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Li X, Wang J, Bai N, Zhang X, Han X, da Silva I, Morris CG, Xu S, Wilary DM, Sun Y, Cheng Y, Murray CA, Tang CC, Frogley MD, Cinque G, Lowe T, Zhang H, Ramirez-Cuesta AJ, Thomas KM, Bolton LW, Yang S, Schröder M. Refinement of pore size at sub-angstrom precision in robust metal-organic frameworks for separation of xylenes. Nat Commun 2020; 11:4280. [PMID: 32855396 PMCID: PMC7453017 DOI: 10.1038/s41467-020-17640-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 07/06/2020] [Indexed: 12/19/2022] Open
Abstract
The demand for xylenes is projected to increase over the coming decades. The separation of xylene isomers, particularly p- and m-xylenes, is vital for the production of numerous polymers and materials. However, current state-of-the-art separation is based upon fractional crystallisation at 220 K which is highly energy intensive. Here, we report the discrimination of xylene isomers via refinement of the pore size in a series of porous metal-organic frameworks, MFM-300, at sub-angstrom precision leading to the optimal kinetic separation of all three xylene isomers at room temperature. The exceptional performance of MFM-300 for xylene separation is confirmed by dynamic ternary breakthrough experiments. In-depth structural and vibrational investigations using synchrotron X-ray diffraction and terahertz spectroscopy define the underlying host-guest interactions that give rise to the observed selectivity (p-xylene < o-xylene < m-xylene) and separation factors of 4.6-18 for p- and m-xylenes.
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Affiliation(s)
- Xiaolin Li
- Department of Chemistry, University of Manchester, Manchester, M13 9PL, UK
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, China
| | - Juehua Wang
- Department of Chemistry, University of Manchester, Manchester, M13 9PL, UK
| | - Nannan Bai
- Department of Chemistry, University of Manchester, Manchester, M13 9PL, UK
| | - Xinran Zhang
- Department of Chemistry, University of Manchester, Manchester, M13 9PL, UK
| | - Xue Han
- Department of Chemistry, University of Manchester, Manchester, M13 9PL, UK
| | - Ivan da Silva
- ISIS Facility, STFC Rutherford Appleton Laboratory, Oxfordshire, OX11 0QX, UK
| | | | - Shaojun Xu
- Department of Chemistry, University of Manchester, Manchester, M13 9PL, UK
| | - Damian M Wilary
- Department of Chemistry, University of Manchester, Manchester, M13 9PL, UK
| | - Yinyong Sun
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, China
| | - Yongqiang Cheng
- Neutron Scattering Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Claire A Murray
- Diamond Light Source, Harwell Science Campus, Oxfordshire, OX11 0DE, UK
| | - Chiu C Tang
- Diamond Light Source, Harwell Science Campus, Oxfordshire, OX11 0DE, UK
| | - Mark D Frogley
- Diamond Light Source, Harwell Science Campus, Oxfordshire, OX11 0DE, UK
| | - Gianfelice Cinque
- Diamond Light Source, Harwell Science Campus, Oxfordshire, OX11 0DE, UK
| | - Tristan Lowe
- Henry Moseley X-ray Imaging Facility, Photon Science Institute, University of Manchester, Manchester, M13 9PL, UK
| | - Haifei Zhang
- Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK
| | - Anibal J Ramirez-Cuesta
- Neutron Scattering Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - K Mark Thomas
- School of Chemical Engineering and Advanced Materials, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
| | | | - Sihai Yang
- Department of Chemistry, University of Manchester, Manchester, M13 9PL, UK.
| | - Martin Schröder
- Department of Chemistry, University of Manchester, Manchester, M13 9PL, UK.
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2
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Hrynick TA, Barasa V, Benschop J, Cleaveland S, Crump JA, Davis M, Mariki B, Mmbaga BT, Mtui-Malamsha N, Prinsen G, Sharp J, Sindiyo E, Swai ES, Thomas KM, Zadoks R, Waldman L. Street-level diplomacy and local enforcement for meat safety in northern Tanzania: knowledge, pragmatism and trust. BMC Public Health 2019; 19:863. [PMID: 31269927 PMCID: PMC6610827 DOI: 10.1186/s12889-019-7067-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 05/29/2019] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND With increasing demand for red meat in Tanzania comes heightened potential for zoonotic infections in animals and humans that disproportionately affect poor communities. A range of frontline government employees work to protect public health, providing services for people engaged in animal-based livelihoods (livestock owners and butchers), and enforcing meat safety and food premises standards. In contrast to literature which emphasises the inadequacy of extension support and food safety policy implementation in low- and middle-income countries, this paper foregrounds the 'street-level diplomacy' deployed by frontline actors operating in challenging contexts. METHODS This research is based on semi-structured interviews with 61 government employees, including livestock extension officers/meat inspectors and health officers, across 10 randomly-selected rural and urban wards. RESULTS Frontline actors combined formal and informal strategies including the leveraging of formal policy texts and relationships with other state employees, remaining flexible and recognising that poverty constrained people's ability to comply with health regulations. They emphasised the need to work with livestock keepers and butchers to build their knowledge to self-regulate and to work collaboratively to ensure meat safety. Remaining adaptive and being hesitant to act punitively unless absolutely necessary cultivated trust and positive relations, making those engaged in animal-based livelihoods more open to learning from and cooperating with extension officers and inspectors. This may result in higher levels of meat safety than might be the case if frontline actors stringently enforced regulations. CONCLUSION The current tendency to view frontline actors' partial enforcement of meat safety regulations as a failure obscures the creative and proactive ways in which they seek to ensure meat safety in a context of limited resources. Their application of 'street-level diplomacy' enables them to be sensitive to local socio-economic realities, to respect local social norms and expectations and to build support for health safety interventions when necessary. More explicitly acknowledging the role of trust and positive state-society relations and the diplomatic skills deployed by frontline actors as a formal part of their inspection duties offers new perspectives and enhanced understandings on the complicated nature of their work and what might be done to support them.
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Affiliation(s)
- T A Hrynick
- Institute of Development Studies, University of Sussex, Brighton, UK
| | - V Barasa
- Institute of Development Studies, University of Sussex, Brighton, UK
| | - J Benschop
- mEpiLab, School of Veterinary Science, Massey University, Palmerston, New Zealand
| | - S Cleaveland
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
- Nelson Mandela African Institute of Science and Technology, Arusha, Tanzania
| | - J A Crump
- Centre for International Health, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
- Kilimanjaro Christian Medical University College, Tumaini University, Moshi, Tanzania
| | - M Davis
- Paul G. Allen School for Global Animal Health, College of Veterinary Medicine, Washington State University, Pullman, USA
| | - B Mariki
- Tanzania Chamber of Commerce - Kilimanjaro, Moshi, Tanzania
| | - B T Mmbaga
- Kilimanjaro Christian Medical University College, Tumaini University, Moshi, Tanzania
- Kilimanjaro Clinical Research Institute, Moshi, Tanzania
| | - N Mtui-Malamsha
- Ministry of Livestock and Fisheries Development, Dodoma, Tanzania
| | - G Prinsen
- School of People, Environment and Planning, Massey University, Palmerston North, New Zealand
| | - J Sharp
- School of Geographical and Earth Sciences, University of Glasgow, Glasgow, UK
| | - E Sindiyo
- Mwanga District Council Department of Livestock and Fisheries, Mwanga, Tanzania
| | - E S Swai
- Ministry of Livestock and Fisheries Development, Dodoma, Tanzania
| | - K M Thomas
- Centre for International Health, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
- Kilimanjaro Clinical Research Institute, Moshi, Tanzania
| | - R Zadoks
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - L Waldman
- Institute of Development Studies, University of Sussex, Brighton, UK.
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3
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Yan L, Jiang H, Wang Y, Li L, Gu X, Dai P, Liu D, Tang SF, Zhao G, Zhao X, Thomas KM. One-step and scalable synthesis of Ni2P nanocrystals encapsulated in N,P-codoped hierarchically porous carbon matrix using a bipyridine and phosphonate linked nickel metal–organic framework as highly efficient electrocatalysts for overall water splitting. Electrochim Acta 2019. [DOI: 10.1016/j.electacta.2018.12.020] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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4
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Han X, Godfrey HGW, Briggs L, Davies AJ, Cheng Y, Daemen LL, Sheveleva AM, Tuna F, McInnes EJL, Sun J, Drathen C, George MW, Ramirez-Cuesta AJ, Thomas KM, Yang S, Schröder M. Reversible adsorption of nitrogen dioxide within a robust porous metal-organic framework. Nat Mater 2018; 17:691-696. [PMID: 29891889 DOI: 10.1038/s41563-018-0104-7] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2017] [Accepted: 05/10/2018] [Indexed: 05/20/2023]
Abstract
Nitrogen dioxide (NO2) is a major air pollutant causing significant environmental1,2 and health problems3,4. We report reversible adsorption of NO2 in a robust metal-organic framework. Under ambient conditions, MFM-300(Al) exhibits a reversible NO2 isotherm uptake of 14.1 mmol g-1, and, more importantly, exceptional selective removal of low-concentration NO2 (5,000 to <1 ppm) from gas mixtures. Complementary experiments reveal five types of supramolecular interaction that cooperatively bind both NO2 and N2O4 molecules within MFM-300(Al). We find that the in situ equilibrium 2NO2 ↔ N2O4 within the pores is pressure-independent, whereas ex situ this equilibrium is an exemplary pressure-dependent first-order process. The coexistence of helical monomer-dimer chains of NO2 in MFM-300(Al) could provide a foundation for the fundamental understanding of the chemical properties of guest molecules within porous hosts. This work may pave the way for the development of future capture and conversion technologies.
