187 resultados para In-situ Detection


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A surface plasmon resonance (SPR) biosensor screening assay was developed and validated to detect 11 benzimidazole carbamate (BZT) veterinary drug residues in milk. The polyclonal antibody used was raised in sheep against a methyl 5(6)-[(carboxypentyl)-thio]-2-benzimidazole carbamate protein conjugate. A sample preparation procedure was developed using a modified QuEChERS method. BZT residues were extracted from milk using liquid extraction/partition with a dispersive solid phase extraction clean-up step. The assay was validated in accordance with the performance criteria described in 2002/657/EC. The limit of detection of the assay was calculated from the analysis of 20 known negative milk samples to be 2.7 mu g kg(-1). The detection capability (CC beta) of the assay was determined to be 5 mu g kg(-1) for 11 benzimidazole residues and the mean recovery of analytes was in the range 81-116%. A comparison was made between the SPR-biosensor and UPLC-MS/MS analyses of milk samples (n = 26) taken from cows treated different benzimidazole products, demonstrating the SPR-biosensor assay to be fit for purpose. (C) 2009 Elsevier B.V. All rights reserved.

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A controlled-atmosphere chamber, combined with a CCTV system, is used to monitor continuously the change in shape of water droplets on the self-cleaning commercial glass, Activ, and a sol-gel TiO2 substrate during their irradiation with either UVA or UVC light. This system allows the photoinduced superhydrophilic effect (PSH) exhibited by these materials to be studied in real time under a variety of different conditions. UVA was less effective than UVC in terms of PSH for both titania-coated glasses, and plain glass was unaffected by either form of UV irradiation and so showed no PSH activity. With UVA, ozone increased significantly the rate of PSH for both substrates, but had no effect on the wettability of plain glass. For both titania substrates and plain glass, no PSH activity was observed under an O-2-free atmosphere. A more detailed study of the PSH effect exhibited by Activ revealed that doping the water droplet with either an electron acceptor (Na2S2O8), electron donor (Na2S2O4), or simple electrolyte (KCl) in the absence of oxygen did not promote PSH. However, when Activ was UV irradiated, while immersed in a deoxygenated KCl solution, prior to testing for PSH activity, only a small change in contact angle was observed, whereas under the same conditions, but using a deoxygenated persulfate-containing immersion solution, it was rendered superhydrophilic. The correlation between organic contaminant removal and surface wetting was also investigated by using thick sol-gel films coated with stearic acid; the destruction of SA was monitored by FTIR and sudden wetting of the surface was seen to coincide with the substantial removal of the organic layer. The results of this work are discussed in the context of the current debate on the underlying cause of PSH.

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Objectives This study describes the in-situ gelling of econazole nitrate containing thermosensitive polymers composed of poloxamer 407 and 188 as a novel treatment platform for vaginal candidiasis.

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We have used interphase fluorescence in situ hybridization (IFISH) to detect trisomy 8, trisomy 9 and 20q deletion in circulating granulocytes from patients with polycythaemia vera (PV). Out of 64 PV patients, 15 (23%) exhibited an abnormality. Two patients had trisomy 9, three had trisomy 8 and 10 patients had hemizygous deletion of D20S108 (a locus in the 20q common deleted region). Aberrant nuclei ranged from 10% to 80% in these 15 cases. There was no correlation between the presence of a marker and sex, age, interval between presentation and IFISH analysis, neutrophil or platelet count or therapy. Conventional marrow cytogenetic karyotype results were available in 23 cases and there was concurrence between these and blood IFISH in 16 cases (13 normal and three with 20q/D20S108 deletion by both methods). Three patients with D20S108 deletion by IFISH were normal by previous marrow cytogenetic testing and four cases with 20q deletion by previous marrow cytogenetics had normal blood granulocytes according to IFISH. Thus, we confirm that trisomies 8 and 9 and deletion of 20q are diagnostically useful markers of PV. IFISH analysis of blood granulocytes is a practical method for detecting these markers, but as an adjunct to, not as a substitute for, conventional marrow cytogenetics.

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With greater emphasis now being placed on the durability of concrete and the need for on-site characterization of concrete for durability, there is an increasing dependence on the measurement of the permeation properties of concrete. Such properties can be measured in the laboratory under controlled ambient conditions, namely, temperature and relative humidity, and comparisons made between samples not affected by testing conditions. An important factor that influences permeation measurements is the moisture state of the concrete prior to testing. Moisture gradients are known to exist in exposed concretes; therefore, all laboratory tests are generally carried out after preconditioning to a reference moisture state. This is reasonably easy to achieve in the laboratory, but more difficult to carry out on-site. Different methods of surface preconditioning in situ concrete are available; however, there is no general agreement on the suitability of any one method. Therefore, a comprehensive set of experiments was carried out with four different preconditioning methods. Results from these investigations indicated that only superficial drying could be achieved by using any of the preconditioning methods investigated and that significant moisture movement below a depth of 15 mm was not evident.

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Numerous methods are available to measure the permeation properties of concrete, which can be classified in terms of the diffusion, absorption and permeability properties. The results from these tests are generally used to infer 'quality' or relative durability. Some of these tests involve the laboratory assessment of a sample of concrete extracted from the structure. However, this Technical Note concentrates on the alternative methods appropriate for use on site. Guidance is given on the choice of an appropriate test method, which in most practical situations depends on the predominant mechanism acting on the concrete under consideration.

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A full-scale seven-storey in-situ advanced reinforced concrete building frame was constructed in the Building Research Establishment's Cardington laboratory encompassing a range of different concrete mixes and construction techniques. This provided an opportunity to use in-situ non-destructive test methods, namely Lok and CAPO tests, on a systematic basis during the construction of the building. They were used in conjunction with both standard and temperature-matched cube specimens to assess their practicality and their individual capabilities under field conditions. Results have been analysed and presented to enable comparisons of the performance of the individual test methods employed.