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Corrosion Inhibition and Disinfection of Heating and Cooling Water Systems Using In Situ Generated Hydrogen Peroxide. NEW J CHEM 2022. [DOI: 10.1039/d2nj03806d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Aqueous solutions of MnCl2·4H2O and Tiron (disodium 4,5-dihydroxy-1,3-benzenedisulfonate) rapidly remove dioxygen (O2) from aqueous solution at a rate of ~20 mg∙ L -1 min-1 with turnover frequencies (TOFs) of up...
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Abstract
The structure of phosphate glasses of general composition 10Na2O : (20 + x/2)ZnO : (20 + x/2)CaO : (50 -x)P2O5 (0 ≤x≤ 20) has been investigated using IR spectroscopy, 1D 31P and 43Ca MAS Bloch decay, 31P-31P double quantum MAS-NMR and 43Ca and 67Zn static NMR techniques, as well as neutron diffraction analysis. Zinc is shown to aid glass formation in this system. Glass transition temperature and density increase with increasing cation : phosphate ratio. However, free volume calculations show structures becoming significantly more compact from x = 5 to x = 10. The structural data confirm depolymerisation of the glasses with increasing cation : phosphate ratio. Zinc oxide is found to act in a network forming role in the system, with 67Zn NMR and neutron diffraction analysis confirming zinc exhibits predominantly four-coordinate geometry. Solubility in deionised water and tris/HCl buffer solution is seen to decrease significantly with increasing x-value. This is discussed in terms of water ingress and the degree of structural openness, associated with increased cross-linking and a decrease in concentration of P-O-P linkages. pH measurements confirm invert phosphate compositions maintain physiological pH levels on immersion in water and buffer solutions for up to four weeks.
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Abstract
Ab initio molecular dynamics calculations show low energy barriers for oxide ion conduction along c-axis channels in βIII-Bi14YO22.5.
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Total scattering analysis of cation coordination and vacancy pair distribution in Yb substituted δ-Bi2O3. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:454207. [PMID: 24141081 DOI: 10.1088/0953-8984/25/45/454207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Reverse Monte Carlo (RMC) modelling of neutron total scattering data, combined with conventional Rietveld analysis of x-ray and neutron data, has been used to describe the cation coordination environments and vacancy pair distribution in the oxide ion conducting electrolyte Bi3YbO6. The thermal variation of the cubic fluorite unit cell volume, monitored by variable temperature x-ray and neutron experiments, reveals significant curvature, which is explained by changes in the oxide ion distribution. There is a significant increase in tetrahedral oxide ion vacancy concentration relative to δ-Bi2O3, due to the creation of Frenkel defects associated with the Yb(3+) cation. The tetrahedral oxide ion vacancy concentration increases from room temperature to 800 °C, but little change is observed in the vacancy pair distribution with temperature. The vacancy pair distributions at both temperatures are consistent with a favouring of [100] vacancy pairs.
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Phase and electrical behaviour in Bi4NbO8.5. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2012; 24:045904. [PMID: 22214934 DOI: 10.1088/0953-8984/24/4/045904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A study of phase and electrical behaviour in the bismuth niobate, Bi(4)NbO(8.5), using x-ray and neutron powder diffraction, thermogravimetric analysis (TGA), x-ray photoelectron spectroscopy (XPS) and ac impedance spectroscopy is presented. Two polymorphs were identified in this composition, a tetragonal phase (type III), which can appear at temperatures above 800 °C and a pseudo-cubic phase (type II) evident at lower temperatures. The defect structure analysis of the type II phase is consistent with the existence of chains of niobate polyhedra, which facilitate electronic conduction at low temperatures. The appearance of the type III phase is strongly dependent on experimental conditions and TGA and XPS measurements suggest a likely association with change in oxygen stoichiometry.
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Structures of the chain metaphosphates NaM(PO3)3 (M = Ca or Sr). MAGNETIC RESONANCE IN CHEMISTRY : MRC 2008; 46:316-322. [PMID: 18306173 DOI: 10.1002/mrc.2161] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Solid-state (23)Na and (31)P magic-angle spinning nuclear magnetic resonance spectroscopy and X-ray crystallography have been used to study the structures of the chain metaphosphates NaCa(PO(3))(3) and NaSr(PO(3))(3). The compounds are isostructural and crystallise in space group P(-1) with the following parameters: NaCa(PO(3))(3), a = 6.711 A, b = 6.934 A, c = 7.619 A, alpha = 83.44 degrees , beta = 81.41 degrees , gamma = 82.80 degrees ; NaSr(PO(3))(3)a = 6.805 A, b = 7.133 A, c = 7.720 A and alpha = 83.71 degrees , beta = 80.48 degrees , gamma = 82.87 degrees . Both structures contain anionic metaphosphate chains of (PO(3))(n) (n) with ionic contacts to Na(+) ions in distorted octahedral sites and Ca(2+) (or Sr(2+)) in distorted dodecahedral sites. (31)P and (23)Na NMR are entirely consistent with the crystallographic data and an empirical method for assigning (31)P resonances to particular crystallographically unique P atoms is described.