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Affiliation(s)
- Xue Han
- School of Chemistry, University of Manchester, Manchester, UK
| | | | - Lydia Briggs
- School of Chemistry, University of Manchester, Manchester, UK
| | - Andrew J Davies
- School of Chemistry, University of Nottingham, Nottingham, UK
| | - Yongqiang Cheng
- Chemical and Engineering Materials Division (CEMD), Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Luke L Daemen
- Chemical and Engineering Materials Division (CEMD), Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Alena M Sheveleva
- School of Chemistry, University of Manchester, Manchester, UK
- International Tomography Center SB RAS and Novosibirsk State University, Novosibirsk, Russia
| | - Floriana Tuna
- School of Chemistry, University of Manchester, Manchester, UK
| | | | - Junliang Sun
- College of Chemistry and Molecular Engineering, Peking University, Beijing, China
| | | | - Michael W George
- School of Chemistry, University of Nottingham, Nottingham, UK
- Department of Chemical and Environmental Engineering, University of Nottingham Ningbo China, Ningbo, China
| | - Anibal J Ramirez-Cuesta
- Chemical and Engineering Materials Division (CEMD), Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - K Mark Thomas
- Northern Carbon Research Laboratories, School of Chemical Engineering and Advanced Materials, University of Newcastle upon Tyne, Newcastle upon Tyne, UK
| | - Sihai Yang
- School of Chemistry, University of Manchester, Manchester, UK.
| | - Martin Schröder
- School of Chemistry, University of Manchester, Manchester, UK.
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5
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Martí-Gastaldo C, Warren JE, Briggs ME, Armstrong JA, Thomas KM, Rosseinsky MJ. Sponge-Like Behaviour in Isoreticular Cu(Gly-His-X) Peptide-Based Porous Materials. Chemistry 2015; 21:16027-34. [PMID: 26406996 PMCID: PMC4676333 DOI: 10.1002/chem.201502098] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 08/18/2015] [Indexed: 11/08/2022]
Abstract
We report two isoreticular 3D peptide-based porous frameworks formed by coordination of the tripeptides Gly-L-His-Gly and Gly-L-His-L-Lys to Cu(II) which display sponge-like behaviour. These porous materials undergo structural collapse upon evacuation that can be reversed by exposure to water vapour, which permits recovery of the original open channel structure. This is further confirmed by sorption studies that reveal that both solids exhibit selective sorption of H2 O while CO2 adsorption does not result in recovery of the original structures. We also show how the pendant aliphatic amine chains, present in the framework from the introduction of the lysine amino acid in the peptidic backbone, can be post-synthetically modified to produce urea-functionalised networks by following methodologies typically used for metal-organic frameworks built from more rigid "classical" linkers.
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Affiliation(s)
- Carlos Martí-Gastaldo
- Department of Chemistry, University of LiverpoolCrown Street, Liverpool, L69 7ZD (UK)E-mail:
- Instituto de Ciencia Molecular (ICMol), Universidad de ValenciaPaterna, 46980 (Spain)E-mail:
| | - John E Warren
- Department of Chemistry, University of LiverpoolCrown Street, Liverpool, L69 7ZD (UK)E-mail:
- School of Materials, The University of ManchesterSackville Street, Manchester, M1 3BB (UK)
| | - Michael E Briggs
- Department of Chemistry, University of LiverpoolCrown Street, Liverpool, L69 7ZD (UK)E-mail:
| | - Jayne A Armstrong
- Wolfson Northern Carbon Reduction LaboratoriesSchool of Chemical, Engineering and Advanced Materials, Newcastle University, Newcastle upon Tyne, NE1 7RU (UK)
| | - K Mark Thomas
- Wolfson Northern Carbon Reduction LaboratoriesSchool of Chemical, Engineering and Advanced Materials, Newcastle University, Newcastle upon Tyne, NE1 7RU (UK)
| | - Matthew J Rosseinsky
- Department of Chemistry, University of LiverpoolCrown Street, Liverpool, L69 7ZD (UK)E-mail:
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6
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Holcroft JM, Hartlieb KJ, Moghadam PZ, Bell JG, Barin G, Ferris DP, Bloch ED, Algaradah MM, Nassar MS, Botros YY, Thomas KM, Long JR, Snurr RQ, Stoddart JF. Carbohydrate-Mediated Purification of Petrochemicals. J Am Chem Soc 2015; 137:5706-19. [DOI: 10.1021/ja511878b] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- James M. Holcroft
- Department
of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - Karel J. Hartlieb
- Department
of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - Peyman Z. Moghadam
- Department of Chemical & Biological Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3120, United States
| | - Jon G. Bell
- Wolfson Northern Carbon Research Laboratories, School of Chemical
Engineering and Advanced Materials, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - Gokhan Barin
- Department
of Chemistry, University of California, Berkeley, California 94720-1460, United States
| | - Daniel P. Ferris
- Department
of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - Eric D. Bloch
- Department
of Chemistry, University of California, Berkeley, California 94720-1460, United States
| | - Mohammed M. Algaradah
- Joint
Center
of Excellence in Integrated Nano-Systems (JCIN), King Abdul-Aziz City for Science and Technology (KACST), P.O. Box 6086, Riyadh 11442, Kingdom of Saudi Arabia
| | - Majed S. Nassar
- Joint
Center
of Excellence in Integrated Nano-Systems (JCIN), King Abdul-Aziz City for Science and Technology (KACST), P.O. Box 6086, Riyadh 11442, Kingdom of Saudi Arabia
| | - Youssry Y. Botros
- Joint
Center
of Excellence in Integrated Nano-Systems (JCIN), King Abdul-Aziz City for Science and Technology (KACST), P.O. Box 6086, Riyadh 11442, Kingdom of Saudi Arabia
- University
Research Office, Intel Corporation, Building RNB-6-64, 2200 Mission
College Boulevard, Santa Clara, California 95054-1549, United States
| | - K. Mark Thomas
- Wolfson Northern Carbon Research Laboratories, School of Chemical
Engineering and Advanced Materials, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - Jeffrey R. Long
- Department
of Chemistry, University of California, Berkeley, California 94720-1460, United States
| | - Randall Q. Snurr
- Department of Chemical & Biological Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3120, United States
| | - J. Fraser Stoddart
- Department
of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
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7
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Chen L, Reiss PS, Chong SY, Holden D, Jelfs KE, Hasell T, Little MA, Kewley A, Briggs ME, Stephenson A, Thomas KM, Armstrong JA, Bell J, Busto J, Noel R, Liu J, Strachan DM, Thallapally PK, Cooper AI. Separation of rare gases and chiral molecules by selective binding in porous organic cages. Nat Mater 2014; 13:954-960. [PMID: 25038731 DOI: 10.1038/nmat4035] [Citation(s) in RCA: 384] [Impact Index Per Article: 38.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Accepted: 06/16/2014] [Indexed: 06/03/2023]
Abstract
The separation of molecules with similar size and shape is an important technological challenge. For example, rare gases can pose either an economic opportunity or an environmental hazard and there is a need to separate these spherical molecules selectively at low concentrations in air. Likewise, chiral molecules are important building blocks for pharmaceuticals, but chiral enantiomers, by definition, have identical size and shape, and their separation can be challenging. Here we show that a porous organic cage molecule has unprecedented performance in the solid state for the separation of rare gases, such as krypton and xenon. The selectivity arises from a precise size match between the rare gas and the organic cage cavity, as predicted by molecular simulations. Breakthrough experiments demonstrate real practical potential for the separation of krypton, xenon and radon from air at concentrations of only a few parts per million. We also demonstrate selective binding of chiral organic molecules such as 1-phenylethanol, suggesting applications in enantioselective separation.
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Affiliation(s)
- Linjiang Chen
- Department of Chemistry and Centre for Materials Discovery, University of Liverpool, Crown Street, Liverpool L69 7ZD, UK
| | - Paul S Reiss
- Department of Chemistry and Centre for Materials Discovery, University of Liverpool, Crown Street, Liverpool L69 7ZD, UK
| | - Samantha Y Chong
- Department of Chemistry and Centre for Materials Discovery, University of Liverpool, Crown Street, Liverpool L69 7ZD, UK
| | - Daniel Holden
- Department of Chemistry and Centre for Materials Discovery, University of Liverpool, Crown Street, Liverpool L69 7ZD, UK
| | - Kim E Jelfs
- Department of Chemistry and Centre for Materials Discovery, University of Liverpool, Crown Street, Liverpool L69 7ZD, UK
| | - Tom Hasell
- Department of Chemistry and Centre for Materials Discovery, University of Liverpool, Crown Street, Liverpool L69 7ZD, UK
| | - Marc A Little
- Department of Chemistry and Centre for Materials Discovery, University of Liverpool, Crown Street, Liverpool L69 7ZD, UK
| | - Adam Kewley
- Department of Chemistry and Centre for Materials Discovery, University of Liverpool, Crown Street, Liverpool L69 7ZD, UK
| | - Michael E Briggs
- Department of Chemistry and Centre for Materials Discovery, University of Liverpool, Crown Street, Liverpool L69 7ZD, UK
| | - Andrew Stephenson
- Department of Chemistry and Centre for Materials Discovery, University of Liverpool, Crown Street, Liverpool L69 7ZD, UK
| | - K Mark Thomas
- Wolfson Northern Carbon Reduction Laboratories, Drummond Building, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
| | - Jayne A Armstrong
- Wolfson Northern Carbon Reduction Laboratories, Drummond Building, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
| | - Jon Bell
- Wolfson Northern Carbon Reduction Laboratories, Drummond Building, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
| | - Jose Busto
- CPPM, Aix-Marseille Université, CNRS/IN2P3, 163 avenue de Luminy, case 902, 13009 Marseille, France
| | - Raymond Noel
- CPPM, Aix-Marseille Université, CNRS/IN2P3, 163 avenue de Luminy, case 902, 13009 Marseille, France
