a b s t r a c tDispositional optimism has been related to positive physical and mental health outcomes, increased positive mood ratings and cognitions about the future. In order to determine the causal relation between optimism and mood and cognitions optimism should be manipulated experimentally. The current study tested the effects of a best-possible-self mental imagery exercise on affect and mood ratings and dysfunctional cognitions following a sad mood induction in undergraduate students (N ¼40). Participants in the experimental condition wrote about their best possible self in the future for 15 min and engaged in a mental imagery task about their best possible self in the future for 5 min in order to experimentally induce optimism. Participants in the control condition wrote about a typical day for 15 min and engaged in mental imagery about a typical day for 5 min. We assessed affect, mood and dysfunctional cognitions before and after the experimental manipulation. Participants in the experimental condition had higher positive mood ratings and higher positive affect compared to participants in the control condition. Participants in the control condition reported decreased dysfunctional cognitions whereas dysfunctional cognitions in the experimental group remained unchanged. Future studies should replicate these findings in clinical groups with more profound levels of negative affect and dysfunctional cognitions.

In chemically fueled supramolecular materials, molecular self‐assembly is coupled to a fuel‐driven chemical reaction cycle. The fuel‐dependence makes the material dynamic and endows it with exciting properties like adaptivity and autonomy. In contrast to the large work on the self‐assembly of small molecules, we herein designed a diblock copolymer, which self‐assembles into transient micelles when coupled to a fuel‐driven chemical reaction cycle. Moreover, we used these transient block copolymer micelles to locally increase the concentration of hydrophobic reagents and thereby function as a transient nanoreactor.

Using molecular self-assembly, supramolecular chemists can create Gigadalton-structures with angstrom precision held together by non-covalent interactions. However, despite relying on the same molecular toolbox for self-assembly, these synthetic structures lack...

First examples of the coordination chemistry of the As 4 S 3 cage were obtained from solutions of As 4 S 3 ·M(CO) 5 (M = Cr, W) in CH 2 Cl 2 and CuCl n in CH 3 CN (n = 1) or CH 3 OH (n = 2) through interdiffusion techniques. The compounds (As 4 S 3 )-(CuCl) n (1: n = 1; 2: n = 2) exhibit Cu coordination exclusively through the sulfur bridges. The crystal structure of 1 contains a saw-like ϱ 1 [CuCl] backbone to which As 4 S 3 cages are alternately fixed on both sides through two of their sulfur atoms.

An all-electrical velocity feedback control to enhance the quality factor of piezoelectric aluminium nitride (AlN)-based microcantilevers and microbridges was implemented. Two alternatives to obtain a velocity-proportional signal were demonstrated depending on the top electrode configuration. For a straightforward electrode design in one-port configuration (i.e. self-actuation and self-sensing), a velocity signal, proportional to the piezoelectric current, was used in the feedback loop by cancelling out the dielectric current electronically. For top electrodes allowing a two-port configuration (i.e. one for actuation and one for sensing), the piezoelectric current is directly extracted and its relationship with velocity is analysed taking the symmetry of the modal shape into account. Standard operational amplifier-based configurations for the feedback circuits were implemented on a printed circuit board. Quality factors were determined from the transient electrical response of the devices. Comparable results were obtained from the displacement spectrum applying a laser Doppler vibrometer. Quality factors as high as 2 × 105, corresponding to an enhancement factor of about 200, were achieved in air for the lowest gain margin achievable before the circuit becomes unstable, making this kind of device more competitive for mass sensor applications due to enhanced spectral resolution.