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A label-free DNA-based electrochemical biosensor owning high sensitivity and selectivity has been established for detecting bisphenol A in a wide range of applications. Coupling the high electrochemical performance of graphene oxide-thionine-Au nanomaterial with the specific binding capacity of the aptamers to BPA, the monitoring of trace amount of BPA was realized, the detection limit was 3.3 pg ⋅ mL−1 with strong anti-interference. Besides, using molecular docking, it was found that BPA binds to the bases DC-49, DC-51, DG-52, DG-53 and DA-63 on the aptamer via hydrogen bonding and π-π stacking interactions. Finally, the biosensor had been successfully applied in different real samples. 相似文献
3.
In this Note we present an approach to determine the local minima of a specific class of minimization problems. Attention is focused on the inextensibility condition of flexible rods expressed as a nonconvex constraint. Two algorithms are derived from a special splitting of the Lagrangian into the difference of two convex functions (DC). They are compared to the augmented Lagrangian methods used in this context. These DC formulations are easily extended to contact problems and applied to the determination of confined buckling shapes. To cite this article: P. Alart, S. Pagano, C. R. Mecanique 330 (2002) 819–824. 相似文献
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Abstract Modifications induced by the combined application of pressure (up to 800 MPa) and temperature (up to 80° C) were studied on wet and dry semolina, and on fresh pasta as such and after cooking. Rheological and immunochemical properties of the treated products were investigated, along with parameters indicating the extent of protein denaturation. No modification occurs in semolina treated at less than 45% water, below 60°C/800MPa for 10min. Egg noodles prepared from pressure/heat treated semolina had increased protein digestibility and low recognition by anti-gliadin antibodies either before or after cooking. The same effects were observed in heat/pressure treated pasta, but were lost upon subsequent cooking, although we found decreased immunochemical reactivity after heat/pressure treatment of cooked pasta. No sensory difference was found between cooked and pressure-treated semolina products. 相似文献
6.
K. Runge 《Isotopes in environmental and health studies》2013,49(4):176-177
Neben ihrer breiten Anwendung in der Nuklearmedizin gewinnen Radionuklidgeneratoren zunehmend auch für die verfahrensctechnische Forsehung Bedeutung. Es konnte gezeigt warden, daß die Generatorsysteme 99Mo/99mTe und 113Sn/113mI für zahlreiche Untersuchungen von Transportund Mischvorgängen in technischen Anlagen genutzt warden könnea [1, 2]. Der Radionuklidgenerator 110Ba/110La hat für den Einsatz in der Technik günstigere Eigenschaftcn als die für die Nuklearmedizin entwickelten Generatoren. Insbesondere für die Untersuchung der Materialtransportvorgänge in Polykondensationsreaktoren der Chemiefaserindustrie hat sich ein Lanthan-140-Generator gut bewährt, der mit Tributylphosphat (gesättigt mit 13 N HN03) als Elutionsmittel arbeitet [3, 4]. 相似文献
7.
Colorimetric and Spectrofluorimetric Methods for the Determination of Melatonin in Tablets and Serum
Abstract Two sensitive and accurate colorimetric and spectrofluonmetric methods, are presented for the determination of melatonin in tablets and serum. The first method utilizes the reactions of p-dimethylaminobenzaldehyde in hydrochloric acid (van Urk reagent)-ferric chloride in sulphuric acid (Salkowski reagent) mixture. The blue color of the resulting reaction product is measured at 630 nm. The second method is based on the reaction of melatonin with o-phthalaldehyde in acid medium which yields highly fluorescent condensation product that is measured at 465 nm as emission wavelength, using excitation wavelength at 355 nm. No interference was observed from tableting additives, and the applicability of the methods was examined by analysing tablets containing melatonin (single and combined with pyridoxine). Mean percentage recoveries from tablets were found to be 99.9+0.31 for single and 100.5+0.15 for combined tablets using colorimetric method, while by applying spectrofluorimetric method the recoveries were found to be 100.610.41 for single and 100.2+0.39 for combined tablets. Furthermore, the proposed methods were extended to the in-vitro determination of melatonin in serum. The detection limits are 0.27 ug ml?1 for colorimetric method and 0.00035 ug ml?1 for spectrofluorimetric method. 相似文献
8.
A modified method for preparing 99mTc-FHMA for pulmonary studies is elabrated. It includes a new antioxidant sodium metabisulphite. The optimum conditions for the reparation are given. A simple and rapid procedure with a yield more than 98% is described which eliminates a further purification step. 相似文献
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The ac conductivity of three fluorides of A2MII+ MIII + F9 type, Sr2NiAlF9, Sr2ZnGaF9 and Ba2MnCrF9, between 293 and 773K, has been analyzed within a combined complex impedance and modulus formalism. The antiferroelectric-paraelectric phase transition of Sr2ZnGaF9 has been characterized. A hopping mechanism for charge carriers is suggested for the three materials; their electrical performance are relatively weak. Sr2NiAlF9 and Sr2ZnGaF9 can be considered as ionic conductors of the F- ion. On the contrary, the conductivity in Ba2MnCrF9 is rather of an electronic nature. 相似文献
10.
Due to the anisotropy of the conductivity in AsF5-intercalated HOPG, eddy current methods have to be used for the measurement of transport effects. The measurements yield carrier concentration, mobility and charge transfer for C8nAsF5 with n=l-4 at temperatures between 4.2K and 300K. 相似文献