1
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Naseeb W, Liu Q, Nichols F, Pan D, Kaleem Khosa M, Chen S. Ru-CoO heterostructured nanoparticles supported on nitrogen and sulfur codoped graphene nanosheets as effective electrocatalysts for hydrogen evolution reaction in alkaline media. J Electroanal Chem (Lausanne) 2023. [DOI: 10.1016/j.jelechem.2023.117272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
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2
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Liu Q, Peng Y, Masood Z, DuBois D, Tressel J, Nichols F, Ashby P, Mercado R, Assafa T, Pan D, Kuo HL, Lu JQ, Bridges F, Millhauser G, Ge Q, Chen S. Stable Cuprous Hydroxide Nanostructures by Organic Ligand Functionalization. Adv Mater 2023; 35:e2208665. [PMID: 36462218 PMCID: PMC9975062 DOI: 10.1002/adma.202208665] [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: 09/21/2022] [Revised: 11/19/2022] [Indexed: 06/17/2023]
Abstract
Copper compounds have been extensively investigated for diverse applications. However, studies of cuprous hydroxide (CuOH) have been scarce due to structural metastability. Herein, a facile, wet-chemistry procedure is reported for the preparation of stable CuOH nanostructures via deliberate functionalization with select organic ligands, such as acetylene and mercapto derivatives. The resulting nanostructures are found to exhibit a nanoribbon morphology consisting of small nanocrystals embedded within a largely amorphous nanosheet-like scaffold. The acetylene derivatives are found to anchor onto the CuOH forming CuC linkages, whereas CuS interfacial bonds are formed with the mercapto ligands. Effective electronic coupling occurs at the ligand-core interface in the former, in contrast to mostly non-conjugated interfacial bonds in the latter, as manifested in spectroscopic measurements and confirmed in theoretical studies based on first principles calculations. Notably, the acetylene-capped CuOH nanostructures exhibit markedly enhanced photodynamic activity in the inhibition of bacteria growth, as compared to the mercapto-capped counterparts due to a reduced material bandgap and effective photocatalytic generation of reactive oxygen species. Results from this study demonstrate that deliberate structural engineering with select organic ligands is an effective strategy in the stabilization and functionalization of CuOH nanostructures, a critical first step in exploring their diverse applications.
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Affiliation(s)
- Qiming Liu
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064
| | - Yi Peng
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064
| | - Zaheer Masood
- School of Chemical and Biomolecular Sciences, Southern Illinois University, Carbondale, Illinois 62901
| | - Davida DuBois
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064
| | - John Tressel
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064
| | - Forrest Nichols
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064
| | - Paul Ashby
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| | - Rene Mercado
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064
| | - Tufa Assafa
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064
| | - Dingjie Pan
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064
| | - Han-Lin Kuo
- School of Engineering, University of California, 5200 North Lake Road, Merced, California 95343
| | - Jennifer Q. Lu
- School of Engineering, University of California, 5200 North Lake Road, Merced, California 95343
| | - Frank Bridges
- Department of Physics, University of California, 1156 High Street, Santa Cruz, California 95064
| | - Glenn Millhauser
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064
| | - Qingfeng Ge
- School of Chemical and Biomolecular Sciences, Southern Illinois University, Carbondale, Illinois 62901
| | - Shaowei Chen
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064
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3
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Pan D, Liu Q, Nichols F, Mercado R, Kuo HL, Lu JQ, Bridges F, Chen S. Impacts of ruthenium valence state on the electrocatalytic activity of ruthenium ion-complexed graphitic carbon nitride/reduced graphene oxide nanosheets towards hydrogen evolution reaction. J Colloid Interface Sci 2023; 629:591-597. [PMID: 36179578 DOI: 10.1016/j.jcis.2022.09.080] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 09/12/2022] [Accepted: 09/14/2022] [Indexed: 11/21/2022]
Abstract
Design and engineering of effective electrode catalysts represents a critical first step for hydrogen production by electrochemical water splitting. Nanocomposites based on ruthenium atomically dispersed within a carbon scaffold have emerged as viable candidates. In the present study, ruthenium metal centers are atomically embedded within graphitic carbon nitride/reduced graphene oxide nanosheets by thermal refluxing. Subsequent chemical reduction/oxidation leads to ready manipulation of the ruthenium valence state, as evidenced in microscopic and spectroscopic measurements, and hence enhancement/diminishment of the electrocatalytic activity towards hydrogen evolution reaction in both acidic and alkaline media. This is largely ascribed to the increased/reduced contribution of the Ru valence electrons to the density of state near the Fermi level which dictates the binding and reduction of hydrogen. Results from this study highlight the significance of the valence state of metal centers in the manipulation and optimization of the catalytic performance of single atom catalysts.
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Affiliation(s)
- Dingjie Pan
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, CA 95064, USA
| | - Qiming Liu
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, CA 95064, USA
| | - Forrest Nichols
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, CA 95064, USA
| | - Rene Mercado
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, CA 95064, USA
| | - Han-Lin Kuo
- School of Engineering, University of California, 5200 North Lake Road, Merced, CA 95343, USA
| | - Jennifer Q Lu
- School of Engineering, University of California, 5200 North Lake Road, Merced, CA 95343, USA
| | - Frank Bridges
- Department of Physics, University of California, 1156 High Street, Santa Cruz, CA 95064, USA
| | - Shaowei Chen
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, CA 95064, USA.
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Ogada JJ, Ipadeola AK, Mwonga PV, Haruna AB, Nichols F, Chen S, Miller HA, Pagliaro MV, Vizza F, Varcoe JR, Meira DM, Wamwangi DM, Ozoemena KI. Correction to “CeO 2 Modulates the Electronic States of Palladium Onion-like Carbon Interface into a Highly Active and Durable Electrocatalyst for Hydrogen Oxidation in Anion Exchange Membrane Fuel Cells”. ACS Catal 2022. [DOI: 10.1021/acscatal.2c03927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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5
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Nichols F, Ozoemena KI, Chen S. Electrocatalytic generation of reactive species and implications in microbial inactivation. Chinese Journal of Catalysis 2022. [DOI: 10.1016/s1872-2067(21)63941-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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6
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Lu B, Liu Q, Wang C, Masood Z, Morris DJ, Nichols F, Mercado R, Zhang P, Ge Q, Xin HL, Chen S. Ultrafast Preparation of Nonequilibrium FeNi Spinels by Magnetic Induction Heating for Unprecedented Oxygen Evolution Electrocatalysis. Research 2022; 2022:9756983. [PMID: 35707048 PMCID: PMC9185434 DOI: 10.34133/2022/9756983] [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] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 04/18/2022] [Indexed: 11/06/2022]
Abstract
Carbon-supported nanocomposites are attracting particular attention as high-performance, low-cost electrocatalysts for electrochemical water splitting. These are mostly prepared by pyrolysis and hydrothermal procedures that are time-consuming (from hours to days) and typically difficult to produce a nonequilibrium phase. Herein, for the first time ever, we exploit magnetic induction heating-quenching for ultrafast production of carbon-FeNi spinel oxide nanocomposites (within seconds), which exhibit an unprecedentedly high performance towards oxygen evolution reaction (OER), with an ultralow overpotential of only +260 mV to reach the high current density of 100 mA cm−2. Experimental and theoretical studies show that the rapid heating and quenching process (ca. 103 K s−1) impedes the Ni and Fe phase segregation and produces a Cl-rich surface, both contributing to the remarkable catalytic activity. Results from this study highlight the unique advantage of ultrafast heating/quenching in the structural engineering of functional nanocomposites to achieve high electrocatalytic performance towards important electrochemical reactions.
