664 research outputs found

    Definitions of relapse in trials comparing antipsychotic maintenance with discontinuation or reduction for schizophrenia spectrum disorders: A systematic review

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    INTRODUCTION: Avoidance of relapse is the main aim of long-term antipsychotic treatment in schizophrenia, yet how 'relapse' is defined in trials is not well-known. METHODS: We conducted a systematic review of definitions of relapse in trials of continuous antipsychotic treatment compared with discontinuation, intermittent treatment or dose reduction for people with schizophrenia spectrum disorders. Trials were identified from previous Cochrane reviews and a new search. The quality of relapse definitions was rated in terms of reliability and clinical relevance and associations between quality of definitions and trial characteristics and outcome were explored. RESULTS: We identified 82 reports of 81 trials which employed 54 different definitions of relapse. There were 33 definitions in the 35 trials published since 1990, with recent trials employing complex definitions often involving alternative criteria. Only ten primary definitions of relapse required the presence of psychotic symptoms in all cases, and only three specified this in combination with a measure of overall severity or functional decline. Only two definitions specified a duration longer than two days. Relapse definitions were rated as showing good reliability in 37 trials, but only seven showed good clinical relevance. Six trials with definitions that were both reliable and clinically relevant were slightly longer, but did not differ from remaining trials in other characteristics or overall or relative risk of relapse. CONCLUSIONS: Antipsychotic trials define relapse in numerous different ways, and few definitions consistently reflect suggested indications of a clinically significant relapse

    A recoil detector for the measurement of antiproton-proton elastic scattering at angles close to 90∘^{\circ}

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    The design and construction of a recoil detector for the measurement of recoil protons of antiproton-proton elastic scattering at scattering angles close to 90∘^{\circ} are described. The performance of the recoil detector has been tested in the laboratory with radioactive sources and at COSY with proton beams by measuring proton-proton elastic scattering. The results of laboratory tests and commissioning with beam are presented. Excellent energy resolution and proper working performance of the recoil detector validate the conceptual design of the KOALA experiment at HESR to provide the cross section data needed to achieve a precise luminosity determination at the PANDA experiment.Comment: 10 pages, 15 figure

    Geometric and impurity effects on quantum rings in magnetic fields

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    We investigate the effects of impurities and changing ring geometry on the energetics of quantum rings under different magnetic field strengths. We show that as the magnetic field and/or the electron number are/is increased, both the quasiperiodic Aharonov-Bohm oscillations and various magnetic phases become insensitive to whether the ring is circular or square in shape. This is in qualitative agreement with experiments. However, we also find that the Aharonov-Bohm oscillation can be greatly phase-shifted by only a few impurities and can be completely obliterated by a high level of impurity density. In the many-electron calculations we use a recently developed fourth-order imaginary time projection algorithm that can exactly compute the density matrix of a free-electron in a uniform magnetic field.Comment: 8 pages, 7 figures, to appear in PR

    A novel variant of the 13C-methacetin liver function breath test that eliminates the confounding effect of individual differences in sytemic CO2 kinetics

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    The principle of dynamic liver function breath tests is founded on the administration of a 13C-labeled drug and subsequent monitoring of 13CO2 in the breath, quantified as time series delta over natural baseline 13CO2 (DOB) liberated from the drug during hepatic CYP-dependent detoxification. One confounding factor limiting the diagnostic value of such tests is that only a fraction of the liberated 13CO2 is immediately exhaled, while another fraction is taken up by body compartments from which it returns with delay to the plasma. The aims of this study were to establish a novel variant of the methacetin-based breath test LiMAx that allows to estimate and to eliminate the confounding effect of systemic 13CO2 distribution on the DOB curve and thus enables a more reliable assessment of the hepatic detoxification capacity compared with the conventional LiMAx test. We designed a new test variant (named "2DOB") consisting of two consecutive phases. Phase 1 is initiated by the intravenous administration of 13C-bicarbonate. Phase 2 starts about 30 min later with the intravenous administration of the 13C-labelled test drug. Using compartment modelling, the resulting 2-phasic DOB curve yields the rate constants for the irreversible elimination and the reversible exchange of plasma 13CO2 with body compartments (phase 1) and for the detoxification and exchange of the drug with body compartments (phase 2). We carried out the 2DOB test with the test drug 13C-methacetin in 16 subjects with chronic liver pathologies and 22 normal subjects, who also underwent the conventional LiMAx test. Individual differences in the systemic CO2 kinetics can lead to deviations up to a factor of 2 in the maximum of DOB curves (coefficient of variation CV ≈ 0.2) which, in particular, may hamper the discrimination between subjects with normal or mildly impaired detoxification capacities. The novel test revealed that a significant portion of the drug is not immediately metabolized, but transiently taken up into a storage compartment. Intriguingly, not only the hepatic detoxification rate but also the storage capacity of the drug, turned out to be indicative for a normal liver function. We thus used both parameters to define a scoring function which yielded an excellent disease classification (AUC = 0.95) and a high correlation with the MELD score (RSpearman = 0.92). The novel test variant 2DOB promises a significant improvement in the assessment of impaired hepatic detoxification capacity. The suitability of the test for the reliable characterization of the natural history of chronic liver diseases (fatty liver-fibrosis-cirrhosis) has to be assessed in further studies

