ASP had recommended changes in carbapenem regimen, from January to December 2011. We compared clinical outcomes between two groups of patients: patients whose physicians accepted and those whose physicians rejected ASP interventions. There were 749 carbapenem cases reviewed. Ninety-nine were suggested to either de-escalate, discontinue antibiotics, or narrow the spectrum of empiric treatment, based on procalcitonin trends. While there was no statistical difference in the mortality within 30 days post-ASP intervention (accepted: 8/65 patients vs. rejected: 9/34 patients; p = 0.076), the median duration of carbapenem therapy was significantly shorter (5 vs. 7 days; p = 0.002). Procalcitonin use safely facilitates decisions on antibiotics discontinuation and de-escalation in patients with malignancies in the ASP.
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Affiliation(s)
- Y X Liew
- Department of Pharmacy, Singapore General Hospital, Outram Road, Singapore, 169608, Singapore
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26
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Li L, Cai YY, Li GD, Mu XY, Wang KX, Chen JS. Synergistic Effect on the Photoactivation of the Methane CH Bond over Ga3+-Modified ETS-10. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201200045] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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27
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Li L, Cai YY, Li GD, Mu XY, Wang KX, Chen JS. Synergistic Effect on the Photoactivation of the Methane CH Bond over Ga3+-Modified ETS-10. Angew Chem Int Ed Engl 2012; 51:4702-6. [DOI: 10.1002/anie.201200045] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Indexed: 11/09/2022]
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28
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Indhumathi C, Cai YY, Guan YQ, Opas M, Zheng J. Adaptive-weighted cubic B-spline using lookup tables for fast and efficient axial resampling of 3D confocal microscopy images. Microsc Res Tech 2011; 75:20-7. [PMID: 21618651 DOI: 10.1002/jemt.21017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2010] [Accepted: 03/17/2011] [Indexed: 11/08/2022]
Abstract
Confocal laser scanning microscopy has become a most powerful tool to visualize and analyze the dynamic behavior of cellular molecules. Photobleaching of fluorochromes is a major problem with confocal image acquisition that will lead to intensity attenuation. Photobleaching effect can be reduced by optimizing the collection efficiency of the confocal image by fast z-scanning. However, such images suffer from distortions, particularly in the z dimension, which causes disparities in the x, y, and z directions of the voxels with the original image stacks. As a result, reliable segmentation and feature extraction of these images may be difficult or even impossible. Image interpolation is especially needed for the correction of undersampling artifact in the axial plane of three-dimensional images generated by a confocal microscope to obtain cubic voxels. In this work, we present an adaptive cubic B-spline-based interpolation with the aid of lookup tables by deriving adaptive weights based on local gradients for the sampling nodes in the interpolation formulae. Thus, the proposed method enhances the axial resolution of confocal images by improving the accuracy of the interpolated value simultaneously with great reduction in computational cost. Numerical experimental results confirm the effectiveness of the proposed interpolation approach and demonstrate its superiority both in terms of accuracy and speed compared to other interpolation algorithms.
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Affiliation(s)
- C Indhumathi
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore
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29
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Abstract
With the rapid advance of three-dimensional (3D) confocal imaging technology, more and more 3D cellular images will be available. Segmentation of intact cells is a critical task in automated image analysis and quantification of cellular microscopic images. One of the major complications in the automatic segmentation of cellular images arises due to the fact that cells are often closely clustered. Several algorithms are proposed for segmenting cell clusters but most of them are 2D based. In other words, these algorithms are designed to segment 2D cell clusters from a single image. Given 2D segmentation methods developed, they can certainly be applied to each image slice with the 3D cellular volume to obtain the segmented cell clusters. Apparently, in such case, the 3D depth information with the volumetric images is not really used. Often, 3D reconstruction is conducted after the individualized segmentation to build the 3D cellular models from segmented 2D cellular contours. Such 2D native process is not appropriate as stacking of individually segmented 2D cells or nuclei do not necessarily form the correct and complete 3D cells or nuclei in 3D. This paper proposes a novel and efficient 3D cluster splitting algorithm based on concavity analysis and interslice spatial coherence. We have taken the advantage of using the 3D boundary points detected using higher order statistics as an input contour for performing the 3D cluster splitting algorithm. The idea is to separate the touching or overlapping cells or nuclei in a 3D native way. Experimental results show the efficiency of our algorithm for 3D microscopic cellular images.