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Affiliation(s)
- Bingzhang Lu
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064, USA
| | - Qiming Liu
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064, USA
| | - Chunyang Wang
- Department of Physics and Astronomy, University of California, Irvine, California 92697, USA
| | - Zaheer Masood
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois 62901, USA
| | - David J. Morris
- Department of Chemistry, Dalhousie University, 6274 Coburg Road, Halifax, NS, Canada B3H 4R2
| | - Forrest Nichols
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064, USA
| | - Rene Mercado
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064, USA
| | - Peng Zhang
- Department of Chemistry, Dalhousie University, 6274 Coburg Road, Halifax, NS, Canada B3H 4R2
| | - Qingfeng Ge
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois 62901, USA
| | - Huolin L. Xin
- Department of Physics and Astronomy, University of California, Irvine, California 92697, USA
| | - Shaowei Chen
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064, USA
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7
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Ogada JJ, Ipadeola AK, Mwonga PV, Haruna AB, Nichols F, Chen S, Miller HA, Pagliaro MV, Vizza F, Varcoe JR, Meira DM, Wamwangi DM, Ozoemena KI. CeO 2 Modulates the Electronic States of a Palladium Onion-Like Carbon Interface into a Highly Active and Durable Electrocatalyst for Hydrogen Oxidation in Anion-Exchange-Membrane Fuel Cells. ACS Catal 2022. [DOI: 10.1021/acscatal.2c01863] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Jimodo J. Ogada
- School of Physics, University of the Witwatersrand, Johannesburg 2050, South Africa
- School of Chemistry, Molecular Sciences Institute, University of the Witwatersrand, Johannesburg 2050, South Africa
| | - Adewale K. Ipadeola
- School of Chemistry, Molecular Sciences Institute, University of the Witwatersrand, Johannesburg 2050, South Africa
| | - Patrick V. Mwonga
- School of Chemistry, Molecular Sciences Institute, University of the Witwatersrand, Johannesburg 2050, South Africa
| | - Aderemi B. Haruna
- School of Chemistry, Molecular Sciences Institute, University of the Witwatersrand, Johannesburg 2050, South Africa
| | - Forrest Nichols
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064, United States
| | - Shaowei Chen
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064, United States
| | - Hamish A. Miller
- Institute of Chemistry of Organometallic Compounds − National Research Council of Italy (ICCOM-CNR), Via Madonna del Piano 10, 50019 Sesto Fiorentino (Florence), Italy
| | - Maria V. Pagliaro
- Institute of Chemistry of Organometallic Compounds − National Research Council of Italy (ICCOM-CNR), Via Madonna del Piano 10, 50019 Sesto Fiorentino (Florence), Italy
| | - Francesco Vizza
- Institute of Chemistry of Organometallic Compounds − National Research Council of Italy (ICCOM-CNR), Via Madonna del Piano 10, 50019 Sesto Fiorentino (Florence), Italy
| | - John R. Varcoe
- Department of Chemistry, University of Surrey, Guildford, Surrey GU2 7XH, U.K
| | - Debora Motta Meira
- CLS@APS Sector 20, Advanced Photon Source, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, Illinois 60439, United States
- Canadian Light Source Inc., 44 Innovation Boulevard, Saskatoon, Saskatchewan S7N 2V3, Canada
| | - Daniel M. Wamwangi
- School of Physics, University of the Witwatersrand, Johannesburg 2050, South Africa
| | - Kenneth I. Ozoemena
- School of Chemistry, Molecular Sciences Institute, University of the Witwatersrand, Johannesburg 2050, South Africa
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8
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Chata G, Nichols F, Mercado R, Assafa T, Millhauser GL, Saltikov C, Chen S. Photodynamic Activity of Graphene Oxide/Polyaniline/Manganese Oxide Ternary Composites toward Both Gram-Positive and Gram-Negative Bacteria. ACS Appl Bio Mater 2021; 4:7025-7033. [PMID: 35006935 DOI: 10.1021/acsabm.1c00677] [Citation(s) in RCA: 4] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Graphene derivatives have been attracting extensive interest as effective antimicrobial agents. In the present study, ternary nanocomposites are prepared based on graphene oxide quantum dots (GOQD), polyaniline (PANI), and manganese oxides. Because of the hydrophilic GOQD and PANI, the resulting GPM nanocomposites are readily dispersible in water and upon photoirradiation at 365 nm exhibit antimicrobial activity toward both Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus epidermidis (S. epidermidis). Notably, the nanocomposite with a high Mn2+ and Mn4+ content is found to be far more active than that with a predominant Mn3+ component, although both samples feature a similar elemental composition and average Mn valence state. The bactericidal activity is largely ascribed to the photocatalytic production of hydroxy radicals and photogenerated holes; both are known to exert oxidative stress on bacterial cells. Further antimicrobial contributions may arise from the strong affinity of the nanocomposites to the cell surfaces. These results suggest that the metal valence state may be a critical parameter in the design and engineering of high-performance antimicrobial agents based on metal oxide nanocomposites.
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Affiliation(s)
- Gustavo Chata
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064, United States
| | - Forrest Nichols
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064, United States
| | - Rene Mercado
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064, United States
| | - Tufa Assafa
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064, United States
| | - Glenn L Millhauser
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064, United States
| | - Chad Saltikov
- Department of Microbiology and Environmental Toxicology, University of California, 1156 High Street, Santa Cruz, California 95064, United States
| | - Shaowei Chen
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064, United States
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9
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Lu B, Liu Q, Nichols F, Mercado R, Morris D, Li N, Zhang P, Gao P, Ping Y, Chen S. Oxygen Reduction Reaction Catalyzed by Carbon-Supported Platinum Few-Atom Clusters: Significant Enhancement by Doping of Atomic Cobalt. Research (Wash D C) 2021; 2020:9167829. [PMID: 33623914 PMCID: PMC7877387 DOI: 10.34133/2020/9167829] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 09/17/2020] [Indexed: 11/06/2022]
Abstract
Oxygen reduction reaction (ORR) plays an important role in dictating the performance of various electrochemical energy technologies. As platinum nanoparticles have served as the catalysts of choice towards ORR, minimizing the cost of the catalysts by diminishing the platinum nanoparticle size has become a critical route to advancing the technological development. Herein, first-principle calculations show that carbon-supported Pt9 clusters represent the threshold domain size, and the ORR activity can be significantly improved by doping of adjacent cobalt atoms. This is confirmed experimentally, where platinum and cobalt are dispersed in nitrogen-doped carbon nanowires in varied forms, single atoms, few-atom clusters, and nanoparticles, depending on the initial feeds. The sample consisting primarily of Pt2~7 clusters doped with atomic Co species exhibits the best mass activity among the series, with a current density of 4.16 A mgPt -1 at +0.85 V vs. RHE that is almost 50 times higher than that of commercial Pt/C.
