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We report the improved direct access to red-emitting BOIMPY fluorophores (λ ≈ 600 nm) via a simple one-pot approach. Our method starts from easily available benzimidazole-2-carboxylic acids and not only greatly improves the overall yields but also saves both costly reagents and time. In addition, the method facilitates the synthesis of novel unsymmetrical BOIMPY motifs. Therefore, these BOIMPY scaffolds derived from the BODIPY core become more accessible for applications as fluorophores at the appealing red edge of the visible spectrum.

A general approach is described for the formation of tetrahydrothiepines using donor-acceptor cyclopropanes. Thiochalcones, functioning as sulfur-containing four-atom building blocks, were reacted in a Lewis acid catalyzed formal (4 + 3)-cycloaddition reaction with donor-acceptor cyclopropanes as three-atom building blocks. Under mild conditions various tetrahydrothiepines were synthesized in good yields in a stereospecific reaction with high functional group tolerance.

The experimentally measured input-output characteristics of optically pumped semiconductor microcavities exhibits unexpected oscillations modifying the fundamentally linear slope in the excitation power regime below lasing. A systematic microscopic analysis reproduces these oscillations, identifying them as a genuine quantum-memory effect, i.e., a photon-density correlation accumulated during the excitation. With the use of projected quantum measurements, it is shown that the input-output oscillations can be controlled and enhanced by an order of magnitude when the quantum fluctuations of the pump are adjusted.

Information on the neurobiology of empathy and callousness provides clinicians with an opportunity to develop sophisticated understanding of mechanisms underpinning antisocial behavior and its counterpart, moral decision-making. This article provides an integrated in-depth review of hormones (e.g. peripheral steroid hormones such as cortisol) and brain structures (e.g. insula, anterior cingulate cortex, and amygdala) implicated in empathy, callousness, and psychopathic-like behavior. The overarching goal of this article is to relate these hormones and brain structures to moral decision-making. This review will begin in the brain, but will then integrate information about biological functioning in the body, specifically stress-reactivity. Our aim is to integrate understanding of neural processes with hormones such as cortisol, both of which have demonstrated relationships to empathy, psychopathy, and antisocial behavior. The review proposes that neurobiological impairments in individuals who display little empathy are not necessarily due to a reduced ability to understand the emotions of others. Instead, evidence suggests that individuals who show little arousal to the distress of others likewise show decreased physiological arousal to their own distress; one manifestation of reduced stress reactivity may be a dysfunction in empathy, which supports psychopathic-like constructs (e.g. callousness). This integration will assist in the development of objective methodologies that can inform and monitor treatment interventions focused on decreasing antisocial behavior., (Copyright 2009 John Wiley & Sons, Ltd.)

The localization of excitons on quantum-dot-like compositional fluctuations has been observed in temperature-dependent near-field magnetophotoluminescence spectra of InGaAsN. Localization is driven by the giant bowing parameter of these alloys and manifests itself by the appearance of ultranarrow lines (half-width <1 meV) at temperatures below 70 K. We show how near-field optical scanning microscopy can be used for the estimation of the size, density, and nitrogen excess of individual compositional fluctuations (clusters), thus revealing random versus phase-separation effects in the distribution of nitrogen.

A minimally invasive laser-induced injury model is described to study thrombus development in mice in vivo. The protocol involves focusing the beam of an argon-ion laser through a compound microscope on the vasculature of a mouse ear that is sufficiently thin such that blood flow can be visualized by intravital microscopy. Two distinct injury models have been established. The first involves direct laser illumination with a short, high-intensity pulse. In this case, thrombus formation is inhibited by the GPIIb/IIIa antagonist, G4120. However, the anticoagulants, hirulog, PPACK, and NapC2 have minimal effect. This indicates that thrombus development induced by this model mainly involves platelet interactions. The second model involves low-intensity laser illumination of mice injected with Rose Bengal dye to induce photochemical injury in the region of laser illumination. Thrombi generated by this latter procedure have a slower development and are inhibited by both anticoagulant and anti-platelet compounds.

Promising approaches for achieving optically addressed spatial light modulators (O-SLMs) are investigated based on combining nipi and multiple quantum well structures. Theoretical aspects of photooptic effects achievable in such structures are treated. Test structures are grown by molecular beam epitaxy using two material systems, (In,Ga)As/GaAs and (Al,Ga)As/GaAs. Experiments show large optically controlled modulation of the absorption coefficient in the quantum well layers ( approximately 10(4) cm(-1)), a log power dependence on the control signal, millisecond and shorter time response, and generally predictable behavior. The results are encouraging for several different O-SLM device structures proposed.

The electron lithographic fabrication of high quality diffraction gratings with periods in the 0.25-microm < a(o) < 1.5-microm range is reported. The negative electron resist employed is a copolymer of glycidyl methacrylate and ethyl acrylate with a sensitivity about 15 times better than that of poly(methyl methacrylate), a positive resist. A new scan generator with linearity accurate to 1 part in 10(4) and locked onto the 60-Hz power supplies is described. Gratings with up to 3000 lines were fabricated with long range order deltaa(o)/a(o)

An optically controlled reflection modulator has been demonstrated that consists of a combination of a GaAs-AlGaAs n-i-p-i doping structure with a multiple-quantum-well structure on top of a distributed Bragg reflector, all grown by molecular-beam epitaxy. A modulation of approximately 60% is obtained on our test structure, corresponding to a differential change of absorption coefficient in the quantum wells of approximately 7500/cm. Changes in reflectance can be observed with a control beam power as low as 1.5 microW. This device structure has the potential of being developed as an optically addressed spatial light modulator for optical information processing.