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Affiliation(s)
- C Indhumathi
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore.
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30
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Lin CC, Liu JX, Cai YY, Li BL, Wang ZL, Chen BB. Study on the relationship between meteorological conditions and acid rain in mid-eastern Fujian. Bull Environ Contam Toxicol 2009; 83:180-187. [PMID: 19352581 DOI: 10.1007/s00128-009-9715-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2007] [Accepted: 03/16/2009] [Indexed: 05/27/2023]
Abstract
Based on the acid rain observation data and the contemporaneous historical synoptic charts of Mid-Eastern Fujian during the period of 1991 to 2003, we analyzed the distribution characteristics of acid rain in different seasons, weather types, precipitation grades and wind directions. The results showed that the acid pollution in Mid-Eastern Fujian was still serious. In winter, the precipitation pH value was 4.79, and the acid rain frequency was 60.62% which was twice higher than that in summer. The pH value of warm shear-type precipitation at 850 hPa was 4.79. Nearly half of these precipitations had the problems of acid rain pollution. The acid rain frequency of the inverted trough type was only 26.11% which was the lowest one in all types. There was no marked difference of the acid rain distribution characteristics between ahead-of-trough and behind-the-trough. The precipitation pH values of the five grades were lower than 5.30 and the acid rain frequency changed as an inverted U shape with the increasing of the rainfall. The pH values of precipitations in the eight wind directions were generally below 5.20, and the acid rain frequencies were about 40%.
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Affiliation(s)
- C C Lin
- Fujian Institute of Meteorological Science, Fuzhou, 350001, China.
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31
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Abstract
Loop-mediated isothermal amplification (LAMP) assay for rapid and sensitive detection of Acute viral necrobiotic virus (AVNV) in scallop Chlamys farreri was developed and evaluated. Four primers recognizing six targets on distinct AVNV DNA sequences were designed and the LAMP reaction was carried out in a water bath. Reaction temperature and time were optimized at 64 degrees C for 60 mins and LAMP products were detected using agarose gel electrophoresis and visual assessment. Confirmation of the expected LAMP products was performed with MboI restriction enzyme analysis. The detection limit of LAMP assay was as low as 1 fg AVNV DNA and accordingly, this assay was 100 times more sensitive than conventional PCR technique. A comparative evaluation of 20 samples using the LAMP and PCR assays revealed a complete accord in positivity or negativity for AVNV. These results indicate that the LAMP assay is simple, sensitive, specific, and has a great potential for detection of AVNV in the laboratory and field.
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Affiliation(s)
- W C Ren
- Department of Aquaculture, College of Fisheries, Ocean University of China, 5 Yushan Road, Qingdao, Shandong 266003, P.R. China
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32
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Affiliation(s)
- Y Q Guan
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore
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33
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Guan YQ, Cai YY, Lee YT, Opas M. An automatic method for identifying appropriate gradient magnitude for 3D boundary detection of confocal image stacks. J Microsc 2006; 223:66-72. [PMID: 16872433 DOI: 10.1111/j.1365-2818.2006.01600.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Gradients play an important role in 2D image processing. Many edge detection algorithms are gradient-based. We are interested in 3D boundary detection which can be considered as an extension of 2D edge detection in 3D space. In this paper, an algorithm to automatically and quantitatively measure the suitability of gradient magnitudes in detection of 3D boundary points of confocal image stacks is presented. A Measurement Function is defined to evaluate the suitability of each gradient magnitude chosen to be the threshold for 3D boundary detection. The application of Gauss's Divergence Theorem provides a solution to calculate the Measurement Function numerically. The gradient magnitude at which the maximum of the Measurement Function is achieved can be utilized as the most appropriate threshold for gradient-based boundary detection and other operations like volume visualization.