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Affiliation(s)
- Bingzhang Lu
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 950564, USA
| | - Qiming Liu
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 950564, USA
| | - Forrest Nichols
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 950564, USA
| | - Rene Mercado
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 950564, USA
| | - David Morris
- Department of Chemistry, Dalhousie University, 6274 Coburg Road, Halifax, Nova Scotia, Canada B3H 4R2
| | - Ning Li
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China.,Electron Microscopy Laboratory, School of Physics, Peking University, Beijing 100871, China
| | - Peng Zhang
- Department of Chemistry, Dalhousie University, 6274 Coburg Road, Halifax, Nova Scotia, Canada B3H 4R2
| | - Peng Gao
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China.,Electron Microscopy Laboratory, School of Physics, Peking University, Beijing 100871, China.,Collaborative Innovation Centre of Quantum Matter, Beijing 100871, China
| | - Yuan Ping
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 950564, USA
| | - Shaowei Chen
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 950564, USA
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10
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Peng Y, Liu Q, Lu B, He T, Nichols F, Hu X, Huang T, Huang G, Guzman L, Ping Y, Chen S. Organically Capped Iridium Nanoparticles as High-Performance Bifunctional Electrocatalysts for Full Water Splitting in Both Acidic and Alkaline Media: Impacts of Metal–Ligand Interfacial Interactions. ACS Catal 2021. [DOI: 10.1021/acscatal.0c03747] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yi Peng
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064, United States
| | - Qiming Liu
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064, United States
| | - Bingzhang Lu
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064, United States
| | - Ting He
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064, United States
- College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan 410083, China
| | - Forrest Nichols
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064, United States
| | - Xiao Hu
- School of Environment and Energy, South China University of Technology, Guangzhou, Guangdong 510006, China
| | - Tiffanie Huang
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064, United States
| | - Grace Huang
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064, United States
| | - Lizette Guzman
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064, United States
| | - Yuan Ping
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064, United States
| | - Shaowei Chen
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064, United States
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11
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Ullah A, Heneidi S, Biddinger P, Patel N, Wehrle C, Sinkler M, Klaassen Z, Kruse E, Nichols F, Wallace G. Paraneoplastic Limbic Encephalitis Secondary To Mixed Non-Seminomatous Germ Cell Tumours. Am J Clin Pathol 2020. [DOI: 10.1093/ajcp/aqaa161.119] [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: 11/13/2022] Open
Abstract
Abstract
Casestudy: Testicular tumors account for 1–2% of all tumors in men, with 95% of these being germ cell tumors. The main risk factor for the development of testicular cancer is cryptorchidism. Paraneoplastic limbic encephalitis is a rare sequela of testicular tumor associated with anti-Ma2 and KLH11 antibodies. The most effective treatment for paraneoplastic limbic encephalitis is treatment of the primary malignancy.
We present a 41-year-old male that presented to the emergency department with two weeks of episodic alteration of consciousness and memory disturbances. Negative neurologic evaluation and imaging led to concern for a paraneoplastic process from a distant malignancy. CT imaging revealed an enlarged, necrotic para-aortic lymph node and subsequent ultrasound demonstrated a right sided testicular mass. Right radical orchiectomy was performed.
Microscopically, the mass consisted of mixed respiratory epithelium, gastrointestinal glands and squamous epithelium with keratinization consistent with a post-pubertal testicular teratoma with associated in-situ germ cell neoplasia.
Resection of the para-aortic mass revealed large anaplastic cells with epithelioid features, nuclear pleomorphism and frequent mitoses. Immunostaining was positive for Pan-Keratin and OCT4, consistent with poorly differentiated embryonal carcinoma. Resection of the primary and metastatic disease, as well as treatment with corticosteroids resulted in resolution of the encephalitis.
This presentation of severe neurological disturbances in the setting of a metastatic mixed nonseminomatous germ cell tumor represents a rare presentation of paraneoplastic limbic encephalitis.
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Affiliation(s)
- A Ullah
- Pathology, Medical college of Georgia at Augusta university, Augusta, Georgia, UNITED STATES
| | - S Heneidi
- Pathology, Medical college of Georgia at Augusta university, Augusta, Georgia, UNITED STATES
| | - P Biddinger
- Pathology, Medical college of Georgia at Augusta university, Augusta, Georgia, UNITED STATES
| | - N Patel
- Pathology, Medical college of Georgia at Augusta university, Augusta, Georgia, UNITED STATES
| | - C Wehrle
- Medical College of Georgia, Augusta, Georgia, UNITED STATES
| | - M Sinkler
- Medical College of Georgia, Augusta, Georgia, UNITED STATES
| | - Z Klaassen
- Surgery, Medical College of Georgia at Augusta University, Augusta, Georgia, UNITED STATES
| | - E Kruse
- Surgery, Medical College of Georgia at Augusta University, Augusta, Georgia, UNITED STATES
| | - F Nichols
- Neurology, Medical College of Gerogia at Augusta University, Augusta, Georgia, UNITED STATES
| | - G Wallace
- Neurology, Medical College of Gerogia at Augusta University, Augusta, Georgia, UNITED STATES
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12
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Nichols F, Lu JE, Mercado R, Rojas-Andrade MD, Ning S, Azhar Z, Sandhu J, Cazares R, Saltikov C, Chen S. Antibacterial Activity of Nitrogen-Doped Carbon Dots Enhanced by Atomic Dispersion of Copper. Langmuir 2020; 36:11629-11636. [PMID: 32924514 DOI: 10.1021/acs.langmuir.0c02293] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Antibiotic resistance is an imminent threat to human health, requiring the development of effective alternate antibacterial agents. One such alternative includes nanoparticle (photo)catalysts that are good at producing reactive oxygen species (ROS). Herein, we report the design and preparation of nitrogen-doped carbon dots functionalized with atomically dispersed copper centers by Cu-N coordination (Cu/NCD) that exhibit apparent antibacterial activity toward Gram-negative Escherichia coli (E. coli) under photoirradiation. The growth of E. coli cells is found to be markedly inhibited by Cu/NCD under 365 nm photoirradiation, whereas no apparent inhibition is observed in the dark or with the copper-free carbon dots alone. This is ascribed to the prolonged photoluminescence lifetime of Cu/NCD that facilitates the separation of photogenerated electron-hole pairs and ROS formation. The addition of tert-butyl alcohol is found to completely diminish the antimicrobial activity, suggesting that hydroxyl radicals are responsible for microbial death. Consistent results are obtained from fluorescence microscopic studies using CellROX green as the probe. Similar bactericidal behaviors are observed with Gram-positive Staphylococcus epidermidis (S. epidermidis). The copper content within the carbon material is optimized at a low loading of 1.09 wt %, reducing the possibility of toxic copper-ion leaching. Results from this study highlight the significance of carbon-based nanocomposites with isolated metal species as potent antimicrobial reagents.