| | - Jian Liu
- Pacific Northwest National Laboratory, Richland, Washington 99352, USA
| | - Denis M Strachan
- Pacific Northwest National Laboratory, Richland, Washington 99352, USA
| | | | - Andrew I Cooper
- Department of Chemistry and Centre for Materials Discovery, University of Liverpool, Crown Street, Liverpool L69 7ZD, UK
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8
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Thomas KM, McCann MS, Collery MM, Moschonas G, Whyte P, McDowell DA, Duffy G. Transfer of verocytotoxigenic Escherichia coli O157, O26, O111, O103 and O145 from fleece to carcass during sheep slaughter in an Irish export abattoir. Food Microbiol 2013; 34:38-45. [DOI: 10.1016/j.fm.2012.11.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 11/23/2012] [Indexed: 01/26/2023]
Affiliation(s)
- K M Thomas
- Teagasc Food Research Centre, Ashtown, Dublin 15, Ireland
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9
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Yang S, Liu L, Sun J, Thomas KM, Davies AJ, George MW, Blake AJ, Hill AH, Fitch AN, Tang CC, Schröder M. Irreversible Network Transformation in a Dynamic Porous Host Catalyzed by Sulfur Dioxide. J Am Chem Soc 2013; 135:4954-7. [DOI: 10.1021/ja401061m] [Citation(s) in RCA: 107] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Sihai Yang
- School of Chemistry, University of Nottingham, University Park, Nottingham,
NG7 2RD, U.K
| | - Leifeng Liu
- Department
of Materials and
Environmental Chemistry, Stockholm University, Stockholm, 10691, Sweden
| | - Junliang Sun
- Department
of Materials and
Environmental Chemistry, Stockholm University, Stockholm, 10691, Sweden
- College of Chemistry and Molecular
Engineering, Peking University, Beijing,
100871, China
| | - K. Mark Thomas
- Wolfson Northern
Carbon Research
Laboratories, School of Chemical Engineering and Advanced Materials, University of Newcastle upon Tyne, Newcastle upon Tyne,
NE1 7RU, U.K
| | - Andrew J. Davies
- School of Chemistry, University of Nottingham, University Park, Nottingham,
NG7 2RD, U.K
| | - Michael W. George
- School of Chemistry, University of Nottingham, University Park, Nottingham,
NG7 2RD, U.K
| | - Alexander J. Blake
- School of Chemistry, University of Nottingham, University Park, Nottingham,
NG7 2RD, U.K
| | - Adrian H. Hill
- European Synchrotron Radiation Facility, Grenoble, 38043, France
| | - Andrew N. Fitch
- European Synchrotron Radiation Facility, Grenoble, 38043, France
| | - Chiu C. Tang
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11
0DE, U.K
| | - Martin Schröder
- School of Chemistry, University of Nottingham, University Park, Nottingham,
NG7 2RD, U.K
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10
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Bell JG, Angus K, Todd C, Thomas KM. Functional Hollow Fiber Adsorbent Materials with a Self-Regulating Composite Outer Layer for Gas Purification with Energy Efficient Electrothermal Regeneration. Ind Eng Chem Res 2013. [DOI: 10.1021/ie3022362] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Jon G. Bell
- Wolfson Northern Carbon Reduction Laboratories,
School of Chemical Engineering and Advanced Materials, Drummond Building, Newcastle University, Newcastle upon Tyne, NE1 7RU,
U.K
| | - Katy Angus
- Nano-Porous Solutions Ltd., Dukesway, Team Valley, Gateshead, Tyne
and Wear NE11 0PZ, U.K
| | - Christopher Todd
- Nano-Porous Solutions Ltd., Dukesway, Team Valley, Gateshead, Tyne
and Wear NE11 0PZ, U.K
| | - K. Mark Thomas
- Wolfson Northern Carbon Reduction Laboratories,
School of Chemical Engineering and Advanced Materials, Drummond Building, Newcastle University, Newcastle upon Tyne, NE1 7RU,
U.K
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11
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Hasell T, Armstrong JA, Jelfs KE, Tay FH, Thomas KM, Kazarian SG, Cooper AI. High-pressure carbon dioxide uptake for porous organic cages: comparison of spectroscopic and manometric measurement techniques. Chem Commun (Camb) 2013; 49:9410-2. [DOI: 10.1039/c3cc45924a] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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12
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Stylianou KC, Rabone J, Chong SY, Heck R, Armstrong J, Wiper PV, Jelfs KE, Zlatogorsky S, Bacsa J, McLennan AG, Ireland CP, Khimyak YZ, Thomas KM, Bradshaw D, Rosseinsky MJ. Dimensionality transformation through paddlewheel reconfiguration in a flexible and porous Zn-based metal-organic framework. J Am Chem Soc 2012; 134:20466-78. [PMID: 23121122 DOI: 10.1021/ja308995t] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The reaction between Zn and a pyrene-based ligand decorated with benzoate fragments (H(4)TBAPy) yields a 2D layered porous network with the metal coordination based on a paddlewheel motif. Upon desolvation, the structure undergoes a significant and reversible structural adjustment with a corresponding reduction in crystallinity. The combination of computationally assisted structure determination and experimental data analysis of the desolvated phase revealed a structural change in the metal coordination geometry from square-pyramidal to tetrahedral. Simulations of desolvation showed that the local distortion of the ligand geometry followed by the rotation and displacement of the pyrene core permits the breakup of the metal-paddlewheel motifs and the formation of 1D Zn-O chains that cross-link adjacent layers, resulting in a dimensionality change from the 2D layered structure to a 3D structure. Constrained Rietveld refinement of the powder X-ray diffraction pattern of the desolvated phase and the use of other analytical techniques such as porosity measurements, (13)C CP MAS NMR spectroscopy, and fluorescence spectroscopy strongly supported the observed structural transformation. The 3D network is stable up to 425 °C and is permanently porous to CO(2) with an apparent BET surface area of 523(8) m(2)/g (p/p° = 0.02-0.22). Because of the hydrophobic nature, size, and shape of the pores of the 3D framework, the adsorption behavior of the structure toward p-xylene and m-xylene was studied, and the results indicated that the shape of the isotherm and the kinetics of the adsorption process are determined mainly by the shape of the xylene isomers, with each xylene isomer interacting with the host framework in a different manner.
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Yang S, Lin X, Lewis W, Suyetin M, Bichoutskaia E, Parker JE, Tang CC, Allan DR, Rizkallah PJ, Hubberstey P, Champness NR, Thomas KM, Blake AJ, Schröder M. A partially interpenetrated metal-organic framework for selective hysteretic sorption of carbon dioxide. Nat Mater 2012; 11:710-716. [PMID: 22660661 DOI: 10.1038/nmat3343] [Citation(s) in RCA: 295] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Accepted: 04/25/2012] [Indexed: 05/28/2023]
Abstract
The selective capture of carbon dioxide in porous materials has potential for the storage and purification of fuel and flue gases. However, adsorption capacities under dynamic conditions are often insufficient for practical applications, and strategies to enhance CO(2)-host selectivity are required. The unique partially interpenetrated metal-organic framework NOTT-202 represents a new class of dynamic material that undergoes pronounced framework phase transition on desolvation. We report temperature-dependent adsorption/desorption hysteresis in desolvated NOTT-202a that responds selectively to CO(2). The CO(2) isotherm shows three steps in the adsorption profile at 195 K, and stepwise filling of pores generated within the observed partially interpenetrated structure has been modelled by grand canonical Monte Carlo simulations. Adsorption of N(2), CH(4), O(2), Ar and H(2) exhibits reversible isotherms without hysteresis under the same conditions, and this allows capture of gases at high pressure, but selectively leaves CO(2) trapped in the nanopores at low pressure.
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Affiliation(s)
- Sihai Yang
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
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Das MC, Guo Q, He Y, Kim J, Zhao CG, Hong K, Xiang S, Zhang Z, Thomas KM, Krishna R, Chen B. Interplay of Metalloligand and Organic Ligand to Tune Micropores within Isostructural Mixed-Metal Organic Frameworks (M′MOFs) for Their Highly Selective Separation of Chiral and Achiral Small Molecules. J Am Chem Soc 2012; 134:8703-10. [DOI: 10.1021/ja302380x] [Citation(s) in RCA: 307] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Madhab C. Das
- Department of Chemistry, University of Texas at San Antonio, One UTSA Circle,
San Antonio, Texas 78249-0698, United States
| | - Qunsheng Guo
- Department of Chemistry, University of Texas at San Antonio, One UTSA Circle,
San Antonio, Texas 78249-0698, United States
| | - Yabing He
- Department of Chemistry, University of Texas at San Antonio, One UTSA Circle,
San Antonio, Texas 78249-0698, United States
| | - Jaheon Kim
- Department of Chemistry, Soongsil University, Seoul 156-743, Korea
| | - Cong-Gui Zhao
- Department of Chemistry, University of Texas at San Antonio, One UTSA Circle,
San Antonio, Texas 78249-0698, United States
| | - Kunlun Hong
- Center for Nanophase Materials
Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Shengchang Xiang
- Department of Chemistry, University of Texas at San Antonio, One UTSA Circle,
San Antonio, Texas 78249-0698, United States
- College of Chemistry and Materials, Fujian Normal University, 3 Shangsan Road, Cangshang
Region, Fuzhou, China 350007
| | - Zhangjing Zhang
- Department of Chemistry, University of Texas at San Antonio, One UTSA Circle,
San Antonio, Texas 78249-0698, United States
- College of Chemistry and Materials, Fujian Normal University, 3 Shangsan Road, Cangshang
Region, Fuzhou, China 350007
| | - K. Mark Thomas
- Northern Carbon Research Laboratories,
Sir Joseph Swan Institute for Energy Research and School of Chemical
Engineering and Advanced Materials, University of Newcastle upon Tyne, Bedson Building, Newcastle upon Tyne, NE1
7RU, U.K
| | - Rajamani Krishna
- Van ‘t Hoff Institute
for Molecular
Sciences, University of Amsterdam, Science
Park 904, 1098 XH Amsterdam, The Netherlands
| | - Banglin Chen
- Department of Chemistry, University of Texas at San Antonio, One UTSA Circle,