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Affiliation(s)
- Y Q Guan
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, Singapore.
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34
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Cai YY, Chui CK, Ye XZ, Fan Z, Anderson JH. Tactile VR for hand-eye coordination in simulated PTCA. Comput Biol Med 2005; 36:167-80. [PMID: 16389076 DOI: 10.1016/j.compbiomed.2004.10.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2004] [Revised: 10/07/2004] [Accepted: 10/07/2004] [Indexed: 11/29/2022]
Abstract
Percutaneous transluminal coronary angioplasty (PTCA) is a minimally invasive image-guided technique for treatment of coronary diseases. PTCA procedure requires physicians to have good skills of hand-eye coordination in performing the operation. Training of PTCA thus very much emphasizes skill building for hand-eye coordination. We have been developing virtual reality (VR) technology for medical simulation. In this paper, we will address the issue of VR-based simulation for the enhancement of hand-eye coordination for PTCA operation. Starting from the characterization of PTCA procedure, we examine what roles VR can play in training of PTCA physicians. We then describe a computerized PTCA training system we have developed which is composed of a tactile interface and a visual interface. The system is designed in such a way that real PTCA devices (including catheters and guide-wires) can be used to mimic the requirements of the CathLab. The backend computational engine supporting the real-time and realistic PTCA simulation is also presented.
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Affiliation(s)
- Y Y Cai
- School of Mechanical & Production Engineering, Nanyang Technological University, Singapore.
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35
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Abstract
We propose a dose-finding weighted design for an early clinical trial which aims to determine the optimal dose, selected on the basis of both efficacy and toxicity, to be used in patients entering subsequent studies in a drug development process. The goal is to identify the optimal dose, while using a minimal number of subjects. For each dose under test, a decision table is defined with a utility value attached to each possible decision. The relationship between the utility and the target probability for each outcome is shown. A Dirichlet prior is used and we illustrate the process of maximizing the expected utility under the resulting posterior distribution to find the optimal decision at each stage of the trial. We show how this affects the eventual choice of optimal dose in various scenarios. Properties of our design are discussed and compared with a current standard design.
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Affiliation(s)
- Yee-Chong Loke
- Divison of Clinical Trials & Epidemiological Sciences, National Cancer Centre Singapore, 11 Hospital Drive, Singapore 169610, Singapore
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36
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Zhao XJ, Meng Y, Liu JY, Shen J, Liu L, Liu ZH, Cai YY. [Chromosomal mapping of ld gene which causes congenital limb deformity syndrome in KM-ld mouse]. Yi Chuan Xue Bao 2000; 26:610-5. [PMID: 10876660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Fourteen biochemical marker loci and 61 SSLP loci in congenic strain C57BL/6.KM-ld were screened to determine the loci linkage to ld gene, an autosomal recessive mutant gene in KM mouse which causes congenital limb deformity in mouse by means of electrophoresis and PCR amplification. The result showed that ld gene linked to D2Mit30, D2Mit62 and D2Mit63. To locate ld gene more accurately on chromosome 2, 86 backcross offsprings (C57BL/6 x KM-ld) F1 x KM-ld were produced for linkage analysis. From the backcross progeny genomic DNAs were amplified for D2Mit13, D2Mit30, D2Mit62 and D2Mit63 loci in vitro. According to phenotypes, the linkage between the four SSLP loci and ld gene was analysed by calculating genetic distance, ld gene was located exactly on Chr. 2, 76cM, with distances of 25.58cM to D2Mit30, D2Mit62 and D2Mit63, of 31.39cM to D2Mit13.