    Ssri and Snri Withdrawal Symptoms Reported on an Internet Forum

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    BACKGROUND: Antidepressant withdrawal symptoms are well-recognised, but their potential duration remains uncertain. OBJECTIVE: We aimed to describe the characteristics of withdrawal associated with two popular classes of antidepressants, including duration. METHODS: We analysed the content of a sample of posts on an antidepressant withdrawal website. We compared the characteristics of withdrawal associated with SSRIs and SNRIs, including time of onset, duration and nature of symptoms. RESULTS: 110 posts about SSRI withdrawal, and 63 concerning SNRI withdrawal, were analysed. The mean duration of withdrawal symptoms was significantly longer with SSRIs than SNRIs: 90.5 weeks (standard deviation, SD, 150.0) and 50.8 weeks (SD 76.0) respectively; p = 0.043). Neurological symptoms, such as 'brain zaps,' were more common among SNRI users (p = 0.023). Psychosexual/genitourinary symptoms may be more common among SSRI users (p = 0.054). LIMITATIONS: The website aims to help people with antidepressant withdrawal, and is therefore likely to attract people who have difficulties. Length of prior use of antidepressants was long, with a mean of 252.2 weeks (SD 250.8). CONCLUSIONS: People accessing antidepressant withdrawal websites report experiencing protracted withdrawal symptoms. There are some differences in the characteristics of withdrawal associated with different classes of antidepressants

    A new test specimen for the determination of the field of view of small-area X-ray photoelectron spectrometers

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    Small-area/spot photoelectron spectroscopy (SAXPS) is a powerful tool for the investigation of small surface features like microstructures of electronic devices, sensors or other functional surfaces, and so forth. For evaluating the quality of such microstructures, it is often crucial to know whether a small signal in a spectrum is an unwanted contamination of the field of view (FoV), defined by the instrument settings, or it originated from outside. To address this issue, the d80/20 parameter of a line scan across a chemical edge is often used. However, the typical d80/20 parameter does not give information on contributions from the long tails of the X-ray beam intensity distribution or the electron-optical system as defined by apertures. In the VAMAS TWA2 A22 project “Applying planar, patterned, multi-metallic samples to assess the impact of analysis area in surface-chemical analysis,” new test specimen was developed and tested. The here presented testing material consists of a silicon wafer substrate with an Au-film and embedded Cr circular and square spots with decreasing dimensions from 200 ÎŒm down to 5 ÎŒm. The spot sizes are traceable to the length unit due to size measurements with a metrological SEM. For the evaluation of the FoV, we determined the Au4f intensities measured with the center of the FoV aligned with the center of the spot and normalized to the Au4f intensity determined on the Au-film. With this test specimen, it was possible to characterize, as an example, the FoV of a Kratos AXIS Ultra DLD XPS instrument

    Effects of comorbidity on Tourette's tic severity and quality of life

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    Objective The aim of this study is to gain more insight in the differential contributions of anxiety, depression and obsessive-compulsive (OC) symptom severity to quality of life (QoL) and tic severity in adults with Tourette Disorder (TD). Methods Self-reported OC symptom, anxiety and depression severity measures were used to investigate their predictive value on QoL and Tic severity in adult TD patients (N = 187), using correlation, regression, and mediation analyses. Results Tic severity has no effect on QoL. Depression severity directly reduces QoL, whereas anxiety and OC symptom severity have an indirect effect on QoL, mediated by depression severity. OC symptom severity directly affects tic severity, whereas depression and anxiety severity do not have a direct effect on tic or OC severity. Finally, anxiety severity indirectly impacts tic severity, with OC symptom severity functioning as a mediator. Conclusion In line with and extending previous studies, these findings indicate that OC symptom severity directly influences tic symptom severity whereas depression severity directly influences QoL in TD. Results imply that to improve QoL in TD patients, treatment should primarily focus on diminishing OC and depressive symptom severity rather than focusing on tic reduction

    Electrochemical assessment of water|ionic liquid biphasic systems towards cesium extraction from nuclear waste

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    A room temperature ionic liquid (IL) composed of a quaternary alkylphosphonium (trihexyltetradecylphosphonium, P66614(+)) and tetrakis(pentafluorophenyl) borate anion (TB) was employed within a water| P66614TB (w|P66614TB or w|IL) biphasic system to evaluate cesium ion extraction in comparison to that with a traditional water|organic solvent (w|o) combination. Cs-137 is a major contributor to the radioactivity of spent nuclear fuel as it leaves the reactor, and its extraction efficiency is therefore of considerable importance. The extraction was facilitated by the ligand octyl(phenyl)-N, N'-diisobutylcarbamoylphosphine oxide (CMPO) used in TRans- Uranium EXtraction processes and investigated through well established liquid| liquid electrochemistry. This study gave access to the metal ion to ligand (1: n) stoichiometry and overall complexation constant, beta, of the interfacial complexation reaction which were determined to be 1: 3 and 1.6 x 10(11) at the w| P66614TB interface while the study at w|o elicited an n equal to 1 with beta equal to 86.5. Through a straightforward relationship, these complexation constant values were converted to distribution coefficients, da, with the ligand concentrations studied for comparison to other studies present in the literature; the w|o and w|IL systems gave delta(alpha) of 2 and 8.2 x 10(7), respectively, indicating a higher overall extraction efficiency for the latter. For the w|o system, the metal ion-ligand stoichiometries were confirmed through isotopic distribution analysis of mass spectra obtained by the direct injection of an emulsified water-organic solvent mixture into an electron spray ionization mass spectrometer. (c) 2014 Elsevier B.V. All rights reserved

    Periodic Orbits in Polygonal Billiards

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    We review some properties of periodic orbit families in polygonal billiards and discuss in particular a sum rule that they obey. In addition, we provide algorithms to determine periodic orbit families and present numerical results that shed new light on the proliferation law and its variation with the genus of the invariant surface. Finally, we deal with correlations in the length spectrum and find that long orbits display Poisson fluctuations.Comment: 30 pages (Latex) including 11 figure
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