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Lone pair effects in trihalo-stannate and -plumbate anions in the crystal structures of Sr(MX3)2·5H2O (M=Sn, X=Cl, Br; M=Pb, X=Br): A joint crystallographic and electronic structure calculation approach. Polyhedron 2006. [DOI: 10.1016/j.poly.2005.11.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Multinuclear magnetic resonance studies of borosilicate glasses for use in glass ionomer cements: incorporation of CaO and Al2O3. ACTA ACUST UNITED AC 2006. [DOI: 10.1039/b601593j] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Study on the role of 5-fluorouracil in the polymerization of butylcyanoacrylate during the formation of nanoparticles. J Drug Target 2004; 12:49-56. [PMID: 15203911 DOI: 10.1080/1061186042000207011] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The possible involvement of 5-fluorouracil (5FU) in the initiation process of the polymerization of n-butylcyanoacrylate monomer during nanoparticle formation was investigated. 5FU in acidic solution (pH 2-3) may interfere in the initiation process through its amino groups via the formation of zwitterions. The proposed zwitterionic mechanism of initiation was supported by the molecular weight profiles of the polymer, determined by gel permeation chromatography, and the covalent linkage of the cytostatic to the main polymer chain. H NMR analyses clearly demonstrated that a significant fraction of 5FU was covalently bonded to the poly(butylcyanoacrylate) chains through its amino groups preferentially through one of the two nitrogen atoms. In vitro release study performed shows that the investigated 5FU-loaded PBCN are suitable for sustaining delivery of 5FU.
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Abstract
Poly(butylcyanoacrylate) nanoparticles (PBCN) as a drug carrier of 5-fluorouracil (5FU) intended for topical treatment of skin lesia were investigated. The presence of 5FU (as saline solution, pH 10-11) in the polymerization medium affected the polymerization as well as the nanoparticle formation by influencing the initiation of the polymerization reaction. 5FU acted as an initiator in the anionic polymerization of n-butylcyanoacrylate monomer through its nucleophilic nitrogen centers. The results obtained by GPC, 1H NMR, and X-ray diffraction allude to a possible mechanism of cytostatic immobilization in the polymer matrix, with evidence for both free and bound forms of the drug.
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Abstract
Glasses from the quaternary glass system K2O-Na2O-CaO-P2O5 were produced by standard glass forming techniques. The compositions were limited by fixing the P2O5 at 45 mol%, fixing the CaO content at either 20, 24 or 28 mol%. The K2O and Na2O made up the residual varying from 0 to 25 mol% K2O. General trends showed that with increasing CaO content, the glasses showed a decrease in solubility as expected. For a single system of fixed CaO content, with increasing K2O content, there was an increase in solubility. This was seen at all three CaO contents. All the glasses showed an initial increase in pH followed by a gradual decrease with time and this was accounted for by the initial release of Na+ ions into solution. For the ion release curves, for all fixed CaO contents, the glass with 0 mol% K2O showed the lowest Ca2+ release. This was accounted for as being due to the low solubility compared to the K2O containing glasses. The Na+ release appeared anomalous, as it was higher than all the K2O containing glasses. Even though the glasses with 0 mol% K2O showed the lowest solubility, the amount of Na+ contained in the glass was high, hence the high levels of release.
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Investigation of thermal parameters and crytallisation in a ternary CaO-Na2O-P2O5-based glass system. Biomaterials 2001; 22:497-501. [PMID: 11214761 DOI: 10.1016/s0142-9612(00)00207-6] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
This paper presents the results of a study of the thermal properties of a range of phosphate-based glasses in the system CaO-Na2O-P2O5. The glasses had a fixed P2O5 content of 45 mol% and the CaO:Na2O ratio was varied. The glasses were produced and ground and their thermal properties measured using a Setaram differential thermal analyser (DTA). Initial data showed that for the high Na2O containing glass, NaPO3 forms and a second unidentified phase that is probably calcium rich. In the middle compositional region, multiple phases precipitated out and were identified as NaPO3 and Na4Ca(PO3)6. For the high CaO content glasses, Na4Ca(PO3)6 was the only phase formed. Further studies were carried out to examine whether the phases were bulk or surface nucleating, by grinding the samples to different particle sizes. From this data, it is evident that the NaPO3 forms via a bulk nucleation mechanism and that Na4Ca(PO3)6 forms via surface nucleation. The factors controlling this precipitation process are discussed and ionic radius as a controlling factor is hypothesised.
