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1.
ACS Appl Mater Interfaces ; 11(45): 42280-42287, 2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31682096

RESUMO

Glass and glass-ceramic samples of metastable lithium thiophosphates with compositions of 70Li2S-30P2S5 and Li7P3S11 were controllably prepared by using a rapid assisted-microwave procedure in under 30 min. The rapid preparation times and weak coupling of the evacuated silica ampules with microwave radiation ensure minimal reactivity of the reactants and the container. The microwave-prepared samples display comparable conductivity values with more conventionally prepared (melt quenched) glass and glass-ceramic samples, on the order of 0.1 and 1 mS cm-1 at room temperature, respectively. Rietveld analysis of synchrotron X-ray diffraction data acquired with an internal standard quantitatively yields phase amounts of the glassy and amorphous components, establishing the tunable nature of the microwave preparation. X-ray photoelectron spectroscopy and Raman spectroscopy confirm the composition and the appropriate ratios of isolated and corner-sharing tetrahedra in these semicrystalline systems. Solid-state 7Li nuclear magnetic resonance (NMR) spectroscopy resolves the seven crystallographic Li sites in the crystalline compound into three main environments. The diffusion behavior of these Li environments as obtained from pulsed-field gradient NMR methods can be separated into one slow and one fast component. The rapid and tunable approach to the preparation of high quality "Li7P3S11" samples presented here coupled with detailed structural and compositional analysis opens the door to new and promising metastable solid electrolytes.

2.
Ir J Psychol Med ; 29(2): 96-101, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30199955

RESUMO

OBJECTIVE: Alcoholism ultimately leads to impairment of memory and other cognitive functions. This can interfere with treatment, if cognitively impaired alcohol-dependent individuals have difficulties recalling and implementing skills acquired during therapy. We investigate if alcohol-dependent individuals without clinically apparent withdrawal symptoms may still be impaired in higher-order cognitive functions. METHODS: Thirty-four alcohol-dependent patients and 20 matched healthy controls were tested with the Verbal Learning and Memory Test which includes seven measurement points. The test comprises free recall, free recall after distraction and after 30 minute delay, and a word recognition task. Testing was performed between day seven and day 10 after the beginning of abstinence, when clinical withdrawal symptoms had ceased. RESULTS: Compared to healthy controls, alcohol-dependent patients performed worse in free recall after delay, but not in word recognition. Healthy controls showed a more linear progression of improvement in verbal memory performance. Overall, alcohol-dependent individuals showed reduced verbal learning efficiency. The extent of impaired recall after distraction was positively associated (one-tailed test) with history of delirium (r=0.34, p=0.04), seizures (r=0.46, p=0.01), and years since diagnosis for alcohol dependency (r=0.39, p=0.01). CONCLUSIONS: Our results provide evidence that unmedicated alcohol-dependent patients without obvious withdrawal symptoms had impaired verbal recall, but normal recognition performance, at seven to 10 days after onset of abstinence. This deficit may deteriorate treatment outcomes due to poorer implementation of skills newly-learned during this time period.

3.
Psychosoc Med ; 7: Doc07, 2010 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-21160546

RESUMO

OBJECTIVE: Alcohol-dependent patients in early abstinence show an impairment of cognitive functions which can be seen in poor implementation of newly learned skills for avoiding relapse. Executive dysfunction may persist during abstinence in alcohol-dependent persons, thus mitigating long-term abstinence. This study assessed visual memory function and choice of organizational strategies in alcoholics, as these are major factors necessary to implement ongoing behavior changes which are required for maintaining abstinence. METHODS: We investigated 25 severely alcohol-dependent male patients between days 7 to 10 of abstinence, immediately after clinical withdrawal symptoms have ceased, compared to 15 healthy age, sex, and education matched controls. Pharmacological therapy had been terminated at least four half-lifes before inclusion into the study. Visual perceptual learning and organizational strategies were assessed with the Rey-Osterrieth Complex Figure Test (R-OCF). RESULTS: There were no group differences in copying or recalling the figure, but time differences occurred. Alcoholics and healthy controls performed worse in recalling than in copying. But, alcoholics used less effective organizational strategies. CONCLUSIONS: There was a deficit in choice of organizational strategy in newly abstinent and unmedicated alcohol-dependent patients. Due to the imperfect organizational strategies, alcoholics might need auxiliary therapeutic care to strengthen their cognitive ability.

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