A Highly Selective Fluorescent Sensor for Distinguishing Cadmium from Zinc Ions Based on a Quinoline Platform

A fluorescent sensor, <i>N</i>-(quinolin-8-yl)-2-(quinolin-8-yloxy)­acetamide (<b>HL</b>), based on 8-aminoquinoline and 8-hydroxyquinoline platforms has been synthesized. This sensor displays high selectivity and sensitive fluorescence enhancement to Cd²⁺ in ethanol. Moreover, sensor <b>HL</b> can distinguish Cd²⁺ from Zn²⁺ via two different sensing mechanisms (photoinduced electron transfer for Cd²⁺; internal charge transfer for Zn²⁺). The composition of the complex Cd²⁺/<b>HL</b> or Zn²⁺/<b>L</b>^– has been found to be 1:1, based on the fluorescence/absorption titration and further confirmed by X-ray crystallography

A Highly Selective Fluorescent Sensor for Distinguishing Cadmium from Zinc Ions Based on a Quinoline Platform

A fluorescent sensor, <i>N</i>-(quinolin-8-yl)-2-(quinolin-8-yloxy)­acetamide (<b>HL</b>), based on 8-aminoquinoline and 8-hydroxyquinoline platforms has been synthesized. This sensor displays high selectivity and sensitive fluorescence enhancement to Cd²⁺ in ethanol. Moreover, sensor <b>HL</b> can distinguish Cd²⁺ from Zn²⁺ via two different sensing mechanisms (photoinduced electron transfer for Cd²⁺; internal charge transfer for Zn²⁺). The composition of the complex Cd²⁺/<b>HL</b> or Zn²⁺/<b>L</b>^– has been found to be 1:1, based on the fluorescence/absorption titration and further confirmed by X-ray crystallography

Stretch-Induced Coil–Helix Transition in Isotactic Polypropylene: A Molecular Dynamics Simulation

The stretch-induced coil–helix transition (CHT) of isotactic polypropylene (iPP) was studied with full-atom molecular dynamics (MD) simulations during the uniaxial stretch process. The results show that imposing stretch induces CHT, which increases both the content and the average length of helices. As strain exceeding a certain value, long helices initially not presented in melt start to emerge, which mainly follow a kinetic pathway of merging adjacent short helices, while overstretch at large strain leads to the helix-extended coil transition. Based on statistics on the distribution of helical length and theoretical calculation, stretch is found to reduce free energy gap for CHT. At small strain, the single-chain model is sufficient to account stretch-induced CHT for the formation of short helices, but the gap reduction is mainly contributed by intrachain energy rather than entropy, which is different from current theories for stretch-induced CHT. While the formation of long helices at large strain requires interchain cooperative interactions, which is accompanied by the formation of helix-rich clusters. Additionally, we found that the content of helices with odd atoms in backbone is higher than their even counterparts, which exhibits an odd–even effect due to their corresponding helical lengths

Na₂CaSn₂Ge₃O₁₂: A Novel Host Lattice for Sm³⁺-Doped Long-Persistent Phosphorescence Materials Emitting Reddish Orange Light

A novel host lattice disodium calcium ditin­(IV) trigermanium oxide Na₂CaSn₂Ge₃O₁₂ was utilized for synthesizing long-persistent phosphorescence materials for the first time. Reddish orange long-persistent phosphorescence was observed in Na₂CaSn₂Ge₃O₁₂:Sm³⁺ phosphors with persistence time more than 4.8 h. The phosphors were synthesized by a conventional solid-state reaction pathway in air atmosphere. A predominant cubic phase of Na₂CaSn₂Ge₃O₁₂ was observed in all XRD patterns. Photoluminescence measurements indicated that the emission spectrum was composed of the peaks located at 566 (the strongest), 605, 664, and 724 nm. The results of the decay curves in terms of a biexponential model suggest that different defects appear in the crystal lattice. The defects acting as traps were investigated by thermoluminescence, which demonstrated that doping Sm³⁺ ions into the Na₂CaSn₂Ge₃O₁₂ host has made the trap types abundant. Furthermore, the origin of the long-persistent phosphorescence has also been discussed. On the basis of the above results, Sm³⁺-doped Na₂CaSn₂Ge₃O₁₂ phosphors are considered to have potential practical applications

