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Chatterjee S, Del Negro AS, Edwards MK, Bryan SA, Kaval N, Pantelic N, Morris LK, Heineman WR, Seliskar CJ. Luminescence-Based Spectroelectrochemical Sensor for [Tc(dmpe)3]2+/+ (dmpe = 1,2-bis(dimethylphosphino)ethane) within a Charge-Selective Polymer Film. Anal Chem 2011; 83:1766-72. [DOI: 10.1021/ac1030368] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Chatterjee S, Del Negro AS, Edwards MK, Twamley B, Krause JA, Bryan SA. trans-K(3)[TcO(2)(CN)(4)]. Acta Crystallogr Sect E Struct Rep Online 2010; 66:i61-i62. [PMID: 21588082 PMCID: PMC3007308 DOI: 10.1107/s1600536810028205] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2010] [Accepted: 07/14/2010] [Indexed: 05/30/2023]
Abstract
The structure of the title compound, tripotassium trans-tetra-cyanidodioxidotechnetate(V), is isotypic with its Re analogue. The [TcO(2)(CN)(4)](3-)trans-tetra-cyanido-dioxido-technetate anion has a slightly distorted octa-hedral configuration. The Tc atom is located on a center of inversion and is bound to two O atoms in axial and to four cyanide ligands in equatorial positions. The Tc-O distance is consistent with a double-bond character. The two potassium cations, one located on a center of inversion and one in a general position, reside in octa-hedral or tetra-hedral environments, respectively. K⋯O and K⋯N inter-actions occur in the 2.7877 (19)-2.8598 (15) Å range.
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Del Negro AS, Seliskar CJ, Heineman WR, Hightower SE, Bryan SA, Sullivan BP. Highly Oxidizing Excited States of Re and Tc Complexes. J Am Chem Soc 2006; 128:16494-5. [PMID: 17177386 DOI: 10.1021/ja067114g] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Like the Re analogue, the ligand-to-metal charge transfer (LMCT) excited-state of [Tc(dmpe)3]2+ (dmpe is bis-1,2-(dimethylphosphino)ethane) is luminescent in solution at room temperature. Surprisingly, both [M(dmpe)3]2+* species have extremely large excited-state potentials (ESPs) as oxidants-the highest for any simple coordination complex of a transition metal. Furthermore, this potential is available using a photon of visible light (calculated for M = Re(Tc); E1/2* = +2.61(2.52) V versus SCE; lambdamax = 526(585) nm). Using a Rehm-Weller analysis with a series of aromatic hydrocarbons as electron-transfer quenchers, E1/2(Re2+*/Re+) has been determined to be 2.58 V, in good agreement with the calculated value. Both [M(dmpe)3]2+* species are quenched by chloride ion and both can function as excited-state oxidants in water solution.
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Del Negro AS, Wang Z, Seliskar CJ, Heineman WR, Sullivan BP, Hightower SE, Hubler TL, Bryan SA. Luminescence from the trans-Dioxotechnetium(V) Chromophore. J Am Chem Soc 2005; 127:14978-9. [PMID: 16248608 DOI: 10.1021/ja054906m] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The luminescence of trans-[TcO2(L)4]+ (L = pyridine (py) or picoline (pic)) and trans-[TcO2(CN)4]3- at room and low temperature is described and represents the first example of room temperature excited-state luminescence observed for Tc complexes. At room temperature, the complexes exhibited broad luminescence with emission maxima ranging from 745 to 780 nm. Analogous to the Re complexes (emission at 635-655 nm), the low-temperature emission spectra of microcrystalline samples of [TcO2(py)4]BPh4 and [TcO2(pic)4]BPh4 display the characteristic progressions of the symmetric O=Tc=O and Tc-L stretching modes. DFT/TDDFT calculations were performed on the trans-[MO2(L)4]+ (M = Re, Tc) congeners and predicted the dioxotechnetium emission to be 0.41 eV lower in energy than its Re analogue. Low-temperature lifetimes (8 K) ranging from 15 to 1926 mus for the series of Tc complexes are consistent with the Re analogues.