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Affiliation(s)
- Forrest Nichols
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064, United States
| | - Jia En Lu
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064, United States
| | - Rene Mercado
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064, United States
| | - Mauricio D Rojas-Andrade
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064, United States
| | - Shunlian Ning
- School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou 510006, China
| | - Zahra Azhar
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064, United States
| | - Jasleen Sandhu
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064, United States
| | - Rafael Cazares
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064, United States
| | - Chad Saltikov
- Department of Microbiology and Environmental Toxicology, University of California, 1156 High Street, Santa Cruz, California 95064, United States
| | - Shaowei Chen
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California 95064, United States
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13
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Nichols F, Chen S. Graphene Oxide Quantum Dot-Based Functional Nanomaterials for Effective Antimicrobial Applications. CHEM REC 2020; 20:1505-1515. [PMID: 32975907 DOI: 10.1002/tcr.202000090] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 09/01/2020] [Accepted: 09/03/2020] [Indexed: 01/22/2023]
Abstract
Conventional β-lactam antibiotics are resisted by bacteria at an increasing rate, prompting studies into the development of alternate antibiotic agents. In this personal account, we summarize recent progress in the design and engineering of graphene oxide quantum dot-based nanomaterials as potent antimicrobial agents. Specifically, we examine the impacts of chemical reduction on the antimicrobial activity of graphene oxide quantum dots, and enhancement of the bactericidal performance by the formation of nanocomposites with metal oxide nanoparticles, within the context of photodynamic generation of reactive oxygen species. A perspective is also included where the promises and challenges are highlighted in the development of high-performance antimicrobial agents based on graphene derivatives.
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Affiliation(s)
- Forrest Nichols
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California, 95064, United States
| | - Shaowei Chen
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California, 95064, United States
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Liu Q, Peng Y, Li Q, He T, Morris D, Nichols F, Mercado R, Zhang P, Chen S. Atomic Dispersion and Surface Enrichment of Palladium in Nitrogen-Doped Porous Carbon Cages Lead to High-Performance Electrocatalytic Reduction of Oxygen. ACS Appl Mater Interfaces 2020; 12:17641-17650. [PMID: 32203650 DOI: 10.1021/acsami.0c03415] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Metal-nitrogen-carbon (MNC) nanocomposites have been hailed as promising and efficient electrocatalysts toward oxygen reduction reaction (ORR), due to the formation of MNx coordination moieties. However, MNC hybrids are mostly prepared by pyrolysis of organic precursors along with select metal salts, where part of the MNx sites are inevitably buried in the carbon matrix. This limited accessibility compromises the electrocatalytic performance. Herein, we describe a wet-impregnation procedure by facile thermal refluxing, whereby palladium is atomically dispersed and enriched onto the surface of hollow, nitrogen-doped carbon cages (HNC) forming Pd-N coordination bonds. The obtained Pd-HNC nanocomposites exhibit an ORR activity in alkaline media markedly higher than that of metallic Pd nanoparticles, and the best sample even outperforms commercial Pt/C and relevant Pd-based catalysts reported in the literature. The results suggest that atomic dispersion and surface enrichment of palladium in a carbon matrix may serve as an effective strategy in the fabrication of high-performance ORR electrocatalysts.
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Affiliation(s)
- Qiming Liu
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, 1156 High Street, Santa Cruz, California 95064, United States
| | - Yi Peng
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, 1156 High Street, Santa Cruz, California 95064, United States
| | - Qiaoxia Li
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, 1156 High Street, Santa Cruz, California 95064, United States
- Shanghai Key Laboratory of Materials Protection and Advanced Materials in Electric Power, College of Environmental and Chemical Engineering, Shanghai University of Electric Power, 2588 Changyang Road, Yangpu District, Shanghai 200090, China
| | - Ting He
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, 1156 High Street, Santa Cruz, California 95064, United States
- Hunan Provincial Key Laboratory of Chemical Power Sources, College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan 410083, China
| | - David Morris
- Department of Chemistry, Dalhousie University, 6274 Coburg Road, Halifax, NS B3H 4R2, Canada
| | - Forrest Nichols
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, 1156 High Street, Santa Cruz, California 95064, United States
| | - Rene Mercado
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, 1156 High Street, Santa Cruz, California 95064, United States
| | - Peng Zhang
- Department of Chemistry, Dalhousie University, 6274 Coburg Road, Halifax, NS B3H 4R2, Canada
| | - Shaowei Chen
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, 1156 High Street, Santa Cruz, California 95064, United States
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15
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Nichols F, Lu JE, Mercado R, Dudschus R, Bridges F, Chen S. Platinum Oxide Nanoparticles for Electrochemical Hydrogen Evolution: Influence of Platinum Valence State. Chemistry 2020; 26:4136-4142. [PMID: 31659785 DOI: 10.1002/chem.201904559] [Citation(s) in RCA: 8] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Indexed: 12/31/2022]
Abstract
Electrochemical hydrogen generation is a rising prospect for future renewable energy storage and conversion. Platinum remains a leading choice of catalyst, but because of its high cost and low natural abundance, it is critical to optimize its use. In the present study, platinum oxide nanoparticles of approximately 2 nm in diameter are deposited on carbon nitride (C3N4) nanosheets by thermal refluxing of C3N4 and PtCl2 or PtCl4 in water. These nanoparticles exhibit apparent electrocatalytic activity toward the hydrogen evolution reaction (HER) in acid. Interestingly, the HER activity increases with increasing Pt4+ concentration in the nanoparticles, and the optimized catalyst even outperforms commercial Pt/C, exhibiting an overpotential of only -7.7 mV to reach the current density of 10 mA cm-2 and a Tafel slope of -26.3 mV dec-1 . The results from this study suggest that the future design of platinum oxide catalysts should strive to maximize the Pt4+ sites and minimize the formation of the less active Pt2+ species.
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Affiliation(s)
- Forrest Nichols
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California, 95064, USA
| | - Jia En Lu
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California, 95064, USA
| | - Rene Mercado
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California, 95064, USA
| | - Ryan Dudschus
- Department of Physics, University of California, 1156 High Street, Santa Cruz, California, 95064, USA
| | - Frank Bridges
- Department of Physics, University of California, 1156 High Street, Santa Cruz, California, 95064, USA
| | - Shaowei Chen
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California, 95064, USA
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16
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Rojas-Andrade MD, Nguyen TA, Mistler WP, Armas J, Lu JE, Roseman G, Hollingsworth WR, Nichols F, Millhauser GL, Ayzner A, Saltikov C, Chen S. Antimicrobial activity of graphene oxide quantum dots: impacts of chemical reduction. Nanoscale Adv 2020; 2:1074-1083. [PMID: 36133054 PMCID: PMC9417586 DOI: 10.1039/c9na00698b] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 01/19/2020] [Indexed: 06/11/2023]
Abstract
Design and engineering of graphene-based functional nanomaterials for effective antimicrobial applications has been attracting extensive interest. In the present study, graphene oxide quantum dots (GOQDs) were prepared by chemical exfoliation of carbon fibers and exhibited apparent antimicrobial activity. Transmission electron microscopic measurements showed that the lateral length ranged from a few tens to a few hundred nanometers. Upon reduction by sodium borohydride, whereas the UV-vis absorption profile remained largely unchanged, steady-state photoluminescence measurements exhibited a marked blue-shift and increase in intensity of the emission, due to (partial) removal of phenanthroline-like structural defects within the carbon skeletons. Consistent results were obtained in Raman and time-resolved photoluminescence measurements. Interestingly, the samples exhibited apparent, but clearly different, antimicrobial activity against Staphylococcus epidermidis cells. In the dark and under photoirradiation (400 nm), the as-produced GOQDs exhibited markedly higher cytotoxicity than the chemically reduced counterparts, likely because of (i) effective removal by NaBH4 reduction of redox-active phenanthroline-like moieties that interacted with the electron-transport chain of the bacterial cells, and (ii) diminished production of hydroxyl radicals that were potent bactericidal agents after chemical reduction as a result of increased conjugation within the carbon skeletons.
