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Luis Palomo Rafael Rodríguez Samara Medina Emilio Quio Juan Casado Flix Freire Francisco J. Ramírez 《Angewandte Chemie (International ed. in English)》2020,59(23):9080-9087
Poly(phenylacetylene)s are a family of helical polymers constituted by conjugated double bonds. Raman spectra of these polymers show a structural fingerprint of the polyene backbone which, in combination with its helical orientation, makes them good candidates to be studied by Raman optical activity (ROA). Four different well‐known poly(phenylacetylene)s adopting different scaffolds and ten different helical senses have been prepared. Raman and ROA spectra were recorded and allowed to establish ROA‐spectrum/helical‐sense relationships: a left/right‐handed orientation of the polyene backbone (Mhelix/Phelix) produces a triplet of positive/negative ROA bands. Raman and ROA spectra of each polymer exhibited the same profile, and the sign of the ROA spectrum was opposite to the lowest‐energy electronic circular dichroism (ECD) band, indicating a resonance effect. Resonance ROA appears then as an indicator of the helical sense of poly(phenylacetylene)s, especially for those with an extra Cotton band in the ECD spectrum, where a wrong helical sense is assigned based on ECD, while ROA alerts of this misassignment. 相似文献
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《Electroanalysis》2017,29(8):1840-1849
The integration of biomolecular logic principles with electronic transducers allows designing novel digital biosensors with direct electrical output, logically triggered drug‐release, and closed‐loop sense/act/treat systems. This opens new opportunities for advanced personalized medicine in the context of theranostics. In the present work, we will discuss selected examples of recent developments in the field of interfacing enzyme logic gates with electrodes and semiconductor field‐effect devices. Special attention is given to an enzyme OR/Reset logic gate based on a capacitive field‐effect electrolyte‐insulator‐semiconductor sensor modified with a multi‐enzyme membrane. Further examples are a digital adrenaline biosensor based on an AND logic gate with binary YES/NO output and an integrated closed‐loop sense/act/treat system comprising an amperometric glucose sensor, a hydrogel actuator, and an insulin (drug) sensor. 相似文献
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This paper illustrates how young children (age 1–5) use mathematical properties in collective reasoning during free outdoor play. The analysis of three episodes is presented. The results from the analysis of the argumentation show that the children used a variation of mathematical products and procedures, to challenge, support and drive the reasoning forward. When needed, they utilise concrete materials to illustrate and strengthen their arguments, and as an aid in order to reach conclusions. The children also use abstract social constructs, such as jokes, as part of their reasoning. 相似文献
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Antibacterial Drug Release Electrochemically Stimulated by the Presence of Bacterial Cells – Theranostic Approach 下载免费PDF全文
Maria Gamella Nataliia Guz Shay Mailloux José M. Pingarrón Evgeny Katz 《Electroanalysis》2014,26(12):2552-2557
A modified electrode with bioaffinity to E. coli bacterial cells was used to detect bacteria presence on its surface and to produce an electrical signal triggering antibacterial drug release from another coupled electrode. The Sense‐and‐Treat system was realized in two different versions and suggested as the first step to future theranostic applications where bacteria presence results in automatic antibacterial treatment. 相似文献
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Hagit Benbaji 《Acta Analytica》2008,23(1):55-67
Two-dimensional semantics aims to eliminate the puzzle of necessary a posteriori and contingent a priori truths. Recently
many argue that even assuming two-dimensional semantics we are left with the puzzle of necessary and a posteriori propositions.
Stephen Yablo (Pacific Philosophical Quarterly, 81, 98–122, 2000) and Penelope Mackie (Analysis, 62(3), 225–236, 2002) argue that a plausible sense of “knowing which” lets us know the object of such a proposition, and yet its necessity is
“hidden” and thus a posteriori. This paper answers this objection; I argue that given two-dimensional semantics you cannot
know a necessary proposition without knowing that it is true.
相似文献
Hagit BenbajiEmail: |
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Abstract The 60 MHz 1H NMR spectra of the systemic agricultural fungicide, triadimefon, 1, have been studied in CDCl3 at 28±1° (as the racemic free base) with the added achiral lanthanide shift reagent (LSR), tris(6, 6, 7, 7, 8, 8, 8-heptafluoro-2, 2-dimethyl-3, 5-octanedionato) europium(III), Eu(FOD)3, 2, for spectral simplification, and with the chiral LSR, tris [3-(heptafluoropropylhydroxymethylene)-(+) -camphorato)europium(III), Eu(HFC)3, 3, to induce enantiomeric shift differences (ΔΔδ) for several nuclei. Significant ΔΔδ values were seen for the two protons of the heterocyclic ring, the OCH methine, and aryl H-2′, 6′ of the chlorophenoxy ring. For each of these nuclei exhibiting ΔΔδ with added 3, the ΔΔδ magnitudes reached maximum values with 3: 1 molar ratios ca. 0. 18–0. 29, and decreased with higher levels of 3. To confirm analytical utility of 3 for % e. e. determinations of 1, a nonracemic (“spiked”) sample of racemic 1, with added R-(?) triadimefon, was examined with 3. At low 3: 1 ratios, both triazole H-3 and H-5, as well as the OCH and aryl H-2′, 6′ protons of (?)-1 showed a downfield sense of magnetic nonequivalence with (+) -3. With 3: 1 ratios ca. 0. 8, triazole proton H-3 reversed its sense of magnetic noneguivalence. The H-3 and H-5 signals were useful for % e. e determinations at this higher 3: 1 ratio. 相似文献
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An edge-labeling λ for a directed graph G has a weak sense of direction (WSD) if there is a function f that satisfies the condition that for any node u and for any two label sequences α and α′ generated by non-trivial walks on G starting at u, f(α)=f(α′) if and only if the two walks end at the same node. The function f is referred to as a coding function of λ. The weak sense of direction number of G, WSD(G), is the smallest integer k so that G has a WSD-labeling that uses k labels. It is known that WSD(G)≥Δ+(G), where Δ+(G) is the maximum outdegree of G.Let us say that a function τ:V(G)→V(H) is an embedding from G onto H if τ demonstrates that G is isomorphic to a subgraph of H. We show that there are deep connections between WSD-labelings and graph embeddings. First, we prove that when fH is the coding function that naturally accompanies a Cayley graph H and G has a node that can reach every other node in the graph, then G has a WSD-labeling that has fH as a coding function if and only if G can be embedded onto H. Additionally, we show that the problem “Given G, does G have a WSD-labeling that uses a particular coding function f?” is NP-complete even when G and f are fairly simple.Second, when D is a distributive lattice, H(D) is its Hasse diagram and G(D) is its cover graph, then WSD(H(D))=Δ+(H(D))=d∗, where d∗ is the smallest integer d so that H(D) can be embedded onto the d-dimensional mesh. Along the way, we also prove that the isometric dimension of G(D) is its diameter, and the lattice dimension of G(D) is Δ+(H(D)). Our WSD-labelings are poset-based, making use of Birkhoff’s characterization of distributive lattices and Dilworth’s theorem for posets. 相似文献