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Affiliation(s)
- X J Zhao
- Institute of Laboratory Animal Science, Chinese Academy of Medical Science, Beijing
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37
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Zhu GF, Sun B, Niu SF, Cai YY, Lin K, Lindwall R, Robertson B. Combined surfactant therapy and inhaled nitric oxide in rabbits with oleic acid-induced acute respiratory distress syndrome. Am J Respir Crit Care Med 1998; 158:437-43. [PMID: 9700118 DOI: 10.1164/ajrccm.158.2.9711107] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Intratracheal administration of surfactant and inhaled nitric oxide (INO) have had variable effects in clinical trials on patients with acute respiratory distress syndrome (ARDS). We hypothesized that combined treatment with exogenous surfactant and INO may have effects in experimental ARDS. After intravenous infusion of oleic acid in adult rabbits and 4-6 h of ventilation, there was more than a 40% reduction in both dynamic compliance (Cdyn) of the respiratory system and functional residual capacity (FRC), a 50% increment of respiratory resistance (Rrs), a 70% reduction in PaO2 /FIO2, and an increase in intrapulmonary shunting (Q S/Q T) from 4.4 to 33.5%. The animals were then allocated to groups receiving (1) neither surfactant nor INO (control), (2) 100 mg/kg of surfactant (S) administered intratracheally, (3) 20 ppm INO (NO), or (4) 100 mg/kg of surfactant and 20 ppm INO (SNO), and subsequently ventilated for 6 h. After the period of ventilation, the animal lungs were used for analysis of disaturated phosphatidylcholine (DSPC) and total proteins (TP) in bronchoalveolar lavage fluid (BALF), and for determination of alveolar volume density (VV). The animals in the control group had the lowest survival rate, and no improvement in lung mechanics and blood oxygenation, whereas those in the S group had a modest but statistically significant improvement in Cdyn, Rrs, PaO2 and FRC, reduced Q S/Q T, lowered minimum surface tension (gammamin) of BALF, and increased DSPC/ TP and alveolar VV. The NO group had increased PaO2 and reduced Q S/Q T. The SNO group showed improved Cdyn, Rrs, FRC, DSPC/TP, alveolar VV, and gammamin of BALF comparable to the S group, but there was a further increase in survival rate and PaO2, and additional reduction in Q S/Q T and TP in BALF. These results indicate that, in this animal model of ARDS, a combination of surfactant therapy and INO is more effective than either treatment alone.
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Affiliation(s)
- G F Zhu
- Children's Hospital Research Institute; Department of Pulmonology, Zhongshan Hospital, Shanghai Medical University, Shanghai 200032, China
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38
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Su XY, Zhu YL, Cai YY. [An investigation on anxiety and coping patterns of patients under cancer chemotherapy and the strategies]. Zhonghua Hu Li Za Zhi 1997; 32:687-90. [PMID: 10455594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
100 cases of patients under cancer chemotherapy were investigated by using Self-Rating Anxiety Scale (SAS) and questionnaire on coping patterns. The results showed that scores of SAS were significantly higher than that of the normal population. The state of the anxiety reached 45% among the patients. The patients' coping patterns tended to be passive. Linear analysis revealed a negative correlation between the coping patterns and the scores of SAS. It is recommended that cognitive behavioral therapy can be used to relieve the anxiety of patients under cancer chemotherapy.
