Low-lying excited states and nonradiative processes of 9-methyl-2-aminopurine

he UV spectrum of the adenine analogue 9-methyl-2-aminopurine (9M-2AP) is investigated with one- and two-color resonant two-photon ionization spectroscopy at 0.3 and 0.05 cm−1 resolution in a supersonic jet. The electronic origin at 32 252 cm−1 exhibits methyl torsional subbands that originate from the 0A′′1 (l = 0) and 1E ″ (l = ±1) torsional levels. These and further torsional bands that appear up to 000+230 cm−1 allow to fit the threefold (V 3) barriers of the torsional potentials as ∣∣V′′3∣∣=50 cm−1 in the S 0 and ∣∣V′3∣∣=126 cm−1 in the S 1 state. Using the B3LYP density functional and correlated approximate second-order coupled cluster CC2 methods, the methyl orientation is calculated to be symmetric relative to the 2AP plane in both states, with barriers of V′′3=20 cm−1 and V′3=115 cm−1. The 000 rotational band contour is 75% in-plane (a/b) polarized, characteristic for a dominantly long-axis 1ππ* excitation. The residual 25% c-axis polarization may indicate coupling of the 1ππ* to the close-lying 1 nπ* state, calculated at 4.00 and 4.01 eV with the CC2 method. However, the CC2 calculated 1 nπ oscillator strength is only 6% of that of the 1ππ* transition. The 1ππ* vibronic spectrum is very complex, showing about 40 bands within the lowest 500 cm−1. The methyl torsion and the low-frequency out-of-plane ν′1 and ν′2 vibrations are strongly coupled in the 1ππ* state. This gives rise to many torsion-vibration combination bands built on out-of-plane fundamentals, which are without precedence in the 1ππ* spectrum of 9H-2-aminopurine [S. Lobsiger, R. K. Sinha, M. Trachsel, and S. Leutwyler, J. Chem. Phys.134, 114307 (2011)]. From the Lorentzian broadening needed to fit the 000 contour of 9M-2AP, the 1ππ* lifetime is τ ⩾ 120 ps, reflecting a rapid nonradiative transition.

Rapid tranquilization of severely agitated patients with schizophrenia spectrum disorders: a naturalistic, rater-blinded, randomized controlled study with oral haloperidol, risperidone, and olanzapine

Agitation is a major problem in acute schizophrenia. Still, only limited evidence exists on antipsychotic efficacy in severely agitated patients after the first 24 hours. We aimed to investigate the efficacy of oral haloperidol, risperidone, and olanzapine in reducing psychotic agitation in severely agitated patients with schizophrenia or schizophreniform or schizoaffective disorder over 96 hours using a prospective, randomized, rater-blinded, controlled design within a naturalistic treatment regimen. We enrolled 43 severely agitated patients at acute care psychiatric units. Participants were randomly assigned to receive either daily haloperidol 15 mg, olanzapine 20 mg, or risperidone 2 – 6 mg over 5 days. Positive and Negative Syndrome Scale psychotic agitation (PANSS-PAS) subscore was the primary outcome variable. A mixed model analyses was applied. All drugs were effective for rapid tranquillization within 2 hours. Over 5 days, the course differed between agents (p < 0.001) but none was superior. Dropouts occurred only in the risperidone and olanzapine groups. Men responded better to treatment than women during the initial 2 hours (p = 0.046) as well as over the 5 day course (p < 0.001). No difference between drug groups was observed regarding diazepam or biperiden use. Oral haloperidol, risperidone, and olanzapine seem to be suitable for treating acute severe psychotic agitation in schizophrenia spectrum disorders. We observed a gender effect with poorer outcome in women.

Essential spectrum of systems of singular differential equations

In this paper we develop a new method to determine the essential spectrum of coupled systems of singular differential equations. Applications to problems from magnetohydrodynamics and astrophysics are given.

Different dark conformations function in color-sensitive photosignaling by the sensory rhodopsin I-HtrI complex.

The haloarchaeal phototaxis receptor sensory rhodopsin I (SRI) in complex with its transducer HtrI delivers an attractant signal from excitation with an orange photon and a repellent signal from a second near-UV photon excitation. Using a proteoliposome system with purified SRI in complex with its transducer HtrI, we identified by site-directed fluorescence labeling a site (Ser(155)) on SRI that is conformationally active in signal relay to HtrI. Using site-directed spin labeling of Ser(155)Cys with a nitroxide side chain, we detected a change in conformation following one-photon excitation such that the spin probe exhibits a splitting of the outer hyperfine extrema (2A'(zz)) significantly smaller than that of the electron paramagnetic resonance spectrum in the dark state. The dark conformations of five mutant complexes that do not discriminate between orange and near-UV excitation show shifts to lower or higher 2A'(zz) values correlated with the alterations in their motility behavior to one- and two-photon stimuli. These data are interpreted in terms of a model in which the dark complex is populated by two conformers in the wild type, one that inhibits the CheA kinase (A) and the other that activates it (R), shifted in the dark by mutations and shifted in the wild-type SRI-HtrI complex in opposite directions by one-photon and two-photon reactions.

