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1.
Rheumatol Int ; 33(5): 1243-53, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23064543

RESUMEN

This study was aimed to assess: (1) the additive diagnostic utility of diffusion-weighted imaging (DWI) and magnetic resonance angiography (MRA) over conventional MRI in detecting brain lesions in patients with acute primary neuropsychiatric systemic lupus erythematosus (NPSLE), and (2) the relevance of their findings to the associated NP manifestations. Included were 34 patients with acute NPSLE with mean age of 33.26 ± 10.14 years and duration of illness of 3.33 ± 1.71 years. Clinical interviewing and psychiatric and cognitive evaluations were performed by applying the criteria of the diagnostic and statistical manual of mental health disorders criteria (DSM-IV), Stanford Binet Subset Testing, Mini-Mental State Examination and Wechsler Memory Scale-Revised. Serologic tests included looking for antinuclear antibodies, anti-double strand DNA, anti-phospholipid antibodies. Radiologic evaluation included conventional MRI, DWI and MRA. One or more NP manifestations were diagnosed in 28 patients, in which cognitive deficits were reported with headache, psychosis and CVS. Anti-phospholipid antibodies were reported in patients with CVS. Twenty patients (71.43 %) with primary NPSLE (n = 28) had MRI abnormalities in which hyperintense signals at subcortical and periventricular white matter and at the junction between the gray and white matter represented 75 % (n = 15) and with headache (n = 6), psychosis (n = 6) and acute confusional state (n = 3) with and without cognitive deficits, respectively. Moderate-sized infarctions with restricted diffusion in the distribution of middle cerebral arteries were represented in 35 % (n = 7) and with CVS, of them, 71.43 % (n = 5) had beading and focal narrowing of carotid arteries were consistent with vasculitis. Brain atrophy represented 20 % (n = 4) and with psychosis. Compared to those with normal MRI, patients with MRI abnormalities were older (P < 0.050) and had longer duration of illness (P < 0.050). To conclude, although DWI and MRA are helping in more precise etiopathologic diagnosis compared to conventional MRI, but their relevance to the present NP manifestations is still limited.


Asunto(s)
Imagen de Difusión por Resonancia Magnética , Vasculitis por Lupus del Sistema Nervioso Central/diagnóstico , Angiografía por Resonancia Magnética , Enfermedad Aguda , Adolescente , Adulto , Anticuerpos Antinucleares/sangre , Anticuerpos Antifosfolípidos/sangre , Atención , Biomarcadores/sangre , Distribución de Chi-Cuadrado , Cognición , Femenino , Humanos , Vasculitis por Lupus del Sistema Nervioso Central/sangre , Vasculitis por Lupus del Sistema Nervioso Central/inmunología , Vasculitis por Lupus del Sistema Nervioso Central/patología , Vasculitis por Lupus del Sistema Nervioso Central/psicología , Masculino , Memoria , Persona de Mediana Edad , Pruebas Neuropsicológicas , Valor Predictivo de las Pruebas , Pronóstico , Desempeño Psicomotor , Adulto Joven
2.
Phys Chem Chem Phys ; 10(16): 2189-99, 2008 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-18404225

RESUMEN

The ability to electrodeposit titanium at low temperatures would be an important breakthrough for making corrosion resistant layers on a variety of technically important materials. Ionic liquids have often been considered as suitable solvents for the electrodeposition of titanium. In the present paper we have extensively investigated whether titanium can be electrodeposited from its halides (TiCl(4), TiF(4), TiI(4)) in different ionic liquids, namely1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide ([EMIm]Tf(2)N), 1-butyl-1-methylpyrrolidinium bis(trifluoromethyl-sulfonyl)amide ([BMP]Tf(2)N), and trihexyltetradecyl-phosphonium bis(trifluoromethylsulfonyl)amide ([P(14,6,6,6)]Tf(2)N). Cyclic voltammetry and EQCM measurements show that, instead of elemental Ti, only non-stoichiometric halides are formed, for example with average stoichiometries of TiCl(0.2), TiCl(0.5) and TiCl(1.1). In situ STM measurements show that-in the best case-an ultrathin layer of Ti or TiCl(x) with thickness below 1 nm can be obtained. In addition, results from both electrochemical and chemical reduction experiments of TiCl(4) in a number of these ionic liquids support the formation of insoluble titanium cation-chloride complex species often involving the solvent. Solubility studies suggest that TiCl(3) and, particularly, TiCl(2) have very limited solubility in these Tf(2)N based ionic liquids. Therefore it does not appear possible to reduce Ti(4+) completely to the metal in the presence of chloride. Successful deposition processing for titanium in ionic liquids will require different maybe tailor-made titanium precursors that avoid these problems.