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Affiliation(s)
- Mauricio D Rojas-Andrade
- Department of Chemistry and Biochemistry, University of California 1156 High Street Santa Cruz California 95064 USA
| | - Tuan Anh Nguyen
- Department of Chemistry and Biochemistry, University of California 1156 High Street Santa Cruz California 95064 USA
| | - William P Mistler
- Department of Chemistry and Biochemistry, University of California 1156 High Street Santa Cruz California 95064 USA
| | - Juan Armas
- Department of Chemistry and Biochemistry, University of California 1156 High Street Santa Cruz California 95064 USA
| | - Jia En Lu
- Department of Chemistry and Biochemistry, University of California 1156 High Street Santa Cruz California 95064 USA
| | - Graham Roseman
- Department of Chemistry and Biochemistry, University of California 1156 High Street Santa Cruz California 95064 USA
| | - William R Hollingsworth
- Department of Chemistry and Biochemistry, University of California 1156 High Street Santa Cruz California 95064 USA
| | - Forrest Nichols
- Department of Chemistry and Biochemistry, University of California 1156 High Street Santa Cruz California 95064 USA
| | - Glenn L Millhauser
- Department of Chemistry and Biochemistry, University of California 1156 High Street Santa Cruz California 95064 USA
| | - Alexander Ayzner
- Department of Chemistry and Biochemistry, University of California 1156 High Street Santa Cruz California 95064 USA
| | - Chad Saltikov
- Department of Microbiology and Environmental Toxicology, University of California 1156 High Street Santa Cruz California 95064 USA
| | - Shaowei Chen
- Department of Chemistry and Biochemistry, University of California 1156 High Street Santa Cruz California 95064 USA
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He T, Peng Y, Li Q, Lu JE, Liu Q, Mercado R, Chen Y, Nichols F, Zhang Y, Chen S. Nanocomposites Based on Ruthenium Nanoparticles Supported on Cobalt and Nitrogen-Codoped Graphene Nanosheets as Bifunctional Catalysts for Electrochemical Water Splitting. ACS Appl Mater Interfaces 2019; 11:46912-46919. [PMID: 31755691 DOI: 10.1021/acsami.9b17056] [Citation(s) in RCA: 10] [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: 06/10/2023]
Abstract
Rational design and engineering of high-efficiency electrocatalysts toward overall water splitting is crucial for the development of hydrogen energy technology. Herein, a facile procedure is described for the preparation of effective bifunctional electrocatalysts for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), where ruthenium nanoparticles are supported on graphene nanosheets that are codoped with atomic cobalt and nitrogen by controlled pyrolysis of melamine-functionalized graphene oxide and metal ion precursors. The obtained nanocomposites (CoNG/Ru) exhibit a remarkable electrocatalytic activity toward both HER and OER in alkaline media, with a respective overpotential of only -15 and +350 mV to reach the current density of 10 mA cm-2, which is much better than the monometallic counterparts and relevant catalysts in the literature. With CoNG/Ru as bifunctional catalysts for overall water splitting in a two-electrode system, a low potential of 1.58 V is needed to reach the current density of 10 mA cm-2, which is even better than that with commercial Pt/C and RuO2 catalysts. This is ascribed to the synergistic interactions between the metal species by metal-metal charge transfer. These results highlight the significance of exploiting the electronic interactions between metal species in carbon-based nanocomposites to develop bifunctional catalysts for electrochemical energy technologies.
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Affiliation(s)
- Ting He
- Hunan Provincial Key Laboratory of Chemical Power Sources, College of Chemistry and Chemical Engineering , Central South University , Changsha 410083 , China
- Department of Chemistry and Biochemistry , University of California , 1156 High Street , Santa Cruz , California 95064 , United States
| | - Yi Peng
- Department of Chemistry and Biochemistry , University of California , 1156 High Street , Santa Cruz , California 95064 , United States
| | - Qiaoxia Li
- Department of Chemistry and Biochemistry , University of California , 1156 High Street , Santa Cruz , California 95064 , United States
- Shanghai Key Laboratory of Materials Protection and Advanced Materials in Electric Power, College of Environmental and Chemical Engineering , Shanghai University of Electric Power , 2588 Changyang Road , Yangpu District, Shanghai 200090 , China
| | - Jia En Lu
- Department of Chemistry and Biochemistry , University of California , 1156 High Street , Santa Cruz , California 95064 , United States
| | - Qiming Liu
- Department of Chemistry and Biochemistry , University of California , 1156 High Street , Santa Cruz , California 95064 , United States
| | - Rene Mercado
- Department of Chemistry and Biochemistry , University of California , 1156 High Street , Santa Cruz , California 95064 , United States
| | - Yang Chen
- Hunan Provincial Key Laboratory of Chemical Power Sources, College of Chemistry and Chemical Engineering , Central South University , Changsha 410083 , China
| | - Forrest Nichols
- Department of Chemistry and Biochemistry , University of California , 1156 High Street , Santa Cruz , California 95064 , United States
| | - Yi Zhang
- Hunan Provincial Key Laboratory of Chemical Power Sources, College of Chemistry and Chemical Engineering , Central South University , Changsha 410083 , China
| | - Shaowei Chen
- Department of Chemistry and Biochemistry , University of California , 1156 High Street , Santa Cruz , California 95064 , United States
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Fujiwara M, Anstadt EJ, Flynn B, Morse K, Ng C, Paczkowski P, Zhou J, Mackay S, Wasko N, Nichols F, Clark RB. Enhanced TLR2 responses in multiple sclerosis. Clin Exp Immunol 2018; 193:313-326. [PMID: 30043528 PMCID: PMC6150258 DOI: 10.1111/cei.13150] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 03/29/2018] [Accepted: 04/18/2018] [Indexed: 12/17/2022] Open
Abstract
The roles of the microbiome and innate immunity in the pathogenesis of multiple sclerosis (MS) remain unclear. We have previously documented abnormally low levels of a microbiome‐derived Toll‐like receptor (TLR)2‐stimulating bacterial lipid in the blood of MS patients and postulated that this is indicative of a deficiency in the innate immune regulating function of the microbiome in MS. We postulated further that the resulting enhanced TLR2 responsiveness plays a critical role in the pathogenesis of MS. As proof‐of‐concept, we reported that decreasing systemic TLR2 responsiveness by administering very low‐dose TLR2 ligands attenuated significantly the mouse model of MS, experimental autoimmune encephalomyelitis. Studies of Toll‐like receptor responses in patients with MS have been conflicting. Importantly, most of these investigations have focused on the response to TLR4 ligation and few have characterized TLR2 responses in MS. In the present study, our goal was to characterize TLR2 responses of MS patients using multiple approaches. Studying a total of 26 MS patients and 32 healthy controls, we now document for the first time that a large fraction of MS patients (50%) demonstrate enhanced responsiveness to TLR2 stimulation. Interestingly, the enhanced TLR2 responders include a significant fraction of those with progressive forms of MS, a subset of patients considered unresponsive to adaptive immune system‐targeting therapies. Our results suggest the presence of a pathologically relevant TLR2 related innate immune abnormality in patients with both relapsing–remitting and progressive MS. These findings may have significant implications for understanding the role of innate immunity in the pathogenesis of MS.