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Affiliation(s)
- X Y Su
- Faculty of Nursing of Sun Yat-Sen University of Medical Sciences, Guangzhou
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39
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Xy FO, Cai YY, Nu SF. [Drive-time constant (DTC): a new index of respiratory muscle endurance]. Zhonghua Yi Xue Za Zhi 1993; 73:29-31, 62. [PMID: 8389233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Mouth occlusion pressure (P0.1) and the function of respiratory muscle were measured in 6 unsuccessful weaning patients (group I), 15 successful weaning patients (group II) and 9 normal subjects (group III). The results showed that PImax in the three groups was 4.36 +/- 1.67kPa, 6.19 +/- 2.38kPa and 9.20 +/- 3.51kPa respectively. Pdimax was 5.39 +/- 1.62kPa, 6.90 +/- 2.41kPa and 11.46 +/- 3.16kPa respectively. TTdi was 0.24 +/- 0.07, 0.12 +/- 0.04 and 0.05 +/- 0.02 respectively. DTC, the product of P0.1/PImax and Ti/Ttot, was 0.06 +/- 0.01, 0.03 +/- 0.01 and 0.01 +/- 0.003 respectively. Both group I and group II had lower PImax and Pdimax but higher TTdi and DTC other than group III. Both PImax and Pdimax between group I and group II showed no significant difference, but TTdi and DTC of group I were higher than those of group II. If DTC 0.04 and TTdi 0.15 were used as the criteria for predicting whether or not the patients could perform a successful weaning trial, the values of sensitivity were 83% and 100%, and the values of specificity 93% and 87% respectively. We conclude that DTC as a noninvasive and convenient measurement is of clinical value in evaluating the endurance of respiratory muscles.
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Affiliation(s)
- F O Xy
- Department of Chest Medicine, Zhongshan Hospital, Medical University, Shanghai
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40
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Cai YY, Niu SF, Bai CX. [A comparison between nasotracheal and orotracheal intubation in treating chronic obstructive pulmonary disease complicated by respiratory failure]. Zhonghua Nei Ke Za Zhi 1992; 31:332-4, 380. [PMID: 1286580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Endotracheal intubation and mechanical ventilation were given to 100 COPD patients complicated by respiratory failure from Dec. 1977 to May 1990. Among them 42 were intubated through mouth. The tubes were kept from 1 to 6 days. In only 8 cases (19.0%) the tubes could be withdrawn according to the criterion, and 25 patients (59.0%) were tracheostomized. Nasotracheal intubation were given to 58 patients. The tubes were kept from 1 to 220 days and could be withdrawn in 39 cases (81.0%), with an incidence higher than that in patients intubated orotracheally (P < 0.01). Tracheostomy mas given to 6 patients intubated nasotracheally (10.3%), being fewer than in patients intubated through mouth (P < 0.01). Although the tubes have been kept for longer time, the duration of hospitalization was not prolonged.
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Affiliation(s)
- Y Y Cai
- Dept. of Chest Medicine, Zhongshan Hospital, Shanghai Medical University
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41
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Cai YY. [Pathological changes in the trachea after tracheostomy in patients with respiratory failure]. Zhonghua Jie He He Hu Xi Za Zhi 1992; 15:18-9, 61. [PMID: 1394579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A variety of pathological changes in trachea were observed in 7 cases with tracheostomy. The common lesions were inflammation, necrosis and ulcer, and squamous metaplasia or granuloma were seen in those with tracheal tube for longer time. The dilatation of trachea was manifested by dislocating of the tube and not sealing of the cuff. Cuff-radiography could show the site and degree of the dilatation of trachea. In order to alleviate the lesions, the tubes made of plastic or silica gel with lower pressure cuff were recommended. The prevention of local infection and improvement of nutritional status were also important.
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Affiliation(s)
- Y Y Cai
- Zhongshan Hospital, Shanghai
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42
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Shen X, Niu SF, Cai YY. [A clinical trial of treating asthma of moderate severity with beclomethasone dipropionate aerosol]. Zhonghua Nei Ke Za Zhi 1991; 30:536-8, 593. [PMID: 1806334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
In order to investigate the efficacy of steroid inhalation in treating asthma of moderate severity, a single-blind, randomized short-term (3-4 weeks) trial was performed in 25 asthmatics uncontrolled by salbutamol inhalation, oral aminophylline and beta 2-agonist. 22 patients finished the trial. Among them, twelve received beclomethasone dipropionate 300 mcg/day and ten received placebo. There was significant improvement in asthmatic symptoms and pulmonary function (FEV1.0, V50, V25) in the group treated with steroid inhalation at the end of this trial, whereas no significant changes were observed in the placebo group. The results demonstrated that steroid inhalation could effectively control asthma of moderate severity.