San Antonio, Texas 78249-0698, United States
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Zhang Z, Xiang S, Hong K, Das MC, Arman HD, Garcia M, Mondal JU, Thomas KM, Chen B. Triple Framework Interpenetration and Immobilization of Open Metal Sites within a Microporous Mixed Metal–Organic Framework for Highly Selective Gas Adsorption. Inorg Chem 2012; 51:4947-53. [DOI: 10.1021/ic2021275] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Zhangjing Zhang
- Department of Chemistry, University of Texas at San Antonio, One UTSA Circle,
San Antonio, Texas 78249-069, United States
- College of Chemistry and Materials, Fujian Normal University, 3 Shangsan Road, Cangshang
Region, Fuzhou, China 350007
| | - Shengchang Xiang
- Department of Chemistry, University of Texas at San Antonio, One UTSA Circle,
San Antonio, Texas 78249-069, United States
- College of Chemistry and Materials, Fujian Normal University, 3 Shangsan Road, Cangshang
Region, Fuzhou, China 350007
| | - Kunlun Hong
- Center for
Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Madhab, C. Das
- Department of Chemistry, University of Texas at San Antonio, One UTSA Circle,
San Antonio, Texas 78249-069, United States
| | - Hadi D. Arman
- Department of Chemistry, University of Texas at San Antonio, One UTSA Circle,
San Antonio, Texas 78249-069, United States
| | - Maya Garcia
- Department of Chemistry, University of Texas−Pan American, 1201 West University Drive, Edinburg, Texas
78541,
United States
| | - Jalal U. Mondal
- Department of Chemistry, University of Texas−Pan American, 1201 West University Drive, Edinburg, Texas
78541,
United States
| | - K. Mark Thomas
- Northern Carbon Research Laboratories, Sir
Joseph Swan Institute for Energy Research and School of Chemical Engineering
and Advanced Materials, University of Newcastle upon Tyne, Bedson Building, Newcastle upon Tyne, NE1 7RU,
U.K
| | - Banglin Chen
- Department of Chemistry, University of Texas at San Antonio, One UTSA Circle,
San Antonio, Texas 78249-069, United States
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Thomas KM, McCann MS, Collery MM, Logan A, Whyte P, McDowell DA, Duffy G. Tracking verocytotoxigenic Escherichia coli O157, O26, O111, O103 and O145 in Irish cattle. Int J Food Microbiol 2011; 153:288-96. [PMID: 22209630 DOI: 10.1016/j.ijfoodmicro.2011.11.012] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Revised: 10/24/2011] [Accepted: 11/11/2011] [Indexed: 11/28/2022]
Abstract
The purpose of this study was to investigate carriage and transfer of verocytotoxigenic Escherichia coli (VTEC) O157, O26, O111, O103 and O145 from faeces and hide to dressed carcasses of Irish cattle as well as establishing the virulence potential of VTEC carried by these cattle. Individual cattle was tracked and faecal samples, hide and carcass (pre-evisceration and post-wash) swabs were analysed for verotoxin (vt1 and vt2) genes using a duplex real-time PCR assay. Positive samples were screened for the five serogroups of interest by real-time PCR. Isolates were recovered from PCR positive samples using immunomagnetic separation and confirmed by latex agglutination and PCR. Isolates were subject to a virulence screen (vt1, vt2, eaeA and hlyA) by PCR. Isolates carrying vt genes were examined by Pulsed-Field Gel Electrophoresis (PFGE). Of the VTEC isolated, E. coli O157 was the most frequently recovered from hide (17.6%), faeces (2.3%) and pre-evisceration/post-wash carcass (0.7%) samples. VTEC O26 was isolated from 0.2% of hide swabs and 1.5% of faeces samples. VTEC O145 was isolated from 0.7% of faeces samples. VTEC O26 and VTEC O145 were not recovered from carcass swabs. Non-VTEC O103 was recovered from all sample types (27.1% hide, 8.5% faeces, 5.5% pre-evisceration carcass, 2.2% post-wash carcass), with 0.2% of hide swabs and 1.0% of faeces samples found to be positive for VTEC O103 isolates. E. coli O111 was not detected in any samples. For the four serogroups recovered, the direct transfer from hide to carcass was not observed. This study shows that while VTEC O157 are being carried by cattle presented for slaughter in Ireland, a number of other verotoxin producing strains are beginning to emerge.
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Affiliation(s)
- K M Thomas
- Teagasc Food Research Centre, Ashtown, Dublin 15, Ireland
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Mohideen MIH, Xiao B, Wheatley PS, McKinlay AC, Li Y, Slawin AMZ, Aldous DW, Cessford NF, Düren T, Zhao X, Gill R, Thomas KM, Griffin JM, Ashbrook SE, Morris RE. Protecting group and switchable pore-discriminating adsorption properties of a hydrophilic–hydrophobic metal–organic framework. Nat Chem 2011; 3:304-10. [DOI: 10.1038/nchem.1003] [Citation(s) in RCA: 134] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2010] [Accepted: 01/27/2011] [Indexed: 11/09/2022]
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Xiang SC, Zhang Z, Zhao CG, Hong K, Zhao X, Ding DR, Xie MH, Wu CD, Das MC, Gill R, Thomas KM, Chen B. Rationally tuned micropores within enantiopure metal-organic frameworks for highly selective separation of acetylene and ethylene. Nat Commun 2011; 2:204. [DOI: 10.1038/ncomms1206] [Citation(s) in RCA: 450] [Impact Index Per Article: 34.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2010] [Accepted: 01/24/2011] [Indexed: 11/09/2022] Open
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Aparna P, Rao SV, Thomas KM, Mukkanti K, Badarinadh Gupta P, Rangarao K, Narayan GK, Sandip T, Upendra K. Identification, isolation, and characterization of potential degradation products in a triple combination lamivudine, zidovudine, and nevirapine tablet for oral suspension. Pharmazie 2010; 65:331-335. [PMID: 20503923] [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: 05/29/2023]
Abstract
An unknown impurity (degradation product) present at a level below 0.1% in the initial sample was increased to 0.25% in 50 degrees C 3 M stability samples of lamivudine, zidovudine and nevirapine tablets for oral suspension, as detected by gradient reverse phase HPLC. This degradation product was isolated using reverse phase preparative HPLC. Based on the spectral data, the structure of this degradation product is characterized as 1-[5-hydroxymethyl-4-(5-methyl-2,3-dihydro-[1,2,3]triazole-1-yl)-tetrahydrofuran-2-yl]-5-methyl-1 H-pyrimidine-2,4-(1H,3H)dione. Structural elucidation of this degradation product was carried out using MS, 1H NMR, 13C NMR, DEPT and IR spectral data. The formation of this impurity and its mechanism are discussed.
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Affiliation(s)
- P Aparna
- APL Research Centre, Bachupally, Hyderabad, India
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20
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Casey BJ, Glatt CE, Tottenham N, Soliman F, Bath K, Amso D, Altemus M, Pattwell S, Jones R, Levita L, McEwen B, Magariños AM, Gunnar M, Thomas KM, Mezey J, Clark AG, Hempstead BL, Lee FS. Brain-derived neurotrophic factor as a model system for examining gene by environment interactions across development. Neuroscience 2009; 164:108-20. [PMID: 19358879 PMCID: PMC2760671 DOI: 10.1016/j.neuroscience.2009.03.081] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2009] [Revised: 03/23/2009] [Accepted: 03/30/2009] [Indexed: 01/14/2023]
Abstract
There has been a dramatic rise in gene x environment studies of human behavior over the past decade that have moved the field beyond simple nature versus nurture debates. These studies offer promise in accounting for more variability in behavioral and biological phenotypes than studies that focus on genetic or experiential factors alone. They also provide clues into mechanisms of modifying genetic risk or resilience in neurodevelopmental disorders. Yet, it is rare that these studies consider how these interactions change over the course of development. In this paper, we describe research that focuses on the impact of a polymorphism in a brain-derived neurotrophic factor (BDNF) gene, known to be involved in learning and development. Specifically we present findings that assess the effects of genotypic and environmental loadings on neuroanatomic and behavioral phenotypes across development. The findings illustrate the use of a genetic mouse model that mimics the human polymorphism, to constrain the interpretation of gene-environment interactions across development in humans.
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Affiliation(s)
- B J Casey
- Weill Cornell Medical College, New York, NY 10065, USA.
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21
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Corcoran TE, Thomas KM, Myerburg MM, Muthukrishnan A, Weber L, Frizzell R, Pilewski JM. Absorptive clearance of DTPA as an aerosol-based biomarker in the cystic fibrosis airway. Eur Respir J 2009; 35:781-6. [PMID: 19717485 DOI: 10.1183/09031936.00059009] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Biomarkers providing in vivo quantification of the basic elements of cystic fibrosis (CF) lung disease are needed. A study was performed to determine whether the absorption of a small radiolabelled hydrophilic molecule (Indium-111 (In-)DTPA) would be increased in CF airways. DTPA clearance has been used previously to assess epithelial permeability and may also be useful for quantifying liquid absorption. The absorptive clearance rate of DTPA was quantified in 10 CF and 11 control subjects using a novel aerosol technique. Subjects inhaled an aerosol containing nonabsorbable technetium-99m sulfur colloid (Tc-SC) particles and In-DTPA. Tc-SC clearance from the lung is exclusively mucociliary, while In-DTPA is cleared by both absorption and mucociliary clearance. The difference between the In-DTPA and Tc-SC clearance rates estimates In-DTPA absorption. Tc-SC (mucociliary) clearance was similar in central and peripheral zones in CF and non-CF lungs. Total In-DTPA clearance was increased in both zones in CF lungs. The absorptive component of In-DTPA clearance was increased in the airway-dominated central lung zones in CF (42% x h( -1) versus 32% x h(-1), p = 0.03). The absorption of In-DTPA is increased in the CF airway. Further study is needed to understand the relative roles of fluid absorption, inflammation and other mechanisms potentially affecting epithelial permeability and DTPA absorption.
