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Stringer B, Imrich A, Kobzik L. Lung epithelial cell (A549) interaction with unopsonized environmental particulates: quantitation of particle-specific binding and IL-8 production. Exp Lung Res 1996; 22:495-508. [PMID: 8886755 DOI: 10.3109/01902149609046038] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The A549 cell line was used to model in vitro the interaction of alveolar epithelium with environmental particulates. Confocal and electron microscopy demonstrated A549 binding and internalization of titanium dioxide (TiO2), iron oxide (Fe2O3), concentrated ambient air particulates (CAPs), and the fibrogenic particle alpha-quartz. Flow cytometry allowed quantitation of particle binding by measuring increased right angle light scatter (RAS) (TiO2) [40 micrograms/mL], Fe2O3 [100 micrograms/mL], alpha-quartz [200 micrograms/mL], or CAPs [40 micrograms/mL] fold increase RAS: 8.1 +/- 0.9, 4.3 +/- 0.4, 2 +/- 0.1, 1.6 +/- 0.1, respectively). With this quantitative assay, binding of particle was found to be calcium-dependent for TiO2 and Fe2O3 (% inhibition, 61.0 +/- 1.9, 40.0 +/- 5.6, respectively), while alpha-quartz binding was calcium-independent. A panel of polyanionic ligands known to inhibit scavenger-type receptors was used to identify binding mechanisms for environmental particulates. Both heparin and polyinosinic acid (polyI), but not the control polyanion chondroitin sulfate, caused marked inhibition of particulate binding by A549 cells (e.g., TiO2 [40 micrograms/mL] binding; polyI, heparin, and chondroitin sulfate: 73.8 +/- 3.5, 75.5 +/- 6.0, 7.5 +/- 6.7% inhibition, respectively; mean +/- SE, n > or = 4), indicating that scavenger receptor(s), albeit those distinct from the heparin-insensitive acetylated-LDL receptor, mediate particulate binding. The particulates ability to stimulate interleukin (IL-8) production in A549 cells was also tested. alpha-quartz, but not TiO2 or CAPs, caused a dose-dependent production of IL-8 (range 1-6 ng/mL), demonstrating a particle-specific spectrum of epithelial cell cytokine (IL-8) response. The results suggest that lung epithelial cell interaction with environmental particles is mediated by distinct receptors and can lead to particle dependent cytokine responses.
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Stringer B, Kobzik L. Alveolar macrophage uptake of the environmental particulate titanium dioxide: role of surfactant components. Am J Respir Cell Mol Biol 1996; 14:155-60. [PMID: 8630265 DOI: 10.1165/ajrcmb.14.2.8630265] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Pulmonary surfactant components can modulate uptake of microorganisms and viruses by alveolar macrophages (AMs), but little is known about their role in the uptake and clearance of inert environmental particulates. We tested the hypotheses that surfactant components [e.g., surfactant protein A (SpA) and the artificial bovine surfactant Survanta] modulate phagocytosis of inert environmental particulates by acting as particle opsonins, or by direct activation of AMs. AM uptake of a model inert particulate [titanium dioxide (TiO2)] was measured using flow cytometry to quantitate increased right angle scatter caused by particle uptake (e.g., fold increase in right angle scatter versus control: 2.6 +/- 0.3; and 5.0 +/- 0.2 for AMs plus TiO2, 20 and 80 micrograms/ml TiO2, respectively). Opsonization of TiO2 with surfactant components resulted in a modest increase in AM uptake compared with that of unopsonized TiO2 [e.g., fold increase, uptake of TiO2 (50 micrograms/ml), opsonized with SpA, Survanta, and rat immunoglobulin G, respectively: 1.6 +/- 0.1; 1.3 +/- 0.01; 1.5 + 0.02, n = 3-4]. Uptake of inert latex beads was similarly enhanced after opsonizing with SpA and Survanta (beads per cell: unopsonized, 3.2 +/- 0.40; SpA, 5.0 +/- 0.55; Survanta, 6.0 +/- 0.12; n = 3-6). Pretreating AMs with surfactant components and measuring the subsequent uptake of unopsonized TiO2 resulted in approximately the same magnitude of enhancement. The data indicate that surfactant components can increase AM phagocytosis of environmental particulates in vitro, but only slightly relative to the already avid AM uptake of unopsonized particles.
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Stringer B. Reducing the occupational risk of TB. THE CANADIAN NURSE 1995; 91:27-31. [PMID: 8714912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Tuberculosis, an infectious disease caused by the micro-organism Mycobacterium tuberculosis, has wrought devastation for centuries. According to estimates, in the 1800s alone, say estimates, it was responsible for almost one-third of the deaths in Europe. In the 20th century, the incidence of TB declined dramatically in developed countries, especially after the development of anti-TB drugs in the late 1940s. Yet in under-developed countries today, roughly one-third of the world's population is thought to be infected with the tubercle bacillus.
