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Skinner LB, Benmore CJ, Weber JKR, Du J, Neuefeind J, Tumber SK, Parise JB. Low cation coordination in oxide melts. Phys Rev Lett 2014; 112:157801. [PMID: 24785072 DOI: 10.1103/physrevlett.112.157801] [Citation(s) in RCA: 12] [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] [Received: 09/12/2013] [Indexed: 06/03/2023]
Abstract
The complete set of partial pair distribution functions for a rare earth oxide liquid are measured by combining aerodynamic levitation, neutron and x-ray diffraction on Y2O3, and Ho2O3 melts at 2870 K. The average Y-O (or Ho-O) coordination of these isomorphic melts is measured to be 5.5(2), which is significantly less than the octahedral coordination of crystalline Y2O3 (or Ho2O3). Investigation of La2O3, ZrO2, and Al2O3 melts by x-ray diffraction and molecular dynamics simulations also show lower-than-crystal cation-oxygen coordination. These measurements suggest a general trend towards lower coordination compared to their crystalline counterparts. It is found that the coordination drop is larger for lower field strength, larger radius cations and is negligible for high field strength (network forming) cations, such as SiO2. These findings have broad implications for predicting the local structure and related physical properties of metal-oxide melts and oxide glasses.
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Affiliation(s)
- L B Skinner
- Mineral Physics Institute, Stony Brook University, Stony Brook, New York 11794-2100, USA and X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA and Materials Development Inc., Arlington Heights, Illinois 60004, USA
| | - C J Benmore
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - J K R Weber
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA and Materials Development Inc., Arlington Heights, Illinois 60004, USA
| | - J Du
- Materials Science & Engineering, University of North Texas, Denton, Texas 76203, USA
| | - J Neuefeind
- Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - S K Tumber
- Materials Development Inc., Arlington Heights, Illinois 60004, USA
| | - J B Parise
- Mineral Physics Institute, Stony Brook University, Stony Brook, New York 11794-2100, USA
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Skinner LB, Benmore CJ, Weber JKR, Wilding MC, Tumber SK, Parise JB. A time resolved high energy X-ray diffraction study of cooling liquid SiO2. Phys Chem Chem Phys 2013; 15:8566-72. [PMID: 23588490 DOI: 10.1039/c3cp44347g] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- L B Skinner
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA
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Abstract
The aggregation of mucoid and nonmucoid Pseudomonas aeruginosa by submandibular, parotid, and whole saliva from patients with cystic fibrosis (CF) and non-CF subjects was investigated. There were significant differences (P less than 0.01) in aggregation of mucoid and nonmucoid variants of P. aeruginosa by submandibular and whole saliva from CF patients and non-CF subjects. However, the differences in the parotid secretion were not as pronounced. Patients with CF who were colonized with P. aeruginosa demonstrated a significantly higher (P less than 0.05) percent aggregation of the mucoid variants by the submandibular secretion and of both mucoid and nonmucoid variants by whole saliva, compared with corresponding secretions from patients with CF not colonized with this pathogen. The parotid saliva aggregation activity was not markedly different for the two groups with CF. From patients with CF, whole saliva demonstrated a higher percent P. aeruginosa aggregation than did the submandibular saliva. In non-CF subjects, however, the percent aggregation of P. aeruginosa by submandibular saliva was higher than that by whole saliva. Our results indicate that the sero-mucous products of the submandibular gland have a more significant role in P. aeruginosa aggregation than the serous secreting parotid cells and that the submandibular secretion is possibly responsible for the differences in oral colonization by this pathogen in subjects with and without CF.
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Affiliation(s)
- K Komiyama
- Department of Oral Biology, University of Saskatchewan, Saskatoon, Canada
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Komiyama K, Habbick BF, Tumber SK. Role of sialic acid in saliva-mediated aggregation of Pseudomonas aeruginosa isolated from cystic fibrosis patients. Infect Immun 1987; 55:2364-9. [PMID: 3115896 PMCID: PMC260714 DOI: 10.1128/iai.55.10.2364-2369.1987] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The mechanism of saliva-mediated aggregation of Pseudomonas aeruginosa in subjects with and without cystic fibrosis (CF) was investigated. Virtually all saliva from CF patients that we tested strongly agglutinated the Pseudomonas cells and was heat stable to 56 degrees C, whereas saliva from subjects without CF had a decreased aggregating ability and was heat sensitive. When saliva was treated with neuraminidase and proteases, and also when P. aeruginosa cells were treated with mixed gangliosides, there was a decrease in aggregating activities. However, neither the addition of the acid-hydrolyzed ganglioside nor the treatment of the P. aeruginosa cells by sugars had any effect on subsequent aggregating activities. Therefore, the release of sialic acid by enzymatic treatments of saliva, as well as the blockage of the sialic acid-binding sites on the cell wall by mixed gangliosides, resulted in the parallel loss of saliva-mediated aggregating activity of P. aeruginosa. The level of free sialic acid released by endogenous neuraminidase was higher in the saliva from CF patients than in that from the non-CF subjects examined. The increased aggregation of P. aeruginosa mediated by saliva from patients with CF seems to be directly related to the sialic acid content present, suggesting that this acid molecule acts as the salivary receptor for P. aeruginosa.
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Affiliation(s)
- K Komiyama
- Department of Oral Biology, College of Dentistry, University of Saskatchewan, Saskatoon, Canada
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Komiyama K, Habbick BF, Martin T, Tumber SK. Characterization by pyocine typing and serotyping of oral and sputum strains of Pseudomonas aeruginosa isolated from cystic fibrosis patients. Can J Microbiol 1987; 33:221-5. [PMID: 3105857 DOI: 10.1139/m87-038] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Oral and sputum isolates of Pseudomonas aeruginosa in patients with cystic fibrosis were investigated. Of the 17 patients studied, 12 patients (71%) yielded both mucoid and nonmucoid variants of Pseudomonas aeruginosa from sputum and (or) various oral ecological sites, such as buccal mucosa, tongue dorsum, dental plaques, and saliva. A total of 51 strains of mucoid and nonmucoid Pseudomonas aeruginosa were isolated from these patients and were phenotypically characterized by both pyocine typing and serotyping. Five patients (42%) were colonized or infected by a single strain of Pseudomonas aeruginosa, whereas 7 patients (58%) were cocolonized or coinfected by two or more phenotypically different strains of Pseudomonas aeruginosa. To understand the mechanisms involved in Pseudomonas aeruginosa colonization, it may be necessary to identify multiple isolates of Pseudomonas aeruginosa not only from the sputum but also from the various oral ecological sites and to further explore the role of the oral cavity in this colonization.
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