177,445 research outputs found
Domino reactions of 1,3-bis-silyl enol ethers with benzopyrylium triflates: Efficient synthesis of fluorescent 6H-benzo[c]chromen-6-ones, dibenzo[c,d]chromen-6-ones, and 2,3-dihydro-1H-4,6-dioxachrysen-5-ones
No full textThe condensation of 1,3-bissilyl enol ethers with benzopyrylium triflates, generated in situ by the reaction of chromones with Me3SiOTf, afforded functionalized 2,3-dihydrobenzopyrans; treatment of the latter with NEt3 or BBr3 resulted in a domino retro-Michael-aldol-lactonization reaction and the formation of a variety of 7-hydroxy-6H-benzo[c]chromen-6-ones. The hydroxy group was functionalized by using Suzuki cross-coupling reactions. The methodology reported was applied to the synthesis of the natural product autumnariol and a new fluorescence dye, which exhibits promising optical properties. 2,3-Dihydro-1H-4,6-dioxachrysen-5-ones were prepared by condensation of chromones with 1,3-bis-silyl enol ethers containing a remote chloride group, domino retro-Mich ael-aldol-lactonization, and an intramolecular Williamson reaction
Appel à consultance IRSEM C-2012-01
No full textL'IRSEM lance un appel à consultance irsem "IRSEM C-2012-01". Il s'agit d'une Etude comparative des livres blancs des 27 Etats-membres de l’Union européenne. Plus d'informations, c'est ici : http://www.irsem.defense.gouv.fr/spip.php?rubrique65 Les modalités de la candidature se trouvent ici : http://www.irsem.defense.gouv.fr/spip.php?article179 La date de clôture de cet appel est fixée au Vendredi 6 janvier 2012, 12h00. Merci à Guillaume Pichard, responsable du Bureau des Etudes et de la Rec..
Equilibrium reconstruction in an iron core tokamak using a deterministic magnetisation model
No full textIn many tokamaks ferromagnetic material, usually referred to as an iron-core, is present in order to improve the magnetic coupling between the solenoid and the plasma. The presence of the iron core in proximity to the plasma changes the magnetic topology with consequent effects on the magnetic field structure and the plasma boundary. This paper considers the problem of obtaining the free-boundary plasma equilibrium solution in the presence of ferromagnetic material based on measured constraints. The current approach employs, a model described by O'Brien et al. (1992) in which the magnetisation currents at the iron-air boundary are represented by a set of free parameters and appropriate boundary conditions are enforced via a set of quasi-measurements on the material boundary. This can lead to the possibility of overfitting the data and hiding underlying issues with the measured signals. Although the model typically achieves good fits to measured magnetic signals there are significant discrepancies in the inferred magnetic topology compared with other plasma diagnostic measurements that are independent of the magnetic field. An alternative approach for equilibrium reconstruction in iron-core tokamaks, termed the deterministic magnetisation model is developed and implemented in EFIT++. The iron is represented by a boundary current with the gradients in the magnetisation dipole state generating macroscopic internal magnetisation currents. A model for the boundary magnetisation currents at the iron-air interface is developed using B-Splines enabling continuity to arbitrary order; internal magnetisation currents are allocated to triangulated regions within the iron, and a method to enable adaptive refinement is implemented. The deterministic model has been validated by comparing it with a synthetic 2-D electromagnetic model of JET. It is established that the maximum field discrepancy is less than 1.5 mT throughout the vacuum region enclosing the plasma. The discrepancies of simulated magnetic probe signals are accurate to within 1% for signals with absolute magnitude greater than 100 mT; in all other cases agreement is to within 1 mT. The effect of neglecting the internal magnetisation currents increases the maximum discrepancy in the vacuum region to >20 mT, resulting in errors of 5%-10% in the simulated probe signals. The fact that the previous model neglects the internal magnetisation currents (and also has additional free parameters when fitting the measured data) makes it unsuitable for analysing data in the absence of plasma current. The discrepancy of the poloidal magnetic flux within the vacuum vessel is to within 0.1 Wb. Finally the deterministic model is applied to an equilibrium force-balance solution of a JET discharge using experimental data. It is shown that the discrepancies of the outboard separatrix position, and the outer strike-point position inferred from Thomson Scattering and Infrared camera data are much improved beyond the routine equilibrium reconstruction, whereas the discrepancy of the inner strike-point position is similar. (C) 2017 Published by Elsevier B.V
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
VRCT: Randomized Controlled Trial Evaluating the Impact of Virtual Reality on behavioral and Psychological Symptoms and Quality of Life of Acute Care Inpatients with Dementia
No full textEvaluating the Impact of Virtual Reality on the Behavioral and Psychological Symptoms of Dementia and Quality of Life of Inpatients With Dementia in Acute Care: Randomized Controlled Trial (VRCT)
No full textBackground:
Virtual reality (VR) is increasingly considered a valuable therapeutic tool for people with dementia. However, rigorous studies are still needed to evaluate its impact on behavioral and psychological symptoms of dementia (BPSDs) and quality of life (QoL) across care settings.
Objective:
The primary aim of this study was to evaluate the impact of VR therapy on managing BPSDs, falls, length of stay, and QoL in inpatients with dementia admitted to an acute care hospital. The secondary aim was to evaluate the intervention’s feasibility in terms of acceptability, safety, and patient experience.
Methods:
A prospective, open-label, mixed methods, randomized controlled clinical trial was conducted between April 2019 and March 2020. A total of 69 participants (aged ≥65 years with a diagnosis of dementia and who did not meet the exclusion criteria) were randomly assigned to either the control (n=35, 51%) or VR (n=34, 49%) arm. Participants in the experimental (VR) arm were visited by a researcher and watched 360° VR films on a head-mounted display for up to 20 minutes every 1 to 3 days, whereas individuals in the control arm received standard of care. Instances of daily BPSDs and falls were collected from nurses’ daily notes. QoL was measured through semistructured interviews and the Quality of Life in Late-Stage Dementia scale. Structured observations and semistructured interviews were used to measure treatment feasibility. The primary outcomes were analyzed at a 95% significance level based on the intention-to-treat method.
Results:
VR therapy had a statistically significant effect on reducing aggressiveness (ie, physical aggression and loud vociferation; P=.01). Substantial impact of VR therapy was not found for other BPSDs (eg, apathy), falls, length of stay, or QoL as measured using the Quality of Life in Late-Stage Dementia scale. The average VR therapy session lasted 6.8 (SD 6.6; range 0-20) minutes, and the intervention was overall an acceptable and enjoyable experience for participants. No adverse events occurred as a result of VR therapy.
Conclusions:
Immersive VR therapy appears to have an effect on aggressive behaviors in patients with dementia in acute care. Although the randomized controlled trial was stopped before reaching the intended sample size owing to COVID-19 restrictions, trends in the results are promising. We suggest conducting future trials with larger samples and, in some cases, more sensitive data collection instruments.
Trial Registration:
ClinicalTrials.gov NCT03941119; https://clinicaltrials.gov/study/NCT03941119
International Registered Report Identifier (IRRID):
RR2-10.2196/2240
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
March of all nations [music] : Freedom march /
No full textCover title.; Copyright 1911 by Fred Heberlein & Co.; Introduced in J.C. Williamson's Ltd. successful pantomime Cinderella.; Also available online http://nla.gov.au/nla.mus-an6341751.Freedom marchCinderella (Pantomime
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Decision-Making Theory. How a multiple perspective approach can generate workplace strategies
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