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Affiliation(s)
- T E Corcoran
- Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
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22
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Lin X, Telepeni I, Blake AJ, Dailly A, Brown CM, Simmons JM, Zoppi M, Walker GS, Thomas KM, Mays TJ, Hubberstey P, Champness NR, Schröder M. High Capacity Hydrogen Adsorption in Cu(II) Tetracarboxylate Framework Materials: The Role of Pore Size, Ligand Functionalization, and Exposed Metal Sites. J Am Chem Soc 2009; 131:2159-71. [DOI: 10.1021/ja806624j] [Citation(s) in RCA: 668] [Impact Index Per Article: 44.5] [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)
- Xiang Lin
- School of Chemistry and School of Mechanical Materials & Manufacturing Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, U.K., Chemical and Environmental Sciences Laboratory, General Motors Corporation, Warren, Michigan 48090, National Institute of Standards and Technology Center for Neutron Research, 100 Bureau Drive, Building 235, STOP 6102, Gaithersburg, Maryland 20899, CNR-Instituto Sistemi Complessi, Via della Madonna del Piano 10, I-50019 Sesto Fiorentino, Italy, Northern
| | - Irvin Telepeni
- School of Chemistry and School of Mechanical Materials & Manufacturing Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, U.K., Chemical and Environmental Sciences Laboratory, General Motors Corporation, Warren, Michigan 48090, National Institute of Standards and Technology Center for Neutron Research, 100 Bureau Drive, Building 235, STOP 6102, Gaithersburg, Maryland 20899, CNR-Instituto Sistemi Complessi, Via della Madonna del Piano 10, I-50019 Sesto Fiorentino, Italy, Northern
| | - Alexander J. Blake
- School of Chemistry and School of Mechanical Materials & Manufacturing Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, U.K., Chemical and Environmental Sciences Laboratory, General Motors Corporation, Warren, Michigan 48090, National Institute of Standards and Technology Center for Neutron Research, 100 Bureau Drive, Building 235, STOP 6102, Gaithersburg, Maryland 20899, CNR-Instituto Sistemi Complessi, Via della Madonna del Piano 10, I-50019 Sesto Fiorentino, Italy, Northern
| | - Anne Dailly
- School of Chemistry and School of Mechanical Materials & Manufacturing Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, U.K., Chemical and Environmental Sciences Laboratory, General Motors Corporation, Warren, Michigan 48090, National Institute of Standards and Technology Center for Neutron Research, 100 Bureau Drive, Building 235, STOP 6102, Gaithersburg, Maryland 20899, CNR-Instituto Sistemi Complessi, Via della Madonna del Piano 10, I-50019 Sesto Fiorentino, Italy, Northern
| | - Craig M. Brown
- School of Chemistry and School of Mechanical Materials & Manufacturing Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, U.K., Chemical and Environmental Sciences Laboratory, General Motors Corporation, Warren, Michigan 48090, National Institute of Standards and Technology Center for Neutron Research, 100 Bureau Drive, Building 235, STOP 6102, Gaithersburg, Maryland 20899, CNR-Instituto Sistemi Complessi, Via della Madonna del Piano 10, I-50019 Sesto Fiorentino, Italy, Northern
| | - Jason M. Simmons
- School of Chemistry and School of Mechanical Materials & Manufacturing Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, U.K., Chemical and Environmental Sciences Laboratory, General Motors Corporation, Warren, Michigan 48090, National Institute of Standards and Technology Center for Neutron Research, 100 Bureau Drive, Building 235, STOP 6102, Gaithersburg, Maryland 20899, CNR-Instituto Sistemi Complessi, Via della Madonna del Piano 10, I-50019 Sesto Fiorentino, Italy, Northern
| | - Marco Zoppi
- School of Chemistry and School of Mechanical Materials & Manufacturing Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, U.K., Chemical and Environmental Sciences Laboratory, General Motors Corporation, Warren, Michigan 48090, National Institute of Standards and Technology Center for Neutron Research, 100 Bureau Drive, Building 235, STOP 6102, Gaithersburg, Maryland 20899, CNR-Instituto Sistemi Complessi, Via della Madonna del Piano 10, I-50019 Sesto Fiorentino, Italy, Northern
| | - Gavin S. Walker
- School of Chemistry and School of Mechanical Materials & Manufacturing Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, U.K., Chemical and Environmental Sciences Laboratory, General Motors Corporation, Warren, Michigan 48090, National Institute of Standards and Technology Center for Neutron Research, 100 Bureau Drive, Building 235, STOP 6102, Gaithersburg, Maryland 20899, CNR-Instituto Sistemi Complessi, Via della Madonna del Piano 10, I-50019 Sesto Fiorentino, Italy, Northern
| | - K. Mark Thomas
- School of Chemistry and School of Mechanical Materials & Manufacturing Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, U.K., Chemical and Environmental Sciences Laboratory, General Motors Corporation, Warren, Michigan 48090, National Institute of Standards and Technology Center for Neutron Research, 100 Bureau Drive, Building 235, STOP 6102, Gaithersburg, Maryland 20899, CNR-Instituto Sistemi Complessi, Via della Madonna del Piano 10, I-50019 Sesto Fiorentino, Italy, Northern
| | - Timothy J. Mays
- School of Chemistry and School of Mechanical Materials & Manufacturing Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, U.K., Chemical and Environmental Sciences Laboratory, General Motors Corporation, Warren, Michigan 48090, National Institute of Standards and Technology Center for Neutron Research, 100 Bureau Drive, Building 235, STOP 6102, Gaithersburg, Maryland 20899, CNR-Instituto Sistemi Complessi, Via della Madonna del Piano 10, I-50019 Sesto Fiorentino, Italy, Northern
| | - Peter Hubberstey
- School of Chemistry and School of Mechanical Materials & Manufacturing Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, U.K., Chemical and Environmental Sciences Laboratory, General Motors Corporation, Warren, Michigan 48090, National Institute of Standards and Technology Center for Neutron Research, 100 Bureau Drive, Building 235, STOP 6102, Gaithersburg, Maryland 20899, CNR-Instituto Sistemi Complessi, Via della Madonna del Piano 10, I-50019 Sesto Fiorentino, Italy, Northern
| | - Neil R. Champness
- School of Chemistry and School of Mechanical Materials & Manufacturing Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, U.K., Chemical and Environmental Sciences Laboratory, General Motors Corporation, Warren, Michigan 48090, National Institute of Standards and Technology Center for Neutron Research, 100 Bureau Drive, Building 235, STOP 6102, Gaithersburg, Maryland 20899, CNR-Instituto Sistemi Complessi, Via della Madonna del Piano 10, I-50019 Sesto Fiorentino, Italy, Northern
| | - Martin Schröder
- School of Chemistry and School of Mechanical Materials & Manufacturing Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, U.K., Chemical and Environmental Sciences Laboratory, General Motors Corporation, Warren, Michigan 48090, National Institute of Standards and Technology Center for Neutron Research, 100 Bureau Drive, Building 235, STOP 6102, Gaithersburg, Maryland 20899, CNR-Instituto Sistemi Complessi, Via della Madonna del Piano 10, I-50019 Sesto Fiorentino, Italy, Northern
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Thomas KM. Adsorption and desorption of hydrogen on metal–organic framework materials for storage applications: comparison with other nanoporous materials. Dalton Trans 2009:1487-505. [DOI: 10.1039/b815583f] [Citation(s) in RCA: 246] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Chen B, Zhao X, Putkham A, Hong K, Lobkovsky EB, Hurtado EJ, Fletcher AJ, Thomas KM. Surface interactions and quantum kinetic molecular sieving for H2 and D2 adsorption on a mixed metal-organic framework material. J Am Chem Soc 2008; 130:6411-23. [PMID: 18435535 DOI: 10.1021/ja710144k] [Citation(s) in RCA: 412] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A rational strategy has been used to immobilize open metal sites in ultramicroporosity for stronger binding of multiple H 2 molecules per unsaturated metal site for H 2 storage applications. The synthesis and structure of a mixed zinc/copper metal-organic framework material Zn 3(BDC) 3[Cu(Pyen)] .(DMF) 5(H 2O) 5 (H 2BDC = 1,4 benzenedicarboxylic acid and PyenH 2 = 5-methyl-4-oxo-1,4-dihydro-pyridine-3-carbaldehyde) is reported. Desolvation provides a bimodal porous structure Zn 3(BDC) 3[Cu(Pyen)] (M'MOF 1) with narrow porosity (<0.56 nm) and an array of pores in the bc crystallographic plane where the adsorbate-adsorbent interactions are maximized by both the presence of open copper centers and overlap of the potential energy fields from pore walls. The H 2 and D 2 adsorption isotherms for M'MOF 1 at 77.3 and 87.3 K were reversible with virtually no hysteresis. Methods for determination of the isosteric enthalpies of H 2 and D 2 adsorption were compared. A virial model gave the best agreement (average deviation <1 standard deviation) with the isotherm data. This was used in conjunction with the van't Hoff isochore giving isosteric enthalpies at zero surface coverage of 12.29 +/- 0.53 and 12.44 +/- 0.50 kJ mol (-1) for H 2 and D 2 adsorption, respectively. This is the highest value so far observed for hydrogen adsorption on a porous material. The enthalpy of adsorption, decreases with increasing amount adsorbed to 9.5 kJ mol (-1) at approximately 1.9 mmol g (-1) (2 H 2 or D 2 molecules per Cu corresponding to adsorption on both sides of planar Cu open centers) and is virtually unchanged in the range 1.9-3.6 mmol g (-1). Virial analysis of isotherms at 87.3 K is also consistent with two H 2 or D 2 molecules being bound to each open Cu center. The adsorption kinetics follow a double exponential model, corresponding to diffusion along two types of pores, a slow component with high activation energy (13.35 +/- 0.59 kJ mol (-1)) for the narrow pores and a faster component with low activation energy (8.56 +/- 0.41 kJ mol (-1)). The D 2 adsorption kinetic constants for both components were significantly faster than the corresponding H 2 kinetics for specific pressure increments and had slightly lower activation energies than the corresponding values for H 2 adsorption. The kD 2/ kH 2 ratio for the slow component was 1.62 +/- 0.07, while the fast component was 1.38 +/- 0.04 at 77.3 K, and the corresponding ratios were smaller at 87.3 K. These observations of kinetic isotope quantum molecular sieving in porous materials are due to the larger zero-point energy for the lighter H 2, resulting in slower adsorption kinetics compared with the heavier D 2. The results show that a combination of open metal centers and confinement in ultramicroporosity leads to a high enthalpy for H 2 adsorption over a wide range of surface coverage and quantum effects influence diffusion of H 2 and D 2 in pores in M'MOF 1.
