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431.
Aristeidis E. Niotis Christos Mastichiadis Panagiota S. Petrou Ion Christofidis Sotirios E. Kakabakos Athanasia Siafaka-Kapadai Konstantinos Misiakos 《Analytical and bioanalytical chemistry》2010,396(3):1187-1196
The early diagnosis of acute myocardial infarction requires the determination of several markers in serum shortly after its
incidence. The markers most widely employed are the isoenzyme MB of creatine kinase (CK-MB) and the cardiac troponin I (cTnI).
In the present work, a capillary waveguide fluoroimmunosensor for fast and highly sensitive simultaneous determination of
these markers in serum samples is demonstrated. The dual-analyte immunosensor was realized using glass capillaries internally
modified with an ultrathin poly(dimethylsiloxane) film by creating discrete bands of analyte-specific antibodies. The capillary
was then filled with a mixture of sample and biotinylated detection antibodies followed by reaction with streptavidin–horseradish
peroxidase and incubation with a fluorescently labeled tyramide derivative to accumulate fluorescent labels onto immunoreaction
bands. Upon scanning the capillary with a laser beam, part of the emitted fluorescence is trapped and waveguided through the
capillary wall to a photomultiplier placed on one of its ends. The employment of tyramide signal amplification provided detection
limits of 0.2 and 0.5 ng/mL for cTnI and CK-MB, respectively, in a total assay time of 30 min compared to 0.8 and 0.6 ng/mL
obtained for the corresponding assays when the conventional fluorescent label R-phycoerythrin was used in a 65-min assay.
In addition, the proposed immunosensor provided accurate and repeatable measurements (intra-assay and interassay coefficients
of variation lower than 10%), and the values determined in serum samples were in good agreement with those obtained with commercially
available enzyme immunoassays. Thus, the proposed capillary waveguide fluoroimmunosensor has all the required characteristics
for fast and reliable diagnosis of acute myocardial infarction.
相似文献
432.
Claudia Stihi Ion V. Popescu Marina Frontasyeva Cristiana Radulescu Otilia Culicov 《Analytical letters》2017,50(17):2851-2858
ABSTRACTHeavy metal air pollution in Romania was investigated by using passive moss biomonitoring. This study is a component of an international UNECE ICP Vegetation Program – moss survey. A total of 330 samples of Hypnum cupressiforme, Hylocomium splendens, Pleurozium schreberi, and other mosses were collected in Romania in the summer and autumn of 2010. The concentrations of aluminum, cadmium, chromium, copper, iron, lead, nickel, vanadium, and zinc were determined by graphite furnace/flame atomic absorption spectrometry and instrumental neutron activation analysis. The results were statistically processed to obtain spatial distribution maps of factor scores based on elemental concentrations in the moss, together with the spatial distribution maps of heavy metals in moss. The median concentrations of cadmium, 1.20?mg/kg dry weight, and lead, 30.8?mg/kg dry weight, were high compared with other European countries. The results revealed that the atmospheric deposition of these metals is a problem in north and northwest Romania. 相似文献
433.
Ion L Nieto S Pérez J Riera L Riera V Díaz J López R Anderson KM Steed JW 《Inorganic chemistry》2011,50(17):8524-8531
Rhenium(I) compounds [Re(CO)(3)(Hdmpz)(2)(ampy)]BAr'(4) and [Re(CO)(3)(N-MeIm)(2)(ampy)]BAr'(4) (Hdmpz = 3,5-dimethylpyrazole, N-MeIm = N-methylimidazole, ampy = 2-aminopyridine or 3-aminopyridine) have been prepared stepwise as the sole reaction products in good yields. The cationic complexes feature two different types of hydrogen bond donor ligands, and their anion binding behavior has been studied both in solution and in the solid state. Compounds with 2-ampy ligands are labile in the presence of nearly all of the anions tested. The X-ray structure of the complex [Re(CO)(3)(Hdmpz)(2)(ampy)](+) (2) shows that the 2-ampy ligand is metal-coordinated through the amino group, a fact that can be responsible for its labile character. The 3-ampy derivatives (coordinated through the pyridinic nitrogen atom) are stable toward the addition of several anions and are more selective anion hosts than their tris(pyrazole) or tris(imidazole) counterparts. This selectivity is higher for compound [Re(CO)(3)(N-MeIm)(2)(MeNA)]BAr'(4) (5·BAr'(4), MeNA = N-methylnicotinamide) that features an amido moiety, which is a better hydrogen bond donor than the amino group. Some of the receptor-anion adducts have been characterized in the solid state by X-ray diffraction, showing that both types of hydrogen bond donor ligands of the cationic receptor participate in the interaction with the anion hosts. DFT calculations suggest that coordination of the ampy ligands is more favorable through the amino group only for the cationic complex 2, as a consequence of the existence of a strong intramolecular hydrogen bond. In all other cases, the pyridinic coordination is clearly favored. 相似文献
434.