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Stringer B. Hospital needed for research on hands-free technique. CMAJ 1995; 153:139. [PMID: 7600461 PMCID: PMC1338043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
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Kobzik L, Stringer B, Balligand JL, Reid MB, Stamler JS. Endothelial type nitric oxide synthase in skeletal muscle fibers: mitochondrial relationships. Biochem Biophys Res Commun 1995; 211:375-81. [PMID: 7540837 DOI: 10.1006/bbrc.1995.1824] [Citation(s) in RCA: 307] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Immunohistochemistry shows that skeletal muscle fibers express endothelial-type (ec)-NOS in a heterogeneous pattern distinct from that of neuronal (nc)-NOS. Analysis of adjacent serial sections reveals: 1) a strong correlation of ec-NOS expression to mitochondrial content (visualized histochemically by succinate dehydrogenase); 2) lack of correlation of ec-NOS to fiber ATPase type (in contrast to nc-NOS); and 3) constitutive co-expression of ec- and nc-NOS in some fibers. Preparations of mitochondria from diaphragm exhibited calcium-dependent NOS activity, which functioned to inhibit in vitro oxygen consumption. The results establish that normal skeletal muscle cells can express two constitutive isoforms of NOS (nc- and ec-) and suggest a functional role for ec-NOS in oxidative, mitochondria-rich fibers.
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Stringer B, Imrich A, Kobzik L. Flow cytometric assay of lung macrophage uptake of environmental particulates. CYTOMETRY 1995; 20:23-32. [PMID: 7600897 DOI: 10.1002/cyto.990200106] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We sought to establish a quantitative method using flow cytometry to study uptake of environmental particulates by alveolar macrophages (AMs). We used right angle light scatter (RAS) to measure uptake of titanium dioxide, quartz, and diesel particulates. After incubation with TiO2 in vitro, AMs showed dose-dependent increases in both cell-associated particles visualized by microscopy and RAS measured by flow cytometry (e.g., fold increase RAS at 4, 8, 16, 32, and 80 micrograms/ml, respectively, = 2 +/- 0.1, 4.0 +/- 0.5, 5.5 +/- 0.5, 9.1 +/- 2.5, 14.3 +/- 0.9; mean +/- SEM). Similar results were obtained with quartz and diesel particles. A strong correlation was observed between particle load per cell and AM RAS after uptake of fluorescent latex beads or fluorescent TiO2 (coated with BODIPY-BSA) (R2 = 0.984, 0.997, respectively). Using this technique, we found AM uptake of environmental particulates to be substantially greater than that of a panel of myelomonocytic and epithelial cell lines, consistent with their physiologic role in pulmonary defenses. RAS measurements have also identified both calcium-dependent and calcium-independent components in AM interactions with inert particles. Although this technique does not allow precise quantitation of particle number or mass per cell, flow cytometric analysis of relative increases in RAS is a useful tool to study AM interactions with a variety of environmental particulates.
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Lim RW, Zhu CY, Stringer B. Differential regulation of primary response gene expression in skeletal muscle cells through multiple signal transduction pathways. BIOCHIMICA ET BIOPHYSICA ACTA 1995; 1266:91-100. [PMID: 7718627 DOI: 10.1016/0167-4889(94)00226-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
One of the earliest cellular responses to growth factors is the rapid induction of primary response genes. One group of such genes was originally isolated as tetradecanoyl phorbol acetate (TPA) inducible sequences (TIS genes) from mouse 3T3 cells. Proteins encoded by the TIS genes include two transcription factors: TIS8 (also known as egr1/NGFIA/zif268) and TIS1 (also known as NGFIB/nur77/N10). We have examined the inducibility of these two genes in a skeletal muscle cell line in response to agents that have been reported to block muscle differentiation. We report here that basic fibroblast growth factor (bFGF) induced the expression of both TIS1 and TIS8 in mouse C2C12cells. Both genes were also inducible by TPA while forskolin which activates the cAMP-dependent pathway induced TIS1 but not TIS8. Down-regulation of protein kinase C (PKC) activity by TPA pretreatment repressed the bFGF induction of TIS1 but had little effect on the bFGF-stimulated expression of TIS8. Moreover, while both TPA and bFGF stimulated the hyperphosphorylation of c-RAF and the activity of MAP kinase, TPA pretreatment failed to block RAF phosphorylation or the stimulation of MAP kinase activity by bFGF. Induction of the two TIS genes in skeletal myoblasts therefore appeared to be dependent to different extents on the activation of protein kinase A (PKA), PKC and MAP kinase.