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Affiliation(s)
- M Fujiwara
- Departments of Immunology and Medicine, University of Connecticut School of Medicine, Farmington, CT, USA
| | - E J Anstadt
- Departments of Immunology and Medicine, University of Connecticut School of Medicine, Farmington, CT, USA
| | - B Flynn
- IsoPlexis, Branford, CT, USA
| | - K Morse
- IsoPlexis, Branford, CT, USA
| | - C Ng
- IsoPlexis, Branford, CT, USA
| | | | - J Zhou
- IsoPlexis, Branford, CT, USA
| | | | - N Wasko
- Departments of Immunology and Medicine, University of Connecticut School of Medicine, Farmington, CT, USA
| | - F Nichols
- Division of Periodontology, University of Connecticut School of Medicine and School of Dental Health, Farmington, CT, USA
| | - R B Clark
- Departments of Immunology and Medicine, University of Connecticut School of Medicine, Farmington, CT, USA
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Xie D, Allen M, Marks R, Jiang G, Sun Z, Nichols F, Zhang M, Aubry M, Jatoi A, Garces Y, Mansfield A, Wigle D, Molina J, Deschamps C, Yang P. O-061NOMOGRAM PREDICTS OVERALL SURVIVAL FOR PATIENTS WITH NON-SMALL CELL LUNG CANCER INCORPORATING PRETREATMENT PERIPHERAL BLOOD MARKERS. Interact Cardiovasc Thorac Surg 2017. [DOI: 10.1093/icvts/ivx280.073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Reinersman JM, Allen M, Blackmon S, Cassivi S, Nichols F, Wigle D, Shen K. F-146ANALYSIS OF PATIENTS DISCHARGED FROM THE HOSPITAL WITH A CHEST TUBE IN PLACE AFTER THORACIC SURGERY. Interact Cardiovasc Thorac Surg 2016. [DOI: 10.1093/icvts/ivw260.144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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21
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Reinersman JM, Wigle D, Allen M, Cassivi S, Gostout C, Nichols F, Shen K, Song LWK, Blackmon S. F-154A NOVEL STRATEGY TO INITIATE A PERORAL ENDOSCOPIC MYOTOMY PROGRAM. Interact Cardiovasc Thorac Surg 2016. [DOI: 10.1093/icvts/ivw260.152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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22
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Hamaji M, Shen K, Wigle D, Allen M, Nichols F, Cassivi S, Deschamps C. P-168THE OUTCOME OF PULMONARY RESECTION FOR INVASIVE FUNGAL INFECTION COMPLICATING HAEMATOLOGIC MALIGNANCY. Interact Cardiovasc Thorac Surg 2013. [DOI: 10.1093/icvts/ivt288.168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Hamaji M, Cassivi S, Shen K, Allen M, Nichols F, Deschamps C, Wigle D. P-159REOPERATIVE PULMONARY RESECTION: IS THERE ANY BENEFIT FOR A MINIMALLY INVASIVE APPROACH? Interact Cardiovasc Thorac Surg 2013. [DOI: 10.1093/icvts/ivt288.159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Croghan GA, Nichols F, Cassivi S, Nevala W, Daniels C, Thompson M, Schroeder D, Markovic SN. VEGF A, C, and D levels in malignant pleural effusions. J Clin Oncol 2008. [DOI: 10.1200/jco.2008.26.15_suppl.22126] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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25
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Feldmann E, Wilterdink JL, Kosinski A, Lynn M, Chimowitz MI, Sarafin J, Smith HH, Nichols F, Rogg J, Cloft HJ, Wechsler L, Saver J, Levine SR, Tegeler C, Adams R, Sloan M. The Stroke Outcomes and Neuroimaging of Intracranial Atherosclerosis (SONIA) Trial. Neurology 2007; 68:2099-106. [PMID: 17409371 DOI: 10.1212/01.wnl.0000261488.05906.c1] [Citation(s) in RCA: 211] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Transcranial Doppler ultrasound (TCD) and magnetic resonance angiography (MRA) can identify intracranial atherosclerosis but have not been rigorously validated against the gold standard, catheter angiography. The WASID trial (Warfarin Aspirin Symptomatic Intracranial Disease) required performance of angiography to verify the presence of intracranial stenosis, allowing for prospective evaluation of TCD and MRA. The aims of Stroke Outcomes and Neuroimaging of Intracranial Atherosclerosis (SONIA) trial were to define abnormalities on TCD/MRA to see how well they identify 50 to 99% intracranial stenosis of large proximal arteries on catheter angiography. STUDY DESIGN SONIA standardized the performance and interpretation of TCD, MRA, and angiography. Study-wide cutpoints defining positive TCD/MRA were used. Hard copy TCD/MRA were centrally read, blind to the results of angiography. RESULTS SONIA enrolled 407 patients at 46 sites in the United States. For prospectively tested noninvasive test cutpoints, positive predictive values (PPVs) and negative predictive values (NPVs) were TCD, PPV 36% (95% CI: 27 to 46); NPV, 86% (95% CI: 81 to 89); MRA, PPV 59% (95% CI: 54 to 65); NPV, 91% (95% CI: 89 to 93). For cutpoints modified to maximize PPV, they were TCD, PPV 50% (95% CI: 36 to 64), NPV 85% (95% CI: 81 to 88); MRA PPV 66% (95% CI: 58 to 73), NPV 87% (95% CI: 85 to 89). For each test, a characteristic performance curve showing how the predictive values vary with a changing test cutpoint was obtained. CONCLUSIONS Both transcranial Doppler ultrasound and magnetic resonance angiography noninvasively identify 50 to 99% intracranial large vessel stenoses with substantial negative predictive value. The Stroke Outcomes and Neuroimaging of Intracranial Atherosclerosis trial methods allow transcranial Doppler ultrasound and magnetic resonance angiography to reliably exclude the presence of intracranial stenosis. Abnormal findings on transcranial Doppler ultrasound or magnetic resonance angiography require a confirmatory test such as angiography to reliably identify stenosis.