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Zudans I, Paddock JR, Kuramitz H, Maghasi AT, Wansapura CM, Conklin SD, Kaval N, Shtoyko T, Monk DJ, Bryan SA, Hubler TL, Richardson JN, Seliskar CJ, Heineman WR. Electrochemical and optical evaluation of noble metal– and carbon–ITO hybrid optically transparent electrodes. J Electroanal Chem (Lausanne) 2004. [DOI: 10.1016/j.jelechem.2003.10.025] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Stegemiller ML, Heineman WR, Seliskar CJ, Ridgway TH, Bryan SA, Hubler T, Sell RL. Spectroelectrochemical sensing based on multimode selectivity simultaneously achievable in a single device. 11. Design and evaluation of a small portable sensor for the determination of ferrocyanide in Hanford waste samples. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2003; 37:123-130. [PMID: 12542300 DOI: 10.1021/es020601l] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A portable spectroelectrochemical sensor has been designed, evaluated, and demonstrated on a complex sample of radioactive waste. The sensor consisted of a black delrin sample compartment with a total internal sample volume of 800 microL, attached to an indium tin oxide coated glass multiple internal reflection optical element. Detection was by total internal reflection of light from a blue light emitting diode source. After a 10 min uptake for each standard, the sensor showed a linear response in absorbance change for 5 x 10(-5) to 5 x 10(-3) M ferrocyanide with electrochemical modulation by scanning at 20 mV/s from -0.30 V to +0.55 V vs a Ag/AgCl reference electrode. Due to the complex nature of Hanford radioactive tank waste samples containing ferrocyanide, a standard addition method was developed for analysis. The spectroelectrochemical sensor determined a concentration of 9.2 mM ferrocyanide for U-Plant-2 simulant solution containing 9.38 mM ferrocyanide that was prepared according to Hanford process flowsheets. A radioactive tank waste sample from Hanford Tank 241-C-112 was determined to be 1.0 mM in ferrocyanide using the spectroelectrochemical sensor. A value for the ferrocyanide concentration in the sample of 0.61 mM was determined by FTIR spectroscopy.
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Bryan SA, Dickson MK, Roundhill DM. Thermal, photochemical and electrochemical reactions involving binuclear platinum(II) and -(III) pyrophosphite complexes. Reaction chemistry of tetrakis(diphosphonato)diplatinate(4-) ion (Pt2(P2O5H2)44-) and the halide complexes dihalotetrakis(diphosphonato)diplatinate(4-) ion (Pt2(P2O5H2)4X24-). J Am Chem Soc 2002. [DOI: 10.1021/ja00318a079] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Bryan SA, Schmehl RH, Roundhill DM. Electrochemical oxidation of the tetrakis(.mu.-pyrophosphito-P,P)diplatinum(II) complex Pt2(.+-.-P2O5H2)44- both in the presence and the absence of halide ions and reduction of the axially substituted halodiplatinum(III) complexes Pt2(.+-.-P2O5H2)4X2-1. J Am Chem Soc 2002. [DOI: 10.1021/ja00278a006] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Alexander KA, Bryan SA, Fronczek FR, Fultz WC, Rheingold AL, Roundhill DM, Stein P, Watkins SF. Crystal and molecular structures of dihalotetrakis(pyrophosphito)diplatinum(III) complexes. Integrative use of structural and vibrational data to assess intermetallic bonding and the trans influence of the platinum(III)-platinum(III) bond. Inorg Chem 2002. [DOI: 10.1021/ic00212a020] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Bryan SA, Dickson MK, Roundhill DM. Synthesis, reactivity, kinetics, and photochemical studies on tetrakis(.mu.-pyrophosphito)diplatinate(II) and dihalotetrakis(.mu.-pyrophosphito)diplatinate(III) complexes. Comparison of the substitution mechanisms of the diplatinum(III) complexes with those of monomeric platinum(II) and platinum(IV) compounds. Inorg Chem 2002. [DOI: 10.1021/ic00270a013] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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El-Mehdawi R, Bryan SA, Roundhill DM. Axial ligand anation and aquation reactions in diplatinum(III) complexes. Comparison of aquation rates between hexachloroplatinate(IV) anion and diplatinum(III) chloro complexes having .mu.-phosphato or .mu.-pyrophosphito ligands. J Am Chem Soc 2002. [DOI: 10.1021/ja00308a020] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Bryan SA, Willis RR, Moyer BA. Hydration of 18-crown-6 in carbon tetrachloride: infrared spectral evidence for an equilibrium between monodentate and bidentate forms of bound water in the 1:1 crown-water adduct. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j100376a011] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Bryan SA, O'Connor BJ, Matti S, Leckie MJ, Kanabar V, Khan J, Warrington SJ, Renzetti L, Rames A, Bock JA, Boyce MJ, Hansel TT, Holgate ST, Barnes PJ. Effects of recombinant human interleukin-12 on eosinophils, airway hyper-responsiveness, and the late asthmatic response. Lancet 2000; 356:2149-53. [PMID: 11191543 DOI: 10.1016/s0140-6736(00)03497-8] [Citation(s) in RCA: 292] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Interleukin-12 (IL-12) is a macrophage-derived cytokine that modulates T lymphocyte responses and has the capacity to suppress allergic and eosinophilic inflammation. METHODS We carried out a double-blind, randomised, parallel group clinical study, in which patients with mild allergic asthma were given subcutaneous recombinant human IL-12 at increasing weekly injections of 0.1, 0.25, 0.5 microg/kg (n=19), or placebo (n=20). We compared responses to inhaled allergen challenge 24 h before the first injection and 24 h after the final injection. Airways hyper-responsiveness and concentrations of peripheral blood eosinophils and sputum eosinophils were also assessed. FINDINGS IL-12 caused a significant decrease from baseline in the main peripheral blood eosinophil count 24 h after the fourth injection compared with placebo (p=0.0001). Sputum eosinophils were also significantly decreased 24 h after allergen challenge when treated with IL-12 compared with placebo (p=0.024). IL-12 caused a non-significant trend towards improvement in airway hyper-responsiveness to histamine, but had no significant effect on the late asthmatic reaction after inhaled allergen challenge. After administration of IL-12, four of 19 patients withdrew prematurely; two with cardiac arrhythmias, one with abnormal liver function, and a single patient with severe flu-like symptoms. INTERPRETATION We have shown that IL-12 lowers numbers of blood and sputum eosinophils, but without any significant effects on airway hyper-responsiveness or the late asthmatic reaction. This questions the role of eosinophils in mediating these reactions, and has important implications for development of new anti-inflammatory treatments.