3.
J Phys Chem B ; 111(18): 4693-704, 2007 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-17388503

RESUMEN

In the present paper, the electrodeposition of Al on flame-annealed Au(111) and polycrystalline Au substrates in two air- and water-stable ionic liquids namely, 1-butyl-1-methyl-pyrrolidinium bis(trifluoromethylsulfonyl)amide, [Py(1,4)]Tf(2)N, and 1-ethyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)amide, [EMIm]Tf(2)N, has been investigated by in situ scanning tunneling microscopy (STM), electrochemical quartz crystal microbalance (EQCM), and cyclic voltammetry. The cyclic voltammogram of aluminum deposition and stripping on Au(111) in the upper phase of the biphasic mixture of AlCl(3)/[EMIm]Tf(2)N at room temperature (25 degrees C) shows that the electrodeposition process is completely reversible as also evidenced by in situ STM and EQCM studies. Additionally, a cathodic peak at an electrode potential of about 0.55 V vs Al/Al(III) is correlated to the aluminum UPD process that was evidenced by in situ STM. A surface alloying of Al with Au at the early stage of deposition occurs. It has been found that the Au(111) surface is subject to a restructuring/reconstruction in the upper phase of the biphasic mixture of AlCl(3)/[Py(1,4)]Tf(2)N at room temperature (25 degrees C) and that the deposition is not fully reversible. Furthermore, the underpotential deposition of Al in [Py(1,4)]Tf(2)N is not as clear as in [EMIm]Tf(2)N. The frequency shift in the EQCM experiments in [Py(1,4)]Tf(2)N shows a surprising result as an increase in frequency and a decrease in damping with bulk aluminum deposition at potentials more negative than -1.8 V was observed at room temperature. However, at 100 degrees C there is a frequency decrease with ongoing Al deposition. At -2.0 V vs Al/Al(III), a bulk aluminum deposition sets in.


Asunto(s)
Aluminio/química , Imidazoles/química , Imidas/química , Líquidos Iónicos/química , Microscopía de Túnel de Rastreo/métodos , Pirroles/química , Cuarzo , Aire , Electroquímica , Electrodos , Oro/química , Pirrolidinas , Sensibilidad y Especificidad , Agua/química
4.
Chemphyschem ; 7(7): 1535-43, 2006 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-16789040

RESUMEN

The present work shows, for the first time, a comparative experimental study on the electrodeposition of aluminium in three different water and air stable ionic liquids, namely 1-butyl-1-methylpyrrolidinium-bis(trifluoromethylsulfonyl)imide ([BMP]Tf2N), 1-ethyl-3-methylimidazolium-bis(trifluoromethylsulfonyl)imide ([EMIm] Tf2N), and trihexyl-tetradecyl-phosphoniumbis(trifluoromethylsulfonyl)imide (P(14,6,6,6) Tf2N). The ionic liquids [BMP]Tf2N and [EMIm]Tf2N show biphasic behaviour in the AlCl3 concentration range from 1.6 to 2.5 mol L(-1) and 2.5 to 5 mol L(-1), respectively. The biphasic mixtures become monophasic at temperatures >/=80 degrees C. It was found that nanocrystalline aluminium can be electrodeposited in the ionic liquid [BMP]Tf2N saturated with AlCl3. The deposits obtained are generally uniform, dense, shining, and adherent with very fine crystallites in the nanometer size regime. However, coarse cubic-shaped aluminium particles in the micrometer range are obtained in the ionic liquid [EMIm]Tf2N. In this liquid the particle size significantly increases as the temperature rises. A very thin, mirrorlike aluminium film containing very fine crystallites of about 20 nm is obtained in the ionic liquid [trihexyl-tetradecyl-phosphonium]Tf(2)N at room temperature. At 150 degrees C, the average grain size is found to be 35 nm.

5.
Phys Chem Chem Phys ; 7(11): 2333-9, 2005 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-19785118

RESUMEN

The present paper deals with the electroreduction of TaF5 in the room temperature ionic liquid 1-buty-1-methyl-pyrrolidinium bis(tri-fluoromethylsulfonyl)imide ([BMP]Tf2N) at different temperatures for the sake of electrodeposition of tantalum. The study was carried out using cyclic voltammetry and chronoamperometry measurements complemented by SEM-EDAX and XRD investigations. In situ scanning tunneling microscopy and I-U tunneling spectroscopy were also utilized for characterization of the electrodeposits. The results show that, in addition to the formation of insoluble compounds, Ta can be electrodeposited in the ionic liquid ([BMP]Tf2N) containing 0.5 M TaF5 at 200 degrees C on polycrystalline Pt and Au(111) electrodes. By addition of LiF to the electrolyte, the quality and the adherence of the electrodeposit were found to be improved. An in situ I-U tunneling spectrum with about 300 nm thickness of the electrodeposit shows metallic behaviour indicating the formation of elemental tantalum. Moreover, the XRD patterns of the electrodeposit, obtained potentiostatically at -1.8 V (vs. Pt) in ([BMP]Tf2N) containing 0.25 M TaF5 and 0.25 M LiF on Pt electrode at 200 degrees C, show the characteristic patterns of crystalline tantalum.