435.
436.
We give an extension of Hoeffding’s inequality to the case of supermartingales with differences bounded from above. Our inequality strengthens or extends the inequalities of Freedman, Bernstein, Prohorov, Bennett and Nagaev. 相似文献
437.
Ion Necoara Yurii Nesterov François Glineur 《Journal of Optimization Theory and Applications》2017,173(1):227-254
In this paper we develop random block coordinate descent methods for minimizing large-scale linearly constrained convex problems over networks. Since coupled constraints appear in the problem, we devise an algorithm that updates in parallel at each iteration at least two random components of the solution, chosen according to a given probability distribution. Those computations can be performed in a distributed fashion according to the structure of the network. Complexity per iteration of the proposed methods is usually cheaper than that of the full gradient method when the number of nodes in the network is much larger than the number of updated components. On smooth convex problems, we prove that these methods exhibit a sublinear worst-case convergence rate in the expected value of the objective function. Moreover, this convergence rate depends linearly on the number of components to be updated. On smooth strongly convex problems we prove that our methods converge linearly. We also focus on how to choose the probabilities to make our randomized algorithms converge as fast as possible, which leads us to solving a sparse semidefinite program. We then describe several applications that fit in our framework, in particular the convex feasibility problem. Finally, numerical experiments illustrate the behaviour of our methods, showing in particular that updating more than two components in parallel accelerates the method. 相似文献
438.
Masaru Kawaguchi Atsushi Ikeda Seiji Shinkai Ion Neda 《Journal of inclusion phenomena and macrocyclic chemistry》2000,37(1-4):253-258
[60]Fullerene (C60)-calix[n]areneinteractions were studied in toluene:MeCN = 10:1 (v/v)using an electrochemical method. In the presence ofhomooxacalix[3]arenes and calix[5]arenes, bothEpc and pa shifted to the negativepotential, whereas they were scarcely affected by theaddition of calix[4]arenes. The2values electrochemically determined forthe association with C60
- are generallysmaller than the 1 valuesspectroscopically determined for the association withC60. The tendency indicates that thecharge-transfer-type interaction is one of thedriving forces for C60 inclusion.thanks|Author for correspondence 相似文献
439.
Hervè Pelletier Adele Carradò Jacques Faerber Ion N. Mihailescu 《Applied Physics A: Materials Science & Processing》2011,102(3):629-640
We synthesized by pulsed laser deposition a bilayer of Ti/TiN on Si(100) wafers which was coated in a next step with hydroxyapatite (samples labelled HA-1). Some of the structures were further thermally treated in a water vapour jet (samples labelled HA-2). In SEM, the HA surface looked rough, with micronic droplets. TEM and SAED investigations revealed a compact organization of HA crystals in the case of the HA-1 sample, while two regions (one compact and one porous) were identified for the HA-2 sample, with triclinic HA crystals within the 500 nm range. In XTEM, at the Si/TiN border, a 2–3 nm SiO2 layer was visible, whereas at the TiN/Ti border there was a smooth transition from fcc (111) TiN to hcp (100) Ti. The HA crystals were elongated normal to the surface. According to Berkovich indentation qualitative analyses, the sample HA-1 was more homogeneous and harder but brittle. Scratch tests confirmed quantitatively that HA-1 was more resistant and adherent than HA-2 films. In the first case, the big droplets only were removed by the indenter, while the HA-2 films were delaminated on large areas as a result of wedge spallation failure. 相似文献
440.
George Filoti Juan BartolomePetru Palade Ion PrisecaruCristina Valsangiacom Victor KuncserIoana Mîndru Lumini?a Patron 《Journal of magnetism and magnetic materials》2011,323(8):1044-1053
Oxalates containing various 3d transitional elements and positive NH4 or negative OH groups were newly synthesized. Each above-mentioned component has directly influenced the structure, the electronic or interaction properties, while some unexpected behaviors were revealed by various magnetic and Mössbauer measurements. The main magnetic parameters, the long-range anti-ferromagnetic couplings observed at very low temperature and, particularly the uncompensated moment are discussed in detail. The induced lower spin states for bivalent ions and especially the anti-parallel arrangement of the spins belonging to trivalent and bivalent iron inside the molecule are also emphasized. 相似文献