Shying away: An observer-based microprocess analysis of experiential avoidance and resource activation in outpatients with generalized anxiety spectrum disorder

Despite long-standing calls for patient-focused research on individuals with generalized anxiety spectrum disorder there is little systematized knowledge about the in-session behaviors of these patients. The primary objective of this study was to describe of in-session trajectories of the patients' level of explication (as an indicator of an elaborated exposure of negative emotionality) and the patients' focus on their own resources and how these trajectories are associated with post-treatment outcome. In respect to GAD patients, a high level of explication might be seen as an indicator of successful exposure of avoided negative emotionality during therapy sessions. Observers made minute-by-minute ratings of 1100 minutes of video of 20 patients-therapists dyads. The results indicated that a higher level of explication generally observed at a later stage during the therapy sessions and the patients' focus on competencies at an early stage was highly associated with positive therapy outcome at assessment at post treatment, independent of pretreatment distress, rapid response of well-being and symptom reduction, as well as the therapists' professional experience and therapy lengths. These results will be discussed under the perspective of emotion regulation of patients and therapist's counterregulation. It is assumed that GAD-Patients are especially skilled in masking difficult emotions. Explication level and emotion regulation are important variables for this patient group but there's relation to outcome is different.

Ultrafast Relaxation Dynamics of Osmium-Polypyridine Complexes in Solution

We present steady-state absorption and emission spectroscopy and femtosecond broadband photoluminescence up-conversion spectroscopy studies of the electronic relaxation of Os(dmbp)3 (Os1) and Os(bpy)2(dpp) (Os2) in ethanol, where dmbp is 4,4′-dimethyl-2,2′-biypridine, bpy is 2,2′-biypridine, and dpp is 2,3-dipyridyl pyrazine. In both cases, the steady-state phosphorescence is due to the lowest 3MLCT state, whose quantum yield we estimate to be ≤5.0 × 10–3. For Os1, the steady-state phosphorescence lifetime is 25 ns. In both complexes, the photoluminescence excitation spectra map the absorption spectrum, pointing to an excitation wavelength-independent quantum yield. The ultrafast studies revealed a short-lived (≤100 fs) fluorescence, which stems from the lowest singlet metal-to-ligand-charge-transfer (1MLCT) state and decays by intersystem crossing to the manifold of 3MLCT states. In addition, Os1 exhibits a 50 ps lived emission from an intermediate triplet state at an energy 2000 cm–1 above that of the long-lived (25 ns) phosphorescence. In Os2, the 1MLCT–3MLCT intersystem crossing is faster than that in Os1, and no emission from triplet states is observed other than the lowest one. These observations are attributed to a higher density of states or a smaller energy spacing between them compared with Os1. They highlight the importance of the energetics on the rate of intersystem crossing.

Visual hallucinations in the psychosis spectrum and comparative information from neurodegenerative disorders and eye disease

Much of the research on visual hallucinations (VHs) has been conducted in the context of eye disease and neurodegenerative conditions, but little is known about these phenomena in psychiatric and nonclinical populations. The purpose of this article is to bring together current knowledge regarding VHs in the psychosis phenotype and contrast this data with the literature drawn from neurodegenerative disorders and eye disease. The evidence challenges the traditional views that VHs are atypical or uncommon in psychosis. The weighted mean for VHs is 27% in schizophrenia, 15% in affective psychosis, and 7.3% in the general community. VHs are linked to a more severe psychopathological profile and less favorable outcome in psychosis and neurodegenerative conditions. VHs typically co-occur with auditory hallucinations, suggesting a common etiological cause. VHs in psychosis are also remarkably complex, negative in content, and are interpreted to have personal relevance. The cognitive mechanisms of VHs in psychosis have rarely been investigated, but existing studies point to source-monitoring deficits and distortions in top-down mechanisms, although evidence for visual processing deficits, which feature strongly in the organic literature, is lacking. Brain imaging studies point to the activation of visual cortex during hallucinations on a background of structural and connectivity changes within wider brain networks. The relationship between VHs in psychosis, eye disease, and neurodegeneration remains unclear, although the pattern of similarities and differences described in this review suggests that comparative studies may have potentially important clinical and theoretical implications.