6.
Arch Oral Biol ; 39(11): 955-65, 1994 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-7695509

RESUMEN

This study sought to characterise the electromyographic (EMG) activity patterns of orofacial-muscles during trained tongue-protrusion and biting tasks in two awake monkeys (Macaca fascicularis). Chronic or acute EMG electrodes were placed in the anterior digastric (DIG), genioglossus (GG), masseter (MASS), platysma (PLAT), zygomaticus major (ZYGO), orbicularis oris superior (OOS), and orbicularis oris inferior (OOI) muscles and their EMG activity as well as the force signals of the tongue-protrusion and biting tasks were recorded. A total of 327 tongue-protrusion task trials and a total of 210 biting-task trials were successfully completed in several recording sessions and the EMG patterns were generally consistent between the different sessions. For the tongue task, the mean onset time of increase in GG activity significantly (p < 0.0001) led the mean onset time of increase in the force. The DIG, GG, and OOI (and also the OOS in one of the monkeys) showed a significant (p < 0.0001) increase in mean EMG amplitude during the holding phase, but the GG in both monkeys had the highest mean EMG amplitude ratio (MAR), i.e. the mean EMG amplitude during the holding or dynamic phase divided by the mean EMG amplitude during the pre-trial period. A similar EMG pattern was documented for different directions of the tongue-protrusion task (right, symmetrical, and left) and changes in the levels of EMG activities occurred in GG and OOI as the direction of the tongue-protrusion task changed from left to right. The task at different forces was associated with no apparent change in MAR for the holding phase for each muscle recorded. However, during the dynamic phase, only the GG showed a significant increase in EMG activity as the forces were increased. For the biting task, the mean onset times of the MASS activity and force were not significantly different. The MASS and ZYGO muscles (and the PLAT in one of the monkeys) showed a significant increase in mean EMG amplitude during the holding phase compared with the pre-trial period, and the MASS showed the highest MAR. It was also the only muscle showing a significant increase in the EMG activity when the bite-force level was increased. These findings reveal that certain orofacial muscles are selectively recruited during the two different orofacial tasks.(ABSTRACT TRUNCATED AT 400 WORDS)


Asunto(s)
Fuerza de la Mordida , Músculos Faciales/fisiología , Músculos Masticadores/fisiología , Músculos del Cuello/fisiología , Lengua/fisiología , Animales , Electromiografía , Femenino , Macaca fascicularis , Actividad Motora
7.
J Neurophysiol ; 65(3): 511-30, 1991 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-2051192

RESUMEN

1. Intracortical microstimulation (ICMS) and surface stimulation studies of primate face motor cortex have shown an extensive representation within face motor cortex devoted to movements of the tongue and face; only a very small representation for jaw-closing movements has ever been demonstrated. These data suggest that face motor cortex plays a critical role in the generation of tongue and facial movements but is less important in the generation of jaw-closing movements. Our aim was to determine whether disruption of primate face motor cortical function would indeed interfere with the generation of tongue movements but would not interfere with the generation of jaw-closing movements. 2. The face motor cortex was reversibly inactivated with the use of cooling in two monkeys that were trained to perform both a tongue-protrusion task and a biting task. Recording of single neuronal activity in the cortex beneath the thermode confirmed the reversible inactivation of the cortex. Each task involved a series of trials in which the monkey was required to produce a preset force level for a 0.5-s force holding period; the monkey received a fruit-juice reward if it successfully completed a task trial. Cooling of the ICMS-defined face motor cortex was achieved bilaterally or, in one experiment, unilaterally by circulating coolant through thermodes placed either on intact dura overlying face motor cortex in both monkeys or directly on the exposed pia in one of the monkeys;thermode temperature was lowered to 3-5 degrees C during cooling. Electromyographic (EMG) recordings were also made from masseter, genioglossus, and digastric muscles. 3. During bilateral cooling of the thermodes on the dura overlying the face motor cortex, there was a significant reduction in the success rates for the performance of the tongue-protrusion task in comparison with control series of trials (i.e., precool and postcool) in which the thermodes were kept at 37 degrees C. Quantitative analyses of force and EMG activity showed that the principal deficit was an inability of each monkey to exert sufficient force with its tongue for a sufficient length of time onto the tongue-protrusion task transducer; this deficit was paralleled by a reduction in the level of genioglossus and digastric EMG activity. At 4 min after commencement of rewarming, task performance had returned to control, precool levels.(ABSTRACT TRUNCATED AT 400 WORDS)


Asunto(s)
Corteza Motora/fisiología , Desempeño Psicomotor/fisiología , Animales , Frío , Condicionamiento Operante , Estimulación Eléctrica , Electrodos , Electromiografía , Femenino , Macaca fascicularis , Músculos Masticadores/fisiología , Corteza Motora/anatomía & histología , Corteza Motora/citología , Músculos del Cuello/fisiología , Neuronas/fisiología , Lengua/fisiología
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