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Affiliation(s)
- X Shen
- Department of Pulmonary Medicine, Zhongshan Hospital, Shanghai Medical University
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43
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Cai YY, Xu FP, Niu SF. [Effects of external diaphragm pacing on transdiaphragmatic pressure, ventilation and arterial blood gases in healthy volunteers]. Zhonghua Nei Ke Za Zhi 1990; 29:730-2, 765-6. [PMID: 2092956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The effects of external diaphragm pacing (EDP) were studied in seven healthy volunteers. During EDP the movement of both left and right hemidiaphragms increased on average 1.28 and 1.30 cm respectively. The transdiaphragmatic pressure also increased from 8.63 +/- 1.576 cm H2O to 15.18 +/- 1.946 cm H2O (P less than 0.01). Inductive plethysmography showed that with EDP the mean inspiratory flow rate increased from 308 +/- 28.6 ml/sec. to 454 +/- 36.6 ml/sec. (P less than 0.01), but there was no change in respiratory rate, inspiratory time and the ratio of inspiratory time to respiratory cycle. Both tidal volume and minute volume of ventilation increased from 419 +/- 33.9 ml to 691 +/- 71.5 ml (P less than 0.01) and from 7.02 +/- 0.74 l/min. to 10.14 +/- 0.73 l/min. (P less than 0.01) respectively. Accompanied with the change of ventilation, the consumption of oxygen and the production of CO2 also increased from 258 +/- 14.9 ml/min. to 310 +/- 15.0 ml/min. (P less than 0.05) and from 228 +/- 11.4 ml/min. to 299 +/- 25.9 ml/min. (P less than 0.05) respectively. Consequently PaCO2 reduced from 5.24 +/- 0.22 kPa to 4.27 +/- 0.25 kPa (P less than 0.05), whereas PaO2 increased from 12.7 +/- 0.32 kPa to 14.5 +/- 0.42 kPa (P less than 0.01).
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Affiliation(s)
- Y Y Cai
- Department of Chest Medicine, Zhongshan Hospital, Shanghai Medical University
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44
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Xu FP, Cai YY, Niu SF. [The effects of almitrine bismesylate in chronic obstructive pulmonary disease with CO2 retention]. Zhonghua Nei Ke Za Zhi 1990; 29:479-81, 511. [PMID: 2128259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Ten cases of chronic obstructive pulmonary disease (COPD) were examined before and 2 hours after oral administration of 150 mg of almitrine bismesylate while breathing 31% oxygen. The agent induced a rise in mouth occlusion pressure (P 0.1) from 2.67 +/- 0.64 cmH2O to 3.74 +/- 1.02 cmH2O (P less than 0.01). However the central inspiratory drive and ventilation response to hypercapnia did not change after taking almitrine. VT/Ti increased from 0.32 +/- 0.06 L/sec. to 0.40 +/- 0.08 L/sec. (P less than 0.01) and RR, Ti, Ti/Ttot were not changed, so VT and VE increased from 0.37 +/- 0.10 L to 0.42 +/- 0.16 L (P less than 0.05) and from 7.70 +/- 1.72 L to 8.85 +/- 2.28 L (P less than 0.05) respectively. VA also increased from 3.34 +/- 0.06 L to 4.14 +/- 0.86 L (P less than 0.01). Analysis of blood gases showed a marked increase in PaO2 from 88.70 +/- 16.19 mmHg to 109.10 +/- 25.57 mmHg (P less than 0.05) and a decrease in PaCO2 from 61.73 +/- 12.15 mmHg to 54.01 +/- 10.37 mmHg (P less than 0.05). Our results suggested that almitrine bismesylate could improve the blood gases in COPD patients with CO2 retention as it is a respiratory stimulant which might act through a peripheral mechanism.