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Development of soluble glasses for biomedical use Part I: in vitro solubility measurement. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2000; 11:609-614. [PMID: 15348084 DOI: 10.1023/a:1008949527695] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In this study soluble glasses have been developed for biomedical applications containing P2O5 as a network former and CaO and Na2O as modifiers. This study shows that as expected, the glasses have an inverse exponential relationship between solubility and CaO content. Furthermore, there is evidence for compositional related non-linearity in the dissolution of the glasses with time. This is thought to be due to either layer formation on the glass surface hindering ion diffusion, ion exchange process or change of ionic strength of the solution. Bioactivity of these glasses is indicated by the formation of a brushite precipitate, a precursor to apatite formation. Further evidence for bioactivity is also presented in the second part of this paper.
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Porphyria cutanea tarda occurring in a patient with renal failure, systemic lupus erythematosus and chronic hepatitis C infection treated with hemodialysis. Cutis 1999; 64:237-9. [PMID: 10544877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
The diagnosis and management of porphyria cutanea tarda (PCT) is complicated when it occurs in the context of renal failure, chronic hemodialysis, and anemia. We report a case of a woman who presented with painful acral blisters and hyperpigmentation. Her medical history included systemic lupus erythematosus, chronic hepatitis C infection, and renal failure necessitating chronic hemodialysis with a baseline anemia. A highly elevated serum porphyrin level led to the diagnosis of PCT. Treatment with small repeated phlebotomies and concomitant administration of erythropoietin was effective in managing her PCT.
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Abstract
Giant cell lichenoid dermatitis is a recently described dermatosis thought to be an unusual lichenoid drug eruption. It is characterized by a generalized, pruritic, papulosquamous eruption sparing palms, soles, face and mucous membranes. Histopathologic findings include areas of epidermal hyperplasia and atrophy with focal vacuolar alteration of the basal layer, exocytosis and cytoid body formation. The dermis contains a band-like, mononuclear cell infiltrate at the dermoepidermal junction with admixed eosinophils, plasma cells and large multinucleate cells. The histologic differential diagnosis includes infectious processes, sarcoidosis, lichen nitidus, lupus erythematosus and lichen planus. We report 3 patients with giant cell lichenoid dermatitis, one of whom was subsequently diagnosed as having sarcoidosis. Because giant cell lichenoid dermatitis may resemble sarcoidosis both clinically and histologically, and because cutaneous sarcoid is often associated with systemic involvement, the diagnosis of sarcoid should be strongly considered in patients with giant cell lichenoid dermatitis.
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Defect clustering in the superionic conductor lithium germanium vanadate. ACTA CRYSTALLOGRAPHICA SECTION B: STRUCTURAL SCIENCE 1991. [DOI: 10.1107/s0108768191004548] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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A re-examination of the lisicon structure using high-resolution powder neutron diffraction: evidence for defect clustering. ACTA CRYSTALLOGRAPHICA SECTION B: STRUCTURAL SCIENCE 1989. [DOI: 10.1107/s0108768189006245] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Abstract
Extended x-ray absorption fine structure (EXAFS) has been used to investigate the metal environment in a number of metallothioneins (MT). In all cases, the primary coordination sphere consists of sulphur atoms. In some cases, evidence for cluster formation is obtained.
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Noise reduction in an AutoAnalyzer II direct cholesterol method. Clin Chem 1978; 24:168. [PMID: 618649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Progress in screening for neural tube defects. JAMA 1977; 237:2187. [PMID: 67226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Shirodkar suture for cervical incompetence. CANADIAN MEDICAL ASSOCIATION JOURNAL 1973; 108:1102. [PMID: 4574407 PMCID: PMC1941378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Pulmonary intracavitary aspergilloma fungus ball. Report of three cases. J Thorac Cardiovasc Surg 1971; 61:619-23. [PMID: 5549115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Further studies on acquired resistance to murine cryptococcosis: enhancing effect of Bordetella pertussis. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 1966; 96:525-9. [PMID: 4286684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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CRST syndrome (calcinosis, Raynaud's disease, sclerodactyly, and telangiectasias). ARCHIVES OF DERMATOLOGY 1965; 92:209-10. [PMID: 11873727 DOI: 10.1001/archderm.92.2.209] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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In Vitro Action of Sulfonamides and Penicillin on Actinomyces. J Bacteriol 1946; 51:145-8. [PMID: 16561063 PMCID: PMC518034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023] Open
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