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1.
Child Psychiatry Hum Dev ; 52(5): 978-993, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-33067711

RESUMEN

Youth with a family history of substance use disorder (FH+) are more prone to have externalizing and internalizing problems compared to youth without a family history of substance use disorder (FH-), increasing the likelihood of later maladjustment. However, mechanisms for this association remain understudied. In this longitudinal study, we examined if FH+ youth are more likely to experience early-life stressors (ELS), which in turn would increase impulsivity and the expression of externalizing and internalizing behaviors. Data were collected from youth and a parent (n = 386) during a baseline assessment (age 10-12 years) and every six months when the youth was 13-16 years old. In support of the primary hypothesis, FH+ youth reported higher levels of externalizing and internalizing behaviors through ELS to impulsivity providing a developmental pathway through which FH+ youth are more prone to externalizing and internalizing problems.


Asunto(s)
Experiencias Adversas de la Infancia , Trastornos Relacionados con Sustancias , Adolescente , Niño , Humanos , Conducta Impulsiva , Estudios Longitudinales , Padres
2.
Spectrochim Acta A Mol Biomol Spectrosc ; 69(5): 1344-53, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-17988940

RESUMEN

Molecular dynamics of polyacrylamide gels, polymeric micelles and hydrogel of polyacrylic acid and macrodiisocyanate was investigated by the ESR spectroscopy of spin probes. The local mobility in network junction of polyacrylamide gels is found to be essentially slower than that in the micelles created by the low molecular weight detergents and does not depend on the amount and length of hydrophobic groups (C9 or C12) in the polymer chain. The immersion of 10-30 mol.% of ionic monomers into the polymer chain (sodium acrylate) influences insufficiently on the local mobility of network junctions. In aqueous solutions, polystyrene-block-poly-(N-ethyl-4-vinylpyridinium bromide) block copolymers create polymeric micelles. The local mobility in the polystyrene core of the micelles is about twice as much as that in the solid polystyrene. Partially swellable polymer network in aqueous solutions was synthesized from polyacrylic acid and macrodiisocyanate. The local mobility in hydrophobic regions of the gel is substantially lower than that in the hydrophilic regions. It was concluded that the hydrophobic and hydrophilic regions and the local dynamics of them dictate practical application of the polymer associative systems.


Asunto(s)
Polímeros/química , Marcadores de Spin , Acrilatos/química , Espectroscopía de Resonancia por Spin del Electrón , Hidrogeles/química , Interacciones Hidrofóbicas e Hidrofílicas , Isocianatos/química , Micelas , Poliestirenos/química , Rotación , Temperatura
3.
Spectrochim Acta A Mol Biomol Spectrosc ; 63(4): 802-15, 2006 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-16488661

RESUMEN

The stable radicals derived from different compounds were detected in process of styrene autopolymerization. The nitroxide radicals are produced from nitrosocompound, hindered hydroxylamine, nitrophenols and nitroanisoles. The phenoxyl radicals are formed from quinine methides, and naphtoxyl radicals are generated from 2-nitro-1-naphtol. The radicals are identified, the kinetics of their formation and follow-up evolution are studied. These radicals can participate in process of living radical polymerization as the mediators and can effect significantly on kinetics of polymerization and structure of the resulting polymer.


Asunto(s)
Radicales Libres/química , Polímeros , Estireno/química , Anisoles/química , Espectroscopía de Resonancia por Spin del Electrón , Cinética , Óxidos de Nitrógeno/química , Nitrofenoles/química , Compuestos Nitrosos/química , Fenoles/química
4.
Spectrochim Acta A Mol Biomol Spectrosc ; 58(6): 1241-55, 2002 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11993472

RESUMEN

Molecular dynamics and organization of the micellar phase of complexes of linear polyelectrolytes with ionogenic and non-ionogenic surfactants was studied by the ESR spin probe method. Complexes of polyacrylic acid (PAA) and sodium polystyrenesulfonate (PSS) with alkyltrimethylammonium bromides (ATAB), as well as complexes of poly-N,N'-dimethyldiallylammonium chloride (PDACL) with sodium dodecylsulfate (SDS) were studied. The micellar phase of such complexes is highly organized molecular system, molecular ordering of which near the polymeric chain is much higher than in the 'center' of the micelle, it depends on the polymer-detergent interaction, flexibility of polymeric chain and length of carbonic part of the detergent molecule. Complexes of polymethacrylic acid (PMAA) with non-ionic detergent (dodecyl-substituted polyethyleneglycol), show that the local mobility of surfactant in such complexes is significantly lower than in 'free' micelles and depends on the number of micellar particles participating in formation of complexes.