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Stringer B. A deadly design. THE CANADIAN NURSE 1993; 89:34-6. [PMID: 8261373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
On September 30, 1991, registered nurse Bev Holmwood sustained a needlestick injury while working in a Vancouver Island operating room. Just over two months later she died, the result of hepatitis C she contracted during the accident. Her story is a sad reminder of what research has already shown: Sharps injuries are the single greatest cause of serious, and often deadly, infection among nurses and other health care workers.
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Stringer B, Smith JA, Scharf S, Valentine A, Walker MM. A study of the use of gloves in a large teaching hospital. Am J Infect Control 1991; 19:233-6. [PMID: 1755547 DOI: 10.1016/s0196-6553(05)80254-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A study was conducted in the wards and laboratory of a 900-bed teaching hospital to determine the appropriateness of glove use. In the wards the rate of appropriate use was 59%, and in the laboratory it was 90%. In general, in the patient areas gloves were used for specific tasks (70%) whereas in the laboratory use for a specific task was only 32%. Financial savings could be realized by educational programs in infection control directed toward a more rational use of gloves.
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Stringer B. Summer of our discontent. THE CANADIAN NURSE 1990; 86:18. [PMID: 2376038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Gupta R, Stringer B, Meakin A. A Study to Access the Effectiveness of Home‐based Reinforcement in a Secondary School: Some Preliminary Findings. EDUCATIONAL PSYCHOLOGY IN PRACTICE 1990. [DOI: 10.1080/0266736900050406] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Lemoine NR, Mayall ES, Wyllie FS, Williams ED, Goyns M, Stringer B, Wynford-Thomas D. High frequency of ras oncogene activation in all stages of human thyroid tumorigenesis. Oncogene 1989; 4:159-64. [PMID: 2648253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Using polymerase chain reaction amplification and oligonucleotide probing, the activation of ras oncogenes in 24 benign and 20 malignant human thyroid neoplasms was examined. The frequency of ras oncogene activation was similar at all stages of tumorigenesis in this system, being found in 33% of adenomas overall (50% of microfollicular tumours), 53% of differentiated follicular carcinomas and 60% of undifferentiated carcinomas. This supports the contention that mutation of these oncogenes occurs at an early step in tumorigenesis. The predominant amino acid substitution in the differentiated tumours was glutamine to arginine at position 61 of Ha-ras or N-ras, but this mutation was not found in any of the undifferentiated tumours. It was noted that while transition mutations predominated in differentiated tumours (both benign and malignant), transversions were more common in the undifferentiated tumours.
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Toraason M, Stringer B, Smith R. Ornithine decarboxylase activity in the neonatal rat heart following prenatal exposure to ethylene glycol monomethyl ether. Drug Chem Toxicol 1986; 9:1-14. [PMID: 3743459 DOI: 10.3109/01480548609042825] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
In mammals, ornithine decarboxylase (ODC) activity is highest during periods of rapid cellular growth and development, and the normal pattern of ODC activity during this period is sensitive to chemical and drug exposure. The industrial solvent ethylene glycol monomethyl ether (EGME) is teratogenic to rats and mice, with the heart being particularly sensitive. Basal ODC activity and ODC activity following an isoproterenol challenge were used to assess heart function in 3-, 9-, 16- and 22-day-old offspring from dams treated with 25 mg/kg EGME by gavage on days 7-13 or 13-19 of gestation. Reproductive outcome was not affected by EGME and none of the offspring had gross physical abnormalities. Gestation length was prolonged by both EGME treatments, but the increase was statistically significant only in the group treated on days 7-13 gestation. ODC activity per mg protein was greatest in 3-day-old rats and dropped off sharply during the following 3 weeks. In 3-day-old rats exposed on days 7-13 of gestation, ODC activity was 54% of that found in controls. ODC activity was comparable to that in controls in 3-day-old rats exposed on days 13-19 of gestation. Isoproterenol increased ODC activity in all groups, but additional functional abnormalities were not revealed by the isoproterenol challenge.