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Affiliation(s)
- E Feldmann
- Department of Clinical Neurosciences, Brown University School of Medicine, Providence, RI 02903, USA.
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Yang P, Visbal A, Ebbert J, Zhang Z, Molina J, Williams B, Sheu S, Wampfler J, Nichols F. O-058 Characteristics of lung cancer patients who were diagnosed younger than 50 or older than 80 years of age. Lung Cancer 2005. [DOI: 10.1016/s0169-5002(05)80190-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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27
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Visbal A, Ebbert JO, Zhang Z, Molina J, Williams B, Sheu S, Wampfler J, Nichols F, Yang P. 052: Lung Cancer in Patients Younger than 50 or Older than 80 Years of Age at Diagnosis. Am J Epidemiol 2005. [DOI: 10.1093/aje/161.supplement_1.s13c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- A Visbal
- Mayo Clinic College of Medicine, Rochester, MN 55905
| | - J O Ebbert
- Mayo Clinic College of Medicine, Rochester, MN 55905
| | - Z Zhang
- Mayo Clinic College of Medicine, Rochester, MN 55905
| | - J Molina
- Mayo Clinic College of Medicine, Rochester, MN 55905
| | - B Williams
- Mayo Clinic College of Medicine, Rochester, MN 55905
| | - S Sheu
- Mayo Clinic College of Medicine, Rochester, MN 55905
| | - J Wampfler
- Mayo Clinic College of Medicine, Rochester, MN 55905
| | - F Nichols
- Mayo Clinic College of Medicine, Rochester, MN 55905
| | - P Yang
- Mayo Clinic College of Medicine, Rochester, MN 55905
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Zahlten J, Riep B, Walter C, Schmeck B, Kruell M, N'Guessan DP, Hippenstiel S, Nichols F, Suttorp N, Bernimoulin J. Aufgereinigte Ceramide von Porphyromonas gingivalis induzieren Apoptose in humanen Endothelzellen. Pneumologie 2005. [DOI: 10.1055/s-2005-864616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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29
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Bennett J, Gross J, Nichols F, Chidambaram N, Burgess D. The chemical and physical stability of a 1:1 mixture of propofol and methohexital. Anesth Prog 2001; 48:61-5. [PMID: 11515949 PMCID: PMC2007364] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
Abstract
Anesthetic drugs are frequently mixed or coadministered to optimize anesthetic effects while minimizing adverse effects. Methohexital advantages include its low cost and rapid onset, while propofol provides improved airway anesthesia and extremely rapid clearance from the plasma. Therefore, a mixture of these agents might well be superior to either drug given alone. We wished to determine whether a mixture of methohexital and propofol is chemically and physically stable. A 1:1 mixture of propofol 10 mg/ml and methohexital was prepared. At times varying from 0 to 48 hours, mixtures with an internal standard of thymol kept at room temperature were thrice extracted with a 2:1 v/v mixture of diethyl ether:pentane, dried under nitrogen, and treated overnight with bis-trimethylsilyl-trifluoroacetamide. The resultant derivatives were transferred to microsample vials and analyzed by GC-MS. Drug stability was quantified by electronic integration of peak areas representing characteristic ions for each drug. For each sample, the peak area of the methohexital ion (m/z 239) or propofol ion (m/z 235) relative to the corresponding thymol ion (m/z 207) served as an index of the concentration of the drug in the sample. At times varying from 0 to 48 hours, mixtures without thymol were used to determine mean droplet size of the particles. This was accomplished using both an Accusizer and a Nicomp 370 Particle Sizer. One way ANOVA tested for significant changes in drug concentrations and mean particle size as a function of time. There was no significant breakdown of propofol or methohexital when combined in a 1:1 mixture and allowed to stand for 48 hours, nor was there an increase in particle size suggestive of emulsion instability. We concluded that a 1:1 mixture of propofol and methohexital was stable up to 48 hours after mixing.
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Affiliation(s)
- J Bennett
- Department of Oral and Maxillofacial Surgery, University of Connecticut School of Dental Medicine, Farmington 06030-1720, USA
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Finucane P, Nichols F, Gannon B, Runciman S, Prideaux D, Nicholas T. Recruiting problem-based learning (PBL) tutors for a PBL-based curriculum: the Flinders University experience. Med Educ 2001; 35:56-61. [PMID: 11123596 DOI: 10.1046/j.1365-2923.2001.00830.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
OBJECTIVES To examine the contribution made to problem-based learning (PBL) by individual teachers and by departments in years 1 and 2 of a new graduate-entry medical programme (GEMP) with a PBL-based curriculum. METHODS We compiled a database on all PBL tutoring undertaken in years 1 and 2 during the first 3 years in which the GEMP was delivered. This allowed us to quantify and analyse the contribution made by individuals and by departments. RESULTS At 3 years following introduction of the GEMP, 136 (25.9%) of the school's 525 staff had trained as PBL tutors and 98 (18.7%) had tutored. Both individuals and departments differed greatly in the amount of time devoted to PBL tutoring. Staff who tutored once tended to tutor again in subsequent years. Compared with staff in clinical departments, those in non-clinical departments (who constituted 12% of the total) made a greater relative contribution though a smaller absolute contribution to tutoring. CONCLUSIONS These findings prompted us to develop a formula that distributes the PBL tutoring load more evenly across departments. This was successfully introduced in 1999. It recognizes the fact that only a minority of staff will volunteer to become PBL tutors. Strategies that might encourage more staff to tutor are briefly discussed.
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Affiliation(s)
- P Finucane
- School of Medicine, Flinders University, Adelaide, South Australia
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Abstract
Bacterial hydroxy fatty acids and alpha-hydroxy fatty acids have been demonstrated in complex lipid extracts of subgingival plaque and gingival tissue. However, little is known about the relationship between these hydroxy fatty acids in plaque and gingival tissues or the significance of these complex lipids in promoting inflammatory periodontal disease. The present study determined the percentages of ester-linked and amide-linked hydroxy fatty acids in complex lipids recovered from plaque and gingival tissue samples and the relationship between bacterial hydroxy fatty acids and alpha-hydroxy fatty acids in the lipid extracts. To evaluate a potential role for these hydroxy fatty acids in inflammatory periodontal disease, gingival tissue samples were examined for a relationship between prostaglandin E2 (PGE2) and hydroxy fatty acids recovered in gingival lipid. This investigation demonstrated that alpha-hydroxy fatty acids are only ester linked in plaque lipids but are largely amide linked in gingival tissue lipids. Furthermore, the level of alpha-hydroxy fatty acid in gingival lipid is directly related to the level of the bacterial hydroxy fatty acid 3-OH iso-branched C17:0 (3-OH iC17:0) in the same lipid extract. However, the relationship between hydroxy fatty acids in gingival lipids does not parallel the fatty acid relationship observed in plaque lipids. Finally, alpha-hydroxy fatty acid levels in gingival tissue lipids correlate directly with the recovery of PGE2 in the same tissue samples. These results demonstrate that alpha-hydroxy fatty acid levels in gingival lipids are directly related to both 3-OH iC17:0 bacterial lipid levels and PGE2 levels. These results indicate that in periodontal tissues there are unusual host-parasite interactions involving penetration of bacterial lipid in association with an altered gingival lipid metabolism and prostaglandin synthesis.
