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351.
Korbakov N Timmerman P Lidich N Urbach B Sa'ar A Yitzchaik S 《Langmuir : the ACS journal of surfaces and colloids》2008,24(6):2580-2587
An inclusion complex between water-soluble p-sulfocalix[n]arene (Cn, n=4, 6, 8) and the chromophore trans-4-[4-(dimethylamino)styryl]-1-methylpyridinium-p-toluenesulfonate (D) formed the basis for a highly sensitive sensor for the selective detection of neurotransmitter acetylcholine (ACh). Formation of the [Cn.D] complex (Ka=approximately 10(5) M(-1)) was accompanied by a drastic increase (up to 20-60-fold) in the chromophore relative quantum yield and by a large hypsochromic shift of the emission band maximum. The observed optical effects are fully reversible: ACh displaces the chromophore molecules from the calixarene cavity as shown by the reappearance of the free chromophore emission band. Formation and dissociation of the complex were studied by fluorescence, 1H NMR, and UV-vis absorption spectroscopies. The [Cn.D] complex is capable of sensing ACh selectively in solution at sub-micromolar concentrations. Immobilization of monocarboxyl p-sulfocalix[4]arene (C4m) on an oxide-containing silicon surface is in keeping with its properties, such as chromophore binding and the ability of the immobilized inclusion complex to detect ACh. The unique [Cn.D] complex optical switching paves the way for application in ACh imaging and optoelectronic sensing. 相似文献
352.
Julia Gatenyo Kevin Johnson Anuruddha Rajapakse Kent S. Gates Shlomo Rozen 《Tetrahedron》2012,68(43):8942-8944
Heterocyclic benzotriazine N-oxides are an interesting class of experimental anticancer and antibacterial agents. Analogs with 18O incorporated into the N-oxide group may offer useful mechanistic tools. We describe the use of H218OF·CH3CN in a fast, readily executed and high-yielding preparation of 1,2,4-benzotriazine 1,4-dioxides containing an 18O-label at the 4-oxide position. 相似文献
353.
Phylogenetic reconstruction methods attempt to reconstruct a tree describing the evolution of a given set of species using sequences of characters (e.g. DNA) extracted from these species as input. A central goal in this area is to design algorithms which guarantee reliable reconstruction of the tree from short input sequences, assuming common stochastic models of evolution. The fast converging reconstruction algorithms introduced in the last decade dramatically reduced the sequence length required to guarantee accurate reconstruction of the entire tree. However, if the tree in question contains even few edges which cannot be reliably reconstructed from the input sequences, then known fast converging algorithms may fail to reliably reconstruct all or most of the other edges. This calls for an adaptive approach suggested in this paper, called adaptive fast convergence, in which the set of edges which can be reliably reconstructed gradually increases with the amount of information (length of input sequences) available to the algorithm. This paper presents an adaptive fast converging algorithm which returns a partially resolved topology containing no false edges: edges that cannot be reliably reconstructed are contracted into high degree vertices. We also present an upper bound on the weights of those contracted edges, which is determined by the length of input sequences and the depth of the tree. As such, the reconstruction guarantee provided by our algorithm for individual edges is significantly stronger than any previously published edge reconstruction guarantee. This fact, together with the optimal complexity of our algorithm (linear space and quadratic‐time), makes it appealing for practical use. © 2011 Wiley Periodicals, Inc. Random Struct. Alg., 40, 350–384, 2011 相似文献
354.
Hagel K Wada R Qin L Natowitz JB Shlomo S Bonasera A Röpke G Typel S Chen Z Huang M Wang J Zheng H Kowalski S Bottosso C Barbui M Rodrigues MR Schmidt K Fabris D Lunardon M Moretto S Nebbia G Pesente S Rizzi V Viesti G Cinausero M Prete G Keutgen T El Masri Y Majka Z 《Physical review letters》2012,108(6):062702
In-medium binding energies and Mott points for d, t, 3He and α clusters in low-density nuclear matter have been determined at specific combinations of temperature and density in low-density nuclear matter produced in collisions of 47A MeV 40Ar and 64Zn projectiles with 112Sn and 124Sn target nuclei. The experimentally derived values of the in-medium modified binding energies are in good agreement with recent theoretical predictions based upon the implementation of Pauli blocking effects in a quantum statistical approach. 相似文献
355.
Alexander Kamyshny Matti Ben‐Moshe Shai Aviezer Shlomo Magdassi 《Macromolecular rapid communications》2005,26(4):281-288
Summary: Two types of ink‐jet inks are presented: ink containing an aqueous dispersion of silver nanoparticles and an oil‐in‐water microemulsion‐based ink. The metallic ink contains nanoparticles of silver, which are formed in the presence of an ionic polymeric stabilizer. Sintering of the printed image obtained with the use of such silver‐based inks at temperatures as low as 300 °C results in formation of patterns possessing noticeable conductivity. The microemulsion inks are based on a thermodynamically stable microemulsion, in which the dispersed oil phase is a volatile solvent containing a water‐insoluble colorant. After contact of the jetted ink droplets with a substrate, nanodroplets of the microemulsion are converted into nanoparticles of the solubilized colorant. In some cases, it was found that the evaporation of microemulsion ink droplets leads to formation of rings composed of ordered nanoparticles.