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Leckie MJ, Bryan SA, Khan J, Dewar A, Aikman SL, McGrath J, Okrongly DA, Burman JF, Barnes PJ, Hansel TT. Automated quantitation of circulating neutrophil and eosinophil activation in asthmatic patients. Thorax 2000; 55:471-7. [PMID: 10817795 PMCID: PMC1745769 DOI: 10.1136/thorax.55.6.471] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND Asthma has been associated with eosinophil activation, measured in serum, sputum, bronchoalveolar lavage (BAL) fluid, and urine. A whole blood automated method was developed to assess eosinophil and neutrophil activity in terms of peroxidase content and cell morphology using the Bayer haematology analyser. The method was applied to an in vitro stimulation model when fMLP was added to whole blood and the samples were then analysed for changes in granularity and shape. In addition, cells stimulated with interleukin (IL)-8 were examined by electron microscopy. METHODS A cross sectional analysis was performed on venous blood from non-atopic, non-asthmatic normal subjects (n = 37), mild (n = 46) and symptomatic (n = 22) asthmatic patients on inhaled beta(2) agonist only, and more severe asthmatic patients (n = 17) on inhaled and oral corticosteroid therapy. Samples were analysed by the haematology analyser and peroxidase leucograms gated using the WinMDI software program. RESULTS There were significant differences in the amount of light scatter by the neutrophil populations in the symptomatic (p = 0.007) and severe asthmatic (p = 0.0001) groups compared with the control group. However, abnormalities in eosinophil populations were not observed. In vitro activation of whole blood with fMLP caused similar changes in neutrophil light scatter, suggesting that neutrophil activation is present in peripheral blood of symptomatic asthmatic patients. IL-8 caused a change in shape of the neutrophils seen using transmission electron microscopy. CONCLUSIONS Evidence of neutrophil activation can be seen in whole blood from patients with asthma using a novel automated method. This may potentially be applied to other inflammatory diseases.
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Abstract
The incidence of chronic obstructive pulmonary disease (COPD) is increasing throughout the world. Much less is known about the pathogenesis of COPD than that of asthma and there is little response to current therapy. Most patients with COPD have acquired their lung disease through smoking cigarettes, and the major step in management is to minimise further damage by stopping this habit. A number of therapies are being developed for the treatment of COPD; including new bronchodilators such as tiotropium bromide, agents to block inflammation induced by neutrophils and macrophages, as well as strategies to combat proteases and oxidants. The long-term goal is to provide therapy that retards the accelerated loss of lung function occurring in COPD. Development of novel therapies for COPD requires reliable Phase II decision making before entering large scale Phase III studies. The patient with COPD is often overlooked compared to their asthmatic counterpart, who benefit from an urgent need to identify novel targets and better therapy.
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Abstract
The health burden of asthma is increasing globally at an alarming rate, providing a strong impetus for the development of new therapeutics. Currently available inhaled bronchodilators and anti-inflammatory drugs are effective in most asthmatics, but this palliative therapy requires long-term daily administration. Despite considerable efforts by the pharmaceutical industry, it has been difficult to develop novel therapeutic agents; the leukotriene antagonists and synthesis inhibitors being the only new class of asthma treatments to have been licensed in the last 30 years. It is clearly important to understand more about the underlying mechanisms of asthma and about how current drugs work before rational improvements in therapy can be expected. There are numerous therapies in clinical development that combat the inflammation found in asthma, specifically targeting eosinophils, IgE, adhesion molecules, cytokines and chemokines, inflammatory mediators and cell signalling. In particular, there is the obvious need for new therapy for severe asthma that is poorly controlled by high doses of corticosteroids, as well as agents to counter acute emergency asthma. A long-term goal is to develop disease-modifying immunotherapy, that could be introduced in childhood to alter the natural history of asthma. Thanks to the extensive efforts of the pharmaceutical industry, in the near future we can expect the introduction of a range of novel therapies for asthma.
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Bryan SA. Wrong emphasis? Nurs Outlook 1979; 27:155. [PMID: 254049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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