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101.
Assessment of block and random copolymer overlayers on polymer optical fibers toward protein detection through electrostatic interaction 下载免费PDF全文
Alexandros El Sachat Anastasia Meristoudi Stergios Pispas Christos Riziotis 《Journal of Polymer Science.Polymer Physics》2015,53(5):327-334
A simple fiber optic based scheme for the selective detection of proteins, based on surface electrostatic interactions, is presented. The implementation of this method is conducted using a modified polymer optical fiber's surface and thin overlayers of properly designed sensitive copolymer materials with predesigned molecular characteristics. Block poly(styrene‐b‐2vinylpyridine) (PS‐b‐P2VP) and random PS‐r‐P2VP copolymers of the same monomers and similar molecular weights, were modified and used as sensing materials. This configuration proved to be efficient concerning the fast detection of charged proteins, and also the efficient discrimination of differently charged proteins such as lysozyme and bovine serum albumin. Results on the sensing performance of block and random copolymers are also discussed drawing conclusion on their efficiency given their considerable different fabrication cost. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 327–334 相似文献
102.
Maria I. Krevvata Nikos Afratis Anastasia Spiliopoulou Christina J. Malavaki Fevronia Kolonitsiou Evangelos Anastassiou Nikos K. Karamanos 《Biomedical chromatography : BMC》2011,25(5):531-534
The extracellular slime of Staphylococcus epidermidis contains, amongst various macromolecules, an acidic polysaccharide (PS) of a molecular mass of 20 kDa with significant antigenic and biological properties. The isolation procedure used so far includes multiple fractionations in anion‐exchange chromatographic columns before its final purification by gel filtration chromatography. This protocol is laborious, time‐consuming and includes the risk of unnecessary loss of PS quantities. Because of the significance of this PS, a modified protocol resulting in an easier and quicker isolation procedure was developed. Furthermore, identification, purity, charge density and molecular integity of the isolated polysaccharide were evaluated by a reverse‐polarity capillary electrophoresis method. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
103.
The synthesis of four deuterated sialic acids and their 1,7-lactones has been performed in two ways, one based on sialic acid classical chemistry, and the other involving a direct exchange of the unlabeled acyl group of N-acetylneuraminic acid with a labeled one mediated by a perfluorinated amide. The final lactonization is promoted by benzyloxycarbonyl chloride. 相似文献
104.
105.
A method for the determination of vapor–liquid phase diagram structure of five-component systems based on the analysis of types and Poincare indexes of singular points of the geometric scan and full structure of the concentration simplex is proposed. Validity of the proposed method was demonstrated by vapor–liquid equilibrium modeling in five-component mixtures: ethanol + water + toluene + butanol + chlorbenzene and acetone + chloroform + ethanol + cyclohexane + water. 相似文献
106.
Teng-yi Huang Anastasia Kharlamova Scott A. McLuckey 《Journal of the American Society for Mass Spectrometry》2010,21(1):144-153
Gas-phase dissociation of model locked nucleic acid (LNA) oligonucleotides and functional LNA-DNA chimeras have been investigated
as a function of precursor ion charge state using ion trap collision-induced dissociation (CID). For the model LNA 5 and 8
mer, containing all four LNA monomers in the sequence, cleavage of all backbone bonds, generating a/w-, b/x-, c/y-, and d/z-ions,
was observed with no significant preference at lower charge states. Base loss ions, except loss of thymine, from the cleavage
of N-glycosidic bonds were also present. In general, complete sequence coverage was achieved in all charge states. For the
two LNA-DNA chimeras, however, dramatic differences in the relative contributions of the competing dissociation channels were
observed among different precursor ion charge states. At lower charge states, sequence information limited to the a-Base/w-fragment
ions from cleavage of the 3′C-O bond of DNA nucleotides, except thymidine (dT), was acquired from CID of both the LNA gapmer
and mixmer ions. On the other hand, extensive fragmentation from various dissociation channels was observed from post-ion/ion
ion trap CID of the higher charge state ions of both LNA-DNA chimeras. This report demonstrates that tandem mass spectrometry
is effective in the sequence characterization of LNA oligonucleotides and LNA-DNA chimeric therapeutics. 相似文献
107.
A new, rapid, sensitive and selective HPLC method with fluorescence detection is described for the simultaneous determination of 12 sulfonamides, in the presence of putrescine as internal standard, after pre‐column derivatization with fluorescamine. The drugs were separated on a Chromolith Performance RP‐18 column (100×4.6 mm), using a gradient elution with a binary mobile phase of methanol/0.05 M acetate buffer (pH 3.4). Linearity of derivatization was obtained for concentrations from 3.0 to 300 μg/L in standard solutions. The whole procedure was evaluated and fully validated, according to the European Union Decision 2002/657/EC, for the determination of sulfonamides in turkey muscle and hen eggs following SPE. The LODs varied from 2 to 17 μg/kg in turkey and 2 to 15 μg/kg in egg samples. The average recoveries ranged between 96.9–108.6% in turkey muscle and 96.0–108.4% in egg samples, respectively. 相似文献
108.
Anastasia Rusina Maxim Durach Mark I. Stockman 《Applied Physics A: Materials Science & Processing》2010,100(2):375-378
In this Letter we develop a theory of spoof plasmons propagating on real metals perforated with planar periodic grooves. Deviation
from the spoof plasmons on perfect conductor due to finite skin depth has been analytically described. This allowed us to
investigate important propagation characteristics of spoof plasmons such as quality factor and propagation length as the function
of the geometrical parameters of the structure. We have also considered THz field confinement by adiabatic increase of the
depth of the grooves. It is shown that the finite skin depth limits the propagation length of spoof plasmons as well as a
possibility to localize THz field. Geometrical parameters of the structure are found which provide optimal guiding and localization
of THz energy. 相似文献
109.
We start from a realistic half space model for thermal imaging, which we then use to develop a mathematical asymptotic analysis well suited for the design of reconstruction algorithms. We seek to reconstruct thermal anomalies only through their rough features. With this way our proposed algorithms are stable against measurement noise and geometry perturbations. Based on rigorous asymptotic estimates, we first obtain an approximation for the temperature profile which we then use to design nonit-erative detection algorithms. We show on numerical simulations evidence that they are accurate and robust. Moreover, we provide a mathematical model for ultrasonic temperature imaging, which is an important technique in cancerous tissue ablation therapy.AMS subject classifications: 35R20, 35B30 相似文献
110.
The paper deals with the assignment of a single server to two retrial queues. Each customer reapplies for service after an
exponentially distributed amount of time. The server operates at customer dependent exponential rates. There are holding costs
and costs during service per customer and per unit of time. We provide conditions on which it is optimal to allocate the server
to queue 1 or 2 in order to minimize the expected total costs until the system is cleared. 相似文献