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Affiliation(s)
- Banglin Chen
- Department of Chemistry, University of Texas-Pan American, Edinburg, Texas 78539, USA
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25
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Yang S, Lin X, Blake AJ, Thomas KM, Hubberstey P, Champness NR, Schröder M. Enhancement of H2 adsorption in Li+-exchanged co-ordination framework materials. Chem Commun (Camb) 2008:6108-10. [DOI: 10.1039/b814155j] [Citation(s) in RCA: 152] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Abstract
BACKGROUND Standard two-step HIV testing is limited by poor return-for-results rates and misses high-risk individuals who do not access conventional testing facilities. METHODS We describe a community-based rapid HIV testing programme in which homeless and marginally housed adults recruited from shelters, free meal programmes and single room occupancy hotels in San Francisco received OraQuick Rapid HIV-1 Antibody testing (OraSure Technologies, Bethlehem, PA, USA). RESULTS Over 8 months, 1614 adults were invited to participate and 1213 (75.2%) underwent testing. HIV seroprevalence was 15.4% (187 of 1213 individuals) overall and 3.5% (37 of 1063) amongst high-risk individuals reporting no previous testing, a prior negative test, or previous testing without result disclosure. All 1213 participants received their results. Of 30 newly diagnosed persons who received confirmatory results, 26 (86.7%) reported at least one contact with a primary healthcare provider in the 6 months following diagnosis. CONCLUSIONS We conclude that community-based rapid testing is feasible, acceptable and effective based on the numbers of high-risk persons tested over a short period, the participation rate, the prevalence of new infection, the rate of result disclosure, and the proportion linked to care.
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Affiliation(s)
- J B Buchér
- University of California, San Francisco (UCSF) School of Medicine, San Francisco, CA 94143, USA
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Thomas MB, Thomas KM, Awotedu AA, Blanco-Blanco E, Anwary M. Cardiocysticercosis. S Afr Med J 2007; 97:504-5. [PMID: 17824138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023] Open
Affiliation(s)
- M B Thomas
- Department of Internal Medicine, Nelson Mandela Academic Complex, E Cape
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Xiao B, Wheatley PS, Zhao X, Fletcher AJ, Fox S, Rossi AG, Megson IL, Bordiga S, Regli L, Thomas KM, Morris RE. High-Capacity Hydrogen and Nitric Oxide Adsorption and Storage in a Metal−Organic Framework. J Am Chem Soc 2007; 129:1203-9. [PMID: 17263402 DOI: 10.1021/ja066098k] [Citation(s) in RCA: 339] [Impact Index Per Article: 19.9] [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: 10/23/2022]
Abstract
Gas adsorption experiments have been carried out on a copper benzene tricarboxylate metal-organic framework material, HKUST-1. Hydrogen adsorption at 1 and 10 bar (both 77 K) gives an adsorption capacity of 11.16 mmol H2 per g of HKUST-1 (22.7 mg g(-)1, 2.27 wt %) at 1 bar and 18 mmol per g (36.28 mg g(-)1, 3.6 wt %) at 10 bar. Adsorption of D2 at 1 bar (77 K) is between 1.09 (at 1 bar) and 1.20(at <100 mbar) times the H2 values depending on the pressure, agreeing with the theoretical expectations. Gravimetric adsorption measurements of NO on HKUST-1 at 196 K (1 bar) gives a large adsorption capacity of approximately 9 mmol g(-1), which is significantly greater than any other adsorption capacity reported on a porous solid. At 298 K the adsorption capacity at 1 bar is just over 3 mmol g(-1). Infra red experiments show that the NO binds to the empty copper metal sites in HKUST-1. Chemiluminescence and platelet aggregometry experiments indicate that the amount of NO recovered on exposure of the resulting complex to water is enough to be biologically active, completely inhibiting platelet aggregation in platelet rich plasma.
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Affiliation(s)
- Bo Xiao
- EaStChem School of Chemistry, University of St. Andrews, Purdie Building, St. Andrews KY16 9ST, United Kingdom
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Lin X, Jia J, Zhao X, Thomas KM, Blake AJ, Walker GS, Champness NR, Hubberstey P, Schröder M. High H2 Adsorption by Coordination-Framework Materials. Angew Chem Int Ed Engl 2006. [DOI: 10.1002/ange.200601991] [Citation(s) in RCA: 96] [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] [Indexed: 11/09/2022]
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Lin X, Jia J, Zhao X, Thomas KM, Blake AJ, Walker GS, Champness NR, Hubberstey P, Schröder M. High H2 Adsorption by Coordination-Framework Materials. Angew Chem Int Ed Engl 2006; 45:7358-64. [PMID: 16927440 DOI: 10.1002/anie.200601991] [Citation(s) in RCA: 494] [Impact Index Per Article: 27.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Xiang Lin
- School of Chemistry, University of Nottingham, University Park, UK
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Zhao X, Villar-Rodil S, Fletcher AJ, Thomas KM. Kinetic Isotope Effect for H2and D2Quantum Molecular Sieving in Adsorption/Desorption on Porous Carbon Materials. J Phys Chem B 2006; 110:9947-55. [PMID: 16706452 DOI: 10.1021/jp060748p] [Citation(s) in RCA: 124] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Adsorption and desorption of H(2) and D(2) from porous carbon materials, such as activated carbon at 77 K, are usually fully reversible with very rapid adsorption/desorption kinetics. The adsorption and desorption of H(2) and D(2) at 77 K on a carbon molecular sieve (Takeda 3A), where the kinetic selectivity was incorporated by carbon deposition, and a carbon, where the pore structure was modified by thermal annealing to give similar pore structure characteristics to the carbon molecular sieve substrate, were studied. The D(2) adsorption and desorption kinetics were significantly faster (up to x1.9) than the corresponding H(2) kinetics for specific pressure increments/decrements. This represents the first experimental observation of kinetic isotope quantum molecular sieving in porous materials due to the larger zero-point energy for the lighter H(2), resulting in slower adsorption/desorption kinetics compared with the heavier D(2). The results are discussed in terms of the adsorption mechanism.
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Affiliation(s)
- Xuebo Zhao
- Northern Carbon Research Laboratories, School of Natural Sciences, University of Newcastle upon Tyne, Newcastle upon Tyne, UK
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Lin P, Clegg W, Harrington RW, Henderson RA, Fletcher AJ, Bell J, Thomas KM. Assembly of Heterometallic Clusters and Coordination Polymers by Combining Mo−S-Based Clusters with Mn2+. Inorg Chem 2006; 45:4284-302. [PMID: 16676992 DOI: 10.1021/ic060205u] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Addition of [Mo(V)2O2S2(edt)2]2- (edt =1,2-ethanedithiolate) to acetonitrile and/or methanol solutions of MnII containing bipyridines [4,4'-trimethylenedipyridine (TDP), 4,4'-bipyridine (4,4'-bpy), 2,2'-bipyridine (2,2'-bpy)] or 15-crown-5 produces three new heterometallic cluster coordination polymers, [Mn2[Mo2O2S2(edt)2]2(TDP)3(CH3OH)2(NCMe)2].3CH3OH.0.25MeCN (1), [Mn(TDP)2(H2O)2]2+[Mn[Mo2O2S2(edt)2)2(TDP)2]]2-.6CH3OH (2), [Mn[Mo2O2S2(edt)2](TDP)2(CH3OH)(H2O)].CH3OH (3), and three new multinuclear clusters, [Mn[Mo2O2S2(edt)2](4,4'-bpy)(CH3OH)4].0.5(4,4'-bpy) (4), [Mn[Mo2O2S2(edt)2](2,2'-bpy)2].2CH3OH (5), and (NEt4)2[Mn(15-crown-5)[Mo2O2S2(edt)2]2] (6). All compounds were characterized by X-ray crystallography. The coordination mode of Mn in these compounds depends on the ligands and the crystallization conditions. Compound 2 readily converts to 1 or 3 depending on the reaction and solvent conditions. Compounds 1 and 2 were analyzed using thermogravimetric analysis combined with mass spectroscopy (TG-MS) in the temperature range 25-500 degrees C. The room-temperature magnetic moments for compounds 1-6 were determined.
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Affiliation(s)
- Ping Lin
- Chemisty, School of Natural Sciences, University of Newcastle, Newcastle upon Tyne, NE1 7RU, UK
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Xiao B, Thomas KM. Adsorption of aqueous metal ions on oxygen and nitrogen functionalized nanoporous activated carbons. Langmuir 2005; 21:3892-3902. [PMID: 15835952 DOI: 10.1021/la047135t] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In this study, the adsorption characteristics of two series of oxygen and nitrogen functionalized activated carbons were investigated. These series were a low nitrogen content (approximately 1 wt % daf) carbon series derived from coconut shell and a high nitrogen content (approximately 8 wt % daf) carbon series derived from polyacrylonitrile. In both series, the oxygen contents were varied over the range approximately 2-22 wt % daf. The porous structures of the functionalized activated carbons were characterized using N(2) (77 K) and CO(2) (273 K) adsorption. Only minor changes in the porous structure were observed in both series. This allowed the effect of changes in functional group concentrations on metal ion adsorption to be studied without major influences due to differences in porous structure characteristics. The surface group characteristics were examined by Fourier transform infrared (FTIR) spectroscopy, acid/base titrations, and measurement of the point of zero charge (pH(PZC)). The adsorption of aqueous metal ion species, M(2+)(aq), on acidic oxygen functional group sites mainly involves an ion exchange mechanism. The ratios of protons displaced to the amount of M(2+)(aq) metal species adsorbed have a linear relationship for the carbons with pH(PZC) < or = 4.15. Hydrolysis of metal species in solution may affect the adsorption of metal ion species and displacement of protons. In the case of basic carbons, both protons and metal ions are adsorbed on the carbons. The complex nature of competitive adsorption between the proton and metal ion species and the amphoteric character of carbon surfaces are discussed in relation to the mechanism of adsorption.
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Affiliation(s)
- B Xiao
- Northern Carbon Research Laboratories, School of Natural Sciences, Bedson Building, University of Newcastle upon Tyne, Newcastle upon Tyne NE1 7RU, U.K
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Abstract
There is considerable interest in hydrogen adsorption on carbon nanotubes and porous carbons as a method of storage for transport and related energy applications. This investigation has involved a systematic investigation of the role of functional groups and porous structure characteristics in determining the hydrogen adsorption characteristics of porous carbons. Suites of carbons were prepared with a wide range of nitrogen and oxygen contents and types of functional groups to investigate their effect on hydrogen adsorption. The porous structures of the carbons were characterized by nitrogen (77 K) and carbon dioxide (273 K) adsorption methods. Hydrogen adsorption isotherms were studied at 77 K and pressure up to 100 kPa. All the isotherms were Type I in the IUPAC classification scheme. Hydrogen isobars indicated that the adsorption of hydrogen is very temperature dependent with little or no hydrogen adsorption above 195 K. The isosteric enthalpies of adsorption at zero surface coverage were obtained using a virial equation, while the values at various surface coverages were obtained from the van't Hoff isochore. The values were in the range 3.9-5.2 kJ mol(-1) for the carbons studied. The thermodynamics of the adsorption process are discussed in relation to temperature limitations for hydrogen storage applications. The maximum amounts of hydrogen adsorbed correlated with the micropore volume obtained from extrapolation of the Dubinin-Radushkevich equation for carbon dioxide adsorption. Functional groups have a small detrimental effect on hydrogen adsorption, and this is related to decreased adsorbate-adsorbent and increased adsorbate-adsorbate interactions.