Asunto(s)
Electrólitos/química , Micelas , Tensoactivos/química , Resinas Acrílicas/química , Bromuros/química , Tampones (Química) , Detergentes/farmacología , Espectroscopía de Resonancia por Spin del Electrón/métodos , Iones , Modelos Químicos , Polietilenos/química , Poliestirenos/química , Compuestos de Amonio Cuaternario/química , Dodecil Sulfato de Sodio/química
5.
Brain Res ; 880(1-2): 118-30, 2000 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-11032996

RESUMEN

Our previous data obtained in the cat suggest that the neurons of the ventrolateral subnucleus of the tractus solitarius (vlNTS) act as an inspiratory off-switch and terminate the inspiratory phase of the respiratory cycle (Berger et al., Eur. J. Pharmacol. 277 (1995) 195-208; Gillis et al., Neurosci. Abstr. 23 (1997) 725). The purpose of the present study was to determine whether inhibition of the region of the vlNTS of the rat using drugs that hyperpolarize, disfacilitate or block both axonal conduction and action potential generation would alter the inspiratory phase of the respiratory cycle. Experiments were conducted in anesthetized, vagotomized and spontaneously breathing rats while monitoring diaphragmatic electromyogram activity. Vagus nerves were sectioned in order to rule out prolongation of inspiration evoked by microinjection of agents into the vlNTS which block excitatory drive from lung afferent inputs. Bilateral microinjection of the inhibitory amino acid gamma-aminobutyric acid (GABA) 25 nmol/45 nl produced an immediate prolongation of inspiratory duration (484+/-18 to 1291+/-84 ms) and an apneustic pattern of breathing. Other effects observed were a significant shortening of expiratory duration (778+/-36 to 432+/-38 ms), rise in blood pressure (83+/-4 to 108+/-6 mmHg) and a small but significant increase in heart rate (439+/-17 to 452+/-18 beats/min). Bilateral microinjection of the ionotropic glutamate receptor antagonist kynurenic acid (1 nmol) and the Na(+) channel blocker tetrodotoxin (10 pmol) into the region of the vlNTS consistently produced a similar prolongation of inspiratory duration and an apneustic pattern of breathing. These results support the hypothesis that neurons in the region of the vlNTS promote the transition from inspiration to expiration and function as part of the 'Inspiratory Off Switch'.


Asunto(s)
Inhalación/fisiología , Ácido Quinurénico/farmacología , Neuronas/fisiología , Mecánica Respiratoria , Núcleo Solitario/fisiología , Ácido gamma-Aminobutírico/farmacología , Potenciales de Acción/efectos de los fármacos , Potenciales de Acción/fisiología , Animales , Axones/efectos de los fármacos , Axones/fisiología , Gatos , Lateralidad Funcional , Inhalación/efectos de los fármacos , Ácido Quinurénico/administración & dosificación , Masculino , Microinyecciones , Neuronas/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Mecánica Respiratoria/efectos de los fármacos , Núcleo Solitario/efectos de los fármacos , Transmisión Sináptica/efectos de los fármacos , Transmisión Sináptica/fisiología , Tetrodotoxina/administración & dosificación , Tetrodotoxina/farmacología , Nervio Vago/fisiología , Ácido gamma-Aminobutírico/administración & dosificación
6.
J Pharmacol Exp Ther ; 292(2): 704-13, 2000 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10640309

RESUMEN

The purpose of our study was to test the hypothesis that 5-hydroxytryptamine (5-HT)(1A) receptor agonists counteract morphine-induced respiratory depression. Studies were conducted in anesthetized rats, and respiratory activity was monitored with diaphragm electromyography. Morphine was administered i.v. in doses that produce apnea. Once apnea was established, i.v. administration of the 5-HT(1A) receptor agonist drug 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) at 10 or 100 microgram/kg restored normal breathing in each animal (n = 24). This antagonistic effect of 8-OH-DPAT on morphine-induced respiratory depression was observed in both spontaneously breathing and artificially ventilated animals. Results obtained with 8-OH-DPAT were mimicked by buspirone (50 microgram/kg i.v.), another 5-HT(1A) receptor agonist drug. Pretreatment with 4-(2'-methoxyphenyl)-1-[2'[N-(2'-pyridinyl]-p-iodo-benzamido]ethyl]pi perazine, an antagonist of 5-HT(1A) receptors, prevented 8-OH-DPAT from counteracting morphine-induced apnea. These results indicate that activation of central nervous system 5-HT(1A) receptors is an effective way of reversing morphine-induced respiratory depression. Most important, this is the third model of disturbed respiratory function in which drugs that stimulate 5-HT(1A) receptors have been shown to restore breathing to near-normal levels.


Asunto(s)
Apnea/inducido químicamente , Morfina/farmacología , Receptores de Serotonina/efectos de los fármacos , Antagonistas de la Serotonina/farmacología , Agonistas de Receptores de Serotonina/farmacología , 8-Hidroxi-2-(di-n-propilamino)tetralin/farmacología , Aminopiridinas/farmacología , Animales , Buspirona/farmacología , Diafragma/efectos de los fármacos , Interacciones Farmacológicas , Electromiografía , Masculino , Contracción Muscular/efectos de los fármacos , Piperazinas/farmacología , Ratas , Ratas Sprague-Dawley , Receptores de Serotonina/clasificación
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