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Affiliation(s)
- F Nichols
- Department of Periodontology, School of Dental Medicine, University of Connecticut, Farmington, Connecticut, USA.
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Bennett J, Nichols F, Rosenblum M, Condry J. Subcutaneous administration of midazolam: a comparison of the Bioject jet injector with the conventional syringe and needle. J Oral Maxillofac Surg 1998; 56:1249-54. [PMID: 9820211 DOI: 10.1016/s0278-2391(98)90601-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [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: 11/24/2022]
Abstract
PURPOSE The purpose of this study was to compare jet injection to a syringe and needle in terms of the difference in discomfort and pharmacokinetics after the subcutaneous administration of midazolam. PATIENTS AND METHODS Using a prospective, randomized, double-blinded study design, 14 subjects were administered midazolam on two separate occasions (at least 2 weeks apart). The subjects were randomly distributed into two groups: syringe and needle (saline)/jet injector (midazolam) or syringe and needle (midazolam)/jet injector (saline). The subjects were randomly assigned to receive either EMLA (eutectic mixture of local anesthetics) or a placebo at the injection site for the first administration and the other topical agent on the second visit. Each subject received one subcutaneous injection in the deltoid region per arm per day. Each injection contained the same volume of solution. Subjects completed visual analog scale (VAS) questionnaires assessing the discomfort of the injection. Blood samples were taken at specified intervals over 2 hours for determination of midazolam levels. RESULTS The discomfort associated with the injection was less with the Biojector 2000 (Bioject Inc, Portland, OR) although this was not statistically significant. However, persistent discomfort was significantly greater at the needle site. The mean peak plasma level of midazolam was achieved more rapidly with the Biojector 2000 than with the syringe and needle (P < .05). However, the peak plasma level after jet injection or injection with a syringe and needle was not statistically different. CONCLUSION The results of the study show that the Biojector 2000 is a needle-free injection system that can be used for the administration of a premedicant before induction of anesthesia. It has several advantages, including the potential reduction of anxiety associated with the "fear of needles" and occupational injuries.
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Affiliation(s)
- J Bennett
- Department of OMFS, University of Connecticut School of Dental Medicine, Farmington 06030, USA
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Hernichel-Gorbach E, Kornman KS, Holt SC, Nichols F, Meador H, Kung JT, Thomas CA. Host responses in patients with generalized refractory periodontitis. J Periodontol 1994; 65:8-16. [PMID: 8133419 DOI: 10.1902/jop.1994.65.1.8] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Although patients with refractory periodontitis have been widely reported, no clear biologic profile of these patients has been noted. The purpose of the present study was to evaluate host responsiveness of a well-defined group of refractory periodontitis patients by determining the effect of a lipopolysaccharide (LPS) challenge on monocyte surface receptor density and on the release of inflammatory mediators. Venous blood was obtained from 7 refractory periodontitis, 8 stable periodontal maintenance, and 8 gingivitis patients with no evidence of periodontitis. Mononuclear cells were cultured in either control media or media treated with Actinobacillus actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), or Salmonella typhimurium (S. typh) LPS. At 0 and 24 hours supernatants were assayed for prostaglandin-E2 (PGE2) and interleukin-1 beta (Il-1 beta) release by ELISA. Using flow cytometry the density of specific monocyte surface receptors were assayed with Mo3e and LeuM3 monoclonal antibodies (mAb); T-cell CD4/CD8 ratios were assayed with OKT-3, OKT-4, and OKT-8 mAb. After 24 hours incubation with Pg or S. typh LPS, the upregulation of the Mo3e receptor was significantly decreased for refractory periodontitis patients (P < 0.05) when compared to gingivitis and to stable maintenance patients. In refractory periodontitis patients the T-cell CD4/CD8 ratio was decreased. Upon stimulation with Pg or S. typh LPS, monocytes from stable maintenance and refractory periodontitis patients released more Il-1 beta (P < 0.05) and PGE2 (P = 0.13 and 0.15) than monocytes from gingivitis subjects.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- E Hernichel-Gorbach
- Department of Periodontics, University of Texas Health Science Center at San Antonio
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Safavi K, Nichols F. Abstract #75 — Alteration of biological properties of bacterial LPS by Ca(OH)2 treatment. J Endod 1993. [DOI: 10.1016/s0099-2399(06)80760-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Adams R, McKie V, Nichols F, Carl E, Zhang DL, McKie K, Figueroa R, Litaker M, Thompson W, Hess D. The use of transcranial ultrasonography to predict stroke in sickle cell disease. N Engl J Med 1992; 326:605-10. [PMID: 1734251 DOI: 10.1056/nejm199202273260905] [Citation(s) in RCA: 415] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BACKGROUND Stroke, especially cerebral infarction, is a major cause of morbidity and mortality in children with sickle cell disease. Primary prevention of stroke by transfusion therapy may be feasible if there is a way to identify the patients at greatest risk. Transcranial Doppler ultrasonography can measure flow velocity in the large intracranial arteries. The narrowing of these arteries, which leads to cerebral infarction, is characterized by an increased velocity of flow. METHODS Using transcranial Doppler ultrasonography, we prospectively measured the velocity of cerebral blood flow in children and young adults being followed because of sickle cell disease. The results were classified as either normal or abnormal on the basis of the highest velocity of flow in the middle cerebral artery. Abnormal velocity was defined as a flow greater than or equal to 170 cm per second, a definition determined by post hoc analysis to maximize the predictive success of the test. The end point was a clinically apparent first cerebral infarction. RESULTS Two hundred eighty-three transcranial ultrasound examinations were performed in 190 patients with sickle cell disease (age at entry, 3 to 18 years). After an average follow-up of 29 months, cerebral infarction was diagnosed in seven patients. In 23 patients the results of the ultrasound examinations were abnormal, and in 167 patients they were normal. The clinical and hematologic characteristics of the two groups were similar, but six of the seven strokes occurred among the 23 patients with abnormal ultrasound results (P less than 0.00001 by Fisher's exact test). In this group, the relative risk of stroke was 44 (95 percent confidence interval, 5.5 to 346). CONCLUSIONS Transcranial ultrasonography can identify the children with sickle cell disease who are at highest risk for cerebral infarction. Periodic ultrasound examinations and the selective use of transfusion therapy could make the primary prevention of stroke an achievable goal.
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Affiliation(s)
- R Adams
- Department of Neurology, Medical College of Georgia, Augusta 30912
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Howard GA, Turner RT, Puzas JE, Nichols F, Baylink DJ. Bone cells on microcarrier spheres. JAMA 1983; 249:258-9. [PMID: 6848817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Nichols F. Prophylactic removal of impacted third molars. Mayan 1966; 2:24-8. [PMID: 5229189] [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: 01/14/2023]
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