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Affiliation(s)
- F P Xu
- Department of Chest Medicine, Zhongshan Hospital, Shanghai Medical University
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45
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Qian SS, Gao J, Wang JX, Cai YY, Liu Y, Li BG, Dong HY, De Bruyne G, Mareel M. Establishment and characterization of a continuous murine uterine cervix cancer cell line metastatic to lymph nodes and lungs. In Vitro Cell Dev Biol 1987; 23:738-44. [PMID: 3680100 DOI: 10.1007/bf02623673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The murine uterine cervix cancer (MUCC) cell line was derived from a chemically induced Kunming mouse uterine cervix cancer (U27) and maintained in culture on solid substrates for over 100 passages. Cultures were morphotypically heterogeneous and heteroploid, with a modal number of chromosomes = 80. Each cell showed at least two abnormal chromosomes. Immunogold-silver staining was positive for keratin, vimentin, and laminin but not for desmin. The population doubling time was 27.8 h with a saturation density of 3.2 X 10(5) cells/cm2 and a peak mitotic index of about 6%. MUCC cells produced colonies on tissue culture plastic (68%) and in soft agar (8%). MUCC cells were fully malignant inasmuch as they produced in syngeneic mice invasive tumors that reproducibly were metastatic to lymph nodes and lungs. The MUCC cell line is the first mouse cervix cancer cell line useful for the study of invasion and metastasis.
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Affiliation(s)
- S S Qian
- Department of Pathology, Chinese Academy of Medical Sciences, Beijing
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46
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Xue SP, Zhang JB, Yuan J, Xu Y, Cai YY, Wang ZQ, Liu YH, Li LJ, Hu X. [Studies on the regulatory effect of rabbit reticulocyte cytoplasmic factors on the malignancy of mouse myeloma cells]. Zhongguo Yi Xue Ke Xue Yuan Xue Bao 1986; 8:339-46. [PMID: 2952304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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47
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Qian SS, Gao J, Wang JX, Cai YY, Liu Y, Li BG, Dong HY. [Establishment and biologic properties of a mouse uterine cervix cancer cell line (MUCC) with lymphatic and hematogenous metastatic capacities]. Zhonghua Zhong Liu Za Zhi 1986; 8:324-7. [PMID: 3568983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
For study of tumor metastatic mechanism, a mouse uterine cervix cancer cell line (MUCC), as derived from a transplantable mouse uterine cervix cancer No. 27 (U 27) with metastatic capacities through lymphatics and blood, was established in vitro. It has been successfully maintained for more than 24 months through more than 100 passages. MUCC cells are epithelioid with definite malignant morphological features. The doubling time of the cell population is 27.8 hours. The average mitotic index is 30.6%, with a maximum of 58.9%. Chromosomes show aberration in number and structure. The homotransplant rate is 75% (9/12). The solid tumor, produced by homotransplant, is similar to the tumor U 27. Metastases are present in the lymph nodes and lungs in these 9 animal models. It is evident that this cell line retains the capacity of inducing daughter tumor lines with spontaneous lymphatic and blood metastases. MUCC cell line might be very useful in isolating subpopulations which possess the different metastatic abilities and the study of metastatic mechanism.
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48
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49
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Cai YY. [A specific method of suppressing sinoatrial nodal automaticity]. Zhonghua Xin Xue Guan Bing Za Zhi 1985; 13:135-6. [PMID: 4042849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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50
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Cai YY, Li SH, Zhang JP. [Karyotype of Citellus dauricus Brandt]. Zhongguo Yi Xue Ke Xue Yuan Xue Bao 1985; 7:72-3. [PMID: 3158424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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