Highly Selective and Sensitive One- and Two-Photon Ratiometric Fluorescent Probe for Intracellular Hydrogen Polysulfide Sensing

Hydrogen polysulfide (H₂S_<i>n</i>) has attracted increasing attention due to the fact that it is actually the key signaling molecule rather than hydrogen sulfide (H₂S). Therefore, developing a sensitive and accurate assay to investigate the biosynthetic pathways of H₂S_<i>n</i> is of physiological and pathological significance. In this work, based on the commonly used two-photon fluorophore, 1,8-naphthalimide, a new probe, NRT-HP, has been designed and synthesized that displayed both one- and two-photon ratiometric fluorescence changes toward H₂S_<i>n</i> via H₂S_<i>n</i>-mediated benzodithiolone formation. NRT-HP exhibits excellent pH stability, high selectivity and low detection limit (0.1 μM) in aqueous media. Furthermore, two-photon fluorescence microscopy experiments have demonstrated that NRT-HP could be used for the H₂S_<i>n</i> detection in live cells as well as tissue slices

Political theory and the European Union

As the most developed political organisation beyond the state, the EU has been regarded by many political theorists as indicative of a major shift towards post- and supranational forms of global governance, as well as offering a model for how such new political forms might be organised. However, as a growing number of political theorists have engaged more closely with the specifics of European integration and the operations of its institutions, these idealisations have largely fallen away. The process of European integration has been less straightforward and far more contested than has been often assumed, while the peculiar nature of the European political community and the uniquely complex organisation of its institutions have presented intriguing challenges to the core categories with which political theory operates. These concepts, which have been developed over the last centuries with the nation-state in mind as the primary example of modern political organization, cannot be applied wholesale to the EU. Concepts such as legitimacy, sovereignty, democracy, identity, citizenship, constitutionalism, representation, solidarity, etc. must be reassessed if they are to be useful for understanding and normatively scrutinising this political entity. This volume brings together some of the most important scholarly contributions over the last decades that have sought to contribute towards developing a political theory of the EU as an idiosyncratic political organisation. These contributions raise issues not only about the feasibility of attempts to construct political forms beyond the nation state, but also the extent to which they may be desirable. A mixed picture emerges from the state of the art: one that emphasises the existence and importance of continuities with the past in the development of international institutions on the one hand, and conceptual and practical innovations that point towards the need to break with the familiar on the other.Acknowledgments Introduction Part 1: The Normative Turn in EU Studies: The Issue of Legitimacy 1. Erik Oddvar Eriksen and John Erik Fossum, ‘Europe in Search of Legitimacy: Strategies of Legitimation Assessed’, International Political Science Review 25, 4, 2004, 435-459. 2. Richard Bellamy and Dario Castiglione, `Legitimising the Euro-"Polity" and its "Regime": The Normative Turn in EU Studies’, European Journal of Political Theory 2, 1, 2003, 7-34. Part 2: Conceptualising Sovereignty in the EU 3. Daniel J. Elazar, ‘The New Europe: A Federal State or a Confederation of States?’, Swiss Political Science Review 4, 4, 1998, 119-139. 4. Olivier Costa and Paul Magnette, ‘The EU as a Consociation: A Methodologial Assessment’, West European Politics 26, 3, 2003, 1-18. 5. Nicole Bolleyer and Christine Reh, ‘EU Legitimacy Revisited: The Normative Foundations of a Multilevel Polity’, Journal of European Public Policy 19, 4, 2012, 472-490. 6. Kalypso Nicolaïdis, ‘We, the Peoples of Europe…’, Foreign Affairs 83, 6, 2004, 97-110. Part 3: Constitution and constitutionalism in the EU 7. Jürgen Habermas, ‘Why Europe Needs a Constitution’, New Left Review 11, 2001, 5-26. 8. Pavlos Eleftheriadis, ‘The Idea of a European Constitution’, Oxford Journal of Legal Studies 27, 1, 2007, 1-21. 9. Dieter Grimm, ‘The Democratic Costs of Constitutionalisation: The European Case’, European Law Journal 21, 4, 2015, 460–473. 10. Sergio Fabbrini, ‘The Constitutional Conundrum of the European Union’, Journal of European Public Policy 23, 1, 2016, 84-100. Part 4: The Democratic Deficit Debate 11. Giandomenico Majone, ‘Europe’s "Democratic Deficit": The Question of Standards’, European Law Journal 4, 1, 1998, 5-28. 12. Andrew Moravcsik, ‘The Myth of Europe’s Democratic Deficit’, Intereconomics November/December 2008, 331-340. 13. Andreas Follesdal and Simon Hix, ‘Why There is a Democratic Deficit in the EU: A Response to Majone and Moravcsik’, Journal of Common Market Studies 44, 3, 2006, 533-562. 14. Fritz W. Scharpf, ‘Legitimacy in the Multilevel European Polity’, European Political Science Review 1, 2, 2009, 173-204. 15. Sandra Kröger and Richard Bellamy, ‘Beyond a Constraining Dissensus: The Role of National Parliaments in Domesticating and Normalising the Politicization of European Integration’, Comparative European Politics 14, 2016, 131-153. Part 5: The European Public: Communication and Identity 16. Erik Odvar Eriksen, ‘An Emerging European Public Sphere’, European Journal of Social Theory 8, 3, 2005, 341-363. 17. Klaus Eder, ‘A Theory of Collective Identity: Making Sense of the Debate on a European Identity’, European Journal of Social Theory 12, 4, 2009, 427-447. 18. Joseph Lacey, ‘Must Europe be Swiss? On the Idea of a Voting Space and the Possibility of a Multilingual Demos’, British Journal of Political Science 44, 1, 2014, 61-82. 19. Beate Kohler-Koch, ‘Civil Society and EU Democracy: "Astroturf" Representation?’, Journal of European Public Policy 17, 1, 2011, 100-116. Part 6: European Citizenship 20. Chris Shore, `Whither European Citizenship? Eros and Civilisation Revisited’, European Journal of Social Theory 7, 1, 2004, 27-44. 21. Rainer Baubock, ‘Why European Citizenship? Normative Approaches to Supranational Union’, Theoretical Inquiries in Law 8, 2, 2007, 452-488. 22. Yasemin Nuhoglu Soysal, ‘Citizenship, Immigration, and the European Social Project: Rights and Obligations of Individuality', British Journal of Sociology 63, 1, 2012, 1-21. 23. Andrea Sangiovanni, ‘Solidarity in the European Union’, Oxford Journal of Legal Studies 33, 2, 2013, 213-241