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Affiliation(s)
- X B Zhao
- Northern Carbon Research Laboratories, School of Natural Sciences, Bedson Building, University of Newcastle upon Tyne, Newcastle upon Tyne, NE1 7RU, UK
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Xiao B, Boudou JP, Thomas KM. Reactions of nitrogen and oxygen surface groups in nanoporous carbons under inert and reducing atmospheres. Langmuir 2005; 21:3400-9. [PMID: 15807580 DOI: 10.1021/la0472495] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The reactions of surface functional groups have an important role in controlling conversion of char nitrogen to NOx during coal combustion. This study involved an investigation of the thermal stability and reactions of nitrogen surface functional groups in nanoporous carbons. Four suites of carbons, which were used as models for coal chars, were prepared with a wide range of nitrogen and oxygen contents and types of functional groups. The porous structures of the carbons were characterized by gas adsorption methods while chemical analysis, X-ray photoelectron spectroscopy, and X-ray near edge structure spectroscopy were used to characterize the surface functional groups. Temperature programmed desorption and temperature programmed reduction methods were used to study the reactivity of the surface functional groups during heat treatment under inert and reducing conditions. Heat treatment studies show that the order of stability of the functional groups is quaternary nitrogen > pyridinic > pyrrolic > pyridine N-oxide. Pyridine N-oxide surface groups desorb NO and form N2 via surface reactions at low temperature. Pyrrolic and pyridinic functional groups decompose and react with surface species to give NH3, HCN, and N2 as desorption products, but most pyrrolic groups are preferentially converted to pyridinic and quaternary nitrogen. The main desorption product is N2. Approximately 15-40 wt % of the original nitrogen was retained in the carbons mainly as quaternary nitrogen after heat treatment to 1673 K. The results are discussed in terms of decomposition ranges for surface functional groups and reaction mechanisms of surface species.
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Affiliation(s)
- B Xiao
- Northern Carbon Research Laboratories, School of Natural Sciences, Bedson Building, University of Newcastle upon Tyne, Newcastle upon Tyne, NE1 7RU United Kingdom
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Levchuk AA, Vasilenko SL, Bulyga IM, Titok MA, Thomas KM. [Characteristics of natural strains of naphthalene-utilizing bacteria of the genus Pseudomonas]. Izv Akad Nauk Ser Biol 2005:162-7. [PMID: 16004276] [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: 05/03/2023]
Abstract
Sixty-three strains of bacteria capable of utilizing naphthalene as the sole source of carbon and energy were isolated from 137 samples of soil taken in different sites in Belarus. All isolated bacteria contained extrachromosomal genetic elements of 45 to 150 kb in length. It was found that bacteria of 31 strains contained the IncP-9 incompatibility group plasmids, bacteria of one strain carried a plasmid containing replicons IncP-9 and IncP-7, and bacteria of 31 strains contained unidentified plasmids. Primary identification showed that the hosts of plasmids of naphthalene biodegradation are fluorescent bacteria of the genus Pseudomonas (P. putida and P. aeruginosa; a total of 47 strains) and unidentified nonfluorescent microorganisms (a total of 16 strains). In addition to the ability to utilize naphthalene, some strains exhibited the ability to stimulate the growth and development of the root system of Secale cereale.
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Zhao X, Xiao B, Fletcher AJ, Thomas KM, Bradshaw D, Rosseinsky MJ. Hysteretic Adsorption and Desorption of Hydrogen by Nanoporous Metal-Organic Frameworks. Science 2004; 306:1012-5. [PMID: 15486255 DOI: 10.1126/science.1101982] [Citation(s) in RCA: 1065] [Impact Index Per Article: 53.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Adsorption and desorption of hydrogen from nanoporous materials, such as activated carbon, is usually fully reversible. We have prepared nanoporous metal-organic framework materials with flexible linkers in which the pore openings, as characterized in the static structures, appear to be too small to allow H2 to pass. We observe hysteresis in their adsorption and desorption kinetics above the supercritical temperature of H2 that reflects the dynamical opening of the "windows" between pores. This behavior would allow H2 to be adsorbed at high pressures but stored at lower pressures.
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Affiliation(s)
- Xuebo Zhao
- Northern Carbon Research Laboratories, School of Natural Sciences, Bedson Building, University of Newcastle upon Tyne, Newcastle upon Tyne, NE1 7RU, UK
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Affiliation(s)
- Yongfeng Jia
- Department of Chemistry, University of Newcastle, Newcastle upon Tyne, NE1 7RU, United Kingdom
| | - K. Mark Thomas
- Department of Chemistry, University of Newcastle, Newcastle upon Tyne, NE1 7RU, United Kingdom
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Fletcher AJ, Cussen EJ, Bradshaw D, Rosseinsky MJ, Thomas KM. Adsorption of Gases and Vapors on Nanoporous Ni2(4,4‘-Bipyridine)3(NO3)4 Metal−Organic Framework Materials Templated with Methanol and Ethanol: Structural Effects in Adsorption Kinetics. J Am Chem Soc 2004; 126:9750-9. [PMID: 15291578 DOI: 10.1021/ja0490267] [Citation(s) in RCA: 199] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Desolvation of Ni(2)(4,4'-bipyridine)(3)(NO(3))(4).2CH(3)OH and Ni(2)(4,4'-bipyridine)(3)(NO(3))(4).2C(2)H(5)OH give flexible metal-organic porous structures M and E, respectively, which have the same stoichiometry, but subtly different structures. This study combines measurements of the thermodynamics and kinetics of carbon dioxide, methanol, and ethanol sorption on adsorbents M and E over a range of temperatures with adsorbent structural characterization at different adsorbate (guest) loadings. The adsorption kinetics for methanol and ethanol adsorption on porous structure E obey a linear driving force (LDF) mass transfer model for adsorption at low surface coverage. The corresponding adsorption kinetics for porous structure M follow a double exponential (DE) model, which is consistent with two different barriers for diffusion through the windows and along the pores in the structure. The former is a high-energy barrier due to the opening of the windows in the structure, required to allow adsorption to occur, while the latter is a lower-energy barrier for diffusion in the pore cavities. X-ray diffraction studies at various methanol and ethanol loadings showed that the host porous structures E and M underwent different scissoring motions, leading to an increase in unit cell volume with the space group remaining unchanged during adsorption. The results are discussed in terms of reversible adsorbate/adsorbent (host/guest) structural changes and the adsorption mechanism involving hydrogen-bonding interactions with specific surface sites for methanol and ethanol adsorption in relation to pore size and extent of filling. This paper contains the first evidence for individual kinetic barriers to diffusion through windows and pore cavities in flexible porous coordination polymer frameworks.
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Affiliation(s)
- Ashleigh J Fletcher
- Northern Carbon Research Laboratories, School of Natural Sciences, Bedson Building, University of Newcastle upon Tyne, Newcastle upon Tyne, NE1 7RU, UK
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Abstract
Competitive adsorption is the usual situation in real applications, and it is of critical importance in determining the overall performance of an adsorbent. In this study, the competitive adsorption characteristics of all the combinations of binary mixtures of aqueous metal ion species Ca2+(aq), Cd2+(aq), Pb2+(aq), and Hg2+(aq) on a functionalized activated carbon were investigated. The porous structure of the functionalized active carbon was characterized using N2 (77 K) and CO2 (273 K) adsorption. The surface group characteristics were examined by temperature-programmed desorption, Fourier transform infrared spectroscopy, Raman spectroscopy, acid/base titrations, and measurement of the point of zero charge (pHpzc). The adsorption of aqueous metal ion species, M2+(aq), on acidic oxygen functional group sites mainly involves an ion exchange mechanism. The ratios of protons displaced to the amount of M2+(aq) metal species adsorbed have a linear relationship for both single-ion and binary mixtures of these species. Hydrolysis of metal species in solution may affect the adsorption, and this is the case for adsorption of Hg2+(aq) and Pb2+(aq). Competitive adsorption decreases the amounts of individual metal ions adsorbed, but the maximum amounts adsorbed still follow the order Hg2+(aq) > Pb2+(aq) > Cd2+(aq) > Ca2+(aq) obtained for single metal ion adsorption. The adsorption isotherms for single metal ion species were used to develop a model for competitive adsorption in binary mixtures, involving exchange of ions in solution with surface proton sites and adsorbed metal ions, with the species having different accessibilities to the porous structure. The model was validated against the experimental data.
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Affiliation(s)
- B Xiao
- Northern Carbon Research Laboratories, Department of Chemistry, School of Natural Sciences, Bedson Building, University of Newcastle upon Tyne, Newcastle upon Tyne, NE1 7RU United Kingdom
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Abstract
Advancements in magnetic imaging techniques have revolutionized our ability to study the developing human brain in vivo. The ability to noninvasively image both anatomy and function in healthy volunteers, including young children, has already enhanced our understanding of brain and behavior relations. The application of these techniques to developmental research offers the opportunity to further explore these relationships and allows us to ask questions about where, when and how cognitive abilities develop in relation to changes in underlying brain systems. It is also possible to explore the contributions of maturation versus learning in the development of these abilities through cross-sectional and longitudinal research involving training and intervention procedures. Current imaging methodologies, in conjunction with new and rapidly evolving techniques, hold the promise of even greater insights into developmental issues in the near future. These methodologies and their application to development and learning are discussed in the current paper.
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Affiliation(s)
- M C Davidson
- Sackler Institute for Developmental Psychobiology, Weill Medical College of Cornell University, New York, New York 10021, USA.