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Sollenberg J, Phipps FC, Stringer B, Lowry LK. Determination of methylhippuric acid in human urine by high-performance liquid chromatography and by isotachophoresis. JOURNAL OF CHROMATOGRAPHY 1985; 343:419-23. [PMID: 4066882 DOI: 10.1016/s0378-4347(00)84612-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Toraason M, Stringer B, Stober P, Hardin BD. Electrocardiographic study of rat fetuses exposed to ethylene glycol monomethyl ether (EGME). TERATOLOGY 1985; 32:33-9. [PMID: 4035590 DOI: 10.1002/tera.1420320106] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The widely used industrial solvent ethylene glycol monomethyl ether (EGME) is teratogenic to rats and mice, inducing a variety of heart and major vessel abnormalities. In the present study, electrocardiography was used to evaluate heart function in day 20 rat (Sprague-Dawley) fetuses from mothers treated on gestation days 7-13 (sperm = day 1) with 0, 25, or 50 mg/kg EGME by gavage in 10 ml/kg water. The increased incidence of fetuses with cardiovascular malformations (primarily right ductus arteriosus and ventricular septal defect) and abnormal electrocardiograms (EKG) was dose dependent. The most prevalent EKG abnormality was a prolonged QRS wave. Mean QRS intervals were not significantly increased by EGME exposure, but there were significantly more litters in the 50-mg/kg EGME group that had one or more fetuses with QRS complexes of 40 msec or longer. The enhanced duration and the appearance of the aberrant QRS's suggested the presence of an intraventricular conduction delay in these fetuses. Heart rate and other EKG characteristics such as the P wave or P-R and Q-T intervals were not significantly affected by exposure to EGME. There did not appear to be an association between abnormal EKG's and fetal heart dysmorphology.
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Stringer B. Health hazards in PARR. Striving for a safer work environment. CANADIAN OPERATING ROOM NURSING JOURNAL 1985; 3:14-20. [PMID: 3855110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Stringer B. Nurse heal thyself: your work could be killing you. THE CANADIAN NURSE 1984; 80:19-22. [PMID: 6568849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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Stringer B, Wynford-Thomas D, Jasani B, Williams ED. Effect of goitrogen administration on the circadian rhythm of serum thyroid stimulating hormone in the rat. ACTA ENDOCRINOLOGICA 1981; 98:396-401. [PMID: 7293669 DOI: 10.1530/acta.0.0980396] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Adult male rats were fed a goitrogen, aminotriazole, for 74 days at a dose known to suppress thyroid function completely. At the end of this period, these animals along with matched controls were killed in groups of seven at 3 hourly intervals throughout a 24 hour period, and serum TSH, T3, T4 and albumin assayed. No significant circadian rhythms of T3, T4 or albumin were found in either, but a highly significant rhythm of TSH was demonstrated both in controls and goitrogen treated groups, with a diminished relative amplitude in the latter. The results indicate that a significant diurnal rhythm of serum TSH persists in the rat despite long-term blockade of thyroid hormone synthesis and that the existence of this rhythm is therefore independent of the presence of circulating T3 or T4.
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Wynford-Thomas D, Stringer B, Newman GR. Hydroxyethylmethacrylate embedding: an improved technique. MEDICAL LABORATORY SCIENCES 1981; 38:121-2. [PMID: 7040897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Balsam D, Goldfarb CR, Stringer B, Farruggia S. Bone scintigraphy for neonatal osteomyelitis: simulation by extravasation of intravenous calcium. Radiology 1980; 135:185-6. [PMID: 7360958 DOI: 10.1148/radiology.135.1.7360958] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Intravenously administered calcium gluconate has become increasingly popular in the treatment of neonatal tetany. Occasionally, extravasation results in cellulitis, leading to a clinical diagnosis of superimposed osteomyelitis. Osseous scintigraphy, as the accepted modality in the early detection of osteomyelitis, would tend to be used in this circumstance. This case illustrates a false-positive result, probably due to soft-tissue calcification.
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Bagnasco FM, Stringer B, Muslim AM. Carbon tetrachloride poisoning. Radiographic findings. NEW YORK STATE JOURNAL OF MEDICINE 1978; 78:646-7. [PMID: 273758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Barker G, Stringer B, Williams M. The determination of electron capture rate constants by the study of photocurrent systems in the non-steady state. ACTA ACUST UNITED AC 1974. [DOI: 10.1016/s0022-0728(74)80247-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Barker GC, Fowles P, Sammon DC, Stringer B. Pulse radiolytic induced transient electrical conductance in liquid solutions. Part 1.—Technique and the radiolysis of water. ACTA ACUST UNITED AC 1970. [DOI: 10.1039/tf9706601498] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Barker GC, Fowles P, Stringer B. Pulse radiolytic induced transient electrical conductance in liquid solutions. Part 2.—Radiolysis of aqueous solutions of NO–3, NO–2 and Fe(CN)3–6. ACTA ACUST UNITED AC 1970. [DOI: 10.1039/tf9706601509] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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