Exploitation and Application of a Highly Sensitive Ru(II) Complex-Based Phosphorescent Chemodosimeter for Hg²⁺ in Aqueous Solutions and Living Cells

A novel Ru­(II) complex-based phosphorescent probe <b>Rubpy-1</b> was designed and synthesized conveniently by incorporating of chemodosimeter into the luminophor, which exhibits good water solubility, longer excitation wavelength, and rapid turn-on phosphorescent response only toward Hg²⁺ in aqueous system under physiological pH. The spectral response mechanism and Hg²⁺-promoted structure change of the chemodosimeter were analyzed in detail by theoretical calculations and electrospray ionization mass spectrometry. When time-resolved photoluminescence techniques were used, the <b>Rubpy-1</b> could eliminate effectively the signal interference from the short-lived background fluorescence in complicated media, accompanied by the significant improvement of the signal-to-noise ratio and the accuracy of the detection. Furthermore, <b>Rubpy-1</b> showed low cytotoxicity and excellent membrane permeability toward living cells, which was successfully applied to monitor intracellular Hg²⁺ effectively by confocal luminescence imaging

Self-Assembly Synthesis, Structural Features, and Photophysical Properties of Dilanthanide Complexes Derived from a Novel Amide Type Ligand: Energy Transfer from Tb(III) to Eu(III) in a Heterodinuclear Derivative

