The Hydrolysis of the Anhydride of 2-Cyano-2-phenylpropanoic Acid Triggers the Repeated Back and Forth Motions of an Acid–Base Operated Molecular Switch

This work aimed to render phenomenologically autonomous the otherwise stepwise operation of a catenane-based molecular switch, which is chemically triggered by the decarboxylation of 2-cyano-2-phenylpropanoic acid ( 2 ). Given that any amount of 2 in stoichiometric excess with respect to the catenane is consumed in a side reaction, the authors resorted to the corresponding anhydride 5 , the slow hydrolysis of which, due to adventitious water in dichloromethane, continuously produces in situ the actual fuel 2 . As a consequence, the machine does not require a reloading after each cycle, but switches back and forth as long as fuel is present.     

Robust mean–variance hedging via G-expectation

In this paper we study mean–variance hedging under the $G$-expectation framework. Our analysis is carried out by exploiting the $G$-martingale representation theorem and the related probabilistic tools, in a continuous financial market with two assets, where the discounted risky one is modeled as a symmetric $G$-martingale. By tackling progressively larger classes of contingent claims, we are able to explicitly compute the optimal strategy under general assumptions on the form of the contingent claim.     

Synthesis and evaluation of analogues of HYNIC as bifunctional chelators for technetium

6-Hydrazinonicotinic acid (HYNIC, 1) is a well-established bifunctional technetium-binding ligand often used to synthesise bioconjugates for radiolabelling with Tc-99m. It is capable of efficient capture of technetium at extremely low concentrations, but the structure of the labelled complexes is heterogeneous and incompletely understood. In particular, it is of interest to determine whether, at the no-carrier-added level, it acts in a chelating or non-chelating mode. Here we report two new isomers of HYNIC: 2-hydrazinonicotinic acid (2-HYNIC, 2), which (like 1) is capable of chelation through the mutually ortho hydrazine and pyridine nitrogens and 4-hydrazinonicotinic acid (4-HYNIC, 3), which is not (due to the para-relationship of the hydrazine and pyridine nitrogens). LC-MS shows that the coordination chemistry of 2 with technetium closely parallels that of conventional 1, and no advantages of one over the other in terms of potential labelling efficiency or isomerism were discernable. Both 1 and 2 formed complexes with the loss of 5 protons from the ligand set, whether the co-ligand was tricine or EDDA. Ligand 3, however, failed to complex technetium except at very high ligand concentration: the marked contrast with 1 and 2 suggests that chelation, rather than nonchelating coordination, is a key feature of technetium coordination by HYNIC. Two further new HYNIC analogues, 2-chloro-6-hydrazinonicotinic acid (2-chloro-HYNIC, 4a) and 2,6-dihydrazinonicotinic acid (diHYNIC, 5) were also synthesised. The coordination chemistry of 4a with technetium was broadly parallel to that of 1 and 2 although it was a less efficient chelator, while 5 also behaved as an efficient chelator of technetium, but its coordination chemistry remains poorly defined and requires further investigation before it can sensibly be adopted for (99m)Tc-labelling. The new analogues 4a and 5 present an opportunity to develop trifunctional HYNIC analogues for more complex bioconjugate synthesis.     

Characterization of high heating-rate chars from alternative fuels using an electrodynamic balance

Important advantages in the use of alternative and renewable fuels (CO₂ reduction in the atmosphere, recovery of energy from wastes, limited SO_x, NO_x and heavy metal emissions) can be obtained only by solving technological and economical problems that make direct combustion of such fuels impractical. This is possible after a detailed investigation to determine the most important features of these materials in all steps of the thermal process. At present, few data can actually be found for the char properties of these fuels. Nevertheless, the knowledge of properties of chars (especially after severe devolatilization) is crucial for both modeling purposes (reactivity, kinetics of combustion and gasification, morphology variations, composition, and fate of pollutant precursors) and practical applications (boiler efficiency, ash deposition, and condensation causing fouling and slagging problems).This work deals with the characterization of chars from different classes of materials (biomasses, waste, and low and high volatile matter (VM) coals) obtained after a devolatilization performed in severe thermal conditions, i.e., high temperature and high heating rate. A methodological approach is developed, applied, and discussed, using an electrodynamic balance that is a versatile analyzer for the study of properties of single levitated particles. The specific heat, size, and shape distribution, and density variation between the char and the parent material are evaluated for all materials. Scanning electron microscopy (SEM) analysis is also carried out to investigate morphological variations and support the major results obtained with the electrodynamic analyzer.     

ATP recognition and sensing with a phenanthroline-containing polyammonium receptor

A new polyammonium receptor is able to selectively recognise and sense ATP among triphosphate nucleotides, thanks to ATP-induced quantitative quenching of its fluorescence emission.     

Measurement of thee + e −→π + π − π 0 ande + e −→ωπ + π − reactions in the energy interval 1350–2400 MeV

The cross sections fore ⁺ e ^?→π ⁺ π ^? π ⁰ ande ⁺ e ^?→ωπ ⁺ π ^? have been measured in the 1.35 ≦ \(\sqrt s \) ≦2.4 GeV range from 1900 nb^?1 collected by DM2 at DCI. The second process proceeds via a resonant state at ≈- 1660 MeV/c², ≈- 280 MeV/c² wide. The first one is larger than a VDM extrapolation from the ω-? peaks and, although does not show any clear structure, is compatible with the presence of the above resonance.     

Observation of an isoscalar vector meson at ≃1650 MeV/c2 in thee^ + e^ - \to K\bar K\pi Equation>reaction

The \(e^ + e^ - \to K_s^0 K^ \pm \pi ^ \mp \) andK ⁺ K ^?π⁰ cross sections have been measured in the energy interval \(1350 \leqq \sqrt s \leqq 2400\) with the DM2 detector at DCI. The \(K_s^0 K^ \pm \pi ^ \mp \) cross section shows the contribution of an isoscalar vector meson at ≈1650 MeV/c² in agreement with a previous experiment. The low statisticsK ⁺ K ^?π⁰ measurement is consistent with the above result.     

Baryon pairs production ine + e − annihilation at\sqrt s = 2.4 GeV

Search for baryon pairs production ine ⁺ e ^? annihilation at \(\sqrt s = 2386 MeV\) is reported. The data relate to a luminosity of 161 nb^?1 collected by the DM2 experiment at DCI, the Orsay colliding ring. First measurements of directe ⁺ e ^? annihilation into \(\Lambda \bar \Lambda \) and ofe ⁺ e ^?→ \(p\bar p\) at this energy are presented. First observation of a goode ⁺ e ^?→ \(n\bar n\) candidate is reported and upper limits are given fore ⁺ e ^?→ \(n\bar n, \Lambda \bar \sum ^0 + c.c.\) and \(\Sigma ^0 \bar \Sigma ^0 \) .