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Durston S, Davidson MC, Thomas KM, Worden MS, Tottenham N, Martinez A, Watts R, Ulug AM, Casey BJ. Parametric manipulation of conflict and response competition using rapid mixed-trial event-related fMRI. Neuroimage 2003; 20:2135-41. [PMID: 14683717 DOI: 10.1016/j.neuroimage.2003.08.004] [Citation(s) in RCA: 167] [Impact Index Per Article: 8.0] [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: 11/26/2022] Open
Abstract
In the current study we examined the influence of preceding context on attentional conflict and response competition using a flanker paradigm. Nine healthy right-handed adults participated in a rapid mixed trial event-related functional magnetic resonance imaging (fMRI) study, in which increasing numbers of either compatible or incompatible trials preceded an incompatible trial. Behaviorally, reaction times on incompatible trials increased as a function of the number of preceding compatible trials. Several brain regions showed monotonic changes to the preceding context manipulation. The most common pattern was observed in anterior cingulate, dorsolateral prefrontal, and superior parietal regions. These areas showed an increase in activity for incompatible trials as the number of preceding compatible trials increased and a decrease in activity for incompatible trials as the number of preceding incompatible trials increased. Post hoc analysis showed that while the MR signal in the anterior cingulate and dorsolateral prefrontal regions peaked before the superior parietal region, the dorsolateral prefrontal MR signal peaked early and remained at this level. These findings are consistent with the conflict monitoring theory that postulates that the anterior cingulate cortex detects or monitors conflict, while PFC is involved in control adjustments that may then lead to modulation of superior parietal cortex in top-down biasing of attention.
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Affiliation(s)
- S Durston
- Sackler Institute for Developmental Psychobiology, Weill Medical College of Cornell University, New York, NY 10021, USA.
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Berenguer-Murcia Á, Fletcher AJ, García-Martínez J, Cazorla-Amorós D, Linares-Solano Á, Thomas KM. Probe Molecule Kinetic Studies of Adsorption on MCM-41. J Phys Chem B 2003. [DOI: 10.1021/jp026764d] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ángel Berenguer-Murcia
- Northern Carbon Research Laboratories, Department of Chemistry, Bedson Building, University of Newcastle-upon-Tyne, Newcastle-upon-Tyne NE1 7RU, U.K., and Departamento de Química Inorgánica, Universidad de Alicante, Apdo. 99, E-03080 Alicante, Spain
| | - Ashleigh J. Fletcher
- Northern Carbon Research Laboratories, Department of Chemistry, Bedson Building, University of Newcastle-upon-Tyne, Newcastle-upon-Tyne NE1 7RU, U.K., and Departamento de Química Inorgánica, Universidad de Alicante, Apdo. 99, E-03080 Alicante, Spain
| | - Javier García-Martínez
- Northern Carbon Research Laboratories, Department of Chemistry, Bedson Building, University of Newcastle-upon-Tyne, Newcastle-upon-Tyne NE1 7RU, U.K., and Departamento de Química Inorgánica, Universidad de Alicante, Apdo. 99, E-03080 Alicante, Spain
| | - Diego Cazorla-Amorós
- Northern Carbon Research Laboratories, Department of Chemistry, Bedson Building, University of Newcastle-upon-Tyne, Newcastle-upon-Tyne NE1 7RU, U.K., and Departamento de Química Inorgánica, Universidad de Alicante, Apdo. 99, E-03080 Alicante, Spain
| | - Ángel Linares-Solano
- Northern Carbon Research Laboratories, Department of Chemistry, Bedson Building, University of Newcastle-upon-Tyne, Newcastle-upon-Tyne NE1 7RU, U.K., and Departamento de Química Inorgánica, Universidad de Alicante, Apdo. 99, E-03080 Alicante, Spain
| | - K. Mark Thomas
- Northern Carbon Research Laboratories, Department of Chemistry, Bedson Building, University of Newcastle-upon-Tyne, Newcastle-upon-Tyne NE1 7RU, U.K., and Departamento de Química Inorgánica, Universidad de Alicante, Apdo. 99, E-03080 Alicante, Spain
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Abstract
In this study we combined event-related fMRI with a parametric manipulation of the go nogo paradigm to examine the effect of preceding context on inhibitory processes. Nogo trials were preceded by either 1, 3, or 5 go trials and then compared to one another. Two distinct patterns of activation were associated with behavioral inhibition: First, the ventral prefrontal cortex, cingulate gyrus, and superior parietal regions showed a context effect with an increase in MR signal to nogo trials with increasing number of preceding go trials. Second, anterior regions in the supplementary and premotor cortex showed an increase in MR signal on the nogo condition after 5 preceding go trials, but not after only 1 or 3. A model using the BOLD response in our data was used to verify that the effect of context was not an artifact of the randomization scheme used in the design.
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Affiliation(s)
- S Durston
- Sackler Institute for Developmental Psychobiology, Weill Medical College of Cornell University, New York, New York, USA
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Thomas KM, Drevets WC, Dahl RE, Ryan ND, Birmaher B, Eccard CH, Axelson D, Whalen PJ, Casey BJ. Amygdala response to fearful faces in anxious and depressed children. Arch Gen Psychiatry 2001; 58:1057-63. [PMID: 11695953 DOI: 10.1001/archpsyc.58.11.1057] [Citation(s) in RCA: 392] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
BACKGROUND Alterations in amygdala function have been implicated in the pathophysiological characteristics of adult anxiety and depressive disorders. Studies with healthy adults and children, as well as with adults who have amygdala lesions, have found facial expressions of emotion to be useful probes of amygdala activity. Our study examined the amygdala response to fearful and neutral facial expressions in healthy, anxious, and depressed children. We hypothesized that children with anxiety and depression may show atypical amygdala responses to emotional stimuli. METHODS Twelve children (8-16 years of age) with generalized anxiety or panic disorder and 12 healthy comparison children underwent noninvasive functional magnetic resonance imaging while viewing photographs of fearful and neutral facial expressions. In a second comparison, 5 girls with major depressive disorder were compared with 5 anxious and 5 healthy girls from the previous sample. RESULTS Children with anxiety disorders showed an exaggerated amygdala response to fearful faces compared with healthy children, whereas depressed children showed a blunted amygdala response to these faces. In addition, the magnitude of the amygdala's signal change between fearful and neutral faces was positively correlated with the severity of everyday anxiety symptoms. CONCLUSIONS Our results suggest that amygdala function is affected in both anxiety and depression during childhood and adolescence. Moreover, this disruption appears to be specific to the child's own rating of everyday anxiety.
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Affiliation(s)
- K M Thomas
- Sackler Institute for Developmental Psychobiology, Weill Medical College of Cornell University, 1300 York Ave, Box 140, Suite F-1332, New York, NY 10021.
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Fletcher AJ, Cussen EJ, Prior TJ, Rosseinsky MJ, Kepert CJ, Thomas KM. Adsorption dynamics of gases and vapors on the nanoporous metal organic framework material Ni2(4,4'-bipyridine)3(NO3)4: guest modification of host sorption behavior. J Am Chem Soc 2001; 123:10001-11. [PMID: 11592878 DOI: 10.1021/ja0109895] [Citation(s) in RCA: 207] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This study combines measurements of the thermodynamics and kinetics of guest sorption with powder X-ray diffraction measurements of the nanoporous metal organic framework adsorbent (host) at different adsorptive (guest) loadings. The adsorption characteristics of nitrogen, argon, carbon dioxide, nitrous oxide and ethanol and methanol vapors on Ni2(4,4'-bipyridine)3(NO3)4 were studied over a range of temperatures as a function of pressure. Isotherm steps were observed for both carbon dioxide and nitrous oxide adsorption at approximately 10-20% of the total pore volume and at approximately 70% of total pore volume for methanol adsorption. The adsorption kinetics obey a linear driving force (LDF) mass transfer model for adsorption at low surface coverage. At high surface coverage, both methanol and ethanol adsorption follow a combined barrier resistance/diffusion model. The rates of adsorption in the region of both the carbon dioxide and methanol isotherm steps were significantly slower than those observed either before or after the step. X-ray diffraction studies at various methanol loadings showed that the host structure disordered initially but underwent a structural change in the region of the isotherm step. These isotherm steps are ascribed to discrete structural changes in the host adsorbent that are induced by adsorption on different sites. Isotherm steps were not observed for ethanol adsorption, which followed a Langmuir isotherm. Previous X-ray crystallography studies have shown that all the sites are equivalent for ethanol adsorption on Ni2(4,4'-bipyridine)3(NO3)4, with the host structure undergoing a scissoring motion and the space group remaining unchanged during adsorption. The activation energies and preexponential factors for methanol and ethanol adsorption were calculated for each pressure increment at which the linear driving force model was obeyed. There was a good correlation between activation energy and ln(preexponential factor), indicating a compensation effect. The results are discussed in terms of reversible adsorbate/adsorbent (guest/host) structural changes and interactions and the adsorption mechanism. The paper contains the first evidence of specific interactions between guests and functional groups leading to structural change in flexible porous coordination polymer frameworks.
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Affiliation(s)
- A J Fletcher
- Northern Carbon Research Laboratories, Department of Chemistry, Bedson Building, University of Newcastle upon Tyne, Newcastle upon Tyne, NE1 7RU, UK
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Abstract
Visuomotor sequence learning was assessed in 4- to 10-year-old children using a serial reaction time (SRT) task with both random and sequenced trials. One-half of the children received exposure to the sequence prior to performing the reaction time (RT) task. In Experiment 1, 7- and 10-year-old children demonstrated sequence-specific decreases in RT. As in the adult SRT literature, participants with explicit awareness of the sequence at the end of the session showed larger sequence-specific reaction time decrements than those without explicit awareness. Contrary to expectation, preexposure to the sequence did not reliably predict the level of awareness attained. Results from Experiment 2 indicate that 4-year-olds also demonstrate significant sequence learning on a variant of the SRT task. This article provides preliminary data regarding developmental changes in sequential learning and the development and use of implicit and explicit knowledge. Age-related differences emerged primarily in explicit rather than implicit knowledge.
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Affiliation(s)
- K M Thomas
- Sackler Institute for Developmental Psychobiology, Weill Medical College of Cornell University, New York, NY 10021, USA.
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