A novel amide type ligand benzyl-<i>N</i>,<i>N</i>-bis­[(2′-furfurylaminoformyl)­phenoxyl)­ethyl]-amine (<b>L</b>) has been designed and applied for the self-assembly generation of homodinuclear lanthanide coordination compounds [Ln₂(μ₂-L)₂(NO₃)₆(EtOH)₂] [Ln = Eu (<b>1</b>), Tb (<b>2</b>), and Gd (<b>3</b>)] and a heterodinuclear derivative [EuTb­(μ₂-L)₂(NO₃)₆(EtOH)₂] (<b>4</b>). All the complexes have been characterized by the X-ray single-crystal diffraction analyses. They are isostructural, crystallize in a monoclinic space group <i>P</i>2₁/<i>c</i>, and form [2 + 2] rectangular macrocycle structures. Compound <b>4</b> is the first example of a [2 + 2] rectangular macrocycle heterodinuclear EuTb complex assembled from an amide type ligand. In <b>4</b>, the discrete 0D dimeric [EuTb­(μ₂-L)₂(NO₃)₆(EtOH)₂] units are extended, via the multiple N–H···O hydrogen bonds, into a 2D supramolecular network that has been topologically classified as a uninodal 4-connected underlying net with the <b>sql</b> [Shubnikov tetragonal plane net] topology. The triplet state (³ππ*) of <b>L</b> studied by the Gd­(III) complex <b>3</b> demonstrated that the ligand beautifully populates Tb­(III) emission (Φ = 52%), whereas the corresponding Eu­(III) derivative <b>1</b> shows weak luminescence efficiency (Φ = 0.7%) because the triplet state of <b>L</b> has a poor match with ⁵D₁ energy level of Eu­(III). Furthermore, the photoluminescent properties of heterodinuclear complex <b>4</b> have been compared with those of the analogous homodinuclear compounds. The quantum yield and lifetime measurements prove that energy transfer from Tb­(III) to Eu­(III) is being achieved, namely, that the Tb­(III) center is also acting to sensitize the Eu­(III) and enhancing Eu­(III) emission in <b>4</b>

Water-Soluble Colorimetric and Ratiometric Fluorescent Probe for Selective Imaging of Palladium Species in Living Cells

A novel water-soluble colorimetric and ratiometric fluorescent probe was synthesized and applied to imaging palladium species under physiological conditions in phosphate buffered saline (PBS) containing less than 1% organic cosolvent without adding any additional reagents. Based on palladium triggered terminal propargyl ethers cleavage reaction, the probe exhibited a high selectivity and sensitivity for palladium species of all the typical oxidation states (0, +2, +4), with a low detection limit (25 nM, 2.7 μg/L) and an obvious color change. Furthermore, the probe was successfully used for ratiometric fluorescence imaging of palladium in living cells

Visible Absorption and Fluorescence Spectroscopy of Conformationally Constrained, Annulated BODIPY Dyes

Six conformationally restricted BODIPY dyes with fused carbocycles were synthesized to study the effect of conformational mobility on their visible electronic absorption and fluorescence properties. The symmetrically disubstituted compounds (<b>2</b>, <b>6</b>) have bathochromically shifted absorption and fluorescence spectral maxima compared to those of the respective asymmetrically monosubstituted dyes (<b>1</b>, <b>5</b>). Fusion of conjugation extending rings to the α,β-positions of the BODIPY core is an especially effective method for the construction of boron dipyrromethene dyes absorbing and emitting at longer wavelengths. The fluorescence quantum yields Φ of dyes <b>1</b>–<b>6</b> are high (0.7 ≤ Φ ≤ 1.0). The experimental results are backed up by quantum chemical calculations of the lowest electronic excitations in <b>1</b>, <b>2</b>, <b>5</b>, <b>6</b>, and corresponding dyes of related chemical structure but without conformational restriction. The effect of the molecular structure on the visible absorption and fluorescence emission properties of <b>1</b>–<b>6</b> has been examined as a function of solvent by means of the recent, generalized treatment of the solvent effect, proposed by Catalán (<i>J. Phys. Chem. B</i> <b>2009</b>, <i>113</i>, 5951–5960). Solvent polarizability is the primary factor responsible for the small solvent-dependent shifts of the visible absorption and fluorescence emission bands of these dyes